Muscular pseudohypertrophy particularly involves the muscles of the extremities, leading
to a “Herculean" appearance of these patients. The term pseudohypertrophy is preferred
since histological examination of the affected muscles shows patchy atrophy, necrosis, and
increased interstitial connective tissue without signs of muscle fiber hypertrophy. This
myopathy associated with hypothyroidism typically presents with proximal weakness and
fatigue, exertional pain, muscle cramps and myalgia, slowed movements, diminished deep
tendon reflexes (prolongation of the muscle contraction produces a slow relaxation phase
of the tendon relaxation phase), stiffness, and myxedema. Mental and growth retardation
and macroglossia are further findings reported.