Primitive reflex activity in primary and symptomatic Parkinsonism

J. Neurol. Neurosurg. Psychiat., 1968, 31, 501-508

Primitive reflex activity in primary and symptomaticParkinsonism

JOHN PEARCE, HASAN AZIZ, AND J. C. GALLAGHER

From the Combined Neurological Service, Hull Royal Infirmary

In the normal subject repeated light tapping overthe glabella produces reflex blinking of both eyes.This phenomenon, first described by Overend(1896), has been called the glabella tap sign, thenasopalpebral reflex, the orbicularis oculi reflex, andthe blinking reflex; it has been studied by Wartenberg(1945) and by Rushworth (1962). Electromyo-graphic studies (Kugelberg, 1952) demonstratedthat this reflex has two components-an initialproprioceptive (myotatic) reflex and a later nocicep-tive (defence) reflex. Rushworth (1962) has suggestedthat, where proprioceptive and avoiding reactionsare exaggerated, both components of the glabellatap might be accentuated.A positive glabella tap sign has been used by some

neurologists as an early indication of Parkinsonism.In this context however the value of this sign is notwidely appreciated. One of the few references isthat of Garland (1952) who states 'among theearliest physical signs are those involving the eyes,... infrequent or absent blinking except on tappingthe glabella. This latter is perhaps the most constantand certainly the most characteristic sign. Ontapping the glabella both eyelids blink in time withthe tapping, whether this be slow or fast, and thisblinking will continue indefinitely; the normalperson will only blink after the first few taps. Forall practical purposes this physical sign is diagnosticof the Parkinsonian state'. However the sign hasnever been carefully evaluated in a large series ofpatients with Parkinsonism and with other intra-cranial diseases.The present study is an attempt to assess the

clinical usefulness of this physical sign and inparticular to consider whether or not it has anyspecificity for Parkinsonism. In the course of thisstudy we have been able to identify a group ofpatients with destructive cerebral pathology ofdiverse origins, some of whom on careful scrutinydisplayed evidence of secondary Parkinsonism. Thesignificance of the glabella tap sign, of secondaryParkinsonism, and of their radiological andpathological correlates are considered.

50l

METHODS

An unselected series of consecutive patients admitted tothe combined neurological-neurosurgical ward at theHull Royal Infirmary were examined for the presence ofthe glabella tap sign. To increase the number of patientswith Parkinsonism, new out-patients with this diagnosiswere included in the study. The ward patients includedthose with intracranial diseases of all types, and patientswith extra-cerebral illness were included as controls.Additional controls were -obtained by examining healthydoctors, nurses and auxiliary workers in the hospital.Each subject was examined independently by three

observers. The sign was recorded as being positive,borderline, or negative. Where there was any disagree-ment the three observers re-examined the subjectstogether and a final judgment was recorded. The signwas elicited by light tapping with the index finger overthe glabella region of the forehead and over the bridgeof the nose. Care was taken to avoid reflex blinkingfrom visual threat by ensuring that the examiner's handwas held above the patient's eyes, the finger pointingdownwards. A normal response consists of up to fiveblinks following repeated tapping, further blinkingstopping at this point despite continued tapping. The rateof tapping is some importance; some patients continuingto blink if the tapping was slow (two per second), butceasing to do so with faster rates (greater than five persecond). The vast majority of patients clearly fell intopositive and negative groups. In a small proportion ofcases the result was judged to be borderline; in thesepatients blinking continued on slow tapping up to 10times and then stopped, or stopped when the speed oftapping was increased to more than five per second(Fig. 1).

All patients were subjected to a detailed neurologicalexamination, and contrast radiology or pathologicalstudy was performed if clinically indicated, and in thisway provided more accurate information about the size,site and nature of the cerebral lesion.

RESULTS

Table I shows that there were 100 patients-76 withintracranial disease and 14 with extracranialdisease; 10 healthy subjects served as controls. Themean age of those with intracranial disease was

John Pearce, Hasan Aziz, and J. C. Gallagher

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FIG. 1. Glabella tap reflex.

