Carpal Tunnel Syndrome 2018Anthony Chiodo, MD, MBAMichigan MedicineDepartment of Physical Medicine and Rehabilitation

Definition

Clinical Syndrome

Numbness, Tingling, Burning and Pain

Median nerve distribution of the hand

Localized compression of the median nerve at the wrist

Local ischemia and mechanical damage

Sensory nerves more susceptible

Comparative latencies used to make the diagnosis

Sensitivity 85%, specificity 82-85%

Utility of Symptoms in Predicting Disorder: Hand DiagramCalfee FP. Performance of Simplified Scoring Systems for Hand Diagrams in Carpal Tunnel Syndrome Screening. JHS, 2012.

Sensitivity: 40%

Specificity: 80%

Long finger: 67/73

Utility of Physical Examination in Predicting Disorder Thenar wasting is hard to measure: hand deformities

Thumb abduction strength is hard to measure: baseline, abductor pollicislongus

Whom to Start Treatment and Whom to Consider Study Early Start Treatment

Clear triggers

Periodic and not continuous

Morning symptoms only

Study Early Constant symptoms

Thenar atrophy

Thumb abduction weakness

Common Mimics and Co-Incident Disorders 1st MCC arthritis

Local deformity and tenderness

Weakness vs. pain with resistance

Co-incident: both related to repetitive UE work or activities

DeQuervain’s tenosynovitis Lateral thumb and forearm tenderness

No sensory symptoms

Pain with thumb adduction and opposition

Co-incident: both related to repetitive UE work or activities

Flexor tenosynovitis

Ulnar neuropathy at the elbow

Cervical radiculopathy: C6

Upper trunk brachial plexopathy

Unusual Presentations Inclusion Body Myositis

Myotonic Dystrophy

ALS

Effective First Line Treatments

Hand splints

NSAID’s

Hand occupational therapy

NCS before Invasive Line Treatments

Comparative Testing to eliminate impact of age, temperature, height, and superimposed conditions (polyneuropathy) Sensory comparative: Sensitivity 0.85, specificity 0.97

Motor: Sensitivity 0.63, specificity 0.98

Temperature correction is critical in making the correct diagnosis Severe CTS: CMAP amplitude drop or abnormal needle exam study Population studies

21% with surgery without NCS

14.5% with less than two sensory studies

10.6% with less than two motor studies

6.1% neither

Role of Imaging In Diagnosis of CTS

Test AUC Sensitivity Specificity

EMG Comp Sensory 0.923 90.9 81.2

U/S UPA/UDA 0.751/0.912 88.4/83.7 46.2/76.9

UPE/UDE 0.798/0.835 76.7/86.0 76.9/78.6

CT CPA/CDA 0.838/0.874 97.1/67.6 46.7/86.7

CPD/CDD 0.803/0.798 67.6/70.6 80/75

MRI MPA/MDA 0.823/0.847 42.5/65 100/80

MPI/MDI 0.813/0.722 87.5/87.5 60/40

Effectiveness of Injection for Carpal Tunnel SyndromeBlazar PE. Prognostic Indicators for Recurrent Symptoms After a Single Corticosteroid Injection for Carpal Tunnel Syndrome. JBJS (A), 2015.

53% symptom free for 6 months, 31% for one year

Repeat injection 81% symptom free at 6 months, 66% at one year

35% operation rate in the first year

Concomitant diabetes best predicted failure of injection therapy 2.6 fold greater risk of reporting symptom recurrence

Blind Vs. Ultrasound Guided InjectionEslamian F. A Randomized Prospective Comparison of Ultrasound-Guided andLandmark-Guided Steroid Injections for Carpal Tunnel Syndrome. J Clin Neurophys, 2017.

No difference in change in symptoms

No difference in electrophysiological parameters

When That Does Not Work: Surgical Referral

Effectiveness of CTS Surgery

10-15% with unsatisfactory outcomes in most studies Most severe patients with delayed improvement due to axonal loss

Lack of improvement at one year

Initial improvement followed by recurrence of symptoms

Re-operation rates 5-12%

Clear evidence that CTS Surgery effectiveness is negatively impacted by a negative EMG study

Fact is amplified in patients with worker’s compensation

BEWARE: yellow flags

Effectiveness of CTS Surgery: Who did bestLo YL. Outcome Prediction Value of Nerve Conduction Studies for Endoscopic Carpal Tunnel Surgery. J Clin NM Disease, 2012.

Sensory peak latency less than 6.0 ms (13 cm distance)

VAS 0-10 paresthesia score of 4 or higher Patients with lower paresthesia scores did not do as well

Pain, numbness and weakness scores were not predictive

75% noted improved paresthesias and numbness, 52% for weakness and 34% for pain

In other words: moderate disease and sensory symptoms where pain is not a significant symptom

CTS Surgery Complications

Nerve injury 0.05%

Wound infection 0.36% (deep 0.13%)

Tendon injury 0.1%

Pillar pain: self limited to 6-9 months

Pisotriquetral joint pain

CRPS

CTS Surgery Failures: What is next?

Re-operation in 5-12 % Incomplete release

Scar formation

Incorrect diagnosis

Re-operation rate improvement about 50%

BEWARE: yellow flags

Does Double Crush Exist?Garcia-Santibanez R. Scelsa SN. Frequency of Radiculopathy in Patients With Carpal Tunnel Syndrome and Paracervical Pain. J. Clin NM Dis 2016.

Patients with CTS and paracervical pain are not any more likely to have cervical radiculopathy than patients with CTS alone.

Nerve conduction study parameters of CTS severity are not at all related to whether a patient has cervical radiculopathy (no dose effect)

Risk of developing CTS with abnormal nerve conduction studiesWerner RA. Use of screening nerve conduction studies for predicting future carpal tunnel syndrome. Occ Env Med 1997.

At risk employees without characteristic symptoms but abnormal nerve conduction studies Factory workers

Dental hygienists

Increased risk over 7-11 years compared to aged matched controls

Only 25% became symptomatic in that time frame

Questions