All true about conus syndrome except (AIPG -2008)
|A||Begins at the level of lower 3 sacral and coccygeal segment|
|B||Absent knee and ankle jerks|
|C||Flexor planter reflex|
Absent knee and ankle jerks
• Since the spinal segments involved in knee and ankle jerks are at higher level than the level of lesion, they are preserved, and not lost (B).
• Root value of knee reflex is L-2, 3 & 4 and for the ankle reflex is S-1.
• Conus medullary syndrome is a lower motor neuron lesion and involves the lower 3 sacral and coccygeal segments (A).
• Plantar reflex remains flexor (C) in this syndrome, since its spinal arc is also above the level of lesion and is unaffected.
• Root value of plantar reflex is S-1, 2.
• Conus medullary syndrome produces saddle anaesthesia (D) in the perineal region as per the dermatomal pattern.