Lotte Vinge1, Johannes Jakobsen2, Asger Roer Pedersen3, Henning Andersen1. 1. Department of Neurology, Aarhus University Hospital, Noerrebrogade 44, Building 10, 8000 Aarhus C, Denmark. 2. The Neurocentre, Rigshospitalet, Copenhagen, Denmark. 3. Research Unit, Hammel Neurorehabilitation and Research Centre, Hammel, Denmark.
Abstract
INTRODUCTION: In patients with myasthenia gravis (MG), muscle strength is expected to decrease gradually during the day due to physical activities. METHODS: Isometric muscle strength at the shoulder, knee, and ankle was determined in 10 MG patients (MGFA class II-IV) who were receiving usual medical treatment and in 10 control subjects. To determine diurnal and day-to-day variation, muscle strength was measured 4 times during day 1 and once at day 2. RESULTS: Knee extension strength decreased during the day in both patients and controls. Neither diurnal nor day-to-day variation of muscle strength was higher in patients compared with controls. CONCLUSIONS: Patients with mild to moderate MG did not have increased variation of isometric muscle strength during the day or from day-to-day compared with controls. This suggests that isometric muscle performance can be determined with high reproducibility in similar groups of MG patients without regard to time of day.
INTRODUCTION: In patients with myasthenia gravis (MG), muscle strength is expected to decrease gradually during the day due to physical activities. METHODS: Isometric muscle strength at the shoulder, knee, and ankle was determined in 10 MGpatients (MGFA class II-IV) who were receiving usual medical treatment and in 10 control subjects. To determine diurnal and day-to-day variation, muscle strength was measured 4 times during day 1 and once at day 2. RESULTS: Knee extension strength decreased during the day in both patients and controls. Neither diurnal nor day-to-day variation of muscle strength was higher in patients compared with controls. CONCLUSIONS:Patients with mild to moderate MG did not have increased variation of isometric muscle strength during the day or from day-to-day compared with controls. This suggests that isometric muscle performance can be determined with high reproducibility in similar groups of MGpatients without regard to time of day.