title: Chronological changes of sympathetic outflow to muscles in amyotrophic lateral sclerosis.
abstract: To confirm correlations between muscle sympathetic nerve activity (MSNA) and patients' chronological data, we selected 40 consecutive patients with sporadic amyotrophic lateral sclerosis (ALS) recorded by similar methods. MSNA at rest was quantified as the number of sympathetic bursts per 100 heartbeats and as the value expressed as a percentage of the predicted value based on control data. Twelve patients who underwent recordings of MSNA twice at intervals of 6 months or more showed marked decreases in MSNA amplitudes and frequencies between examinations. There was a slightly positive correlation between the frequency of MSNA and age, though younger patients exhibited higher values of MSNA than older patients. The standardized value of MSNA correlated negatively with disease duration and disability levels (p<0.01, 0.05, respectively), but several patients with duration shorter than 12 months showed low values of MSNA. Twelve patients who underwent repeated recordings of MSNA showed a significant decrease in the mean standardized value of MSNA (102.6+/-24.9%) at the second examination, compared to the value (114.3+/-18.9%) at the first one. In ALS, sympathetic outflow to muscles tends to increase initially and then decrease with increasing age and duration. This pattern may be similar to chronological changes at motor neurons.
authors.affiliation: Department of Neurology, University of Yamanashi Hospital, 1110 Tamaho, Yamanashi 409-3898, Japan. kshindo@yamanashi.ac.jp
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Shindo
authors.forename: Chikashi
authors.initials: C
authors.lastname: Shimokawa
authors.forename: Harue
authors.initials: H
authors.lastname: Watanabe
authors.forename: Haruyasu
authors.initials: H
authors.lastname: Iida
authors.forename: Kenji
authors.initials: K
authors.lastname: Ohashi
authors.forename: Kiyoaki
authors.initials: K
authors.lastname: Nitta
authors.forename: Takamura
authors.initials: T
authors.lastname: Nagasaka
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Tsunoda
authors.forename: Zenji
authors.initials: Z
authors.lastname: Shiozawa
mesh_terms: D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology*; D001784:Blood Gas Analysis / Q000379:methods; D001794:Blood Pressure / Q000502:physiology; D004185:Disability Evaluation; D004562:Electrocardiography / Q000379:methods; D004569:Electroencephalography / Q000379:methods; D004576:Electromyography / Q000379:methods; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000503:physiopathology*; D012119:Respiration; D013223:Statistics as Topic; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D013997:Time Factors; D014797:Vital Capacity / Q000502:physiology