Significant linkage to migraine with aura on chromosome 11q24.

Migraine with aura (MA) is a prevalent neurological condition with strong evidence for a genetic basis. Familial hemiplegic migraine, a rare Mendelian form of MA, can be caused by mutations in the calcium channel gene, CACNA1A or in the ATP1A2 gene, a Na+/K+ pump. Susceptibility genes for the more prevalent forms of migraine have yet to be identified despite several reports of linkage including loci on 4q24, 1q31, 19p13 and Xq24-28.

Transient forearm conduction block in the median nerve.

We present two cases referred for electrophysiological confirmation of carpal tunnel syndrome (CTS). Initial nerve conduction studies were normal. Approximately 20 min into the examination, both patients developed sensory symptoms and weakness in the distal median nerve territory while the elbow was extended and forearm supinated.