CHAPTER 21 COMPRESSION NEUROPATHIES Clinical condition where pressure

CHAPTER 21 COMPRESSION NEUROPATHIES � Clinical condition where pressure on peripheral nerve produces dysfunction in the nerve. � Carpal nerve) Tunnel Syndrome (wrist – median � Cubital nerve) Tunnel Syndrome (elbow – ulnar TONY JABBOUR, MD KNEE & SHOULDER SUBSPECIALTY

ANATOMY OF PERIPHERAL NERVE � Epineurium – outer covering cushions nerve. � Perineurium – surrounds fascicle (group of axons) � Endoneurium – each axon surrounded by collagen shell. Compression causes damage by direct pressure on neural vasculature and tethering nerves to surrounding tissue. TONY JABBOUR, MD KNEE & SHOULDER SUBSPECIALTY

CARPAL TUNNEL SYNDROME � Pain, numbness, weakness in median nerve distribution at wrist. � Median nerve enters wrist volar via carpal tunnel. � Transverse carpal ligament volar, carpal bones dorsally, 9 flexor tendons. � Under transverse carpal ligament. � As it exits carpal tunnel, the median nerve divides into branches to thumb, index and long fingers and the radial aspect of the ring finger. TONY JABBOUR, MD KNEE & SHOULDER SUBSPECIALTY

EPIDEMIOLOGY � More common in females. � Prevalence 2% of population. � Risk factors: Occupational, diabetes, hypothyroidism, pregnancy, masses. TONY JABBOUR, MD KNEE & SHOULDER SUBSPECIALTY

CLINICAL PRESENTATION � Vague wrist pain. � Numb thumb all the way to the radial aspect of the ring finger. � Pain with flexed wrist position (typing, bicycling). � Loss of fine motor control (chronic). � Nocturnal symptoms. � Decreased 2 -point discrimination. TONY JABBOUR, MD KNEE & SHOULDER SUBSPECIALTY

CLINICAL TEST � TINEL’S TEST: Percussing median nerve at volar wrist. � COMPRESSION TEST. � PHALEN’S TEST: Reproduced symptoms with sustained symmetric wrist flexion. � Decreased thenar muscle strength and atrophy (late findings). TONY JABBOUR, MD KNEE & SHOULDER SUBSPECIALTY

DIAGNOSTIC � X-rays � Neck � MRI of wrist (if fracture). (HNP). of wrist to check for masses. TONY JABBOUR, MD KNEE & SHOULDER SUBSPECIALTY

LABS � Rheumatoid arthritis, diabetes, hypothyroidism. TONY JABBOUR, MD KNEE & SHOULDER SUBSPECIALTY

NERVE CONDUCTION TESTING � Nerve conduction velocity and latency across motor and sensory components (EMG/NCV). TONY JABBOUR, MD KNEE & SHOULDER SUBSPECIALTY

DIFFERENTIAL DIAGNOSIS � Pronator Teres Syndrome – compression of median nerve at proximal forearm (FDS to all fingers). � Cervical myelopathy (C 6 -C 7). � Ulnar nerve compression at Guyon’s canal (numbness little finger and ulnar aspect of ring finger). � Cubital tunnel syndrome (Tinel’s at medial aspect of elbow). � Thoracic outlet syndrome (vascular or neural compression of brachial plexus). TONY JABBOUR, MD KNEE & SHOULDER SUBSPECIALTY

TREATMENT � Night splints. � Corticosteroid injection to carpal tunnel. � Surgery. TONY JABBOUR, MD KNEE & SHOULDER SUBSPECIALTY