BackgroundThe risk of osteoporosis is known in myopathies requiring long-term steroid treatment and Pompe disease, but not in other hereditary myopathies or sporadic inclusion body myositis (sIBM).MethodsRisk factors of osteoporosis, laboratory parameters of bone metabolism, frequency of falls and fractures, walking ability, and pain were surveyed using questionnaires in 89 patients with sIBM and genetically confirmed myopathies facioscapulohumeral muscular dystrophy (FSHD), myotonic dystrophy types 1 and 2 (DM1, DM2), limb girdle muscular dystrophies (LGMD2A, LGMD2B, LGMD2I), MATR3 myopathy, and oculopharyngeal muscular dystrophy (OPMD). Additionally laboratory parameters of bone metabolism were determined.ResultsThe mean age at examination per disease group ranged from 32 years in LGMD2A to 70 years in sIBM. Myopathies with a higher degree of walking impairment had a higher risk of falls (sIBM, LGMD2A, LGMD2B). At the time of examination 3.4% had a history of osteoporosis. The 25-OH D3 level was decreased in 20% of patients (and in 55% of patients with LGMDs), 57% of them were ambulatory. The 25-OH D3 level was significantly lower in patients with myopathies than in other neurological disorders (p < 0.001). 2.7 falls per year per person occurred. Fractures were reported in 6.8% of patients within the last year. They involved frequently the tibia bone. The pain score didn't correlate with either the walking disability (WGMS) score or the 25-OH D3 level.ConclusionThe risk for osteoporosis and reduced 25-OH D3 level seems to be increased in wheelchair-bound patients with myopathy but also in patients with DM1 and autosomal-recessive myopathies.
Introduction
Motor unit hyperexcitability (MUH) may become manifest in needle electromyography (EMG) recordings as fasciculation potentials, myokymic discharges, or neuromyotonic discharges. Here, we describe a further MUH phenomenon.
Methods
Needle EMG recordings of the Neurology Hospital of Halle (Saale) stored in a video mode as .wav data between 2000 and 2015 were screened for spontaneous continuous motor unit single discharges (SCMUSD).
Results
We identified 23 video needle EMG waveforms from 14 patients with SCMUSD. The corresponding motor units discharged at a rate of about 6 H Z (6.3 ± 4.0; range, 1.3‐18.1). The coefficient of variation of the discharge rate was 3.5% ± 1.7%. Neurogenic disorders were diagnosed in 12 patients, limb girdle muscle dystrophy was diagnosed in one patient, and stiff‐limb syndrome was diagnosed in one patient.
Discussion
Spontaneous continuous motor unit single discharge, as described here, widens the spectrum of MUH phenomena.
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