Carpal Tunnel Syndrome Stacey Harris-Carriman, M.D. Physical Medicine and Rehabilitation Noon Conference, CCRMC May 8, 2009

Objectives Be familiar with the basic neuroanatomy of the upper limb Understand factors involved in diagnosing CTS Recognize the goals and limitations of NCS Review treatment of CTS

Outline Definition Etiology and Risk Factors Neuroanatomy of the Upper Limb Diagnosis: Symptoms and signs Differential diagnosis NCS/EMG and US Treatment

Definition of CTS Constellation of symptoms and signs secondary to a median neuropathy at the wrist

Outline Definition Etiology and Risk Factors Neuroanatomy of the Upper Limb Diagnosis: Symptoms and signs Differential diagnosis NCS/EMG and US Treatment

Etiology Majority of CTS cases idiopathic

Etiology Small percentage of CTS due to an identifiable cause, such as: –DM, RA, thyroid disease –Conditions that increase total body fluid (e.g. pregnancy, hemodialysis) –Local wrist lesion (e.g. cyst, fracture, infection, tumor) –Congenital (e.g. small carpal tunnel)

Risk Factors Gender: F 3x>M Age: –Older > younger; very rare in children –Peak prevalence in women >55

Risk Factors Family history Certain medical conditions Workers that use hands and wrists repetitively, especially with high force Musicians

Risk Factors Other: Smoking, alcohol, poor nutrition, obesity, high cholesterol

Outline Definition Etiology and Risk Factors Neuroanatomy of the Upper Limb Diagnosis: Symptoms and signs Differential diagnosis NCS/EMG and US Treatment

Outline Definition Etiology and Risk Factors Neuroanatomy of the Upper Limb Diagnosis: Symptoms and signs Differential diagnosis NCS/EMG and US Treatment

Symptoms Pattern recognition Wide variety of symptoms in CTS Some symptoms are more suggestive of CTS than other symptoms

Symptoms Classic symptoms in CTS: –Waking up with pain and numbness/paresthesias of the hand –Triggered by driving, holding phone, reading book, typing, writing –Relieving factors Flick sign Changes in hand posture

Signs Key signs suggestive of CTS –Impaired sensation of the lateral 3-1/2 digits –Weakness of APB and other median- innervated muscles of thenar eminence –Phalen’s, reverse Phalen’s –Tinel’s –Other: Pressure provocation test, hand elevation test, tourniquet test

Signs NOT consistent with CTS –Impaired sensation over the lateral palm (thenar region) –Impaired sensation proximal to wrist –Weakness of hypothenar muscles or other non-median-innervated muscles –Impaired deep tendon reflexes

Outline Definition Etiology and Risk Factors Neuroanatomy of the Upper Limb Diagnosis: Symptoms and signs Differential diagnosis NCS/EMG and US Treatment

Differential Diagnosis of CTS –Peripheral NS Cervical radiculopathy Brachial plexopathy Proximal median neuropathy (e.g. in forearm or elbow) Other mononeuroapthy (e.g. ulnar, radial) Underlying polyneuropathy –Central NS (e.g. TIA, small lacunar infarct, myelopathy) –Musculoskeletal Shoulder pain with distal paresthesias Osteoarthritis Cumulative trauma disorder

Differential Diagnosis Peripheral NS: Cervical radiculopathy

DDx: Cervical Radiculopathy Especially mild cases of cervical radiculopathy C6, C7 Neck pain, radiation to shoulder, arm, +/- distally Worse with neck movement Impaired reflexes and strength Sensory loss beyond distribution of median nerve

Differential Diagnosis Peripheral NS: Brachial Plexopathy

DDx: Brachial Plexopathy Uncommon Etiology: –Trauma –Tumor, Mass –Delayed radiation injury –Plexitis –Postop (e.g. CABG) –Neurogenic TOS

DDx: Brachial Plexopathy Trauma Most common cause of brachial plexopathy Mechanism: –Traction Car/motorcycle/bike accident, newborn Upper trunk C5/6-Erb’s palsy Lower trunk C8/T1-Klumpke’s palsy –Penetrating (knife, bullet)

