Pain as a significant symptom in patients with periodic paralysis-A cross-sectional survey

Muscle Nerve. 2021 Jun;63(6):897-901. doi: 10.1002/mus.27241. Epub 2021 Apr 5.


Introduction: Periodic paralysis (PP) is thought to be limited to episodes of muscle weakness, but there are reports of fibromyalgia-like pain in PP. We aimed to evaluate pain and comorbid sleep, fatigue, and mood disorders in PP patients.

Methods: We administered a cross-sectional survey to PP patients at the 2019 Periodic Paralysis Conference. The survey consisted of the Brief Pain Inventory, Widespread Pain Index, Pittsburgh Sleep Quality Index, Modified Fatigue Impact Scale, and ten-question Center for Epidemiologic Studies Depression Scale (CESD-10). Descriptive statistics for PP patients were calculated and compared with earlier studies.

Results: Forty-four individuals with PP took the survey. Of these patients, 52.3% reported a moderate to severe interference of pain on their lives, and 45.5% met the study criteria for fibromyalgia. Patients with SCN4A mutations had higher rates of fibromyalgia than the next most prevalent gene mutation, CACNA1S. In patients with pain, there were increased rates of comorbid fatigue, depression, and poor sleep quality.

Discussion: Pain, akin to fibromyalgia, is a significant symptom of PP and can affect quality of life. Pain in PP was more prevalent than in the general population, at a rate comparable with other chronic neuromuscular disease groups. PP patients could benefit from a multidisciplinary approach to assess their pain, sleep, fatigue, and mood.

Keywords: fibromyalgia; pain; periodic paralysis.

MeSH terms

  • Adult
  • Cross-Sectional Studies
  • Female
  • Fibromyalgia / complications*
  • Fibromyalgia / genetics
  • Fibromyalgia / physiopathology
  • Humans
  • Male
  • Middle Aged
  • Muscle Weakness / complications*
  • Muscle Weakness / genetics
  • Muscle Weakness / physiopathology
  • NAV1.4 Voltage-Gated Sodium Channel / genetics
  • Pain / etiology*
  • Pain / genetics
  • Pain / physiopathology
  • Paralyses, Familial Periodic / complications*
  • Paralyses, Familial Periodic / genetics
  • Paralyses, Familial Periodic / physiopathology
  • Quality of Life


  • NAV1.4 Voltage-Gated Sodium Channel
  • SCN4A protein, human