EpistemisAtrophy of the hypothenar eminence
Specialty: Musculoskeletal.
Why it occurs
- Severe Guyon's canal syndrome (compression of the ulnar nerve in the wrist from cysts, hamate hook fractures, or use of vibrating tools)
- Cubital tunnel syndrome in the elbow (prolonged compression of the ulnar nerve)
- C8-T1 cervical radiculopathy due to posterolateral disc herniation or foraminal osteoarthritis
- Injury to the lower trunk of the brachial plexus (e.g., due to cervical rib or Thorax Outlet Syndrome)
- Amyotrophic Lateral Sclerosis (ALS)
- Traumatic ulnar mononeuropathy in athletes (road cyclists)
Initial workup
Needle electromyography (EMG) (abductor muscle of the fifth finger, interossei) and motor and sensory nerve conduction velocities of the ulnar nerve, comparing elbow and wrist | MRI of the elbow or cervical spine | Ultrasound of Guyon's canal and cubital tunnel.
red flags
Subacute hypothenar atrophy that is accompanied by progressive weakness of the ulnar finger flexors, fixed ulnar claw deformity of the hand, loss of sweating in the fourth and fifth fingers and intense burning pain on the ulnar edge of the hand that ascends to the shoulder (indicates severe compressive neuropathy of the ulnar nerve with risk of irreversible axonal loss).
Standard management
- Pregabalin — 75-150 mg orally every 12 hours; for management of neuropathic pain and associated dysesthesias
- Amitriptyline — 10-25 mg orally at night
- Methylcobalamin (1000 mcg orally once daily as supportive neurotrophic therapy).
Educational guidance for study. It is NOT a prescription recommendation. The actual choice depends on the cause, the patient, and current guidelines.
- Area
- Musculoskeletal
- Listed causes
- 6
- Treatment options
- 3