Syringomyelia

- intrinsic cord lesion as cyst expands out
- symptoms develop between 20-30 years
- most commonly at cervical and upper thoracic level, but sometimes extending into the medulla
- 90% have type 1 Arnold Chiari malformation
- cardinal sign is dissociative sensory loss (absent pain and temperature sensation; preserved light touch, vibration and joint position)
- pain is exacerbated by coughing and exertion in upper limbs
- "UMN sign in lower limb, LMN sign in upper limb"
- other signs: sensory loss, wasting of small hand muscles, Horner's syndrome, limb hemihypertrophy, syringobulbia, Charcot's joint