Internal Medicine

0521779407-14 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:16

1020 Muscular Dystrophies

MUSCULAR DYSTROPHIES

MICHAEL J. AMINOFF, MD, DSc

history & physical

■Progressive muscle wasting & weakness occurring in a particular

pattern depending on individual disorder

■Characteristic age of onset & pattern of inheritance for different dys-

trophies

■Weak, wasted muscles in characteristic distribution

■May be pseudohypertrophy of muscles, muscle contractures, intel-

lectual changes, skeletal deformities or cardiac involvement w/ cer-

tain dystrophies

■Myotonia is present in myotonic dystrophy

tests

■Genetic testing permits a specific diagnosis in many dystrophies

■Serum CK is elevated, but level varies w/ the type of dystrophy

■EMG typically shows myopathic features; myotonia is also present

in myotonic dystrophy

■ECG may reveal conduction defects

■Muscle biopsy confirms clinical diagnosis

differential diagnosis

■Various dystrophies are distinguished from each other by genetic

studies & by pattern of inheritance & muscle involvement; Duchenne

& Becker dystrophies are X-linked dystrophinopathies

management

■Supportive care includes passive stretching of joints, bracing and

assistive devices

■Tenotomies & surgical stabilization procedures, depending of type

of dystrophy

■Cardiac pacemaker & treatment for CHF, especially in emerin defi-

ciency (Emery-Dreifuss dystrophy)

■Steroids may slow progression of Duchenne dystrophy

specific therapy

■None, except as above

■Genetic counseling is important

follow-up

■Close follow-up by experienced medical team is important to prevent

complications & optimize mobility