50 years in males and 51 years in females; the meanage of those with extracranial lesions was 46 inmales and 45 in females. In the control subjects themean age was 34 in males and 27 in females. Theincidence of a positive sign in patients with extra-cranial disease (14) and controls (10) was verysimilar, and these two groups were thereforecombined under the heading of controls.

Table II shows that in those with intracranialdisease the glabella tap sign was positive in 33patients, borderline in two patients, and negativein 41 patients. In the control group the sign wasborderline in one patient and negative in 23 patients.The reliability in eliciting the glabella tap sign is

illustrated in Table III, which shows the correlationachieved by three independent observers. In thosewith intracranial disease there was complete agree-ment in 67 (88%) instances and disagreement innine (12%) instances. In the control group, agree-ment was achieved in all 24 patients. As this studyprogressed the amount of disagreement diminished,so that, in the last 20 patients studied, completeagreement was obtained by all three observers.

In those patients recorded as borderline, theobserver differing from the other two recorded apositive result in four instances and a negativeresult in four instances. This shows that there wasno particular tendency towards false positive orfalse negative results.

Theresults in patientspresenting with Parkinsonismand in those with other cerebral disorders are shownin Table IV. This demonstrates that in Parkinsonismthe glabella tap sign was almost always positive,and was negative on only one occasion. It should be

TABLE IANALYSIS OF PATIENTS

Intracrania Extracranialdisease lesions

(no.) mean (no.) meanage (yr) age (yr)

Controls

(no.) meanage (yr)

Male 46 50 9 46 4 34Female 30 51 5 45 6 27Total 76 50 5 14 45 8 10 30

TABLE IIGLABELLA TAP SIGN

Intracranial Controldisease

Positive 33 0Borderline 2 1Negative 41 23

TABLE IIIOBSERVER VARIATION

Intracranial Control Wholedisease series

(no.) (%) (no.) (%)

Agreement 67 88 24 100 91Disagreement 9 12 0 0 9Total 76 100 24 100 100

TABLE IVINTRACRANIAL DISEASES

Positive Borderline Negative Total

Parkinsonism 18 1Others 14 1

1 2041 56

502

Primitive reflex activity in primary and symptomatic Parkinsonism

emphasized that these patients were not thoseincapacitated by advanced Parkinsonism and mostpatients were in the early stages of the diseasehaving been sent to the out-patient department fordiagnosis.Table V shows the salient features of patients with

a positive glabella tap, the primary cerebral lesionbeing other than Parkinsonism. Of the diverseconditions included in this group, the commonidentifiable feature was that of widespread destruc-tion or degeneration of brain tissue. The clinicalevidence of Parkinsonism is summarized in thisTable. It will be seen that, apart from the glabellatap sign, there was definite evidence of Parkinsonismin five patients, and mild Parkinsonian signs other

than glabella tap sign were present in three patients.The results of air encephalographic studies in

five patients are shown in Table VI. All of thesepatients showed at least one feature of Parkinsonismother than a positive glabella tap sign. Since thereare still no absolute criteria for the radiologicaldefinition of cerebral atrophy, we have presentedsix different radiological measurements for assess-ment, using the somewhat arbitrary criteria ofnormality suggested by Davidoff and Dyke (1946).In all our patients there was ventricular dilatation asseen in abnormal values for measurements D and E(Figs. 2 and 3). Excessive pools of subarachnoidcortical air were seen when this area was adequatelyvisualized.

