Carpal Tunnel Syndrome

Knife or Needle? Dr Jeremy D P Bland

Consultant in Clinical Neurophysiology

East Kent Hospitals University NHS Trust

ACPOMIT annual meeting, Milton Keynes, June 2015

Topics Epidemiology and Aetiology

Natural History

Diagnosis

Clinical

History

Examination

Provocative tests

Investigations

NCS

Ultrasound imaging

Screening for other diseases

Treatment

Splints

Steroids

Surgery

Topics Epidemiology and Aetiology

Natural History

Diagnosis

Clinical

History – do we pay enough attention?

Examination

Provocative tests – is it time for Jules Tinel to retire?

Investigations

NCS – what are they for?

Ultrasound imaging – is it a substitute for NCS?

Screening for other diseases – A waste of money?

Treatment

Splints

Steroids

Injected dose

Repeat injection

Ultrasound guidance

Surgery – Can we predict the outcome?

Diagnosis “A physician’s forecast of disease by the patient’s pulse and

purse” – Ambrose Bierce

“Listen to your patient – he is

telling you the diagnosis” - Osler

Diagnoses from: Published Papers

HISTORY

EXAMINATION

LAB (or NEVER!)

Sensitivity and specificity

A simplistic approach to diagnostic performance

Jeffrey N Katz

“The Carpal Tunnel Syndrome: Diagnostic Utility of the

History and Physical Examination Findings” Annals of

Internal Medicine 1990 Vol 112 No 5 p 321-327

Sensitivity Specificity

Neurologists assessment 0.84 0.72

Hand diagram 0.61 0.71

Proposed ‘point systems’ HISTORY Kamath 2003 Graham 2006 Lo 2009 Hems 2009 Bland 2011

Age <60 = 2

Gender female -5

Finger distribution no little finger 3 median = 3.5 median=7 median = 2

Timing Night Pain =1, Tingling = 1 4 6 2

Morning 1

Use/Working 1

Wake and Shake 1 2

Splint response 2 1

Dropping objects/clumsiness 1

Duration <2 0

2-12 7

>12 11

Symptoms in pregnancy 1

Neck pain 1 -6

Wrist pain -5

EXAMINATION

Tinel 4 2

Phalen 5 1

Sensory loss "Median" 2PD = 4.5 10 2

1st/2nd 2

2nd/4th 1

Beyond hand -11

Ulnar + -1

Thenar Wasting 7 2

APB Weakness 5 7

PERFORMANCE

Reference comparison Surgical outcome Expert opinion NCS Surgical outcome NCS

Suggested threshold >/=3 >/= 12 ??? >/= 7 >/= 40%

Sensitivity 85% 89% 76% 82% 78%

Specificity ??? 80% 68% 67% 68%

ROC 0.63 None 0.8 0.776 0.79

Frequency of history items in CTS cases Question NonCTS CTS Total % CTS Question NonCTS CTS Total % CTS

