title: Characteristics of muscle cramps in patients with polyneuropathy.
abstract: Muscle cramps are common in the general population and can be disabling for patients, but there is little evidence comprehensively evaluating cramp characteristics in patients with polyneuropathy. This study describes the prevalence and characteristics of muscle cramps in this patient group. Patients over 18 diagnosed with polyneuropathy were invited to join the study. Patients completed nerve conduction studies, the Toronto Clinical Neuropathy score, neuropathy-specific Vickrey's Quality of Life Assessment and a self-administered questionnaire examining demographics, neuropathy symptoms and cramp characteristics. Two hundred and twenty-five participants were enrolled (28.0% female). Sixty-three percent of patients experienced cramps, occurring on average 6 times per week, lasting 10.5 min and scoring 6 out of 10 on a pain scale and described as disabling by 43.6% of patients. No significant difference was found in cramp prevalence according to underlying pathophysiology (p = 0.52) or fiber type (p = 0.41). Patients with disabling cramps rated their physical (p < 0.0001) and mental (p = 0.04) quality of life lower than patients without disabling cramps. This study confirms that muscle cramps are common, disabling and associated with reduced quality of life in patients with polyneuropathy. Similar prevalence of cramps across predominant nerve fiber type suggests a role of sensory afferents in cramp generation, although this needs to be confirmed in larger cohorts.
authors.affiliation: Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Maxwell
authors.affiliation: Division of Neurology, University Health Network, Toronto, Ontario, Canada.
authors.forename: Seint
authors.initials: S
authors.lastname: Kokokyi
authors.affiliation: Division of Neurology, University Health Network, Toronto, Ontario, Canada; Division of Neurology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Ari
authors.initials: A
authors.lastname: Breiner
authors.affiliation: Division of Neurology, University Health Network, Toronto, Ontario, Canada; Division of Neurology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Hamid
authors.initials: H
authors.lastname: Ebadi
authors.affiliation: Division of Neurology, University Health Network, Toronto, Ontario, Canada; Division of Neurology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Vera
authors.initials: V
authors.lastname: Bril
authors.affiliation: Division of Neurology, University Health Network, Toronto, Ontario, Canada; Division of Neurology, University of Toronto, Toronto, Ontario, Canada. Electronic address: hans.katzberg@utoronto.ca.
authors.forename: Hans D
authors.initials: HD
authors.lastname: Katzberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009120:Muscle Cramp / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology; D009431:Neural Conduction; D010147:Pain Measurement; D011115:Polyneuropathies / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology; D015995:Prevalence; D011788:Quality of Life; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Hyperexcitable; Motor; Muscle cramp; Nerve; Neuropathy