TY - JOUR
T1 - Hypokalemic periodic paralysis
T2 - a 3-year follow-up study
AU - Holm-Yildiz, Sonja
AU - Krag, Thomas
AU - Witting, Nanna
AU - Pedersen, Britt Stævnsbo
AU - Dysgaard, Tina
AU - Sloth, Louise
AU - Pedersen, Jonas
AU - Kjær, Rebecca
AU - Kannuberg, Linda
AU - Dahlqvist, Julia
AU - de Stricker Borch, Josefine
AU - Solheim, Tuva
AU - Fornander, Freja
AU - Eisum, Anne-Sofie
AU - Vissing, John
N1 - © 2023. The Author(s).
PY - 2023/12
Y1 - 2023/12
N2 - BACKGROUND AND OBJECTIVES: Primary hypokalemic periodic paralysis (HypoPP) is an inherited channelopathy most commonly caused by mutations in CACNA1S. HypoPP can present with different phenotypes: periodic paralysis (PP), permanent muscle weakness (PW), and mixed weakness (MW) with both periodic and permanent weakness. Little is known about the natural history of HypoPP.METHODS: In this 3-year follow-up study, we used the MRC scale for manual muscle strength testing and whole-body muscle MRI (Mercuri score) to assess disease progression in individuals with HypoPP-causing mutations in CACNA1S.RESULTS: We included 25 men (mean age 43 years, range 18-76 years) and 12 women (mean age 42 years, range 18-76 years). Two participants were asymptomatic, 21 had PP, 12 MW, and two PW. The median number of months between baseline and follow-up was 42 (range 26-52). Muscle strength declined in 11 patients during follow-up. Four of the patients with a decline in muscle strength had no attacks of paralysis during follow-up, and two of these patients had never had attacks of paralysis. Fat replacement of muscles increased in 27 patients during follow-up. Eight of the patients with increased fat replacement had no attacks of paralysis during follow-up, and two of these patients had never had attacks of paralysis.DISCUSSION: The study demonstrates that HypoPP can be a progressive myopathy in both patients with and without attacks of paralysis.
AB - BACKGROUND AND OBJECTIVES: Primary hypokalemic periodic paralysis (HypoPP) is an inherited channelopathy most commonly caused by mutations in CACNA1S. HypoPP can present with different phenotypes: periodic paralysis (PP), permanent muscle weakness (PW), and mixed weakness (MW) with both periodic and permanent weakness. Little is known about the natural history of HypoPP.METHODS: In this 3-year follow-up study, we used the MRC scale for manual muscle strength testing and whole-body muscle MRI (Mercuri score) to assess disease progression in individuals with HypoPP-causing mutations in CACNA1S.RESULTS: We included 25 men (mean age 43 years, range 18-76 years) and 12 women (mean age 42 years, range 18-76 years). Two participants were asymptomatic, 21 had PP, 12 MW, and two PW. The median number of months between baseline and follow-up was 42 (range 26-52). Muscle strength declined in 11 patients during follow-up. Four of the patients with a decline in muscle strength had no attacks of paralysis during follow-up, and two of these patients had never had attacks of paralysis. Fat replacement of muscles increased in 27 patients during follow-up. Eight of the patients with increased fat replacement had no attacks of paralysis during follow-up, and two of these patients had never had attacks of paralysis.DISCUSSION: The study demonstrates that HypoPP can be a progressive myopathy in both patients with and without attacks of paralysis.
UR - http://www.scopus.com/inward/record.url?scp=85169337497&partnerID=8YFLogxK
U2 - 10.1007/s00415-023-11964-z
DO - 10.1007/s00415-023-11964-z
M3 - Journal article
C2 - 37656291
SP - 6057
EP - 6063
JO - Journal of Neurology
JF - Journal of Neurology
SN - 0340-5354
ER -