Mononeuropathies
| Symptoms | Precipitating Activities | Examination | Electro-Diagnosis | Differential Diagnosis | Treatment | |
|---|---|---|---|---|---|---|
| Carpal tunnel syndrome | Numbness, pain or paresthesias in fingers | Sleep or repetitive hand activity | Sensory loss in thumb, second, and third fingers Weakness in thenar muscles; inability to make a circle with thumb and index finger Tinel sign, Phalen maneuver | Slowing of sensory and motor conduction across carpal tunnel | C6 radiculopathy | Splint Surgery definitive treatment |
| Ulnar nerve entrapment (UNE) at the elbow | Numbness or paresthesias in ulnar aspect of hand | Elbow flexion during sleep; elbow resting on desk | Sensory loss in the little finger and ulnar half of ring finger Weakness of the interossei and thumb adductor; claw-hand | Focal slowing of nerve conduction velocity at the elbow | Thoracic outlet syndrome C8-T1 radiculopathy | Elbow pads Avoid further injury Surgery when conservative treatment fails |
| UNE at the wrist | Numbness or weakness in the ulnar distribution in the hand | Unusual hand activities with tools, bicycling | Like UNE but sensory examination spares dorsum of the hand, and selected hand muscles affected | Prolongation of distal motor latency in the hand | UNE | Avoid precipitating activities |
| Radial neuropathy at the spiral groove | Wrist drop | Sleeping on arm after inebriation with alcohol—”Saturday night palsy” | Wrist drop with sparing of elbow extension (triceps sparing); finger and thumb extensors paralyzed; sensory loss in radial region of wrist | Early—conduction block along the spiral groove Late—denervation in radial muscles; reduced radial SNAP | Posterior cord lesion; deltoid also weak Posterior interosseous nerve (PIN); isolated finger drop C7 radiculopathy | Splint Spontaneous recovery provided no ongoing injury |
| Thoracic outlet syndrome | Numbness, paresthesias in medial arm, forearm, hand, and fingers | Lifting heavy objects with the hand | Sensory loss resembles ulnar nerve and motor loss resembles median nerve | Absent ulnar sensory response and reduced median motor response | UNE | Surgery if correctable lesion present |
| Femoral neuropathy | Buckling of knee, numbness or tingling in thigh/medial leg | Abdominal hysterectomy; lithotomy position; hematoma, diabetes | Wasting and weakness of quadriceps; absent knee jerk; sensory loss in medial thigh and lower leg | EMG of quadriceps, iliopsoas, paraspinal muscles, adductor muscles | L2-4 radiculopathy Lumbar plexopathy | Physiotherapy to strengthen quadriceps and mobilize hip joint Surgery if needed |
| Obturator neuropathy | Weakness of the leg, thigh numbness | Stretch during hip surgery; pelvic fracture; childbirth | Weakness of hip adductors; sensory loss in upper medial thigh | EMG—denervation limited to hip adductors sparing the quadriceps | L3-4 radiculopathy Lumbar plexopathy | Conservative management Surgery if needed |
| Meralgia paresthetica | Pain or numbness in the anterior lateral thigh | Standing or walking Recent weight gain | Sensory loss in the pocket of the pant distribution | Sometimes slowing of sensory response can be demonstrated across the inguinal ligament | L2 radiculopathy | Usually resolves spontaneously |
| Peroneal nerve entrapment at the fibular head | Footdrop | Usually an acute compressive episode identifiable; weight loss | Weak dorsiflexion, eversion of the foot Sensory loss in the anterolateral leg and dorsum of the foot | Focal slowing of nerve conduction across fibular head Denervation in tibialis anterior and peroneus longus muscles | L5 radiculopathy | Foot brace; remove external source of compression |
| Sciatic neuropathy | Flail foot and numbness in foot | Injection injury; fracture/dislocation of hip; prolonged pressure on hip (comatose pt) | Weakness of hamstring, plantar and dorsiflexion of foot; sensory loss in tibial and peroneal nerve distribution | NCS—abnormal sural, peroneal, and tibial amplitudes EMG—denervation in sciatic nerve distribution sparing glutei and paraspinal | L5-S1 radiculopathies Common peroneal neuropathy (partial sciatic nerve injury) LS plexopathies | Conservative follow up for partial sciatic nerve injuries Brace and physiotherapy Surgical exploration if needed |
| Tarsal tunnel syndrome | Pain and paresthesias in the sole of the foot but not in the heel | At the end of the day after standing or walking; nocturnal | Sensory loss in the sole of the foot Tinel sign at tarsal tunnel | Reduced amplitude in sensory or motor components of medial and planter nerves | Polyneuropathy, foot deformity, poor circulation | Surgery if no external cause identified |