Seronegative myasthenia gravis associated with atonic urinary bladder and accommodative insufficiency.
We report a 20-year-old female with generalized myasthenia gravis (MG) who developed atonic urinary bladder and accommodative insufficiency. Although her sera did not contain antibodies to either nicotinic acetylcholine receptor (AChR) or voltage-gated calcium channels, a positive intravenous edrophonium test and a waning phenomenon on electromyographic studies indicated a diagnosis of seronegative MG. Myasthenic symptoms as well as urinary incontinence and impaired near vision disappeared with slight sequelae after corticosteroid therapy and total removal of the hyperplastic thymus. These symptoms recurred during a tapering course of corticosteroids, and improved again with an increased dose. Therefore, in this patient, the neuromuscular transmission of muscarinic type of AChR in the smooth muscles was also affected. This patient provides insight into the mechanisms by which some smooth muscles are involved in MG.
Matsui
M
M
Department of Internal Medicine, Saga Medical School, Japan.
Enoki
M
M
Matsui
Y
Y
Oono
S
S
Ohta
M
M
Suenaga
A
A
Kuroda
Y
Y
D000065:Accommodation, Ocular / Q000187:drug effects*; D000328:Adult; D004359:Drug Therapy, Combination; D004491:Edrophonium / Q000627:therapeutic use; D005260:Female; D006801:Humans; D009129:Muscle Tonus; D009157:Myasthenia Gravis / Q000188:drug therapy / Q000276:immunology*; D011239:Prednisolone / Q000627:therapeutic use; D011729:Pyridostigmine Bromide / Q000627:therapeutic use; D014549:Urinary Incontinence / Q000150:complications* / Q000188:drug therapy
D004491:Edrophonium; D011239:Prednisolone; D011729:Pyridostigmine Bromide