Randomized Trial of Thymectomy in Myasthenia Gravis.

BACKGROUND: Thymectomy has been a mainstay in the treatment of myasthenia gravis, but there is no conclusive evidence of its benefit. We conducted a multicenter, randomized trial comparing thymectomy plus prednisone with prednisone alone. METHODS: We compared extended transsternal thymectomy plus alternate-day prednisone with alternate-day prednisone alone. Patients 18 to 65 years of age who had generalized nonthymomatous myasthenia gravis with a disease duration of less than 5 years were included if they had Myasthenia Gravis Foundation of America clinical class II to IV disease (on a scale from I to V, with higher classes indicating more severe disease) and elevated circulating concentrations of acetylcholine-receptor antibody. The primary outcomes were the time-weighted average Quantitative Myasthenia Gravis score (on a scale from 0 to 39, with higher scores indicating more severe disease) over a 3-year period, as assessed by means of blinded rating, and the time-weighted average required dose of prednisone over a 3-year period. RESULTS: A total of 126 patients underwent randomization between 2006 and 2012 at 36 sites. Patients who underwent thymectomy had a lower time-weighted average Quantitative Myasthenia Gravis score over a 3-year period than those who received prednisone alone (6.15 vs. 8.99, P<0.001); patients in the thymectomy group also had a lower average requirement for alternate-day prednisone (44 mg vs. 60 mg, P<0.001). Fewer patients in the thymectomy group than in the prednisone-only group required immunosuppression with azathioprine (17% vs. 48%, P<0.001) or were hospitalized for exacerbations (9% vs. 37%, P<0.001). The number of patients with treatment-associated complications did not differ significantly between groups (P=0.73), but patients in the thymectomy group had fewer treatment-associated symptoms related to immunosuppressive medications (P<0.001) and lower distress levels related to symptoms (P=0.003). CONCLUSIONS: Thymectomy improved clinical outcomes over a 3-year period in patients with nonthymomatous myasthenia gravis. (Funded by the National Institute of Neurological Disorders and Stroke and others; MGTX ClinicalTrials.gov number, NCT00294658.).

Treatment of slow-channel congenital myasthenic syndrome in a Thai family with fluoxetine.

The slow-channel congenital myasthenic syndrome is an autosomal dominant neuromuscular disorder caused by mutations in different subunits of the acetylcholine receptor. Fluoxetine, a common antidepressant and long-lived open-channel blocker of acetylcholine receptor, has been reported to be beneficial in the slow-channel congenital myasthenic syndrome. Here we report a prospective open label study of fluoxetine treatment in some affected members of a Thai family with slow-channel congenital myasthenic syndrome caused by a novel p.Gly153Ala (c.518G > C) mutation in CHRNA1 in the AChR α subunit. These patients showed significant clinical improvement following fluoxetine treatment but their respiratory function responded variably.

Cerebral aspergillosis and cerebral candidiasis; a retrospective analysis of clinicopathologic features in Ramathibodi Hospital.

OBJECTIVE: Determine and compare the clinicopathological findings of cerebral aspergillosis with cerebral candidiasis. MATERIAL AND METHOD: The medical records with cerebral aspergillosis and cerebral candidiasis in Ramathibodi Hospital between January 1997 and December 2008 were analyzed. The criterion for the diagnosis of cerebral aspergillosis and cerebral candidiasis was the evidence of fungal elements from histopathologic section. The age, gender neurological manifestations, duration of symptom, associated underlying disease, predisposing risk factor, laboratory data, extent of systemic organ involvement and treatment outcome were analyzed. RESULTS: The present study included cerebral aspergillosis (n = 41) and candidiasis (n = 15). There were 23 male and 33 female patients. The mean and median ages at diagnosis were 39.7 and 45 years, respectively (range, 1 month to 87 years). The clinical presentations included alteration of consciousness (69.6%), fever (60.7%), weakness of the extremity (14.3%), cranial nerve palsy (12.5%), headache (12.59%) and seizure (5.4%). One third of the cases had underlying hematologic malignancy. The cerebral aspergillosis and cerebral candidiasis were associated with corticosteroids treatment in 32.1%. The frequent associated sites of fungal infection included the lungs (73.2%), alimentary tract (33.9%) and sinonasal tract (19.6%). CONCLUSION: A diagnosis of cerebral aspergillosis and cerebral candidiasis requires a high index of suspicion especially in immunocompromised patients who presented with alteration of consciousness, fever, focal neurological deficit, headache, and seizure. The patients with cerebral aspergillosis and cerebral candidiasis manifest with similar clinicopathologic features. However, the sinonasal tract infection and abscess formation are more common in cerebral aspergillosis. Associated alimentary tract infection is commonly seen in cerebral candidiasis.