TABLE VANALYSIS OF THE 15 PATIENTS SUBJECTED TO THE STUDY

Initials Age Sex Diagnosis Secondary Parkinsonian features Site and extent of lesion

Tremor Rigidity Posture

1. S.G. 65 M Dementia +

2. W.S. 63 M Presenile dementia +

3. D.B. 53 F Alzheimer's disease +

4. G.L. 58 M Epilepsy of late onset +

5. C.W. 57 M Cerebello-striataldegeneration

6. R.T. 37 M Severe head injury

7. R.F. 24 M Severe head injury

8. N.W. 30 M Head injury

9. J.B. 51 M Glioblastoma multiforme +

10. T.M. 68 M Secondary cerebraltumour

11. B.A. 47 F Subarachnoidhaemorrhage

12. A.B. 48 F Subarachnoidhaemorrhage

13. F.B. 40 M Suppurativeencephalitis

14. R.B. 26 M Anoxic cerebral damage +

15. H.J. 50 M Low pressure +hydrocephalus

+ + + Severe dementia, Parkinsonismbronchogenic carcinoma

+ + Diffuse and symmetrical dilatation ofventricular system on AEGDiffuse and symmetrical dilatation ofventricular system on AEGEpilepsy associated with dementia,dilatated ventricles on AEGWidespread atrophy of cerebellumand dilatation of lateral ventricles onAEG

Deeply unconscious for 2 d; rightfrontotemporal contusion andoedema requiring decompression.Total amnesia 3 wDeeply unconscious for 2 d. Amnesiauntil the time of death (3 m). Severediabetes insipidusWhole of left hemisphere infarcted;surgical removal of massive areas ofcontused brain

+- + Right frontal lobectomy 2 m ago.Readmitted with tremor, dementia,and motor intranquillityLarge right frontal lobe metastasisfrom bronchogenic carcinomaremoved by frontal lobectomyPosterior communicating aneurysm,operative ligation. No obviousneurological deficitMiddle cerebral aneurysm, operativeligationSevere diffuse suppurative inflamma-tion of left hemisphere causingaphasia and right hemiplegia

-+- Two cardiac arrests following over-dose with barbiturates (suicidal)

+ -I- + Longstanding hydrocephalus withdiffuse and symmetrical dilatation ofventricles on AEG

Facies

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TABLE VIMEASUREMENTS ON AIR ENCEPHALOGRAMS

Normal figures (cm)*W.S.D.B.G.L.C.W.

H.J.

C D

40-454-83-7504-4

8-0

1-62-03.53-23.53-2

6-3

E F

252-7252-62-7

4-8

05-081-305

1-21I0

1 4

G

0-1.0-303-05

06-0805-06Large pool over cerebellum

*The normal figures from Davidoff and Dyke, 1946.

1,4116 'V

X f iQ c

FIG. 2. Air encephalogram, A-P projection. A ventricularand skull diameters; C and D transverse and diagonalmeasurements of lateral ventricles; Fmaximum transversediameter of third ventricle; G maximum diameter ofcorti-cal air spaces.

FIG. 3. Air encephalogram, lateral projection. E distancefrom foramen of Monro vertically to roof of lateralventricle.

The features of four patients are now described indetail with reference to available radiological andpathological data.

CASE 1

W.S. (H.R.I. D33795), a 63-year-old joiner, was admittedto the unit with a history of progressive weakness of theright arm and unsteadiness of gait. Over the precedingfew months he had been getting progressively forgetfuland had developed some difficulty with his speech. Hehad also complained of some recent severe headaches inthe frontal region. On examination on admission hewas fully conscious and orientated in time and space,but his power of calculation had diminished and hisabstract thought was poor. He had mild right-sidedpyramidal and extrapyramidal signs, but could walkunaided. He had masked facies, diminished automaticmovements, and a positive glabella tap sign. There wasmild but definite cog-wheel rigidity in the right arm, buthe had no rigidity of his neck muscles.

