What suggests segmental demyelination on NCV: (A) Decreased CAMP amplitudes, (B) Uniform slowing of nerve conduction, (C) Decreased area under CAMP curve, (D) No evidence of distal conduction
Answer is A. Answer- A. Decreased CAMP amplitudesSegmental Demyelination : Because there is variable slowing or different nerve fibers withing the nerve, conduction velocity will be slowed and distal latencies will be prolonged in segmentally demyelinatiing injuries.CMAP amplitudes may be decreased because of temporal dispersion, not because of axonal damage. Therefore, the CMAP may be longer in duration. However, the area under the CAMP will be normal.