Minimal manifestation status and prednisone withdrawal in the MGTX trial.

OBJECTIVE: To examine whether sustained minimal manifestation status (MMS) with complete withdrawal of prednisone is better achieved in thymectomized patients with myasthenia gravis (MG). METHODS: This study is a post hoc analysis of data from a randomized trial of thymectomy in MG (Thymectomy Trial in Non-Thymomatous Myasthenia Gravis Patients Receiving Prednisone Therapy [MGTX]). MGTX was a multicenter, randomized, rater-blinded 3-year trial that was followed by a voluntary 2-year extension for patients with acetylcholine receptor (AChR) antibody-positive MG without thymoma. Patients were randomized 1:1 to thymectomy plus prednisone vs prednisone alone. Participants were age 18-65 years at enrollment with disease duration less than 5 years. All patients received oral prednisone titrated up to 100 mg on alternate days until they achieved MMS, which prompted a standardized prednisone taper as long as MMS was maintained. The achievement rate of sustained MMS (no symptoms of MG for 6 months) with complete withdrawal of prednisone was compared between the thymectomy plus prednisone and prednisone alone groups. RESULTS: Patients with MG in the thymectomy plus prednisone group achieved sustained MMS with complete withdrawal of prednisone more frequently (64% vs 38%) and quickly compared to the prednisone alone group (median time 30 months vs no median time achieved, p < 0.001) over the 5-year study period. Prednisone-associated adverse symptoms were more frequent in the prednisone alone group and distress level increased with higher doses of prednisone. CONCLUSIONS: Thymectomy benefits patients with MG by increasing the likelihood of achieving sustained MMS with complete withdrawal of prednisone. CLINICALTRIALSGOV IDENTIFIER: NCT00294658. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for patients with generalized MG with AChR antibody, those receiving thymectomy plus prednisone are more likely to attain sustained MMS and complete prednisone withdrawal than those on prednisone alone.

Long-term effect of thymectomy plus prednisone versus prednisone alone in patients with non-thymomatous myasthenia gravis: 2-year extension of the MGTX randomised trial.

