Plexopathies

Key Features

• Brachial plexus neuropathy

  • May be idiopathic

  • May follow trauma

  • May result from congenital anomalies, neoplastic involvement, or injury by various physical agents

  • May be familial (rare)

• Cervical rib syndrome is the compression of the C8 and T1 roots or the lower trunk of the brachial plexus by a cervical rib or band arising from the seventh cervical vertebra

• Lumbosacral plexus lesions may develop

  • In association with diabetes mellitus, cancer, or bleeding disorders

  • After injury

  • Occasionally occurs as an isolated phenomenon similar to idiopathic brachial plexopathy (nondiabetic lumbosacral radiculoplexus neuropathy)

Clinical Findings

• Brachial plexus neuropathy

  • Initially, severe pain about the shoulder

  • Within days, weakness, reflex changes, and sensory changes, especially involving C5 and C6, develop

  • Symptoms are usually unilateral but may be bilateral

  • Wasting of affected muscles can be profound

• Cervical rib syndrome

  • Weakness and wasting of intrinsic hand muscles, especially those in the thenar eminence

  • Pain and numbness is in the medial two fingers and the ulnar border of the hand and forearm

  • Compression of the subclavian artery may also occur

• Lumbosacral plexus lesions

  • Pain and weakness, more so than sensory symptoms

  • Symptoms depend on the level of neurologic involvement

Diagnosis

• MRI helpful in revealing underlying compressive structure

• Radiographic films and CT scans

  • Can show a cervical rib or a large transverse process of the seventh cervical vertebra

  • Normal findings do not exclude the possibility of a cervical band

• Electrodiagnostic evaluation helps localize a lesion and is important for differential diagnosis

• Brachial plexus neuropathy: Magnetic resonance neurography or high-resolution ultrasound may identify hourglass-like constrictions on affected nerves

Treatment

• Brachial plexus neuropathy

  • Symptomatic

  • Microsurgical neurolysis of hourglass-like constrictions on affected nerves may improve outcome in patients who have not recovered after several months of conservative management

• Surgical excision of the rib or band in cervical rib syndrome

• Physical therapy and adequate analgesia are especially important in idiopathic cases

• Treat underlying cause