• Spinal sensory level? → spinal cord
• Alternating sign? → think brainstem
• Dermatome / Myotome or peripheral nerve distribution?
• Unilateral or bilateral?
  • Bilateral → think spinal cord
• Associated symptom?
• Does it involve the face or the trunk?

Supratentorial

Infratentorial

Spinal

Root

Peripheral

NMJ

Muscles