The Syndrome of Normal-pressure Hydrocephalus Vassilioutis

8/9/2019 The Syndrome of Normal-pressure Hydrocephalus Vassilioutis

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J N eurosurg 61 :501-50 9 , 1984

The syndrom e of normal-pressure hydrocephalus

JOHN VAS S ILOUTHIS, M . D.

Neurosurgical Department, Army Veterans Administration Hospital 417 NITS), Athens, Greece

~" A series of 40 patients with the sy ndro me of normal-pressure hydrocephalus is presented. Diagnosis w a s

based on clinical and computerized tomography (CT) scan criteria and was followed by the insertion of a

ventriculoperitoneal shun t in every instance. All patients responded favorably to trea tm ent (four of th em had

a fair outcom e), and this response was maintained. The re was one postoperative death, b ut no othe r serious

complications. This study demonstrates that it is possible to diagnose the syndrome of normal-pressure

hydrocephalus o n the basis of clinical and C T scan criteria w ithout an y oth er invasive investigations. Such

patients should re spond favorably to an adequately functioning shunting system.

K E Y W O R D S

9

n o r m a l - p r e s s u r e h y d r o c e p h a l u s 9 c o m p u t e r i z e d t o m o g r a p h y 9

v e n t r i c u l o p e r i t o n e a l s h u n t 9 h y d r o c e p h a l u s

T

HE te rm "norma l -p re s sure hydrocepha lus " (NP H)

i s u s e d t o d e s c r i b e a c l i n i c a l s y n d r o m e m a i n l y

c o m p r i s i n g ga i t d i s t u r b a n c e , d e m e n t i a , a n d u r i -

n a r y i n c o n t i n e n c e , a n d i s a s s o c i a t e d w i t h d i l a t a t i o n o f

t h e v e n t r ic u l a r sy s t em o f t h e b r a i n a n d n o r m a l c e r e b r o -

s p i n a l f l u i d ( C S F ) p r e s s u r e a t l u m b a r p u n c t u r e . 27 S i n c e

t h e i n i ti a l r e p o r t s f r o m t h e M a s s a c h u s se t s G e n e r a l H o s -

pi ta l , 1,2.46,47 nu m er ou s series o f pa t ien ts ap pa ren t ly suf-

f e ri n g f r o m t h i s s y n d r o m e h a v e b e e n d e s c r ib e d i n t h e

l it e ra tu re . 3-6'8'9"11'22'24"32-34'36'41'53'56'58'64 In these s tud ie s ,

a t t e n t i o n h a s m a i n l y c o n c e n t r a t e d o n e s t a b l i s h i n g d i -

a g n o s t i c c r it e r i a a n d p r o g n o s t i c f a c t o r s t h a t w o u l d r e l i -

a b l y p r e d i c t a f a v o r a b l e o u t c o m e f o l l o w i n g a v e n t r i c u l a r

s h u n ti n g p ro c e d u r e . 4'6'8'11,22,34,36,53,56,63,64

I n t h is r e p o r t , w e p r e s e n t t h e r e s u lt s o f t r e a t m e n t o f

4 0 p a t ie n t s w i t h t h e s y n d r o m e o f N P H . T h e q u e s t i o n s

w e h a v e a t t e m p t e d t o a n s w e r i n c l u d e : A r e t h e r e a n y

c r i t e r i a o n t h e b a s i s o f w h i c h w e c a n s e l e c t w i t h c e r -

t a i n t y a t le a s t s o m e o f t h e p a t i e n t s w i t h t h e s y n d r o m e ?

A r e t h e re a n y p a t i e n ts w i t h th e s y n d r o m e w h o d o n o t

r e s p o n d f a v o r a b l y t o a s h u n t i n g p r o c e d u r e ? a n d W h y

d o t h e y n o t r e s p o n d ?

C l i n i c a l M a t e r i a l a n d M e t h o d s

T h e s t u d y c o n c e r n s 4 0 p a t i e n t s i n w h o m t h e d i a g -

n o s is o f N P H w a s b as e d o n c l i n ic a l a n d c o m p u t e r i z e d

t o m o g r a p h y ( C T ) c r i t e r i a . A l l t h e p a t i e n t s w e r e h o s p i -

t a l i z e d i n e i t h e r t h e N e u r o s u r g i c a l o r t h e N e u r o l o g i c a l

D e p a r t m e n t s o f t h e A r m y G e n e r a l H o s p i t a l o r t h e

A r m y V e t e r a n s A d m i n i s t r a t io n H o s p i t a l b e t w e e n J a n -

u a r y , 1 9 7 9 , a n d A u g u s t , 1 9 8 3 . F o r t r e a t m e n t a n d i n c l u -

s i o n i n t h e s t u d y , p a t i e n t s m u s t h a v e h a d a c l i n i c a l

h i s t o r y a n d s y m p t o m a t o l o g y s u g g e s t i v e o f t h e s y n -

d r o m e a n d t h e d e m o n s t r a t i o n o f a d i la t e d u n o b s t r u c t e d

v e n t r i c u l a r s y s te m o n t h e C T s c an , t o g e t h e r w i t h s o m e

a d d i t i o n a l f e a t u r e s w h i c h e x c l u d e d d i l a t a ti o n

ex vacuo

o f t h e v e n t r i c u l a r s y s te m . L u m b a r p u n c t u r e w i t h m e a -

s u r e m e n t o f t h e C S F p r e s s u r e w as n o t c o n s i d e r e d n ec -

e s s a r y a n d w a s t h e r e f o r e p e r f o r m e d a c c o r d i n g t o t h e

n e e d s o f e a c h p a t i e n t . A p a r t f r o m r o u t i n e i n v e s t i g a -

t i on s , n o o t h e r t e s ts w e r e p e r f o r m e d b e f o r e t r e a t m e n t

w a s u n d e r t a k e n .

I n t h i s s e r i e s o f p a t i e n t s w e d i d n o t c o n s i d e r s e p a -

r a t in g p a t i e n ts w i t h a k n o w n c a u s e o f t h e i r c o m m u n i -

c a t i n g h y d r o c e p h a l u s f r o m t h o s e w i t h a n u n k n o w n

e t i o l o g y ( i d i o p a t h i c ) . T h e r e a s o n s f o r t h i s a r e d i s -

c u s s e d b e l o w .

Patient Population

A l m o s t h a l f o f t h e p a t i e n t s w e r e s e le c te d f r o m a p o o l

o f p a t i e n t s w i t h o t h e r w i s e u n e x p l a i n e d g a i t d i s tu r b a n c e

a n d d e m e n t i a . T h e r e m a i n d e r w e r e m o s t l y n e u r o su r g i -

c a l p a t i e n t s u n d e r c a r e o r b e i n g f o l l o w e d f o r o t h e r

i n t r a c r a n i a l d i s o r d e rs . T h e r e w e r e 2 4 p a t i e n t s w i t h c o m -

m u n i c a t i n g h y d r o c e p h a l u s o f k n o w n e t i o lo g y , a n d 1 6

i n w h o m n o c a u s e f o r t h e h y d r o c e p h a l u s c o u l d b e

i d e n t i f i e d f r o m e i t h e r t h e i n v e s t i g a t io n s o r t h e p a t i e n t ' s

m e d i c a l h i s to r y , b a s e d o n i n f o r m a t i o n g i v e n m a i n l y b y

the re la t ives (Tab le 1 ).

