title: Electrophysiological diagnosis and patterns of response to treatment of botulism with neuromuscular respiratory failure.
abstract: In this study we describe the electrophysiological findings in botulism patients with neuromuscular respiratory failure from major botulism outbreaks in Thailand. High-rate repetitive nerve stimulation testing (RNST) of the abductor digiti minimi (ADM) muscle of 17 botulism patients with neuromuscular respiratory failure showed mostly incremental responses, especially in response to >20-HZ stimulation. In the most severe stage of neuromuscular respiratory failure, RNST failed to elicit a compound muscle action potential (CMAP) of the ADM muscle. In the moderately severe stage, the initial CMAPs were of very low amplitude, and a 3-HZ RNST elicited incremental or decremental responses. A 10-HZ RNST elicited mainly decremental responses. In the early recovery stage, the initial CMAP amplitudes of the ADM muscle improved, with initially low amplitudes and an incremental response to 3- and 10-HZ RNSTs. Improved electrophysiological patterns of the ADM muscle correlated with improved respiratory muscle function. Incremental responses to 20-HZ RNST were most useful for diagnosis. The initial electrodiagnostic sign of recovery following treatment of neuromuscular respiratory failure was an increased CMAP amplitude and an incremental response to 10-20-HZ RNST. Muscle Nerve 40: 271-278, 2009.
authors.affiliation: Department of Medicine, Rajavithi Hospital, Bangkok, Bangkok, Thailand. skhongsa@hotmail.com
authors.forename: Subsai
authors.initials: S
authors.lastname: Kongsaengdao
authors.forename: Kanoksri
authors.initials: K
authors.lastname: Samintarapanya
authors.forename: Siwarit
authors.initials: S
authors.lastname: Rusmeechan
authors.forename: Pasiri
authors.initials: P
authors.lastname: Sithinamsuwan
authors.forename: Surat
authors.initials: S
authors.lastname: Tanprawate
mesh_terms: D000931:Antidotes / Q000494:pharmacology / Q000627:therapeutic use; D001703:Biophysics; D001906:Botulism / Q000150:complications* / Q000188:drug therapy / Q000401:mortality; D004558:Electric Stimulation / Q000379:methods; D004568:Electrodiagnosis / Q000379:methods*; D004576:Electromyography / Q000379:methods; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008954:Models, Biological; D009132:Muscles / Q000503:physiopathology*; D009431:Neural Conduction / Q000502:physiology; D009469:Neuromuscular Junction / Q000503:physiopathology; D012131:Respiratory Insufficiency / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology* / Q000473:pathology; D013785:Thailand; D013997:Time Factors
chemical_list: D000931:Antidotes