National Study of Muscle Cramps in ALS in the USA

Abstract

The objective of this study was to describe muscle cramps in an US sample of amyotrophic lateral sclerosis (ALS) patients. Utilizing an anonymous web based questionnaire we queried ALS patients regarding the severity, frequency, time-course, treatment of muscle cramps and their relationship to pain. The survey had 282 respondents with 92% reporting that they had cramps. For 20% of the sample, cramps were stated to be the presenting ALS symptom. Cramp severity was rated at a mean of 5.2/10 and the mean cramp frequency was 5.3 cramps per day. Cramp intensity and frequency did not correlate with duration or severity of ALS. Pain as measured with the Patient Reported Outcome Measurement Information System (PROMIS) pain scales was not statistically different from the US general population. Cramp severity and frequency significantly and positively correlated with the PROMIS pain scales. Patients with more severe cramps were more likely to use prescription medications for their cramps compared to patients with milder symptoms. Treatments directed at cramps were tried by 57%. In conclusion, cramps are a common symptom in ALS and it does not correlate with disease duration or severity. The severity of cramps is on average moderate and many patients try treatments.

Keywords:

• Cramp
• questionnaire
• patient reported outcome

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Erratum

Acknowledgements

The contents of this article uses data developed under PROMIS. These contents do not necessarily represent an endorsement by the US Federal Government or PROMIS. See www.nihpromis.org for additional information on the PROMIS initiative. Assessment Center is provided by Northwestern University, copyright 2007-2013 David Cella, Richard Gershon, Michael Bass, and Nan Rothrock. None of the authors have any relevant disclosures.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article. For funding, BO was supported by NIH UL1 TR000002 and KL2 TR000134. Recruitment was made possible through the help of the Agency for Toxic Substances and Disease Registry (ATSDR), National ALS Registry, www.cdc.gov/als. PROMIS® was funded with cooperative agreements from the National Institutes of Health (NIH) Common Fund Initiative.

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