Weakness & Neuromuscular Dysfunction

Feature Upper Motor Neuron Lower Motor Neuron Neuromuscular Junction Myopathy
Distribution of weakness UE Ext, LE Flex, hip abductors Distal, segmental Ocular, bulbar, proximal limb Proximal, symmetric
Atrophy None Severe None Mild
Fasciculations None Common None None
Tone Normal Normal or ↓
Reflexes (DTRs) Normal Normal or ↓
Toes (Babinski) Upgoing Downgoing Downgoing Downgoing

Peripheral Neuropathies

Etiologies based on presentation

  • Mononeuropathy (1 nerve): acute → trauma; chronic → entrapment, compression, DM, Lyme. Common: median n. (carpal tunnel); ulnar n. (elbow or wrist); radial n. (spiral groove); com. (fibular head w/ leg crossing); lat. femoral cutan. n. (inguinal lig)