Which of the following describes myotonic dystrophy?

• A. Impairment of muscular relaxation, diffuse muscle weakness, and cataracts
• B. Proximal weakness with pseudohypertrophy
• C. Progressive hypotonia and areflexia
• D. Distal weakness with fasciculations

Answer: (A)

Myotonic dystrophy is defined by myotonia—slowed relaxation of muscles after contraction—along with progressive muscle weakness and common extramuscular features such as cataracts. The option describing impairment of muscular relaxation, diffuse weakness, and cataracts captures these core findings, so it is the best choice.

Other patterns point to different conditions: proximal weakness with pseudohypertrophy suggests Duchenne muscular dystrophy; hypotonia with absent reflexes can occur in congenital myopathies or spinal muscular atrophy; distal weakness with fasciculations is more typical of motor neuron diseases like ALS.