Psychoses in three cases with myasthenia gravis and thymoma--proposal of a paraneoplastic autoimmune neuropsychiatric syndrome.
Morihiro Musha, Fumio Tanaka, M Ohuti
The Tohoku Journal of Experimental Medicine April 1993 DOI: 10.1620/tjem.169.335 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Case series Case report Peer reviewed |
|---|---|
| Sample size | 3 |
| Population | Patients with thymoma, high serum anti-acetylcholine receptor antibody titers, and generalized myasthenia gravis |
| Measures | electroencephalogram (EEG) |
| Key findings | Three patients shared a homogeneous neuropsychiatric syndrome (altered consciousness, psychosensory symptoms, cognitive and emotional disturbances, and psychotic symptoms) that preceded myasthenia gravis by months to years and tracked its relapse. The authors propose this represents a unique paraneoplastic syndrome from a central autoimmune mechanism and an autoimmune psychiatric syndrome linked to central cholinergic dysfunction. |
Abstract
Three patients with neuropsychiatric symptoms (NPSs) associated with thymoma, high serum titers of antiacetylcholine receptor (AchR) antibody and generalized myasthenia gravis (MG) are reported. The NPSs were homogeneous; (1) Altered consciousness as manifested by dreamy state with paramnesia, (2) psychosensory symptoms (the sudden change of senses of smell and taste with behavior abnormalities, auditory and visual hallucinations, déjà experiences, microteleopsia and derealization), (3) cognitive disturbances (recent memory loss with compulsive behaviors), (4) emotional disturbances (agitation, fear and anger), and (5) psychotic symptoms (secondary delusions and hallucinations) were characteristic. The NPSs preceded by several months to years the onset of MG, and thereafter they were closely related to worsening and relapse of MG. A typical patient showed repeatedly abnormal electroencephalograms (EEG) indicative of cerebral dysfunction. Another showed improvement of the NPSs after thymectomy and immunosuppressive therapy. The organicity of the phenomenology of psychoses with the same NPSs was suggested and it appears to comprise a unique paraneoplastic syndrome by central autoimmune mechanism. We proposed an autoimmune psychiatric syndrome and the genesis of psychosis due to the central cholinergic dysfunction in MG.