Triple-stimulation technique in multifocal neuropathy with conduction block.
In patients with multifocal neuropathy with conduction block (CB), CBs located between the root and Erb's point are not detected in nerve conduction studies. We therefore examined whether the triple-stimulation technique (TST) might provide a useful means of detecting CB proximal to Erb's point. Clinical assessments, extensive nerve conduction studies (NCS), conventional transcranial magnetic stimulation, and TST were performed on 10 patients with multifocal motor neuropathy with CB (MMNCB) and 6 patients with Lewis-Sumner syndrome. Conduction blocks located proximal to Erb's point were detected in 9 patients. Of the CBs, 58% were associated with muscle weakness. The use of TST to detect proximal CB improved the sensitivity of the American Association of Neuromuscular and Electrodiagnostic Medicine criteria for definite or probable MMNCB from 60% to 90%. Thus, the TST is a useful means for detection of proximal CB and gives NCS considerable additional diagnostic power.
Deroide
Nicolas
N
Department of Neurology and Neuromuscular Diseases, CHU La Timone, 264 rue Saint-Pierre, 13385 Marseilles, France.
Uzenot
David
D
Verschueren
Annie
A
Azulay
Jean-Philippe
JP
Pouget
Jean
J
Attarian
Shahram
S
D000328:Adult; D000368:Aged; D004558:Electric Stimulation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016472:Motor Neuron Disease / Q000175:diagnosis* / Q000503:physiopathology*; D009431:Neural Conduction; D012680:Sensitivity and Specificity; D013577:Syndrome