G a i t d i s t u r b a n c e w a s p r e s e n t i n e v e r y p a ti e n t a n d

r a n g e d f r o m a m i l d d e f i c i t i n b a l a n c e t o c o m p l e t e

i n a b i l i t y t o w a l k o r e v e n s t a n d . E x c l u d i n g t h e f o u r

J. Neurosurg. / Volume 61/September, 1984

501


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TABLE 1

Clinical eatures in 40 patients with the NPH syndrome*

J . Vass i louth i s

Duration of Urinary

No. of Deteriora- Ga it Dis-

Etiology Cases Age R a n g e S ym pto m s t ioni" Mu tism Dementia Incont i-

(range) turbance nence

SAH 10 20-63 3 wks-10 mos 4 2 6~ 8 7

craniotomy 6 42-64 3 wks-2 yrs 2 0 6 5 2

CNS infection 3 15-58 2 mo s- 1 yr 0 0 3 3 1

head injury 5 58-75 6 mo s-10 yrs 1 1 4:~ 4 3

unknow n (idiopathic) 16 52-80 1-4 yrs 0 0 16 12 6

total cases 40 7 3 35~; 32 19

* NPH = normal-pressurehydrocephalus;SAH = subarachnoid hemorrhage;CNS - - c entral nervous system.

t Deteriorationof preexistingdeficits or failure o make a good recovery.

The remaining patients were bedridden.

p a t i e n t s w i t h s u b a r a c h n o i d h e m o r r h a g e ( S A H ) w h o

w e r e b e d r i d d e n a t d i a g n o si s , in e v e r y i n s t a n c e t h e o n s e t

o f t h e d i s a b i l i t y w a s i n s i d i o u s a n d r e q u i r e d s o m e t i m e

t o b e c o m e a p p a r e n t t o t h e p a t i e n t o r h i s r e la t iv e s . T h i s

p e r i o d o f t i m e w a s s h o r t e r i n t h e g r o u p w i t h k n o w n

e t i o l o g y ( s e v e r a l w e e k s t o 1 y e a r , w i t h o n e e x c e p t i o n )

t h a n i n t h e i d i o p a t h i c g r o u p ( 1 t o 4 y e a r s ) . I n f o u r

p a t i e n t s i n t h e i d i o p a t h i c g r o u p , i n a b i l i t y t o w a l k w a s

t h e o n l y p r e se n t i n g s y m p t o m , s a v e f o r a m i l d m e m o r y

d e f i c it c o n s i d e r e d " n o r m a l " f o r th e p a t i e n t ' s a g e .

F r a n k d e m e n t i a ( a k i n e t i c m u t i s m i n t h r e e ca s e s) w a s

t h e p r e d o m i n a n t f e a t u r e i n e i g ht p a ti e n ts . I m p a i r m e n t

o f m e m o r y , m a i n l y s h o r t - t e r m , s lo w i n g o f t h o u g h t , a n d

l a c k o f a t t e n t i o n o r i n i t i a t i v e w e r e t h e m o s t c o m m o n

f o r m s o f d i s t u r b a n c e i n t h e r e m a i n i n g 2 4 c a s e s. I n f o u r

p a t i en t s t h e d e m e n t i a a n t e d a t e d t h e d i s t u r b a n c e o f g a i t

b y s e v e r a l m o n t h s t o y e a r s ; i n f a c t i t d o m i n a t e d t h e

c l i n i c a l p i c t u r e . O n e o f t h e s e p a t i e n t s h a d s u f f e r e d

s e v e r e i s c h e m i c d a m a g e t o t h e h y p o t h a l a m u s a n d t h e

m e d i a l a s p e c ts o f t h e f r o n t a l l o b e s f o l l o w i n g r u p t u r e o f

a g i a n t a n t e r i o r c o m m u n i c a t i n g a r t e r y a n e u r y s m , a n -

o t h e r h a d a s e v e r e c lo s e d h e a d i n j u r y , r e s i d u a l a p h a s ia ,

h e m i p a r e s i s , a n d p e r s o n a l i t y c h a n g e s , a n d t w o p a t i e n t s

w e r e i n t h e i d i o p a t h i c g r o u p . T h e s e p a t i e n t s a r e d i s -

c u s s e d s e p a r a t e l y , a s t h e y f o r m t h e g r o u p o f " f a i r "

r e s p o n d e r s t o a s h u n t i n g p r o c e d u r e .

U r i n a r y i n c o n t i n e n c e w a s p r e s e n t in a l m o s t h a l f t h e

p a t i e n t s ( 1 9 o u t o f 4 0 ) , a n d i n e v e r y i n s ta n c e i t f o l l o w e d

d i s t u r b an c e o f g a it a n d m e n t a t i o n . M o s t o f t e n it t o o k

t h e f o r m o f l a c k o f c o n c e r n , b u t i n a f e w p a t i e n t s i t

a p p e a r e d a s u r g e n c y o f m i c t u r i t io n .

O t h e r s y m p t o m s o r s i g n s , s u c h a s h e a d a c h e , d i z z i -

n e s s , v i s u a l d i s t u r b a n c e s , o r p y r a m i d a l o r e x t r a p y r a m -

i d a l s ig n s, w e r e l e ss f r e q u e n t a n d a r e n o t c o n s i d e r e d i n

t h i s s t u d y . I n t h r e e p a t i e n t s ( t w o w i t h S A H a n d o n e

w i t h a h i s t o r y o f h e a d i n j u r y ) , t h e d i a g n o s i s o f t h e

s y n d r o m e w a s s u s p e c te d w h e n t h e i r p r e e x is t in g n e u r o -

log ica l de f i c i t s began to de te r io ra te . In te re s t ing ly , the i r

C T s c a n s d e m o n s t r a t e d , i n a d d i t i o n t o v e n t r i c u l a r d i l-

a t a t i o n , t h e p r e s e n c e o f a r e a s o f l o w d e n s i t y r o u g h l y

c o r r e s p o n d i n g t o t h e u n d e r l y i n g i s ch e m i c w h i t e m a t t e r

w h i c h d i s a p p e a r e d f o l l o w i n g t r e a t m e n t . 59 F i n a l l y , f a il -

u r e t o m a k e a s a t i s f a c t o r y r e c o v e r y f o l l o w i n g S A H o r

s u r g e ry f o r i n t r ac r a n i al t u m o r ( m e n i n g i o m a o r p i t u i t a ry

a d e n o m a ) l e d t o t h e c o r r e c t d i a g n o s i s " n f o u r o t h e r

pa t i en t s .

C o m p u t e r i z e d T o m o g r a p h y F i n d i n g s

M o s t o f t h e C T s c a n s w e r e o b t a i n e d o n a n O h i o

N u c l e a r " D e l t a " h e a d s c a n n e r a n d d i s p l ay e d o n a 1 6 0

x 1 6 0 m a t r i x . I n t h e e i g h t m o s t r e c e n t c a s es , a P f i z e r

A S a n d E O 4 5 0 b o d y s c a n n e r w a s a ls o u s ed . * F o u r C T

s c a n c r i t e r i a w e r e u s e d i n t h i s s t u d y , b a s e d o n o u r

p r e v i o u s e x p e r i e n c e6~ a n d t h e e x p e r i e n c e o f o t h -

ers.6.11,21,26,44,48,56T h e s e c r i t e r i a w e r e t h e p r e s e n c e o n t h e

C T s c a n o f : 1 ) d i l a t a t i o n o f t h e u n o b s t r u c t e d v e n t r i c u l a r

s y s t e m ; 2 ) o b l i t e r a t i o n o f t h e c e r e b r a l s u l ci ; 3 ) a re a s o f

p e r i v e n t ri c u l a r l o w d e n s it y ; a n d 4 ) " r o u n d i n g " o f t h e

f r o n t a l h o r n s o f t h e l a t e r a l v e n t r i c l e s . W e c o n s i d e r e d

t h e s e c h a r a c t e r i s t i c s a s i n d i c a t i n g t h a t t h e c o e x i s t i n g

v e n t r i c u l ar e n l a r g e m e n t w a s n o t a n e x v a c u o v a r i a n t .

S u b s e q u e n t l y , o n l y p a t i e n t s s a t i s f y i n g a t l e a s t o n e o f

t h e f i r s t t w o c r i t e r i a , i n a d d i t i o n t o t h e v e n t r i c u l a r

d i l at a ti o n , w e r e o f f e r e d t r e a t m e n t a n d i n c l u d e d i n

t h e s t u d y .

