title: Trigemino-cervical response in patients with amyotrophic lateral sclerosis.
abstract: OBJECTIVE
  The trigemino-cervical response (TCR) was investigated in the patients with amyotrophic lateral sclerosis (ALS) to evaluate its effect for disclosing the bulbar involvement in this disorder.
  
  
  METHODS
  We studied 100 normal subjects and 45 patients with ALS. In all normal subjects, stimulation of the infraorbital nerve on one side produced bilateral short latency waves, which consisted of a positive/negative wave described with the mean peak latency (P20/N30). The mean square root of the ratio between the amplitude of P20/N30 and the mean rectified surface EMG activity preceding the stimulus was described by A value.
  
  
  RESULTS
  The latency of P20 in controls was 18.5 +/- 1.4 ms, N30 was 28.8 +/- 2.8 ms, and the A value was 1.6 +/- 0.5, respectively. In ALS patients, twelve showed absent, seventeen were delayed in the latencies, six were above normal asymmetry on two sides, and ten showed normal. The latency of P20 in ALS patients was 22.9 +/- 9.4 ms, N30 was 33.7 +/- 11.2 ms, and the A value was 1.5 +/- 0.8, respectively. The parameters of the latencies of TCR between ALS patients and the normal controls were statistically different (P < 0.05).
  
  
  CONCLUSIONS
  TCR can be reliably measured in all normal subjects and help in disclosing lower brainstem lesions in ALS patients, even without bulbar symptoms.
authors.affiliation: Department of Neurology, Peking University Third Hospital, Beijing 100083, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Xu
authors.forename: D
authors.initials: D
authors.lastname: Fan
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: J
authors.initials: J
authors.lastname: Zheng
authors.forename: S
authors.initials: S
authors.lastname: Zhang
authors.forename: D
authors.initials: D
authors.lastname: Kang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D001933:Brain Stem / Q000473:pathology*; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D004558:Electric Stimulation; D004576:Electromyography; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction; D011930:Reaction Time; D015203:Reproducibility of Results; D014276:Trigeminal Nerve / Q000502:physiology*