Handedness Right 12065 16616 28681 58% Flick N 7705 7553 15258 50%

Left 1243 1532 2775 55% Y 5942 10975 16917 65%

Ambidex 350 383 733 52% missing 11 3 14 21%

Sympside Right 5980 9555 15535 62% Splint N 1934 2309 4243 54%

Left 4601 5520 10121 55% U 10441 14078 24519 57%

Bilateral 2894 3347 6241 54% Y 1269 2137 3406 63%

Missing 183 109 292 37% missing 14 7 21 33%

Time_night N 5338 4305 9643 45% Duration missing 6 2 8 25%

Y 8314 14224 22538 63% <3m 1495 1730 3225 54%

missing 6 2 8 25% 3-6m 3244 4361 7605 57%

Time morning N 5671 5761 11432 50% 6-12m 3068 4043 7111 57%

Y 7980 12769 20749 62% 1-2y 2816 3829 6645 58%

missing 7 1 8 13% 2-5y 1763 2537 4300 59%

Time driving N 8812 10947 19759 55% 5-10y 769 1114 1883 59%

Y 4839 7582 12421 61% >10y 497 915 1412 65%

missing 7 2 9 22% Neckpain N 3067 4595 7662 60%

Time working N 4092 5860 9952 59% Y 2796 2769 5565 50%

Y 9537 12643 22180 57% missing 7795 11167 18962 59%

missing 29 28 57 49% CTS preg N 2429 3139 5568 56%

Newsknit N 3796 3909 7705 51% U 2921 3585 6506 55%

Y 2067 3455 5522 63% Y 372 441 813 54%

missing 7795 11167 18962 59% missing 7936 11366 19302 59%

Site tim 4137 8095 12232 66% Dominant N 7366 8620 15986 54%

lr 1182 335 1517 22% Y 6292 9911 16203 61%

mr 994 1936 2930 66%

all 4305 5642 9947 57%

4f 1772 1879 3651 51% TOTAL 32189 new cases

other 1257 637 1894 34%

missing 11 7 18 39%

Questionnaire tools for the diagnosis of carpal tunnel

syndrome from the patient history – 2011 Bland JDP,

Weller P, Rudolfer S, Muscle&Nerve 44:757-62

Kamath Questionnaire

New Models

2616 new patients

www.carpal-tunnel.net

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0+ 10+ 20+ 30+ 40+ 50+ 60+ 70+ 80+ 90+

Website diagnostic score

CTS or not - % confirmed CTS

p < 0.001

Diagnostic performance of carpal-tunnel.net in 2655 patients

0%

2%

4%

6%

8%

10%

12%

14%

16%

0+ 10+ 20+ 30+ 40+ 50+ 60+ 70+ 80+ 90+

Score distribution

Website scores of patients referred for NCS

Diagnostic score and NCS severity

A rational referral policy

GP Consultation

Website

Score threshold 20%

NCS

O&R

ICATS

74%

26%

Severe CTS

Mild CTS

Non-CTS

0

10

20

30

40

50

60

70

80

90

100

Sensitivity

Specificity

Diagnostic performance of Tinel’s sign

Average weighted for sample

size: sensitivity = 50%,

specificity = 77%

“Secondary” CTS – 16622 patients

Pregnancy (37 – 0.2%)

Rheumatoid arthritis (1348 – 8.1% – self reported, most not RA)

Acromegaly (5 – 0.03%)

Glucose (Diabetes) (1866 – 11.2%)

Mechanical (Fractures, anomalous muscle etc) ???

Amyloid ???

Thyroid (279 - 1.68% Hyper, 1213 – 7.3% Hypo)

Infection ??? (never seen a case)

Crystals (Gout and Pseudo-gout) (Never seen a definite case)

What are tests for?

Often not needed for diagnosis!

Graham B, 2008 “The value added by electrodiagnostic testing in

the diagnosis of carpal tunnel syndrome”, JBJS Am 90:2587-93

Reasons for investigation

(Diagnosis when genuinely uncertain)

Detection of other pathology

Prognosis

Follow-up

“SEVERITY” ?

“How bad is it doc?”

“Oh, that’s a pretty

severe one my dear”

…but what do they

mean?

The Patient -Subjective severity?

OED - 6 irrelevant

definitions before:

7.7 Grievousness (of pain,

affliction, penalties, etc.).

But she already knows what

it feels like!

The Doctor – Measures of Severity

‘MILD’

‘SEVERE’

‘WORST I’VE

EVER SEEN

The Real Question

MILD

SEVERE

TOOLS

Subjective severity –

Levine/Boston CTS assessment scale

Symptom Severity Night pain severity

Night pain frequency

Day pain severity

Day pain frequency

Day pain duration

Numbness severity

Weakness severity

Tingling severity

Night tingling severity

Night tingling frequency

Small object manipulation

Functional impairment Writing

Buttoning clothes

Holding a book to read

Gripping telephone

Opening jars

Household chores

Carrying groceries

Bathing/dressing

Each subscale produces a number ranging from 1 (no symptoms) to 5 (worst symptoms)

Subjective outcome- Global outcome scale

1 – Worse than before treatment

2 – Unchanged

3 – Slight improvement

Would still like something done if that is possible

4 – Much better but some residual symptoms

Not sufficient to require further intervention

5 – Complete cure

As good as new (apart from a scar if operated)