D i l a t a t i o n o f t h e u n o b s t r u c t e d v e n t r i c u l a r s y s t e m

w a s p r e s e n t i n e v e r y p a t i e n t a n d w a s c o n s i d e r e d a

p r e r e q u i s i t e f o r t r e a t m e n t a n d i n c l u s i o n i n t h e s t u d y .

O n l y p a t i e n t s w i t h m o r e t h a n m o d e r a t e v e n t r i c u l a r

e n l a r g e m e n t w e r e s e l e c t e d , i n o r d e r t o o v e r c o m e a r g u -

m e n t s r e g a r d i n g t h e a c t u a l s iz e o f t h e v e n t r ic l e s . 66 T h u s ,

o n l y p a ti e n t s in w h o m t h e r a t io o f t h e w i d t h o f t h e

l a t e ra l v e n t r ic l e s a t t h e l e v el o f t h e f o r a m i n a o f M o n r o

t o t h e t r a n s v e r s e i n n e r d i a m e t e r o f t h e s k u l l a t t h e s a m e

leve l was abo ve 1 :5 were in c lude d . 6~

Obl i t e ra t ion o f the ce rebra l su lc i (F igs . 1 , 2 , and 3 ) ,

a s s e e n in t h e u p p e r m o s t C T c u t s , w a s p r e s e n t i n 3 l

c a s e s ( T a b l e 2 ) ; t h u s , n o p a t i e n t s w e r e e x c l u d e d f r o m

t h e s t u d y o n t h e b a s i s o f t h e a b s e n c e o f t h i s c r i t e r i o n .

* Del ta scanner 25 m anufactured by O hio N uclear , Inc .,

2910 Aurora Road, Solon, Ohio. Pfizer AS and EO450 bo dy

scanne r manu facture d by Pfizer Medical Systems, Inc. , 9052

Annapolis Road, Columbia, Maryland.

5 0 2

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Norm al-pressure hydrocephalus

FIG. 1. The c hief comp uter ized tomog raphy character is t ics in a 70-year-old wo ma n wi th normal -pressure

hydrocephalus syndrom e, a and b: Ma rked vent r icular di la ta tion and "round ing" of the frontal horns of the

lateral ventricles are seen. c: Periven tricular areas of low density are indicated by arrows, d: The cerebral

sulci are obliterated (arrows).

FIG. 2. Obli terat ion of the cerebral sulci

(arrows)

in a 72-year-old ma n with ventricular enlargement. N ote

the considerable d ilatat ion o f the sub arach noid spaces at the low er levels ( including the Sylvian fissures).

FIG. 3.

Left Pair:

Obliterat ion of the cerebral sulci in a 58-year-old man with the normal-pressure

hydr ocephal us syndr om e (smal l arrow). No te the widening o f the Sylvian fissures (large arrow). Rig ht Pair.

Reapp earance of the cerebral sulc i 1 year following t reatm ent (small arrows). No te the diminu t ion in the s ize

of th e Sylvian fissures

(large arrow).

T h e w i d t h o f t h e c e r e b r a l s u l c i a n d i t s p r e d i c t i v e v a l u e

r e g a r d i n g r e s p o n s e t o t r e a t m e n t h a v e b e e n d i s c u s s e d

pr ev io us ly . 6J1'22'26'36'56 I n o u r s t u d y , o b l i t e r a t i o n o f t h e

s u l c i w a s s o m e t i m e s o b s e r v e d i n c o m b i n a t i o n w i t h

d i l a t a t i o n o f t h e s u b a r a c h n o i d s p a c e s a t l o w e r l e v e l s ,

i nc l ud i ng t he S y l v i an f i s su r es ( F i gs . 2 and 3 ) . T h i s

f i n d i n g w a s c o n s i d e r e d t o i n d i c a t e o b s t r u c t i o n o f t h e

s u b a r a c h n o i d s p a c e o f t h e c o n v e x i t y ( T a b l e 2 ). I n a f e w

c a se s , w h i c h w e r e f o l lo w e d p o s t o p e r a t i v e l y w i t h C T

s c a n n i n g , r e a p p e a r a n c e o f t h e c e r e b r a l s u lc i w a s d o c u -

m e n t e d ( F i g . 3 ) , a n d t h e v a l i d i t y o f t h i s c r i t e r i o n w a s

r e i n f o r c e d .

J. Neurosurg . / Volum e 6 1/S epte mb er, 1984

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TABLE 2

Computerized tomography characteristics in 40 patients with the NPH syndrome*


> Moderate Obliteration Periventricular

Etiology No. of Cases Ventricular of Cerebral Areas of Low Rounding of Cortical

Enlargement Sulci Density Frontal Horns Atrophy

SAH 10 10 8 (2)? 8 7 1

craniotomy 6 6 4 ( 1)? 5 5 1

CNS infection 3 3 3 3 3 -

head injury 5 5 4 (2)? 3 4 2

unknown (idiopathic) 16 16 12 (4) , 8 9 4

total cases 40 40 31 (9)? 27 28 8

* NPH = normal-pressurehydrocephalus;SAH = subarachnoid hemorrhage;CNS = central nervous system.

t Num bers in parentheses ndicate cases with dilatation of the subarachnoid spaces at lower evels (Sylvianfissures ncluded).

I n o n e S A H p a t i en t , i n o n e h e a d - i n j u r e d p a t ie n t , a n d

i n t w o i n t h e i d i o p a t h i c g r o u p , c e r e b r a l s u l c i w e r e

c l e a r l y v i s ib l e i n t h e u p p e r m o s t c u t s , b u t i n t h e r e m a i n -

i n g c as e s n o f i r m j u d g m e n t c o u l d b e m a d e f o r t e c h n i c a l

r e a s o n s ( i n c l u d i n g m o v e m e n t a r t i f a c t s o r n o a v a i l a b l e

u p p e r m o s t C T c u t s ) . T h e c o m b i n a t i o n o f t h e c l i n i c a l

p i c t u r e a n d t h e p r e s e n c e o f a r e as o f p e r i v e n t ri c u l a r l o w

d e n s i t y i n t h e s e l a s t p a t i e n t s w a s, h o w e v e r , c o n s i d e r e d

s u f f i c i en t f o r i n c l u s i o n o f t h e p a t i e n t s i n t h e s t u d y ( F i g.

4 ) . T h i s f e a t u r e w a s t a k e n t o i n d i c a t e t r a n s e p e n d y m a l

m o v e m e n t a n d a b s o r p t i o n o f C S F , w h i c h i s k n o w n t o

take p lace in co m m un ica t in g hyd roce pha lus . 13'25'3~176

G r a n h o l m 21 h a s s h o w n t h a t p e r i v e n t r i c u l a r a r e a s o f l o w

d e n s i t y a r e p r e s e n t i n c a s e s o f h y d r o c e p h a l u s a n d d i s -

a p p e a r f o l lo w i n g s h u n t i n g . T h i s w a s s u b s e q u e n t l y c o n -

f i rm ed b y o the rs . 43'44 Overa l l , 27 pa t i en t s exh ib i t ed p e r -

i v e n t r i c u l a r lo w - d e n s i t y a r e a s o n C T s c a n n i n g , a n d t h i s

w a s t a k e n a s a n a b s o l u t e i n d i c a t i o n f o r t r e a t m e n t i n

eve ry pa t i en t (F igs . 1 and 4 ) . In te re s t ing ly , th i s fea tu r e

w a s s e e n i n f o u r o f o u r p a t i e n t s w i t h c l e a r l y v i s i b l e

cor t i ca l su lc i (F ig . 4 ), sugges t ing tha t ob l i t e ra t ion o f the

s u b a r a c h n o i d s p a c e i n t h e s e a r e a s i s n o t n e c e s s a r i l y

p r e s e n t i n e v e r y p a t i e n t w i t h th i s s y n d r o m e , a n d t h a t i t

i s a t l e a st p a r t i a ll y d e p e n d e n t o n t h e a c t u a l s i z e o f t h e

ce rebra l gyr i .

