Acute motor and sensory axonal neuropathy (AMSAN) in a 15-year-old boy presenting with severe pain and distal muscle weakness.

Acute motor and sensory axonal neuropathy (AMSAN) is a recently described subtype of Guillain-Barré syndrome characterized by acute onset of distal weakness, loss of deep tendon reflexes and sensory symptoms. Electrophysiological studies show mildly reduced nerve conduction velocities combined with a marked reduction of muscle action and sensory nerve action potentials. Here, we report a 15-year-old boy who suffered from severe burning and knife-like pain that increased over a period of three months and resulted in a disrupted sleep pattern and suicidal intentions as well as marked loss of weight. In addition, he developed muscle weakness in his hands and feet. Neurophysiological and histopathological studies revealed AMSAN. Marked improvement of his condition was achieved by treatment with intravenous immunoglobulins, high-dose methylprednisolone, and a combination of gabapentin, antidepressants, and an oral morphine.