Investigations showed a normal erythrocyte sedi-mentation rate (ESR) and blood count. The plasmaurea and electrolytes were normal.The blood Wassermanreaction (WR) was negative. Cerebrospinal fluid (CSF)contained 30 mg protein/100 ml. 1 lymphocyte/cu. mm,normal Lange curve, and negative WR. The radiographsof his skull and chest were normal. There was adiffuse bilateral theta rhythm with paroxysms of under-lying generalized delta activity in the electroencephalo-gram (EEG). An air encephalogram showed symmetricaldilatation of the ventricular system with excessive poolsof air over the cortex. With reference to Figs. 2 and 3and Table VI, the measurements of parameters D, C, E,F, and G were abnormal.

CONCLUSION (1) Presenile dementia of moderate severitywith cerebral atrophy, strongly suggestive of Alzheimer'sdisease. (2) Definite signs of Parkinsonism.

CASE 2

J.B. (H.R.I. K27104), a 50-year-old labourer wasadmitted to the unit with a history of periodic frontalheadaches for the preceding two months. His wifenoticed that he tended to fall asleep in the chair and thathe had two attacks of loss of consciousness lasting from

AB

0-16-0-290-190-19031033

0-40

504

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v


five to 10 minutes. He tended to be clumsy, occasionallyincontinent, and he had a very poor memory.On examination he was found to be ambidextrous,

right eyed, left handed and right footed. He was fullyconscious. The higher mental functions were preserved.He had bilateral papilloedema, a marked grasp reflex,and a positive sucking reflex. There was no hemiparesisand the tendon jerks were normal; the left plantarresponse was extensor. Investigations showed a normalhaemoglobin, blood count, urea, and electrolytes. Thecerebrospinal fluid protein was 40 mg/100 ml., with onelymphocyte/cu. mm and a negative WR. Radiographs ofthe skull and chest were normal. A carotid angiogramshowed a right frontal lobe tumour which was removedsurgically by a right frontal lobectomy and was foundto be glioblastoma multiforme.The patient was readmitted two months later because

of increasing confusion and disorientation. Examinationshowed a Parkinsonian facies with a fixed expression,diminished automatic movements, and a rapid coarsetremor of both upper limbs. Continuous purposelessfidgety movements of both arms were present as seenin the syndrome of 'motor intranquillity'. A brain scanshowed a dense concentration of radioisotope in theright frontal region, suggesting a recurrence ofthe tumour.

CONCLUSION Frontal lobe signs, motor intranquillity,and Parkinsonism developing with recurrence of a largeright frontal glioblastoma multiforme.

CASE 3

R.B. (H.R.I. 19114), a 29-year-old labourer had beensuffering from dermatitis herpetiformis for a number ofyears. He emigrated to Australia in 1966. His skincondition became worse and precipitated a severereactive depression during which he took an overdoseof barbiturate (55 tablets of Seconal, 100 mg). He wasadmitted to the local hospital. He had severe respiratoryfailure and while being intubated developed cardiacarrests on two separate occasions responding to intra-cardiac adrenaline and external cardiac massage. Hewas unconscious for four days. On recovery he wasfound to have become generally stiff, slow in movements,dysarthric, and incapable of looking after himself.Since then this disability has remained unchanged. Hewas admitted for assessment to the Combined Neuro-logical Service of the Hull Royal Infirmary in 1967.On examination on admission to the unit he was found

to have an extreme degree of dystonia with abnormalhyperpronation and extension of fingers, arms, and legs.He was quite incapable of walking, sitting, standing, orturning himself in bed because of truncal and limbrigidity. He had a Parkinsonian facies, a positive glabellatap sign, but no tremor. There was a severe degree ofgeneralized lead pipe rigidity of neck muscles, trunk,arms, and legs. He had a monotonous low pitched voicewith a scanning type of dysarthria.

It was felt that he had sustained severe and irreversibledamage to his basal ganglia during the period ofrespiratory failure and cardiac arrests. Further radio-logical studies were considered unnecessary, but it is

reasonable to assume that there is extensive cerebralatrophy as a result of prolonged anoxia.

CONCLUSION (1) Severe anoxic brain damage pre-dominantly manifest as truncal and limb dystonia,rigidity, and dysarthria. (2) Definite Parkinsonianfeatures overshadowed by major disability.