F i n a l ly , " r o u n d i n g " o f t h e f r o n t a l h o r n s o f t h e l a t e r a l

v e n t r i c l e s ( F ig . 1 ) w a s d e m o n s t r a t e d i n 2 8 p a t i e n t s a n d

w a s c o n s i d e r e d a s e q u i v a l e n t t o t h e p n e u m o e n c e p h a -

l o g r a p h i c ( P E G ) f i n d i n g t h a t t h e g r e a t e r i m p a c t o f

v e n t r i c u l a r d i l a t a ti o n i s o n t h e a n t e r i o r p o r t i o n s o f t h e

ven t r i cu la r sys tem. 21'37 Th i s fe a tu re d id no t s e rve a s an

a b s o l u t e i n d i c a t i o n f o r t r e a t m e n t i n t h i s s e ri e s.

A n i n t er e s ti n g g r o u p o f e i g h t p at i e nt s , h a l f o f w h o m

w e r e i n t h e i d i o p a t h i c c a t e g o r y , s h o w e d C T f e a t u r e s

s u g g e st i ve o f c o r t i c a l a t r o p h y . T h i s a s a r u l e w a s b e t t e r

s e e n o n C T c u t s l o w e r t h a n t h e u p p e r m o s t o n e s ; f o r

e x a m p l e , c u t s t h r o u g h t h e u p p e r p a r t o f t h e l a t e r a l

v e n t r i c u l a r b o d i e s . N o a t t e m p t w a s m a d e t o d i s ti n g u i s h

t h e s e a p p e a r a n c e s e t i o l o g ic a l ly , as t h i s w a s b e y o n d t h e

s c o p e o f t h i s s t u d y . I t i s e m p h a s i z e d , h o w e v e r , t h a t i n

e v e r y p a t i e n t o f t h is g r o u p t h e c o m b i n a t i o n o f c l in i ca l

a n d a d d i t i o n a l C T s c a n f e a t u r e s s u c h a s t h o s e m e n -

t i o n e d a b o v e s u g g e s t e d t h a t t h e c o e x i s t e n t v e n t r i c u l a r

d i l a t a t i o n w a s a t l e a s t p a r t i a l l y d u e t o o b s t r u c t i o n o f

FIG. 4. Areas of p eriventricular low density

(arrows)

in a 75-year-old patient with ven tricular dilatation 6

mo nths following head injury. Th e cerebral sulci are clearly visible.

5 0 4 J . N e u r os u rg . / V o l u m e 6 1 / S e p t e m b e r , 1 9 8 4


5/9


the CSF bulk flow, and required shunting. This was

shown to be the case in every patient of this group,

even in the three patients who showed only a fair

response to treatment.

Management

Following diagnosis and routine preoperative inves-

tigations (chest radiograph, electrocardiogram, blood

biochemical analysis, blood count and hematocrit, and

urinalysis), all the patients were given prophylactic flu-

cloxacillin (Floxapen) in a dose of 500 mg three times

daily for 1 day pre- and 2 days postoperatively. Surgery

was performed under general anesthesia. A ventriculo-

peritoneal shunting system was installed in every pa-

tient, incorporating a medium-pressure Holter valve

and a standard Rickham reservoir.t The standard sur-

gical technique was used, with special care taken that

no part of the device came in contact with the patient's

skin. Operative time ranged from 50 to 70 minutes.

Patients were encouraged to leave their bed in the 2nd

postoperative day and were usually discharged home

between the 8th and the 10th day. Follow-up exami-

nation was performed at 3 and 6 months, at 1 year, and

thereafter every year.

R e s u l t s

Response to t reatment was graded according to the

criteria proposed by Black, 6 which are as follows:

Excellent: resumed pre-illness activity without deficit

Good: resumed pre-illness activity with moderate

deficit

Fair: improved but no return to previous work

Poor: no change or worse.

Table 3 summarizes the results o f treatment. Thirty

patients achieved an excellent result. Of the remaining

10, six were judged as good responders in that they

obtained complete resolution of gait disturbance but

not the memory deficit. They were nevertheless able to

return to their previous activities. Four patients showed

only a fair response to treatment. These patients deserve

special mention. The first patient was a 23-year-old

man who suffered two SAH's within 1 month from

rupture of a giant anterior communicating aneurysm.

This was clipped elsewhere. Following surgery, he re-

mained inert and apathetic for a few months and then

began to improve, but reached an unsatisfactory plateau

in 1 year. Memory and emotional dysfunction, together

with mild disturbance of gait, were the predominant

symptoms. There was no urinary incontinence. His CT

scan showed ischemic changes of the medial aspects o f

the frontal lobes, more than moderate ventricular dila-

tation, and areas of periventricular low density. Follow-

ing treatment, he demonstrated definite improvement

t Medium-pressure Holter valve and Rickham reservoir,

supplied by Codman and Shurtleff, Inc., Randolph, Massa-

chusetts.

T A B L E 3

Results of surgery in 40 cases of NPH*

Fol low -U p

Etio logy NO.casesOf Ex cellen t G oo d Fai r Pe rio d (yrs)

SAH 10 9 0 1 1-4

craniotom y 6 5 1 0 1-2

CNS infec t ion 3 3 0 0 1 -4

head injury 5 3 1 1 89

un kn ow n (idiopathic) 16 10 4 2 89189

total cases 40 30 6 4

* N P H = normal-pressure hydrocephalus;SAH = subarachnoid

hemorrhage; CNS = central nervoussystem.

of his gait but no other significant change. ACT scan

6 months following surgery showed disappearance of

the periventricular lucencies but no change in the size

of the ventricles.

The second patient with only fair response was a 73-

year-old man with a severe closed head injury and a

left parietal extradural hematoma. When seen 6 months

after the accident he was mute and bedridden with right

spastic hemiparesis. He was incontinent of urine and

feces. A C T scan showed ventricular dilatation with

periventricular lucencies and visible cerebral sulci (Fig.

4). A few days following surgery he began to converse

and take a few steps with support, but 6 months after

surgery he remains dysphasic with right hemiparesis,

and at times he is incontinent of urine. The third

patient was a 72-year-old man, who presented with a 3-

year history of gait disturbance leading to inability to

walk or stand and frank dementia of 2 years' duration.

He was also incontinent of urine. A CT scan demon-

strated some cortical atrophy, ventricular enlargement,

and definite obliteration of the cerebral sulci, together

with dilatation of the subarachnoid spaces at lower

levels (Fig. 2). One year after surgery, this patient walks

normally; he is continent of urine but continues to have

severe memory deficit.

The last patient in this group, a 73-year-old man,

was referred with a history of gait disturbance of 10

months' duration and a longer history of short-term

memory deficit and mild dementia. His medical history

included coronary artery bypass surgery for myocardial

ischemia and two mild ischemic strokes of the right

cerebral hemisphere. ACT scan showed ischemic le-

sions and cortical atrophy in both hemispheres and

ventricular dilatation combined with obliteration of the

cerebral sulci. Soon after surgery he was able to walk

almost normally (and he remains able to do so); how-

ever, his dementia remains unchanged 6 months post-

operatively.

There were four additional patients (two with SAH

and two in the idiopathic group) who showed an ini tial

satisfactory response to surgery only to return to their

preoperative level in 1 to 2 days. In every instance,

palpation of the valve showed that it emptied and filled

J. Neurosurg. / Volume 61 /September, 1984 505


6/9

properly, and the patients' postoperative CT scans

showed no change in the size of the ventricles and no

additional features. Pumping of the valve was then

started three times daily (30 pumpings each time) as

inadequate function of the system was suspected. This

produced a definite improvement in the patients' con-

dition within 48 hours. Improvement was dramatic in

two cases. Eventually, three of these patients achieved

an excellent and one a good response to treatment.

