Case 2
Clinical History and Physical E*am: This 34 year old woman firstnoted intermittent horizontal diplopia and droopiness of hereyelids in her early twenties. It was worse when she was tired andit slowly progressed to the point that the diplopia became constantby age 30. The following year, she developed weakness in her legswith frequent falls and difficulty climbing stairs. She notedmuscle pain if she walked for a prolonged time. She denied havingfatigability in her limb muscles. Cranial nerve testing revealed analmost complete external opthalmoplegia with only a few degrees ofmovement in all directions. There was also bilateral eyelid ptosisand fatigability. Motor e*amination showed normal tone and bulk.There was mild proximal weakness in the upper and lower extremitieswith fatigability after repetitive movement. Reflexes werediminished. The rest of the neurological e*am was normal.
Laboratory Findings: A tensilon test showed a positive responsewith improvement of at least 50% of her eyelid ptosis.Electrodiagnostic studies done to rule out a neuromuscular junctiondisorder (repetitive nerve conductions and single fiber EMG) werenormal. Acetylcholine receptor antibodies were not detected. Theserum CK was normal.
Microscopic Analysis: Sections of muscle tissue revealed mildvariation in fiber size. Some of the fibers had the features ofragged red fibers with disruption of the intermyofibrillar networkand abnormal subsarcolemmal accumulations of granular refractilematerial which may represent mitochondria. Several fibers hadinternally placed nuclei. Inflammatory infiltrates were absent.
Diagnosis and medication/treatments?
