Myotonic dystrophy and ocular dystrophy are rare forms which begin in young adults and progress slowly, and usually do not cause severe disability for decades. Myotonic dystrophy primarily affects the muscles of the hands, and is often accompanied by cataracts in the eyes and facial muscle paralysis. Mental retardation is frequently present. Ocular dystrophy normally affects the eye and throat muscles. In Duchenne's, limb-girdle and facioscapulohumeral dystrophy, most functional limitations result from weakness of the shoulder and hip muscles.
Ambulation becomes difficult and eventually impossible without a wheelchair.
Activities of daily living and vocational tasks involving ambulation and reaching skills become increasingly difficult and often impossible. Physical therapy, exercise and a proper rehabilitation regimen can help maintain function. Communication and sensory functions are generally unaffected, except for low voice volume in advanced cases. Cognitive functioning is not limited in most individuals. In the rare cases of myotonic dystrophy, the hand and facial muscles are primarily affected, causing defects in handling, fingering, and communication.