Pumping, performed by instructed relatives, was suc-

cessfully discontinued in two patients in 3 months, and

is continuing in the rest (6 months and 1 year later,

respectively).

There was one postoperative death in this series. This

was in an 80-year-old man with a 4-year history of gait

disturbance leading to inability to stand or walk; he had

no other symptoms. He responded dramatically to the

shunting procedure, and was able to walk on the 3rd

postoperative day. He was discharged home on the 9th

postoperative day, but died from bronchopneumonia

in another hospital 5 weeks later.

Obstruction of the proximal end of the shunt system

was diagnosed in one patient and the ventricular cath-

eter was revised. Four patients developed postoperative

urinary tract infections or bronchopneumonia, and

were treated successfully with the appropriate antibiot-

ics. There were no cases of shunt infection or postop-

erative subdural hematomas.

D iscuss ion

Eighteen years since its initial description, 2,27 the

syndrome of normal-pressure hydrocephalus continues

to present quest ions, mainly regarding reliable diagnos-

tic criteria and prognostic factors associated with a

shunting procedure. 6'22'36'53'56 There is little disagree-

ment about the clinical symptoms that constitute

the syndrome. Disturbance of gait, dementia, and uri-

nary incontinence are regarded as the predominant

signs. 1,21627 The demonstration o f a dilated ventricular

system on neuroradiological studies is the cardinal fea-

ture, but it is now well appreciated that the CSF pressure

is not normal in these patients, at least not continu-

ously.9.~1.22,28,48,54,55 The demonstrat ion of a definite and

at times dramatic improvement of a patient's symp-

toms following a shunting procedure 1'2'27'46 has stimu-

lated tremendous interest in this treatable cause of

dementia. ~0

The initial enthusiasm5~ has gradually subsided, leav-

ing behind a voluminous amount of information. Nu-

merous studies dealing with the syndrome and propos-

ing criteria for selection of patients appropriate for

treatment have appeared in the literature. These include

PEG

fe a t u re s , 23 '24 '36 '37 '56 '58 '64

iodine- 13 I-labeled human

serum albumin (RIHSA) scanning patterns following

intrathecal administration, 329375658 lumbar45'48 or ven-

triculolumbar38 subarachnoid infusion tests, and eval-

uation of the patients' mental function before and after

withdrawal of small amounts of

C SF. 1 7 ' 6 3

Measure-


ments of cerebral blood ~]OW, 9 CT features, 6"I1"22'26"36

and patterns of continuously measured and recorded

intracranial pressure (ICP) 91122 28485455 have been pro-

posed as predictors of a response to treatment. It is

generally agreed that continuous ICP monitoring offers

one of the most reliable means for selection of patients

likely to respond to treatment.48 Since the pioneering

work of Symon, et al. , 55 many other investigators have

demonstrated that the ICP in these patients is not

normal, thus refuting the title of the syndrome. They

also showed that the presence in the record of the so-

called B-waves is of important prognostic signifi-

cance.T M More recently, B0rgesen, e t aL , 8 found

that measurement of the conductance to outflow of the

CSF is more useful in predicting the ou tcome to treat-

ment than measurement of the ICP.

Obstruction of the bulk flow of the CSF in the

subarachnoid space distal to the outlet foramina of the

fourth ventricle has been proposed as the initial defect

in this syndrome. This eventually leads to ventricular

dilatation, which is responsible for the clinical pic-

ture.

2"23'27'38

Several pathoanatomical reports have

substantiated this proposition, demonstrating lepto-

meningeal fibrosis mainly in the basal cisterns or the

subarachnoid space of the convexities of the hemi-

spheres with or without changes of the arachnoid gran-

ulations in patients with known etiology (SAH, central

nervous system infection, head trauma, intracranial

surgery) or unknown (idiopathic) cause of thei r hydro-

cephalus. 121329495~ Additional findings include ven-

tricular ependymal disruption, periventricular white

matter edema, subependymal glial reaction, and peri-

ventricular loss of myelin staining, 13 features that are

considered to be caused by disturbance of the CSF flow

and ventricular enlargement. As transependymal and

possibly transchoroidal absorption of CSF is en-

hanced,4~ the initial intracranial hypertension sub-

sides but the ventricles continue to enlarge, leading to

destruction o f periventricular nerve fibers. 61 How ven-

tricular enlargement continues in the presence of a fall

in CSF pressure is difficult to explain. Hakim and

Adams27 offered the proposition that, since the total

force on the ventricular wall is related to both area and

pressure, if the area of the ventricles is increased, a

smaller pressure is required to maintain their dilated

state. This theory has since been taken further by other

authorsJ 5'2~ It is also interest ing to note that experi-

mental obliteration of the subarachnoid space leads to

ipsilateral ventricular dilatation,25 which lends support

to the proposition that obliteration of the subarachnoid

space of the convexities contributes to an increase in

cerebral mantle pressure between the ventricles and the

subdural space. 253~

It is well known that some patients are found at

postmortem examination to have changes due to both

Alzheimer's disease and leptomeningeal fibrosis, caus-

ing obstruction of the subarachnoid space. 13 Postmor-

tem studies o f patients with the NPH syndrome show-

ing extensive hypertensive cerebrovascular disease with

506

J . N e u r os u r g. / V o l u m e 6 1 / S e p t e m b e r , 1 9 8 4


7/9


m u l t i p l e s m a l l i n fa r c t s b u t w i t h o u t g r o ss l e p t o m e n i n -

gea l changes sh ou ld be v i ewed wi th c au t ion ; w e l l-o rga -

n i z e d s u b d u r a l m e m b r a n e s w e r e p r e s e n t i n t w o o f t h e

t h r e e r e p o r t e d c as e s a n d i n t h e t h i r d t h e d i a g n o s i s o f

t h e s y n d r o m e w a s n o t certain. 14'35

In c l i n i ca l p rac t i ce , wh en a pa t i en t p re sen t s wi th ga i t

d i s t u r b a n c e a n d m e m o r y d e f i c i t ( w i t h o r w i t h o u t u r i -

n a r y i n c o n t i n e n c e ) , a d e c i s i o n m u s t b e m a d e w h e t h e r

a rad io log ica l ly dem ons t ra t ed v en t r i cu l a r d i l a t a t i on i s

c l i n i ca lly s ign i f i can t and the re fore requ i re s s hun t ing , o r

whe the r i t i s on ly t he re su l t o f was t ing o f ce rebra l

subs t ance (d i l a t a t i on e x v a c u o ) . T h e e x i s t i n g b o d y o f

ev idence does no t o f fe r r e l i ab l e c r i t e r i a on which to

base wi th ce r t a in ty t he d i s t i nc t ion be tween these en t i -

t ies.6'7'48 T h e b a s i c q u e s t i o n r e m a i n s : D o a n y c a s e s o f

N P H s y n d r o m e n o t r e s p o n d t o t r e a tm e n t ? A n d i f, ye s,

W h y d o t h e y n o t r e s p o n d ? A l m o s t a l l i n v e s t i g a t i v e

e f fo r t s h a v e b e e n c o n c e n t r a t e d i n " i d e n t i f y i n g t h e w i n -

ne rs ; " t ha t i s , t he pa t i en t s who wi l l r e spond favorab ly

to a s hun t ing p rocedure . I~ As a re su l t , conc lus ions hav e

b e e n b a s e d o n t h e r e s p o n s e t o t r e a t m e n t o f g r o u p s o f

pa t i en t s wi th v en t r i cu l a r d i l a t a t i o n fu l f i ll i ng va r ious

c r i te r i a . The va l id i t y o f t hese c r i t e r i a was subsequ en t ly

eva lua t ed in re t rospec t accord ing to t he obse rved re -

s p o n s e o f t h e p a t i e n t t o t h e s h u n t i n g p r o c e d u r e . I t i s

obv ious t ha t i n t h i s p rocess two va r i ab l e s a re a t work .

