Hoffmann syndrome is a rare form of hypothyroid myopathy and is not to be confused with Werdnig-Hoffmann disease (a type of spinal muscular atrophy).
There may also be bradycardia, mild anemia, dry skin, hoarse voice, and cold intolerance.
The sign of myoedema (raised muscle tissue in response to percussive tactile stimulus) may be observed.
[3][7] In an individual diagnosed with Hoffmann syndrome whose hypertrophy did not improve after thyroid hormone replacement therapy, muscle biopsy showed hypertrophy of muscle fibres with increased nuclei, few necrotic fibres and mucoid deposits in places.
[16][17] As both hyper- and hypothyroidism disrupts muscle glycogen metabolism, it is important to keep in mind differential diagnoses and their comorbidities when trying to determine whether signs and symptoms are either primary or secondary disease.