BACKGROUND: The Thymectomy Trial in Non-Thymomatous Myasthenia Gravis Patients Receiving Prednisone (MGTX) showed that thymectomy combined with prednisone was superior to prednisone alone in improving clinical status as measured by the Quantitative Myasthenia Gravis (QMG) score in patients with generalised non-thymomatous myasthenia gravis at 3 years. We investigated the long-term effects of thymectomy up to 5 years on clinical status, medication requirements, and adverse events. METHODS: We did a rater-blinded 2-year extension study at 36 centres in 15 countries for all patients who completed the randomised controlled MGTX and were willing to participate. MGTX patients were aged 18 to 65 years at enrolment, had generalised non-thymomatous myasthenia gravis of less than 5 years' duration, had acetylcholine receptor antibody titres of 1·00 nmol/L or higher (or concentrations of 0·50-0·99 nmol/L if diagnosis was confirmed by positive edrophonium or abnormal repetitive nerve stimulation, or abnormal single fibre electromyography), had Myasthenia Gravis Foundation of America Clinical Classification Class II-IV disease, and were on optimal anticholinesterase therapy with or without oral corticosteroids. In MGTX, patients were randomly assigned (1:1) to either thymectomy plus prednisone or prednisone alone. All patients in both groups received oral prednisone at doses titrated up to 100 mg on alternate days until they achieved minimal manifestation status. The primary endpoints of the extension phase were the time-weighted means of the QMG score and alternate-day prednisone dose from month 0 to month 60. Analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00294658. It is closed to new participants, with follow-up completed. FINDINGS: Of the 111 patients who completed the 3-year MGTX, 68 (61%) entered the extension study between Sept 1, 2009, and Aug 26, 2015 (33 in the prednisone alone group and 35 in the prednisone plus thymectomy group). 50 (74%) patients completed the 60-month assessment, 24 in the prednisone alone group and 26 in the prednisone plus thymectomy group. At 5 years, patients in the thymectomy plus prednisone group had significantly lower time-weighted mean QMG scores (5·47 [SD 3·87] vs 9·34 [5·08]; p=0·0007) and mean alternate-day prednisone doses (24 mg [SD 21] vs 48 mg [29]; p=0·0002) than did those in the prednisone alone group. 14 (42%) of 33 patients in the prednisone group, and 12 (34%) of 35 in the thymectomy plus prednisone group, had at least one adverse event by month 60. No treatment-related deaths were reported during the extension phase. INTERPRETATION: At 5 years, thymectomy plus prednisone continues to confer benefits in patients with generalised non-thymomatous myasthenia gravis compared with prednisone alone. Although caution is appropriate when generalising our findings because of the small sample size of our study, they nevertheless provide further support for the benefits of thymectomy in patients with generalised non-thymomatous myasthenia gravis. FUNDING: National Institutes of Health, National Institute of Neurological Disorders and Stroke.

Idiopathic hypertrophic cranial pachymeningitis.

Idiopathic hypertrophic cranial pachymeningitis is a rare chronic inflammatory process of unknown origin that can cause neurological deficits owing to thickening of the dura. Patients with this condition commonly present with cranial neuropathy accompanied by localized headache. The clinical features, neuroimaging findings, histopathological features and treatment outcomes for three patients with this condition are reported here. The first patient presented with subacute dull headache in the left temporal area followed by left abducens nerve palsy. The second patient suffered from a cranial nerve IX-XII lesion accompanied by an occipital headache and the third patient presented with left optic neuropathy and mild headache in the frontal area. In all patients, MRI of the brain revealed prominent dural thickening, and histopathological study of the dura revealed chronic inflammatory cell infiltration. Combined therapy with corticosteroid and immunosuppressive drugs was effective, resulting in almost complete resolution of the symptoms and signs, except for visual impairment in one patient.

Relative fatigability of muscles in response to repetitive nerve stimulation in myasthenia gravis.

BACKGROUND: Repetitive nerve stimulation (RNS) plays an important role in the diagnosis of myasthenia gravis (MG). Technically, this test can be more easily performed on distal muscles than proximal muscles. On the other hand, proximal muscles have been shown to be more easily fatigued or more sensitive than the distal ones. OBJECTIVE: Evaluate the relative fatigability of different muscles in response to RNS in ocular and generalized MG patients. MATERIAL AND METHOD: Two hundred patients with 44 ocular MG and 156 generalized MG were studied The relative fatigability of each muscle was calculated as percentage of cases with abnormal response. A decrement of 10% or more of the amplitude of the compound muscle action potentials was considered abnormal. RESULT: The cases with abnormal response of adductor digiti minimi, anconeus, trapezius, nasalis and orbicularis oculi were 17%, 50%, 55%, 62%, 66% in ocular MG and 53%, 77%, 79%, 85%, 79% in generalized MG respectively. These results showed that in generalized MG the response in all the muscles was more frequently abnormal and was fatigable in a more comparable degree, whereas in ocular MG, the facial muscles were more often abnormal than the limb muscles. CONCLUSION: The abnormal response because of fatigability was more widespread in generalized MG whereas facial muscles were relatively more sensitive in ocular MG. This finding may be useful for the selection of the muscles to be tested in RNS especially in ocular MG.