F i r s t , t he c l i n i ca l ma te r i a l m ay no t be pure . I t is i nev i-

t a b le t h a t s o m e p a t i e n ts w i t h d i l a t a t i o n e x v a c u o a n d /

o r s o m e w i t h b o t h t h e s y n d r o m e a n d a d d i t i o n a l ce r e br a l

pa tho logy ( such a s Alzhe imer ' s d i sease ) e scape recog-

n i t i on and a re i nc luded in t he s tud i e s . These cases

s h o u l d n o t h a v e b e e n i n c l u d e d i n t h e e v a l u a t i o n p r o c es s

b e c a u s e i f t h e y h a d b e e n r e c o g n i z e d a t t h e b e g i n n i n g

t h e y w o u l d n o t h a v e b e e n t r e a t e d b y s h u n t in g . T h e

second fac to r i nvo lved the e f fec t iveness o f t r ea tment .

I n m o s t o f t h e s t u d ie s , th i s w a s j u d g e d o n t h e s u p p o s i -

t i o n t h a t a p r o p e r l y s e le c te d a n d a d e q u a t e l y f u n c t i o n i n g

shunt sys t em had been ins t a l l ed . I t i s su rpr i s ing how

f e w s tu d i e s h a v e a d d r e s s e d t h e q u e s t i o n o f e v a l u a t i o n

o f s h u n t f u n c t i o n , p a r t i c u la r l y i n c a s e s o f i d i o p a t h ic

N PH tha t fa i led to resp on d to t rea tm ent . 4'36'56'65

S e p a r a t i o n o f t h e g r o u p o f p a t i e n t s w i t h N P H o f

u n k n o w n e t i o l o g y ( i d io p a t h i c g r o u p ) b y m a n y a u -

thors 6'22'26'32'59 f r o m t h o s e w i t h k n o w n c a u s e, a s i f d i f-

f e r e n t p a t h o lo g i c a l m e c h a n i s m s a r e i n v o l v e d i n t h e t w o

g r o u p s , h as n o t i n o u r o p i n i o n c o n t r i b u t e d t o t h e c l ar -

i f i ca t ion o f t he i ssues . I f t he re a re d i f fe ren t mecha n i sm s

i n v o lv e d , t h e n w e m u s t a c c e p t t h a t w e a r e d e a l i n g w i t h

d i f fe ren t en ti t ie s . In t h i s r e spec t, i t i s o f i n t e re s t t o n o t e

t h e r e s u l t s o f a r e c e n t s t u d y w h i c h s h o w e d s i m i l a r

p a t t e r n s o f I C P r e c o r d i n g s i n t w o g r o u p s o f h y d r o c e -

p h a l ic p a t ie n t s , o n e w i t h k n o w n e t i o l o g y a n d a n o t h e r

of t he i d iop a th i c t ype . 11 I t cou ld , o f course , be c l a ime d

tha t pa t i en t s o f t he f i r s t g roup , a s a ru l e , r e spond

favorab ly t o t r ea tm ent , 56 and th i s i s no t so i n t he

id iopa th i c g roup . I t i s , however , a l so t rue t ha t t he

d i a g n o si s o f t h e s y n d r o m e i s u s u a l ly c e r ta i n f r o m t h e

m e d i c a l h i s to r y i n t h e f i rs t g ro u p a n d , w h e n r e s p o n s e

to t r ea tment i s no t sa t i s fac to ry , a v igorous sea rch fo r

the poss ib l e f ac to r s fo l l ows . Th i s usua l ly i den t i f i e s an

i n a d e q u a t e l y f u n c t i o n i n g s h u n t , w h i c h i s s u b s e q u e n t l y

revised.

I n o u r s t u d y w e a t t e m p t e d t o i n v e s t i g at e th e p o s s i -

b i l i t y o f us ing re l a t i ve ly s imple c r i t e r i a a s a bas i s fo r

d i a g n o s i n g t h e N P H s y n d r o m e , a v o i d i n g in v a s i v e t e c h -

n iques . The c l i n i ca l c r i t e r i a used a re i n acco rdance w i th

t h o s e r e p o r t e d previously. 6'16'22'24'36'47'53'56G a i t d i s t u rb -

ance was p re sen t i n eve ry pa t i en t ( t ha t i s , no pa t i en t

w i t h o u t t h i s s y m p t o m w a s c o n s i d e r e d f o r t r e a t m e n t ) .

As a ru l e , ga i t d i s tu rbance he ra lded the o the r symp-

toms , 16,18 and imp rov ed in eve ry p a t i en t fo l l owing t r ea t -

m e n t . D e m e n t i a w a s t h e d o m i n a n t s y m p t o m i n e i g h t

p a t i e n ts a n d w a s p r e s e n t i n 3 2 . F o l l o w i n g t r e a t m e n t i t

de f in i t e ly imp rov ed in 22 p a t i en t s , was s l i gh t ly ame l io -

r a t e d i n s i x, a n d r e m a i n e d u n c h a n g e d i n f o u r ( a ll c as e s

w i t h u n d e r l y i n g a d d i t i o n a l c e r eb r a l p a t h o lo g y ) . U r i n a r y

incon t inence , w hen p re sen t , r e so lved fo l lowing t r ea t -

m e n t . T h e s e l e c t i o n o f C T s c a n c r i t e r i a w a s b a s e d o n

publ i shed ev idence ,6'11.22.26.36,44,60 a n d o n th e b e li e f th a t

t h e C T s c a n a p p e a r a n c e w o u l d r e p r e s e n t e x is t in g p a t h -

o a n a t o m i c a l c h a n g e s , a s r e p o r t e d b y p r e v i o u s i n -

vestigators.12'13"25'29'49'50'57

The c r i t e r i a used in t h i s s tudy can be c r i t i c i zed a s

s t r ic t . Howev er , cons id e r ing the fac t t ha t a l l t he pa t i en t s

d i a g n o s e d a s s u ff e r in g f r o m t h e N P H s y n d r o m e o n t h e

bas i s o f t hese c r i t e r i a r e spo nded fav orab ly to shun t ing ,

we con c lude th a t t h ey a re a t l ea s t va l id i n se l ec ting wi th

c e r t a i n t y p a t i e n t s w h o d o h a v e t h e s y n d r o m e . O u r

sugges t ed ind i ca t ions fo r t r ea tment a re g iven , and the

o p p o r t u n i t y to s t u d y t h e r e sp o n s e to t h e m i n a h o m o -

geneou s g roup i s o f fe red .

W i t h r e g a r d t o t r e a t m e n t , w e u s e d a m e d i u m - p r e s -

sure va lve sys t em in a l l pa t i en t s i n an a t t empt t o avo id

t h e d e v e l o p m e n t o f s u b d u r a l h e m a t o m a s , w h i c h a r e

m o r e c o m m o n w h e n l o w - p re s su r e s ys t em s

a r e

us ed . 33

W e a ls o u s e d t h e s a m e s y s t e m t o s t a n d a r d i z e t r e a t m e n t

t h r o u g h o u t t h e s e rie s. T h e f i n d i n g t h a t f o u r o f t h e

p a t i e n ts e v e n t u a l l y r e q u i re d p u m p i n g o f t h e i r v a lv e s in

orde r t o ach ieve and ma in t a in a sa t i s fac to ry re su l t

impl i e s t ha t i n t hese cases a l ow-pressure o r h igh- f low

sys t em was p robab ly requ i red . I t a l so sugges t s t ha t i n

t h e s e p a t i e n t s e v e r y e f f o r t s h o u l d b e u n d e r t a k e n t o

a s s u r e a d e q u a t e f u n c t i o n o f t h e s h u n t i n g s y s t e m b e f o r e

fa i l u re o f t he t r ea tment i s accep ted .