CASE 4

H.J. (H.R.I. 10538). This 57-year-old man was first seenin consultation in June 1967, when he had developedunexplained incontinence of urine while being treatedfor diffuse back and limb pains by an orthopaedicsurgeon. At this time he was remote, disorientated, andshowed no grasp of current events. In the subsequentweeks he became profoundly demented and withdrawnand continued to be incontinent of urine. The strikingfinding on neurological examination was a profoundtruncal apraxia which made it impossible to sit or standunsupported. He had a mask-like facies, and markedcog-wheel rigidity in the neck and both upper limbs.All volitional movements were performed slowly, andthere was an intermittent tremor in both arms.

Full blood count, ESR, radiographs of chest andskull, and numerous investigations for metabolic dis-orders were within normal limits. The lumbar CSFpressure was 110 mm and the CSF protein was 10 mg/100 ml. An attempted lumbar air encephalogram wasunsuccessful, air failing to enter the ventricular system.An air and Myodil ventriculogram showed enormousdilatation of both lateral and the third ventricales. Withreference to Figs. 2 and 3 and Table 6 the measurements

of the parameters -, C, D, D, and F were grossly

abnormal. There was a partial stenosis of the aqueduct,which had been responsible for a low pressure, occulthydrocephalus.A ventriculo-atrial shunt was performed with a low

pressure valve. After this procedure the patient made adramatic recovery with an almost complete reversal ofthe dementia, and with abolition of his incontinence andinability to walk. Three months later the patient was inexcellent health, could walk unlimited distances, andwas returning to work. The glabella tap sign had dis-appeared.

CONCLUSION (1) Low pressure occult hydrocephaluswhich had produced dementia, gait apraxia and incon-tinence. (2) Definite signs of Parkinsonism. (3) Clinicalfeatures including those of Parkinsonism reversed byventriculo-atrial shunt.

DISCUSSION

CLINICAL ASPECTS OF THE GLABELLA TAP REFLEXWartenberg (1945) has reviewed much of the earlierliterature concerning this physical sign. Preferringto call it the 'orbicularis oculi reflex', he stressed thelow threshold for its elicitation, and noted the very

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rapid reaction of the orbicular muscles and thebilateral response evoked. Stimuli as, different aslight, sound, visual threat, and touching the palatecould evoke the reflex. Tapping was an effectivestimulus over a wide area ranging from the nasalto the frontal and temporal bones. Wartenberg dis-cussed earlier views that the reflex might originatein the periosteum or skin, but rejected these notionsasserting that the response was a true musclestretch reflex.He reported its diagnostic importance in that it

was depressed in peripheral facial palsy, and notedthat it was preserved or exaggerated in upper motorneurone facial paralysis. Like Guillain, Alajouanine,and Marquezy (1924) he emphasized its exaggerationin postencephalitic Parkinsonism and stated thatthis was so constant as to be regarded as a definitesign of Parkinsonism.

PHYSIOLOGY OF THE GLABELLA TAP REFLEX The

response to tapping the glabella has two electromyo-graphic components-an initial proprioceptiveelement and a second nociceptive one. The afferentfibres for the reflex are carried, in the majority ofindividuals, by the first division of the trigeminalnerve (Kugelberg, 1952). However, in a smallproportion of normal individuals the afferent path-way lies in the seventh cranial nerve (Rushworth,1962). The efferent fibres are carried by the facialnerve.

It has been shown that the initial response ismyotatic in nature. It has a short latency (15 msec),there are no latency fluctuations, its amplitude isfixed, it has a low threshold, and the reflex showssynchrony. These observations favour the suggestionthat this a proprioceptive reflex (Wartenberg, 1945;Kugelberg, 1952; and Rushworth, 1962).The second component is a defensive response

which has a variable latency and is asynchronous.The response to a second stimulus tends to resultin a shorter latency and a higher amplitude, whichsuggests that this is a response to a potentiallypainful stimulus or an avoiding reflex, and hencehas arisen the term 'nociceptive reflex' (Kugelberg,1952). In a normal individual this reflex character-istically habituates, becoming a response of increasinglatency and decreasing amplitude; for clinicalpurposes in a normal person there is no responseto repeated glabella tapping after the first four orfive stimuli.

