Psychiatric Morbidities among Myasthenia Gravis’ Patients

Abstract

Myasthenia Gravis (MG) is a proto¬typical autoimmune disease of the skel¬etal neuromuscular junction. The clinical symptoms of MG are caused by autoan¬tibodies which in most cases attack the postsynaptic nicotinic acetylcholine re¬ceptor (AChR) of the muscle endplate. In other cases, non-AChR components of the postsynaptic endplate, such as the muscle-specific receptor tyrosine kinase (MuSK), might be attacked by autoanti¬bodies. Accordingly, the characteristic symptom of MG is a fluctuating muscle weakness that increases with effort, difficulty in respiration and swallowing, diplopia and ptosis. All chronic diseases, including MG, may have psychiatric consequences in terms of coping and adaptation. Psychiatric morbidity usually appears as depressive disorder, and as anxiety disorders, such as panic disorder and generalized anxiety disorders. However, there are very few data on the prevalence and etiology of such psychiatric symptoms in patients with MG, and most of those available in the literature are generally from old studies with poor methodology. The interaction between MG and psychiatric disorders needs to be appreciated, especially in the primary care setting, since the symptoms may overlap. MG may be under-recognized initially because the psychiatric symptoms may coincide with those of the actual disease, such as fatigue, lack of energy and shortness of breath. On the other hand, co-morbid psychiatric symptoms that appear during the course of the illness may be misdiagnosed as true myasthenic symptoms; thus, leading to unnecessary drug treatment. Differentiation of the etiology of these symptoms might alter the treatment choice and, therefore, affect the treatment success rate and patients’ well-being. Psychiatric treatments must be carefully planned because of the risk of aggravating the underling neurological disease. Even though there appears to be an intricate relationship between MG and psychiatric symptoms, there is very limited information on this subject. As such, prospective, randomized, controlled pharmaco/psychotherapy studies are needed to better direct the management of patients and, thus, improve quality of life during the course of the illness. The main aim of this study is to recognize the occurrence of psychiatric morbidity among Myasthenia Gravis Patients, assess the socio-demographic, familial and disease specific variations of Myasthenia Gravis patients and assess its relevance. Also we reviewed theoretical considerations of Myasthenia Gravis and its relations to psychopathology of psychiatric disorders. This study has been designed as descriptive cross sectional study, and was conducted at Neurology department, Nasser Institute Hospital within the period between June 2011 and December 2013. The study targeted Patients diagnosed to be Myasthenia Gravis coming to outpatient clinic and/or present in inpatients of Nasser Institute Hospital (diagnosis confirmed according to diagnostic criteria Engel et al., 1994), who ranging from 18 to 50 years old of both sexes. Convenient sample of thirty (30) patients have been selected. Before the start of the study, the requirements of Ain-Shams University Ethics Committee were fulfilled and an informed written consent had been obtained from every patient before participating in the study. Then we subjected all cases to clinical interview according to neuropsychiatry department of Ain Shams faculty of medicine, to examine socio-demographic data, psychiatric history and examination, medical history information and neurological assessment for severity of Myasthenia Gravis. The main step in our study was to apply the structured clinical interview for DSM-IV (SCID I) (First et al., 1995). Then data had been processed and analyzed using computerized version of statistical package for social science (SPSS) v17, by appropriate parametric and non-parametric tests.