F o u r p a t i e n t s s h o w e d a " f a i r " re s p o n s e to t r e a t m e n t

i n t h a t t h e y o n l y a c h i e v e d i m p r o v e m e n t o f g a i t d i s tu r b -

ance . We be l i eve tha t t hese pa t i en t s r epre sen t exam ples

o f c a s es w h e re t h e N P H s y n d r o m e i s s u p e r im p o s e d o n

preex i s t i ng ce rebra l pa tho logy ( i schemia , t r auma , pos-

s ib l e Alzhe imer ' s d i sease , and mul t i - i n fa rc t dement i a ,

respe ctively ). ~1'~9'36'56 Su rgica l tre at m en t is on ly ex-

p e c t e d t o a l l ev i a te s y m p t o m s c a u s e d b y t h e N P H s y n -

d r o m e w i t h o u t i n f l u e n c i n g t h e u n d e r l y i n g p a t h o l o g y ,

a n d i n o u r o p i n i o n t h i s i s w h a t o c c u r r e d i n t h e s e

p a t i e n t s . T h u s , t h e s e c o n d c o n c l u s i o n t h a t e m e r g e s

f r o m t h i s s t u d y i s t h a t a l l p a t i e n t s w i t h th e N P H s y n -

d r o m e r e s p o n d o r s h o u l d r e s p o n d t o t h e p l a c e m e n t o f

a n a d e q u a t e l y f u n c t i o n i n g s h u n t i n g d e v i c e .

J . N e u ro s u rg . / V o l u m e 6 1 / S e p t e m b e r , 1 9 8 4

507


8/9

T h i s s t u d y s u g g e s t s t h a t i t i s p o s s i b l e t o b a s e t h e

d i a g n o si s o f t h e s y n d r o m e o f N P H o n c l i ni c al a n d C T

c r i t e r i a . F a v o r a b l e r e s p o n s e t o t r e a t m e n t i n p a t i e n t s s o

s e l e c t e d c a n b e o b t a i n e d w i t h o u t u n a c c e p t a b l y h i g h

m o r t a l i t y o r m o r b i d i t y r a t e s.

Addendum

S i n c e s u b m i s s i o n o f t h i s m a n u s c r i p t , a r e l e v a n t r e -

p o r t h a s a p p e a r e d ( S al ib i N A , L o u r i e G L , L o u r i e H : A

v a r i a n t o f n o r m a l - p r e s s u r e h y d r o c e p h a l u s s i m u l a t i n g

P i c k ' s d i s e a s e o n c o m p u t e r i z e d t o m o g r a p h y . R e p o r t o f

t wo cases .

J N eu r o s u r g 5 9 : 9 0 2 - 9 0 4 ,

1983) . I n t h i s

p a p e r , d i l a t a t i o n o f t h e S y l v i a n f i ss u r e s, m i m i c k i n g

a t r o p h y o f P i c k ' s d i s e a s e , w a s s h o w n t o b e a f e a t u r e i n

t w o c a s e s o f t h e N P H s y n d r o m e , b o t h o f w h i c h r e -

s p o n d e d f a v o r a b l y to s h u n t i n g .

References

1. Adams RD: Fur ther observat ions of normal pressure

hydrocephalus. Pro c R Soc M ed 59:1135-1140, 1966

2 . Adams R D, F i she r C M, Hak i m S , e t a l : S ympt omat i c

occul t hydroceph alus wi th "nor ma l" cerebrospinal f luid

pressure . A t reatable syndrome. N Engl J Med 273:

117-126, 1965

3. Bannister R, Gilford E, Koc en R: Isotop e encephalogra-

phy i n t he d i agnosi s o f dement i a due t o com muni ca t i ng

hydrocephalus. Lancet 2:1014-1017, 1967

4. Belloni G, di R occo C , Focacci C, et al : Surgical indica-

t ions in normotensive hydrocephalus. A retrospective

analysis of the relat ions of some diagnostic findings to

the results of surgical treatment. Acta Neurnchir 33:

1-21, 1976

5. Benson DF , LeM ay M, Pat ten D H, e t a l: Diagnosis of

normal -pressure hydrocephalus . N Eng l J M ed 283:

609-615, 1970

6. Black PM: Idiopathic normal-pressure hydrocephalus.

Results of shunting in 62 patients. J

Neurosurg

52:

371-377, 1980

7. Black PM: Norm al -pressure hydrocephalus . Current un -

derstanding of diagnostic tests and shunting.

Postgrad

Med

71(2):57-67, 1982

8. B0rgesen SE, Gjerris F, Sorensen SC: Intrac ranial pressure

and conductance to out f low of cerebrospinal f luid in

no rm al pressure hydrocephalus. J N eurosu rg 50:489-493,

1979

9. Chaw la JC, Hu lme A, Coo per R: Int racranial pressure in

pa t i en t s w i th d ement i a and comm uni ca t i ng hydr ocepha -

lus. J N euros urg 40:376-380, 1974

10. Com mu nicat ing hydrocephalus . Lancet 2:1011-1012,

1977 (Editorial)

I 1 . C rockard HA, H anlon K, Du da EE, e t a l : Hydro cephalus

as a cause of dement ia : evaluat ion by computer i sed to-

mo graph y and int racranial pressure m oni tor ing. J N eurol

Neurosurg Psychiatry

40:736-740, 1977

12. DeL and FH, Ja me s AE Jr , Ladd D J , e t a l: Norm al pres-

sure hydrocephalus: a histologic study. Am J Clin Pathol

58:58-63, 1972

13. Di Rocco C, Di Trapani G, Mai ra G, e t a l : Anatomo-

clinical correlat ions in no rmo tensiv e hydrocephalus. Re-

ports on three cases. J Neu rol Sci 33:437-452, 1977

14. Earnes t MP, Fahn S , Karp JH, e t a l : Normal pressure

hydroceph alus and hyper tens ive cerebrovascular disease .

Arch Neu roi 31:262-266, 1974

J . Vass i lou th i s

15. Epstein CM: Th e distribution of intracra nial forces in

acute and chronic hydrocephalus. J Neurol Sci 21:

171-180, 1974

16. Fisher CM : Th e cl inical picture in oc cult hydrocephalus.

Clin Neu rosurg 24:270-284, 1977

17. Fisher CM : Co mm unic ating hydrocephalus. La nce t 1:37,

1978 (Letter)

18. F isher CM: Hyd rocephalus as a cause of di s turbances of

gait in the elderly. Neurology 32:1358-1363, 1982

19. Fisher CM: Lacunar strokes and infarcts: a review. Neu-

rology 32:871-876, 1982

20. Geschwind N: The mec hanism of norma l pressure hyd ro-

cephalus. J N euro l Sci 7:481-493, 1968

21. Granholm L: An explanat ion of the revers ible memory

defect in hydrocephalus, in Beks JW F, Bosch DA, Bro ck

M (eds) : Int racranial Pressure I l l . Ber l in/Heidelbe rg/

New York: Springer-Verlag, 1976, pp 173-176

22. Greenb erg JO, Shenkin HA, Adam R : Idiopathic normal

pressure hydrocephalus -- a report of 73 patients. J

Neurol Neurosurg

Psy chia try 40:336-341, 1977

23. Grei tz T , Grepe A: Encephalography in the diagnosis of

convexi ty block hydrocephalus. Acta Radiol (Diagn)

11:232-242, 1971

24. Guidet t i B , Gagl iardi FM: No rma l pressure hy droceph a-

lus. Acta Neurochi r 27:1-9, 1972

25. Gu inane JE: Wh y does hydrocephalus progress? J

Neurol

Sci 32:1-8, 1977

26. Gunasekera L , Richardson AE: Computer ized axia l to-

mography in idiopathic hydrocephalus .

Brain 100:

749-754, 1977

27. Hakim S , Adams RD: The specia l c l inical problem of

symptomat ic hydrocephalus wi th normal cerebrospinal

fluid pressure. O bserv ations on cerebrospinal f luid hyd ro-

dyn am ics. J N eurol Sci 2:307-327, 1965

28. Ha r tm ann A, Alber ti E : Di f ferent ia t ion of com mu nicat -

ing hydrocephalus and preseni le d eme nt ia by cont inuou s

recording of cerebrospinal fluid pressure. J

Neurol

N e w

rosurg Psychiatry

40:630-640, 1977

29. Heinz ER, Davis DO, Karp HR: Abnormal i sotope c i s -

ternography in sym ptom at ic occult hydrocephalus. A cor-

relative isotopic-neuroradiolog ical stud y in 130 subjects.

