title: Botulinum toxin treatment of muscle cramps: a clinical and neurophysiological study.
abstract: Botulinum toxin is now widely used in the treatment of several hyperkinetic movement disorders. To evaluate its efficacy in treating muscle cramping syndromes, we studied clinical and neurophysiological variables before and after botulinum toxin injections into calf muscles and small flexor muscles of the foot in patients with an inherited benign cramp-fasciculation syndrome. At each assessment the clinical severity of cramp was scored and the cramp threshold frequency was measured with repetitive electrical peripheral nerve stimulation. Botulinum toxin injection significantly lowered our patients' clinical cramp severity scores (mean +/- SD: before, 3.80 +/- 0.44; after, 1.40 +/- 0.54), left muscle strength unchanged and significantly increased their cramp threshold frequencies (before, 4.22 +/- 2.26 Hz; after, 10.0 +/- 3.74 Hz). The clinical benefit induced by botulinum toxin lasted about 3 months. Botulinum toxin injections also significantly reduced fasciculation potentials in relaxed muscles (before, 0.86 +/- 0.19 fasciculations/sec; after, 0.45 +/- 0.11 fasciculations/sec). These findings show that local intramuscular injections of botulinum toxin provide effective, safe, and long-lasting relief of cramps possibly by reducing presynaptic cholinergic stimulation of motor nerve terminals and by impairing the input/output function of intrafusal and extrafusal motor end plates.
authors.affiliation: Dipartimento di Scienze Neurologiche e della Visione, Universita' degli Studi di Verona, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Bertolasi
authors.forename: A
authors.initials: A
authors.lastname: Priori
authors.forename: G
authors.initials: G
authors.lastname: Tomelleri
authors.forename: L G
authors.initials: LG
authors.lastname: Bongiovanni
authors.forename: E
authors.initials: E
authors.lastname: Fincati
authors.forename: A
authors.initials: A
authors.lastname: Simonati
authors.forename: D
authors.initials: D
authors.lastname: De Grandis
authors.forename: N
authors.initials: N
authors.lastname: Rizzuto
mesh_terms: D000328:Adult; D000368:Aged; D001905:Botulinum Toxins / Q000627:therapeutic use*; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009120:Muscle Cramp / Q000188:drug therapy* / Q000503:physiopathology; D011379:Prognosis
chemical_list: D001905:Botulinum Toxins