In Parkinsonism both proprioceptive and noci-ceptive reactions are exaggerated, and both com-ponents of the response to glabella tap are verylarge and of long duration. However, the morecharacteristic response is the absence of habituationof the nociceptive reflex. The clinically positive

glabella tap reflex is shown electromyographically tobe due to the persistence of the nociceptive responsewhich on repeated tapping on the glabella does notfatigue. It has an identical latency in a particularpatient even up to the fiftieth or hundredth stimulus,though the amplitude of the response may be some-what reduced (Rushworth, 1962).

DIAGNOSTIC SIGNIFICANCE OF THE GLABELLA TAP SIGNThe clinical use of the glabella tap sign in thediagnosis of Parkinsonism and extrapyramidaldisorders has attracted little attention. Guillain et al.(1924) found this sign to be constant in all cases ofpostencephalitic Parkinsonism, but absent indisseminated sclerosis, thalamic, hypothalamic, andpseudobulbar syndromes. Rushworth (1962) founda positive sign in all 19 cases of paralysis agitansexamined electromyographically.

In the present series there were 20 cases ofParkinsonism. The glabella tap sign was negative inone, borderline in another one, and unequivocallypositive in 18 of the 20 patients. The majority ofthese patients, referred for consultation, were in theearly stages of Parkinsonism, and our experiencesuggests that this sign is particularly useful in theearly diagnosis of Parkinsonism when other signsare minimal.

It was felt important to assess the specificity ofthe glabella tap sign, and for this purpose 56patients with unselected cerebral lesions wereexamined. The glabella tap sign was positive in 13,and borderline in one. In these patients there wasinvariably a gross and widespread cerebral pathologysuch as presenile dementia with gross cerebralatrophy, severe cerebral anoxia, suppurative ence-phalitis, severe head injury, and cerebral tumour.The occurrence of a positive sign showed mostcorrelation with the anatomical extent of the lesion.There was no definite relationship between apositive glabella tap and the site of the lesion, norwith any specific type of pathological process.

It is evident that the glabella tap sign may bepositive in patients who do not have any othersigns of Parkinsonism. This emphasizes the pointthat the avoiding reflexes may be exaggerated notonly in disorders of the extrapyramidal system butalso in other intracranial diseases. It is also clear thata positive glabella tap in patients presenting withextensive cerebral lesions of diverse aetiology maybe an indication of early Parkinsonism. In thesecases it occurs as a symptom of the primary cerebralpathology, and therefore the sign is not specific forParkinson's disease.

SIGNIFICANCE OF GLABELLA TAP SIGN IN ORGANICBRAIN DISEASE A small but significant number

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(eight out of 56) of patients with organic cerebraldisease showed definite evidence of Parkinsonism.It should be stressed that this was never thedominant clinical feature, and could be easilyoverlooked unless specific attention was paid tothese features. In detecting these signs, the glabellatap reflex was most valuable.

Inspection of Table V shows that, in all caseswith a positive glabella tap and Parkinsonism, therewas a widespread and destructive lesion of thecerebral hemispheres. The groups of disordersassociated with a positive glabella tap sign included:(1) primary cerebral atrophies and degenerations(patients 1 to 5); (2) head injury with prolongedamnesia and gross hemisphere contusion,haemorrhage, and destruction (patients 6, 7, and 8);(3) cerebral tumour, in both cases with extensivecerebral involvement, or multiple lesions (patients 9and 10); (4) subarachnoid haemorrhage, withsurgical exploration, aneurysmal ligation, andevidence of extensive infarction (patients 11 and 12);(5) a miscellaneous group in which there wasconsiderable loss of cerebral tissue secondary tosuppuration, anoxia, and hydrocephalus, respectively(patients 13, 14 and 15). There is therefore nodefinite indication of any specific type of pathologicalprocess which correlates with development of asecondary Parkinsonian syndrome. However, theremay be some correlation with an atrophic process.