Physiological severity –

Canterbury NCS scale for CTS

6 (Extremely severe) – No motor or sensory potential

5 (Very severe) – DML to APB > 6.5msec

4 (Severe) – Prolonged DML, Absent SNAP

3 (Moderately severe)– Prolonged DML, preserved SNAP

2 (Mild) – Normal DML, delayed index SNAP

1 (Very slight)– Only demonstrable with sensitive tests

0 (None) – Normal NCS

Objective vs subjective change with treatment

MaxMin

Mean+2*SEMean-2*SE

Mean

Better ------- Change in neurophysiological grade ------ Worse

Mea

n s

ubje

ctiv

e opin

ion o

f outc

om

e

Worse

Unchanged

Slightly better

Much better

Cured

-5 -4 -3 -2 -1 0 1 2 3 4 5

Comparison of Surgery and Injection benefits

124

2300

90

225

1070

154

62

425

32

13

229

3 7

318 13

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Injection G1-G5 Historical (2y) GP Surgery (3m)

0

0.5

1

1.5

2

2.5

3

3.5

4

Worse Same Better Much Cured

Mean Pre/Post treatment SSS scores in 867 operations (3m) and 1917 injections (6w)

Pre-injection

Pre-surgery

Post-injection

Post-surgery

Measuring change with treatment

Prognosis “Guessing has never been widely acclaimed

as a good gambling strategy.” - Anon

Concannon MJ, et al 1997 The Predictive value of electrodiagnostic

studies in carpal tunnel syndrome. Plast Reconstr Surg 100(6) 1452

The similarities between these two groups suggests that the distinction between them (the positivity of electrodiagnostic studies) is an artificial one and that the clinical diagnosis of carpal tunnel syndrome is sufficient to predict the presence of the disease, as well as outcome of surgery

First group 62 hands with normal NCS

Second group 398 hands with abnormal NCS (348 mild/moderate, 50 ‘severe’

47 280

36

15 68

14

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Normal Mild/moderate Severe

Fail

Success

- P=0.39 --

- P=0.19 --

---------- P=0.67 ---------

Fisher’s exact test comparisons

Concannon MJ, et al 1997 The Predictive value of electrodiagnostic

studies in carpal tunnel syndrome. Plast Reconstr Surg 100(6) 1452

The similarities between these two groups suggests that the distinction between them (the positivity of electrodiagnostic studies) is an artificial one and that the clinical diagnosis of carpal tunnel syndrome is sufficient to predict the presence of the disease, as well as outcome of surgery

First group 62 hands with normal NCS

Second group 398 hands with abnormal NCS (348 mild/moderate, 50 ‘severe’

0

50

100

150

200

250

300

350

400

Normal' NCS Mild/Moderate NCS Severe NCS

Opera

ted H

ands

Fail

Success

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Grade 0 Grade 1 Grade 2 Grade 3 Grade 4 Grade 5 Grade 6

Surgical outcome in 7136 carpal tunnel decompressions

Worse

No change

Better

Much Better

Cured

How does ultrasound compare on:

Diagnosis

Severity

Other findings

Prognosis

NCS vs u/s for diagnosis

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

<=30% 31-40% 41-50% 51-60% 61-70% 71-80% >80%

Probability of CTS from clinical questionnaire

Proportion of abnormal test results from u/s and NCS related to clinical probability of CTS

Proportion with CSA >10

Proportion >Grade 1 NCS

Ideal test

Severity - NCS grade vs u/s CSA – 1000 hands

Canterbury referrals for ?CTS

33,840 tests

21344 CTS

63%

12,496 NOT

CTS

826 Other

neurological

diagnosis (7%)

10 Non-

neurological

diagnosis

11,660

No Diagnosis

Other neurological diagnoses

Ulnar 513 Anatomical anomaly 2

Poyneuropathy 154 CVA 1

Injury 53 Deep palmar 1

Radiculopathy 44 Digital branch lesion 1

Ulnar+PN 26 (Meralgia) 1

TOS 7 MND 1

Motor branch lesions 5 Neurofibroma 1

Pronator syndrome 3 PN+Writers Cramp 1

Median neuropathy 2 Post herpetic neuralgia 1

Radial 2 TIA 1

Ulnar+Root 2 Tumour 1

Writers Cramp 2 Cramp 1

Concomitant disease in CTS

CTS

21,344

'Simple' 20,341

95%

CTS+

1103

Neurological

1074

Other

7

Uncertain

22

Other pathology

Common – osteoarthritis

38% of 13,580 patients

attending Canterbury

department described

themselves as having

osteoarthritis when asked

31% of those with normal

NCS

42% of those with

evidence of CTS

The apparent correlation

is probably mediated via

age

May be linked to CTS

Trigger finger

91/211 patients with

trigger finger but no

predisposing cause also

had CTS (43%) (Kumar

2009)

In Canterbury 11% of

patients with CTS report a

history of trigger finger

These disorders probably

share a common

predispostion

Other interesting findings on u/s?

