TÜà|vÄx The Pattern and Presentation of Myathenia Gravis in Al-Shaab and Omdurman Teaching Hospitals

Introduction: Myasthenia gravis (MG) is the most common acquired autoimmune disorder of neuromuscular transmission. It has different patterns of presentation. Objective: to study the pattern and mode of presentation of Myasthenia Gravis in Al-Shaab and Omdurman Teaching Hospitals, Khartoum Sudan. Methods: The demographic and clinical characteristics of 50 patients of myasthenia gravis (MG) were reviewed in Alshab and Oumdrman Teaching Hospitals for five months period from May to October 2008. Results: Out of 2400 patients attending neurology clinics 50 were found to have Myathenia Gravis [MG] with female; male ratio of 2.5:1. The age at presentation was the second decade of life in 34%. Most of the patients [42%] were from Khartoum State followed by North Kordofan State [14%]. High occurrence of late onset fatigability and weakness was seen in 92 % of our patients. Ocular muscles involvement was detected in 78%. MG was aggravated by hot weather and fever in 12% of the patients. Quinine represented the most common drug which aggravated the myasthenia symptoms in 4%. Diabetes mellitus and thyroid diseases were the most associated auto immune diseases seen in 12% and 4 % respectively. The diagnosis was made by classic history and neurological examinations in 88% and positive neostigmin test in64%. The majority of patients were treated with steroids. Thymectomy was done in 10% patients. The outcome was excellent as 82% improved and only one [2%] patient died. Discussion: Going with literature diagnosis of MG was made depending on classical history, full neurological examination and confirmed by tensilon test. Because of different reasons more sophisticated tests were not done in our patients. Only patients with malaria who were treated with quinine showed deterioration of their symptoms in our study. Strikingly, myasthenia crisis which were reported in 27% of patients were not seen in our population. Because of lack of usage of steroid sparing agents the vast majority [96%] of our patients were treated with steroids. Conclusion: Generalized myasthenia gravis with ocular involvement is common in our patients. However, pure OMG was not seen. Thymectomy was done in a small number of our patients with reference to other studies.

yasthenia gravis (MG) is the most common acquired autoimmune disorder of neuromuscular transmission. The hallmark of MG is fluctuating weakness, fatigability of skeletal, ocular, bulbar and respiratory muscles. The fatigue is manifested by worsening contractile force of muscles due to an antibody mediated T-cell dependant immunological attack. The attack is directed at proteins in post-synaptic membrane of the neuromuscular junction. MG can be classified into two groups: ocular myasthenia gravis (OMG) and generalized myasthenia gravis (GMG).

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In OMG the weakness is limited to the eyelids and extra-ocular muscles. In GMG the weakness involves a variable combination of bulbar, limbs and respiratory muscles in addition to affections of ocular muscles. When antibodies to acetylcholine receptors (AchRAb) are detected the disease is called seropositive myasthenia gravis (SPMG). About half of the patients with pure ocular OMG are seropositive compared with fourfifth of those with GMG. 10-20% of patients with MG have an underlying thymoma ١ .

Objective of the study:
The objective is to study the pattern and mode of presentation of myasthenia gravis in Al-Shaab and Omdurman Teaching Hospitals Khartoum Sudan. Research methods: This is a cross sectional hospital based descriptive retrospective study. It was conducted at Al-Shaab and Omdurman Teaching Hospitals during the period from May to October 2008. All patients attending neurology clinics were seen and the targeted patients were selected. Only the patients who were confirmed to have MG and whose ages were above 16 years were selected. The patients were consented about the study and each patient was interviewed. Files of the patients were retrieved and questionnaires that contain information about the personal data, presentation, aggravating factors, associated autoimmune diseases, diagnostic tools, treatment and the outcome were filled. The data were analyzed and discussed. The result; Out of 2400 patients attending neurology clinics in the period of May to October 2008; 50 were confirmed to have MG. Females were 36 [72%]; the majority 36 (72%) of the patients were singles. The patients presenting in the first decade of life constituted 10% of the total number (Fig.1). It was found that 21 [42%] of the patients were from Khartoum states while the rest were from other parts of Sudan. The Late onset of weakness and fatigability occurred in 92% of patients (table1). Bilateral ocular muscles involvement was seen in all 39 of the patients who developed eye symptoms.  Table 1 Diplopia and ptosis were found in 36 and 34 patients respectively. The duration of ocular muscle involvements before presentations was less than two month in12% of patients while difficulty in walking was seen in 84% ( Myasthenia gravis is the most common understood autoimmune disease. It is relatively common; however the prevalence in Sudan is not studied. In Egypt MG prevalence is about 9.57 per 100.000 while in USA is 100-200 per million 2 affected patients 2 . Table 3 The prevalence of the disease has increased over the last five decades because of good recognition of the disease, aging of the population and the longer life span of the Going with literature diagnosis of MG was made depending on classical history and full neurological examination and confirmed by tensilon test 3 . Table 4 In some other studies AchR-Ab assays 4 which were found to be more specific and sensitive tests were also added 5 . However, somewhere repetitive nerves stimulation and single fiber electro-myography were found even more sensitive and more specific 6,7 . Because of different reasons the above tests were not  This is probably because of the large movements of the population from other states to the capital in the last years. In MG there is a trend to have a bimodal distribution to the age of onset with early peak in the second-third decades where females predominate and a late peak in the sixtheights decades with male predominance 1 . In our study we found no bimodal distribution of age. Different reports have different age-sex distributions 8,9 . In a study done in Libya they found that female to male ratio was 2.6:1 similar to our finding 3 . Bilateral ocular signs and diplobia were seen in 78% and 72% of our patients respectively which are similar to the 73.5% and 85% reported somewhere 10 . However, none of our patients had presented with pure ocular MG. Matching with that; GMG was detected in 94.5% of the patients in Libya. This is different from reports from Dar Elsalam and elsewhere 11,12 .
These differences are probably due to the complexity and variable mode of presentations that characterize MG. Early in the course of the disease the symptoms are usually fluctuant and may be transient. However, the maximum extent of weakness occurs in 77-82% of patients within two to three years. This is probably the reason for the delay of 2.5 years between appearance of symptoms and diagnosis.
Most of our patients had presented within one year of the onset of symptoms. This is likely because a large number of our patients were from Khartoum State where the specialized neurology facility is available. Nevertheless, negligence of the early signs of MG might have also contributed to that 13,14 .
Diabetes mellitus and thyroid disorders [12% and 4%] were the only detected autoimmune diseases associated with MG in our population. This is less than the 27% reported in literature. The lack of availability of other diagnostic tests might have contributed to that. MG was reported to be aggravated by different drugs and diseases 8,10 . Only patients with malaria who were treated with quinine showed deterioration of their symptoms in our study. The relative role played by the malaria and quinine in that is difficult to determine. Strikingly, myasthenia crisis which were reported in 27% of patients were not seen in our population 15

Conclusion:
Generalized myasthenia gravis with ocular involvement is common in our patients. However, pure OMG was not seen. The bimodal age distribution of the disease is not seen in our population. Its association with other autoimmune diseases is not as common as in literature. Thymectomy and steroid sparing drugs were the least modes of treatment in our patients for different reasons. However, the outcome was excellent and myasthenia crisis were not reported.