In attempting to correlate the clinical featureswith the observed degree of cerebral atrophy shownon air encephalography, certain difficulties areencountered. Measurements of ventricular width,diagonal measurements, and ratios of ventricularto skull size are potentially fallacious. The maindifficulties are in standardizing the magnification, inobtaining the same degree of tilt to the head, andin assessing changes which might result from theinjection of different volumes of air. Small differencesin any of these factors may significantly alter thesize of the ventricles on the x-ray plate, and thisis the main factor causing variation in reportednormal valves.

Because of these difficulties we have recordedsix different criteria of cerebral atrophy in the fivepatients studied by air encephalography. The criteriaofnormality have been the figures quoted by Davidoffand Dyke (1946). From our results we have foundthat the diagonal measurement of the frontal hornof the lateral ventricle (D) appears to be the mostreliable of the criteria we have examined (Fig. 2).The next most reliable measurement appears to bethe maximal transverse measurement of bothlateral ventricles (C) in the A-P projection. Thislatter measurement correlates fairly well withmeasurement E in Fig. 3, which is the distance

from the foramen of Monro vertically to the roofof the lateral ventricle in the lateral projection.

It is not claimed that these criteria are satisfactory,but they do provide measurements which approxi-mate to the ventricular size. We have tried tocorrelate these results with the clinical severity of theParkinsonism in the patients studied. There seems tobe a trend in which the greater the degree of cerebralatrophy and consequent ventricular enlargement themore frequent and more severe are the stigmata ofthe Parkinsonian syndrome (Tables V and VI).Of the eight patients with signs of Parkinsonism

additional to a glabella tap sign, six had proven orpresumptive evidence of ventricular dilatation orcerebral atrophy. Regarded from another viewpoint,patients 2, 3, 4, and 5 all presented features sugges-tive of a progressive cerebral degeneration as seenin Alzheimer's disease; in all these patients therewere observable Parkinsonian features.

It is cogent to question the significance of apositive glabella tap in the absence of otherParkinsonian signs. There are two ways of thinkingabout this problem.

Firstly, to regard a positive sign as being the firstsign of Parkinsonism, in which case all 15 patientspresented in this paper would be considered ashaving early or latent Parkinsonism. In favour ofthis view is the striking correlation of the sign inestablished Parkinson's disease (Wartenberg, 1945;Garland, 1952) in which it is rarely absent. Con-versely, to prove that a positive sign in isolation is aprophecy of later Parkinsonism would necessitatea careful prospective follow-up study, which to ourknowledge has never been undertaken.

Secondly, to regard a positive glabella tap sign asa non-specific sign, common to any destructivecerebral lesion of considerable size, and indicatingthe release of a primitive developmental reflex.This is the view which we think is most tenable, butit does fail to explain the remarkable correlationwith Parkinson's disease--even in its early stages.The reasons supporting this hypothesis requirefurther explanation.The glabella tap reflex is probably identical with

the nasopalpebral, and orbicularis oculi reflex(Wartenberg, 1945). It is closely akin to the reflexblepharospasm found for a few days in newborninfants, and in all premature infants in whom itmay persist for up to six months (Fisher, 1963).In the 21-5 cm foetus Minkowski (cited by Fisher,1963) observed a reflex contraction of the orbicularisoculi in response to touching the inner canthus ofthe eye. The primitive nature of the reflex as anormal accompaniment of the developing nervoussystem is not in doubt. Its appearance in acquireddisease of the nervous system can be considered as

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a release phenomenon in the Jacksonian sense ofthe term. As a positive phenomenon it may bethought to reflect a disturbance of frontal lobefunction (Denny-Brown, 1956). Our results stronglysupport this hypothesis, because extensive anddiffuse brain damage was the one finding commonto all 15 patients with a positive glabella tap sign.As stated earlier, if one type of pathology wassignificantly more frequent than any other it wasthat of cerebral atrophy of a diffuse type asexemplified by Alzheimer's disease.