Radiology 95:109-120, 1970

30. Hi rat suka H, Ta bata H, Tsu ruoka S , e t a l : Evaluat ion of

per ivent r icular hypoden si ty in exp er imental hydroceph a-

lus by met r izam ide CT ventr iculography. J

Neurosurg

56:235-240, 1982

31. Ho ff J , Barber R: Transcerebral mant le pressure in no r-

mal pressure hydrocephalus. Arch Neurol 31:101-105,

1974

32. Hu ghes CP, Siegel BA, Coxe WS, et al : Ad ult idiopathic

comm uni ca t i ng hydr ocepha l us w it h and w i t hou t shun t -

ing. J Neurnl


41:961-971, 1978

33. I l l ingworth RD, Logue V, Symon L, et al : The ventricu-

loatrial shunt in the treatment of adult hydrocephalus.

Results and com plication s in 101 patients. J

Neurosurg

35:681-685, 1971

34. Jacobs L , Cont i D, Kinkel WR , e t a l : "No rmal -pressu re"

hydrocephalus. Relat ionship of cl inical and radiographic

f indings to imp rove me nt fol lowing shunt surgery. JA M A

235:510-512, 1976

35. Koto A, Rosenberg G , Zingesser LH, e t a l: Syndrom e of

normal pressure hydrocephalus: possible relat ion to hy-

pertensive and arteriosclerotic vascu lopathy. J Neurol


40:73-79, 1977

36. Law s ER Jr, Mo kri B: Occ ult hydrocephalus: results of

shunting correlated with diagnostic tests. Clin Neurosurg

24:316-333, 1977

37. LeM ay M, New PFJ: Radiological diagnosis o f occult

5 0 8

J. Neurosurg. / Volume 61/S epte mb er, 1984


9/9

Normal-pressurehydrocephalus

normal-pressure hydrocephalus. Radinlogy 96:347-358,

1970

38. Lore nzo AV, Bresnan M J, Barlow CF: Cerebrospinal f luid

absorption defici t in normal pressure hydrocephalus.

Arch Neu rol 30:387-393, 1974

39 . Mat hew NT , Meyer JS , Har t mann A , e t a l : Abnor ma l

cerebrospinal f luid-blood flow dynam ics. Implica tions in

diagnosis, t reatment, and prognosis in normal pressure

hydrocephalus. Arch Neu rol 32:657-664, 1975

40. M cCo mb JG: Recent research into the nature of cerebro-

spinal f luid format ion and abso rpt ion. J Neurosurg

59:369-383, 1983

41. Messer t B, Wannamaker BB: Reappraisal of the adul t

occult hydrocephalus synd rom e. Neu rology 24:224-231,

1974

42. Mi lhorat TH: Th e thi rd c i rcula tion revisi ted. J Neurosurg

42:628-645, 1975

43. Mori K, Murata T , Nakano Y, e t a l : Per ivent r icular

lucency in hydrocephalus on computer ized tomography.

Surg Neuroi 8:337-340, 1977

44. Moseley IF, Radii EW: Factors influencing the develop-

ment of periventricular lucencies in patients with raised

intracranial pressure. Neuro radiology 17:65-69, 1979

45. Nelson JR, Goodman SJ: An evaluat ion of the cerebro-

spinal f luid infusion test for hydrocephalus. Neurology

21:1037-1053, 1971

46. Ojem ann RG : Norm al pressure hydrocephalus. Cl in Neu-

rosurg 18:337-370, 1971

47. Ojemann RG, F isher CM, Adams RD, e t a l : Fur ther

exper ience wi th the syndrome of "normal" pressure hy-

drocephalus. J Neu rosurg 31:279-294, 1969

48. P ickard JD: Adul t com mu nicat ing hydrocephalus. Br J

Hos p Me d 27:35-44, 1982

49. R ibadeau -Dum as JL , Ricou P , Verdure L , e t a l: E tude

anatom ique d 'un cas d 'hydro crphal ie h press ion norma le .

Neurochirurgie22:138-145, 1976

50. Russel l D: Observat ions on the Pathology of Hyd roceph -

alus. London: Her Majesty's Stat ionery Office, 1949

51. Salmon JH, Armi tage JL: Surgical t reatment of hydro-

cephalus

ex-vacuo.

Ventriculoatrial shu nt for degenera-

t ive brain disease. Neurology 18:1223-1226, 1968

52. Shenkin HA , Greenberg JO, Grossm an CB: Vent r icular

size after shunting for idiopathic normal pressure hydro-

cephalus. J Neurol Ne urosurg Psy chiat ry 38:833-837,

1975

53. Stein SC, Langfit t TW: No rma l-pressu re hydrocephalus.

Predicting the results of cerebrospinal fluid shunting. J

Neu rosnrg 41:463-470, 1974

54. Symon L, Dorsch NWC: Use of long- term int racranial

pressure mea sure me nt to assess hydrocephalic patients

prio r to shunt surgery. J N eurnsu rg 42:258-273, 1975

55. Sym on L, Dorsch NW C, S tephens ILl : Pressure waves

in so-called low-pressure hydrocephalus. Lancet 2:

1291-1292, 1972

56. Symon L, Hinzpeter T : The enigma of normal pressure

hydrocephalus: tests to select patients for surgery and to

predict shu nt function. Clin Neu rosurg 24:285-315, 1977

57 . S ype r t GW , L ef f man H , O j emann GA: Occu l t no r ma l

pressure hydrocephalus mani fes ted by parkinsonism-de-

men t ia comp lex. Neurology 23:234-238, 1973

58. Tator CH, Murray SA: A cl inical , pneumoencephalo-

graphic and radioisotopic s tudy of no rmal -pressure com-

mun icat ing hydrocephalus . Can Med Assnc J 1 05:

573-579, 1971

59. Vassilouthis J: Cerebrospinal f luid edema. J Neurosurg

58:625-6 26, 1983 (Letter)

60. Vassilouthis J, Rich ardso n AE: Ven tricular di latat ion a nd

communicat ing hydrocephalus fol lowing spontaneous

subarachnoid hemorrhage. J Neurosurg 51:341-351,

1979

61. Weller RO, Shulm an K : Infanti le hydrocephalus: cl inical,

histological , and ultrastructural study of brain damage. J

Neurosurg

36:255-265, 1972

62. Whi te DN, Wilson KC, Curry GR, e t a l : The l imi ta t ion

of pulsati le f low through the aqueduct of Sylvius as a

cause of hydrocephalus. J Neurol Sci 42:11-5 l , 1979

63. Wikkels0 C, Andersson H, Blomst rand C, e t a l : The

cl inical ef fect of lumbar puncture in normal pressure

hydrocephalus . J Neurnl Neurosurg Psych iat ry 45:64-69,

1982

64. Wo od JH, Bar t le t D, Jam es AE Jr, e t a l: Normal -pressure

hydrocephalus: d iagnosis and p atient selection for shu nt

surgery. Neurology 24:517-526, 1974

65. Woodford J , Saunders RL, Sachs E Jr : Shunt sys tem

patency tes t ing by lumbar infus ion. J Neurosurg 45:

60-65, 1976

66. W yper DJ, P ickard JD, Matheson M : Accuracy o f ven-

t r icular volum e es t imat ion. J N eurol Neurosurg Psychia-

try 42:345-350, 1979

Man uscr ipt received De cem ber 5, 1983.

Accepted in final form March 26, 1984.

Address reprint requests to:

John Vassilouthis, M.D.,

8 Alopekis Street , Kolo nak i, Athens, Greece.

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The Syndrome of Normal-pressure Hydrocephalus Vassilioutis