Numbness

Clinical Features

Localizing the problem by history & physical

• Distribution of symptoms
  • Right vs. left
  • Presence of facial involvement
  • Arm vs. leg
  • Proximal vs. distal
  • Symmetric vs. asymmetric
• Characteristics of symptoms
  • Sensory and motor
  • Painless or Painful
  • Sensory only
  • Autonomic involvement
• Temporal Features
  • Acute or Chronic
  • Static or Progressive

Differential Diagnosis

Peripheral nerve syndromes

• Upper extremity
  • Ulnar
    • Cause of Injury: Elbow injury.
    • Sensory changes in the 5th and medial half of 4th digits, weak wrist flexors, “claw hand”
  • Radial
    • Cause of Injury: Distal humeral shaft fracture, anterior shoulder dislocation, supra-condylar fracture, Radial neuropathy at the spiral groove, Posterior interosseous neuropathy
    • “Wrist drop,” weakness of finger extensors. +/- sensory loss over the dorsum of the hand, weak thumb adduction
  • Median, distal
    • Cause of Injury: Wrist dislocation, laceration, Carpal Tunnel Syndrome
    • Weak flexion of radial half of digits and thumb, loss of abduction and opposition of thumb. Ape hand deformity, benediction sign. Loss of sensation of lateral three and one-half digits and nail beds
  • Median, proximal
    • Cause of Injury: Supracondylar humeral fracture, Pronator teres syndrome, Anterior interosseous neuropathy, tight cast
    • See Median, distal above, loss of forearm pronation, loss of radial half digits and thumb flexion
  • Musculocutaneous
    • Cause of Injury: Anterior shoulder dislocation, entrapment due to hypertrophy
    • Elbow flexion and supination weakness, radial forearm sensory deficits
  • Axillary
    • Cause of Injury: Anterior shoulder dislocation, inferior shoulder dislocation, proximal humerus fracture
    • Weak arm abduction (from 15 to 90 degrees), weak shoulder flexion, extension and rotation of shoulder, loss of sensation of upper lateral arm
  • Suprascapular
    • Cause of Injury: Paralabral cyst, bone/soft tissue tumor, Scapular fracture, traction injury, Parsonage-Turner syndrome
    • Weak arm abduction to 90 degrees, weak shoulder flexion to 30 degrees, weak internal rotation
• Lower extremity
  • Femoral
    • Cause of Injury: Pubic rami fracture, pelvic fractures
    • Weak knee extension, anterior knee sensory deficits
  • Obturator
    • Cause of Injury: Obturator ring fracture, obturator nerve entrapment
    • Weak hip adduction, medial thigh sensory deficit
  • Posterior tibial
    • Cause of Injury: Knee dislocation
    • Weak toe flexion, plantar foot sensory deficit
  • Superficial peroneal
    • Cause of Injury: Fibular neck fracture, knee dislocation
    • Weak ankle eversion, lateral dorsal foot sensory deficits
  • Deep peroneal
    • Cause of Injury: Fibular neck fracture, compartment syndrome
    • Sensory deficit at dorsal 1st web space, weak ankle and toe dorsiflexion
  • Sciatic
    • Cause of Injury: Posterior hip dislocation
    • Lower leg weakness, foot drop, leg sensory deficits
  • Superior gluteal
    • Cause of Injury: Acetabular pelvic fracture
    • Trendelenburg’s gait, Trendelenburg’s sign
  • Inferior gluteal
    • Cause of Injury: Acetabular pelvic fracture, s/p hip replacement
    • Abnormal gait, gluteus maximus weakness resulting in gluteus maximus lurch

Evaluation

Region	Distribution	Facial Involvement	Pain
Brain	Unilateral	Often	No
Spinal cord	Bilateral	No	Possible
Nerve root	Unilateral	No	Yes
Nerve	Unilateral or bilateral	Possible	Yes

Cause	Acute (Days)	Chronic (Weeks-Months)
Immune	Guillain-Barre & variants, vasculitis	Chronic demylinating neuropathy
Toxins	Botulism, buckthorn, diphtheria, tick, arsenic, organophosphates, thallium, vacor	Heavy metals, environmental chemicals
Drugs	Captopril, gangliosides, gold, nitrofurantoin, suramin, zimeldine	chemotheraputic agents
Metabolic	Porphyria	Porphyria, diabetes
Nutritional		Vitamin toxicity or deficiency
Hereditary		Hereditary motor and sensory neuropothy, hereditary sensory neuropathy

See Also

• Focal neurologic deficits