Polyneuropathy from thiamin deficiency associated with thyrotoxicosis.

Polyneuropathy from thiamin deficiency can occur in persons who consume a diet consisting mainly of polished rice with low protein and thiamin content in the setting of excessive physical activity or hypermetabolic states. The authors report here a 17-year-old fisherman who presented with a 3-month history of symptoms and signs consistent with polyneuropathy. There were also clinical features of thyrotoxicosis which was confirmed by thyroid function test. His dietary intake consisted mainly of polished rice and fish both of which contain a small amount of thiamin. This could not cope with his hypermetabolic condition from thyrotoxicosis resulting in thiamin deficiency with polyneuropathy.

POEMS syndrome with venous sinus thrombosis and visual failure: a case report.

POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein and skin changes) syndrome is a multisystem disorder associated with plasma cell dyscrasia. Other clinical signs include clubbing of the fingers, edema, papilledema etc. Although papilledema and increased intracranial pressure are common features, their causes or pathophysiology have been uncertain. The authors report here a 16-year-old Thai patient with these features who also suffered from venous sinus thrombosis and visual failure which have never been reported before. The former is considered to be one of the possible causes of the intracranial hypertension and visual failure. MRI of the brain and optic nerve revealed enhancement and swelling of the optic nerve sheaths and optic discs. MRV findings were compatible with chronic veno-occlusive disease. Bone marrow aspiration and biopsy demonstrated an increase of aggregates of intermediate and mature plasma cells. The CSF pressure was markedly elevated. His clinical condition continued to deteriorate and he expired 3 years and 5 months from the onset of his illness. Although, overproduction of vascular endothelial growth factor has been reported and is being considered to be the possible cause of vascular hyperpermeability, the chronic venous sinus thrombosis may play an important role in the pathogenesis of intracranial hypertension and visual failure.

Streptococcus suis infection: clinical features and diagnostic pitfalls.

Eight cases of Streptococcus suis (S. suis) infection between 1993-1999 were retrospectively studied. There were 6 cases of meningitis and 2 cases of endocarditis. Acute meningitis with early sensorineural hearing loss was the characteristic feature and the most common presentation of S. suis infection. S. suis endocarditis is a rare presentation in Thailand. This organism was often mistaken for Streptococcus pneumoniae or Streptococcus viridans. In this study, this was true in five cases in whom S. suis was identified later. However, the rapid diagnosis of S. suis meningitis may rely on Gram stain of the CSF in the setting of acute meningitis with hearing loss. These cases were treated with intravenous penicillin or ampicillin with a mean duration of 4 weeks. This treatment was very effective and there was no relapse among these patients.

Aspergillosis of the central nervous system: a catastrophic opportunistic infection.

The clinical features and outcome of the treatment of aspergillosis of the central nervous system (CNS) in Thai patients are presented. The patients who were diagnosed as having CNS aspergillosis by tissue biopsy or culture from January 1, 1991 to December 31, 2000 were retrospectively reviewed. The study variables including age, sex, underlying disease, symptoms and signs, neuro-imaging studies, pathological findings and outcome of treatment, are described. There were seven cases of aspergillosis of the central nervous system. Four patients were male. The median age was 65 years (range 36-78 years). The most common underlying disease was diabetes mellitus (4/7; 57.1%). Two patients (28.6%) had no underlying disease. The most common primary site of infection was the paranasal sinuses (6/7; 85.7%). The most common clinical presentation was headache (6/7; 85.7%). Common neurological signs included multiple cranial nerve palsies (5/7; 71.4%) and alteration of consciousness (3/7; 42.9%). The median duration of the symptoms prior to admission was 60 days (range 8-180 days). All patients were treated with intravenous antifungal agents at high doses. Extensive surgery was performed in 6 patients. The mortality rate was very high (6/7; 85.7%). The median time from diagnosis and treatment to death was 53 days (22-720 days). Aspergillosis of the CNS should be considered in those with clinical features of headache, multiple cranial nerve palsies and alteration of consciousness accompanied by sinusitis, especially in elderly and diabetic patients. It remains a catastrophic opportunistic infection in spite of the current intensive and aggressive treatment.

