A case of myasthenia gravis proven by ultrastructural study
Journal of Korean Medical Science
; : 251-254, 2000.
Article
em En
| WPRIM
| ID: wpr-140414
Biblioteca responsável:
WPRO
ABSTRACT
Although light microscopic features of muscle are not pathognomonic in most cases of myasthenia gravis (MG), careful examination of neuromuscular junction by electron microscopy (EM) can reveal important clues for this disease. We report here a case of MG confirmed by EM study to emphasize that tissue diagnosis is still the best adjuvant to confirm the diagnosis. An 18-year-old female visited our hospital complaining of progressive muscle weakness for 3 years. She had difficulty in running, going upstairs and doing routine activities. Symptoms were aggravated with continuous work and resolved after rest. She had weakness of bilateral masseter and facial muscles and proximal portions of extremities without definite diurnal variation. Electromyography showed myopathic changes in proximal muscles of extremities. MG was considered but tensilon test was equivocal. Repetitive nerve stimulation tests revealed 20-30 percent decrease in responses to low and high rate stimulation. Muscle biopsy revealed selective type 2 atrophy. Ultrastructurally, abnormalities of neuromuscular junctions, i.e., wide primary synaptic cleft, and wide and shallow secondary synaptic clefts with mild myopathic features were present. These findings were pathognomonic for MG. Later, her symptoms were improved completely 3 months after thymectomy. The histologic finding of thymus was follicular hyperplasia.
Palavras-chave
Texto completo:
1
Índice:
WPRIM
Assunto principal:
Biópsia
/
Microscopia Eletrônica
/
Adolescente
/
Miosinas
/
Músculo Esquelético
/
Mitocôndrias
/
Miastenia Gravis
/
Miofibrilas
/
Junção Neuromuscular
Limite:
Female
/
Humans
Idioma:
En
Revista:
Journal of Korean Medical Science
Ano de publicação:
2000
Tipo de documento:
Article