Kele et al 2002 (110 wrists)

Synovitis (11)

Muscles in carpal tunnel (10)

High division of median nerve (3)

Thenar branch leaving proximally (3)

Radially positioned median nerve (1)

Ulnar artery near median nerve <3mm (11)

Patent median artery (1)

Thrombosed median artery (1)

My findings so far (350 wrists)

Synovitis (1)

Patent median artery (4)

High division of median nerve (9)

Ulnar artery near median nerve (2)

u/s for prognosis

(multivariate

analysis inc u/s)

Best multivariate model so far

Area under ROC curve = 0.84

Includes

- NCS grade

- u/s CSA

- SSS

- FSS

- Age

- BMI

- Duration

0.0

00

.25

0.5

00

.75

1.0

0

Se

nsitiv

ity

0.00 0.25 0.50 0.75 1.001 - Specificity

Area under ROC curve = 0.8396

Initial response to injection (6 weeks) vs ultrasound imaging

(138 hands - Canterbury Data, normal vs >15 groups p<0.05)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

6-9 10-15 >15

% w

ith init

ial good r

esp

onse

Median nerve CSA at pisiform (mmsq)

Treatment “When a lot of remedies are suggested for a disease, that means

it cannot be cured.”

― Anton Chekhov

What treatments are used ?

Surgery

Open

Endoscopic

Local steroid injection

Splinting

Rest/Job modification

Oral steroids

Steroid iontophoresis

Diuretics

NSAID’s

Vitamin B6

Magnet therapy

Exercise programmes (nerve/tendon gliding)

Yoga

Neurodynamic mobilisation

Carpal bone mobilisation

Chiropractic manipulation

Local ultrasound

Low level laser acupuncture

Microamps TENS

Acupuncture

Cognitive behavioural therapy

HRT

Non-invasive laser neurolysis

Biofeedback

Steroid

Injection

Some surgeons do not approve!

“ to suggest that patients should be offered steroid injection as definitive treatment….is both wrong and irresponsible.... the danger with injections is that the patient feels better, believes [they are] cured, and does not return to see the doctor for two or three years……by this time the thenar muscles may be wasted…….[and] it may not respond to surgical decompression - that is it is permanent” Wallace, BMJ 1999

Guidelines from UK hand surgery center describe steroids as “hazardous” and suitable only for use in CTS occurring during pregnancy. Hayward, Postgrad Med J 2002

“You are comparing a disease modifying treatment (surgery) to a treatment that is palliative at best (steroid injection). The study we need is a comparison of corticosteroid injection vs placebo injection. The results to date would suggest that corticosteroids might not even be palliative. So if corticosteroids are no more than wishful thinking and they simply distract the patient and the surgeon from the issues at hand, how will we change the culture and stop giving steroid injections” – anonymous reviewer of a grant application proposing an injection vs surgery trial

The surgical criticisms

Dangerous

Painful

Always temporary

Surgery is the only disease modifying treatment

Only suppresses the symptoms

Messes up later surgery

Risky? – Major Complications

7000+ injections

Fingertip Gangrene (2)

Tendon rupture

1 definite

1 possible

Intractable arm pain (1)

Risky? – Minor complications

55 Bilateral, 100 unilateral = 155 patients, 210 hands

No ill effects from 139 injections (66%)

Possible side-effects reported in:

23 bilateral injections (42%)

28 unilateral injections (28%)

Significantly more common after bilateral injections

(p=0.006)

Possible side effects – 6 weeks

Localised

Ache/Pain – 30

Depigmentation – 1

Bruising – 1

Stiffness – 1

Weakness – 1

Numbness – 2

Rash – 2

Tremor -1

Fat atrophy – 1

Tingling – 1

Swelling – 1

“weird feeling inside” - 1

Systemic

Facial flushing - 5

Menstrual disturbance – 3

Loss of diabetes control – 2

Night sweats – 1

Stomach upset – 1

Positive

Improved back pain

Improved tennis elbow

Neck and shoulder pain resolved

Painful? - Injection pain

Disease modifying? - Effect of

injection on ultrasound

Results from Cartwright (2011)

29

30

31

32

33

34

35

36

37

0

5

10

15

20

25

Baseline 7 days 30 days 180 days

SSS

SNAP

CSA-wrist

SCV

Unknowns

Always temporary?