It is of interest that in an independent, but similar,study Paulson and Gottlieb (1968) have recentlyreported the reappearance of other developmentalreflexes in 85 aged and demented patients. Theincidence of these reflexes varied from 7% to 53 %.In order of frequency, the abnormal patternselicited were reflex sucking, snout, gegenhalten.palmomental, grasp, and comeomandibular reflexes,The glabella tap reflex was not described in thispaper. The findings of Paulson and Gottlieb (1968)arecomplementary to our own results, and we suggestthat the finding of a positive glabella tap reflexshould be considered as an important but non-specific sign of extensive structural damage to braintissue. Why it should appear in Parkinsonism in theabsence of cerebral atrophy remains unknown, butit is possible that this occurrence represents anenhanced proprioceptive and avoiding responsewhich are recognized phenomena of basal gangliadisorders (Denny-Brown and Chambers, 1958).If this is the correct explanation, then we are ableto recognize two distinct factors which may deter-mine a positive glabella tap sign. First, the releaseof a primitive reflex by diffuse cerebral damage, and,second, the enhancement of proprioceptive andavoiding responses which complicate degenerativelesions of the globus pallidus and substantia nigra.

SUMMARY

The glabella tap reflex has been studied in 100patients. Twenty suffered from Parkinsonism, 56from other unselected cerebral diseases, and therewere 24 controls. An abnormal reflex was found in19 of the 20 examples of Parkinsonism and in noneof the control group. Fourteen patients with thecerebral pathology other than Parkinsonism had apositive sign, and it is suggested that some of thesehad latent Parkinsonism secondary to their primarycerebral lesion, which was always extensive indegree. In the absence of other Parkinsonian signs,a glabella tap sign may indicate the return ofprimitive reflex activity in response to destructivelesions of the cerebral hemisphere. In this group ofpatients the glabella tap reflex has been correlatedwith other clinical and air encephalographic signsof cerebral atrophy and of Parkinsonism. Thepossible significance of the results is discussed.

REFERENCES

Davidoff, L. M., and Dyke, C. G. (1946). The Normal Pneumoence-phalogram, 2nd. ed. Lea and Febiger, Philadelphia.

Denny-Brown, D. (1956). Positive and negative aspects of cerebralcortical functions. N.C. med. J., 17, 295-303.and Chambers, R. A. (1958). The parietal lobe and behaviour.Res. Publ. Ass. nerv. ment. Dis., 36, 35-117.

Fisher, C. M. (1963). Reflex blepharospasm. Neurology (Minneap.),13, 77-78.

Garland, H. G. (1952). Parkinsonism. Brit. med. J., 1, 153-155.Guillain, G., Alajouanine, T., and Marquezy, R. (1924). L'exageration

du reflexe naso-palpebral dans les syndromes post-encephalitiques. C.R. Soc. Biol. (Paris), 91, 364-365.

Kugelberg, E. (1952). Facial reflexes. Brain, 75, 385-396.Overend, W. (1896). Preliminary note on a new cranial reflex. Lancet,

1, 619.Paulson, G., and Gottlieb, G. (1968). Developmental reflexes. The

reappearance of foetal and neonatal reflexes in aged patients.Brain, 91, 37-52.

Rushworth, G. (1962). Observations on blink reflexes. J. Neurol.Neurosurg. Psychiat., 25, 93-108.

Wartenberg, R. (1945). The Examination ofReflexes: A Simplification.Year Book Publishers, Chicago.

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Documents

Primitive reflex activity in primary and symptomatic Parkinsonism