DDx: Brachial Plexopathy Neoplasm, Mass Metastasis to lymph nodes (most common), especially lymphoma, breast, lung cancer Local tumor: Pancoast Other –Direct infilration of nerve: Lymphoma, leukemia –Rare: Primary nerve sheath tumor –Non-neoplastic (unusual): hematoma, vascular anomaly

DDx: Brachial Plexopathy Delayed Radiation VS Onset: Progressive, years after radiation Risk correlated with dose of radiation Sensory sx prominent (paresthesias, numbness) (Recurrent) Neoplasm Onset: Slowly progressive Prominent pain Horner’s syndrome

DDx: Brachial Plexopathy Brachial Plexitis AKA Neuralgic amyotrophy, Parsonage- Turner Idiopathic Often preceded by: viral illness or immunization; also surgery Long thoracic nerve, anterior interosseous nerve, other Shoulder pain –Onset: days to weeks after inciting event –Severe pain, awakens from sleep Weakness and atrophy –Onset: Generally after pain subsides (1-2 weeks) +/- Sensory s/sx

DDx: Brachial Plexopathy Neurogenic TOS Most cases due to fibrous band between cervical rib and 1 st thoracic rib Lower trunk, C8/T1 Exam: –Muscles: hand intrinsics, esp thenar T1; +/- FPL, FDP –Sensory: Ulnar, MABC

Differential Diagnosis Peripheral NS: Proximal Median Neuropathy

DDx: Proximal Median Neuropathy Rare Trauma Ligament of Struthers Anterior Interosseous Syndrome –Pure motor: FPL, PQ, FDP to #2-3 –“Okay” sign “Pronator Syndrome” Possible sites of entrapment –Pronator teres –Lacertus fibrosus (b/t biceps tendon and proximal flexor forearm muscles) –Aponeurotic ridge of FDS (sublimis bridge)

Differential Diagnosis Peripheral NS: Other Mononeuropathy Ulnar, Radial

Differential Diagnosis Peripheral NS: Peripheral Polyneuropathy

Differential Diagnosis CNS: Cervical Myelopathy

Differential Diagnosis Musculoskeletal: Shoulder Pathology with Distal Paresthesias

Outline Definition Etiology and Risk Factors Neuroanatomy of the Upper Limb Diagnosis: Symptoms and signs Differential diagnosis NCS/EMG and US Treatment

Nerve Conduction Studies (NCS) [NOTE: NCS sometimes called NCV “Nerve Conduction Velocity”]

NCS Picture here of NCS set-up

NCS NCS can be useful in confirming CTS and assessing severity of CTS

NCS An extension of the clinical examination Each NCS study must be individualized

NCS NCS is positive in 91-98% of patients with clinically diagnosed CTS (Source: Keles et al, Diagnostic precision of ultrasonography in patients with CTS, Am J Phys Med Rehabil 2005) Risk of false negatives on NCS  generally implies very mild CTS

Diagnostic Ultrasound Real-time imaging of median nerve in carpal tunnel Qualitative and quantitative Measurements can include: –Cross-sectional area (CSA) of median nerve –Bowing of flexor retinaculum –Flattening of median nerve in carpal tunnel

Diagnostic Ultrasound Relatively new development Aids in diagnosis Aids in treatment, ultrasound-guided injection of steroid into carpal tunnel

Outline Definition Etiology and Risk Factors Neuroanatomy of the Upper Limb Diagnosis: Symptoms and signs Differential diagnosis NCS/EMG and US Treatment

Treatment of CTS

Summary and Conclusion

CTS: Summary and Conclusion The diagnosis of CTS is made on clinical grounds Pattern recognition Be systematic: history, physical, differential diagnosis

Summary and Conclusion NCS/EMG can be useful in confirming CTS and assessing severity of CTS Ultrasound can be a helpful adjunct in assessing and treating CTS

Thank You

Questions