Dose – 20/40/80 mg methyprednisolone equivalent?

Lignocaine?

Serial injection?

European recommendations

Our data so far

Ultrasound guidance?

Injection after failed surgery?

824 patients injected

5 year follow-up

372 second injections

(third?)

Surgery

1 year = 15%

5 years = 33%

Always temporary?

Dose? – Possibly the best steroid trial ever!

Rate of surgery at 1 year (111 pts)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Placebo 40mg 80mg

P=0.042

Effectiveness of second corticosteroid injections for

carpal tunnel syndrome. Ashworth NL, Bland JDP Muscle &

Nerve 2013; 48(1); 122-126

First injection (n=1675) Second injection

(n=229)

P value

Age (mean, sd) yrs 60.0 (15.7) 57.4 (14.8) 0.014 *

Gender (% female) 72 75 ns

BMI (mean,sd) 28.8 (5.9) 28.7 (6.0) ns

Duration symptoms before

initial presentation (median)

6-12 months 6-12 months ns

Initial electrodiagnostic

severity (mean Canterbury, sd)

2.5 (1.1) 2.3 (1.1) ns

No difference in SSS between first

and second injections

1.2 1.3

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1st Injection 2nd Injection

Mean improvement in SSS

Better improvement in FSS with

second injection (p<0.001)

0.4

0.7

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1st Injection 2nd Injection

Mean improvement in FSS

No difference in Duration (Days)

336 348

0

50

100

150

200

250

300

350

400

1st Injection 2nd Injection

Are there any predictors of improved

outcome for 2nd injection?

• Δ SSS for 1st injection

• R sq = 0.13 Δ SSS

• Δ SSS for 1st injection

• Menopausal

• R sq =0.21 Δ FSS

Prejudicial to subsequent

surgery?

Telephone survey carried out in 2011 of all patients operated during

2005 at one centre in Estonia

Reliant on patient recall for record of injections

Most patients did not have NCS and almost no contemporaneous

information from the time of surgery was included in the analysis

Injection

Before

surgery

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Inject Inject Direct Direct Inject Inject Direct Direct

SSS (green pre-op, red post-op) FSS

Results – change in score

0

10

20

30

40

50

60

Direct

Pre-inject

All

Subjective improvement post surgery (%)

Ultrasound guidance – reasons

Safer?

Less risk of intraneural injection

Intraneural injections are pretty rare anyway

More precise site

Does it matter if the steroid ends up ‘in’ the carpal tunnel?

‘Hydro-dissection’

Ultrasound guidance? – Cochrane

Makhlouf T (2014) “ Outcomes and cost-effectiveness of carpal tunnel injections using

sonographic needle guidance” Clin Rheumatol 33(6):849-58

Lee J Y (2014) “Effectiveness of ultrasound guided carpal tunnel injection using in-

plane ulnar approach: a prospective randomized, single-blinded study” Medicine

(Baltimore) 93(29):1-6

Ustun N (2013) “ Ultrasound-guided vs blind steroid injections in carpal tunnel

syndrome: A single-blind randomized prospective study” Am J Phys Med Rehabil

92(11):999-1004

But…..

Limitations

No patient blinding – placebo and distraction effects from

very different procedures

In Ustun – different doses were used for the two arms of

the trial

How to do it better?

Use the scanner for both arms of a study but hide the

display from the injector in one arm

Compare an ultrasound guided injection placed between

nerve and ligament with one deliberately placed in the

distal forearm

Conclusions

Quantitative medicine

There are now quite good tools for:

Diagnosis

Severity assessment

Follow-up.......... Use them and record them!

Diagnostic tests

Tinel – forget it in CTS

Ultrasound

Complementary to NCS, not a replacement

Needs more work on injection guidance

Treatment

Injection

Starting to look like a viable alternative to surgery