Evaluation of electrophysiological response to thymectomy in patients with myasthenia gravis.

Clinical response to thymectomy in patients with myasthenia gravis varies in terms of timing and degree of improvement. Electrophysiological test is a reasonably reliable and objective way to evaluate neuromuscular transmission in these patients. The purpose of this study was to evaluate the electrophysiological response before and after thymectomy by repetitive nerve stimulation test in order to estimate the timing of initial improvement, progress and degree of improvement after thymectomy. According to electrophysiological findings, it appeared that neuromuscular transmission in these patients might have begun to improve even as early as one week after thymectomy and steadily improved by the end of one year of the study corresponding to clinical improvement.

Hiccups and multiple sclerosis.

Hiccups is a rare and unfamiliar presenting symptom of multiple sclerosis. Patients admitted to Ramathibodi Hospital from 1969 to 1992 who had a clinical diagnosis of multiple sclerosis were reviewed The presenting symptoms and neurological signs were analysed. The clinical features and course of the disease of cases who initially presented with intractable hiccups were studied in detail. There were 4 cases out of a total of 47 cases (8.5%) who presented with hiccups. These patients all had relapse and remission and two of them had a rather fulminant course of illness. Therefore, multiple sclerosis should be seriously considered as a possible cause of intractable hiccups. It may be of benign or malignant form. In the latter, the patients may develop quadriparesis within hours or days and respiratory failure may ensue. They usually respond well to high dose intravenous corticosteroids especially pulse methylprednisolone.

Oculopharyngodistal myopathy in a Thai family.

There has been controversy whether oculopharyngodistal myopathy (OPDM) commonly seen in Japan is a distinct disease entity or a variant of oculopharyngeal muscular dystrophy (OPMD) initially described in French-Canadians and has since been reported in other ethnic groups. Both diseases have autosomal dominant inheritance and OPDM patients are clinically similar to OPMD with slowly progressive ptosis, ophthalmoplegia and dysphagia except that most of the former usually have distal as opposed to proximal weakness and most of them are genetically different from the latter The authors report here 2 siblings with clinical features of OPDM. This entity is rare outside Japan and this is the first family to be reported from Thailand

Long-term outcome and factors influencing the outcome of thymectomy for myasthenia gravis.

Thymectomy has gained widespread acceptance as a treatment for patients with myasthenia gravis (MG). Patients with myasthenia gravis who had undergone thymectomy by extended transsternal approach between 1981 and 1987 were retrospectively reviewed to evaluate the result of thymectomy, time to remission, time to maximum improvement and factors influencing remission after thymectomy. There were 128 patients, 45 men and 83 women and the mean ages at the time of thymectomy were 35.7 and 32.2 years respectively. After thymectomy, 41.2% of the patients were in remission, 53% improved and 5.8% had no response. The remission rates at 1, 2, 5 and 10 years after thymectomy were 9%, 17%, 37% and 53% respectively and the median time to remission was 9 years. The maximum improvement rates at 1, 2, 5 and 10 years after thymectomy were estimated to be 30%, 40%, 57% and 78% respectively and the median time to maximum improvement was 3.6 years. Patients with ocular MG, longer duration of symptoms before thymectomy and atrophic thymus gland appeared to take longer to achieve remission although none of the factors was significantly associated with the time to remission. Thymectomy is beneficialfor MG patients with satisfactory remission and improvement rates. It is recommended that thymectomy should be advocatedfor these patients early in the course of the disease because the duration of the symptoms appeared to be the main determinant of the outcome.

Differentiation of dementia with Lewy bodies, Alzheimer's disease and vascular dementia by cardiac 131I-meta-iodobenzylguanidine (MIBG) uptake (preliminary report).

OBJECTIVE: Differentiation of dementia with Lewy bodies (DLB), vascular dementia (VAD), and Alzheimer's disease (AD) is difficult in clinical practice. Several new techniques have been used for differentiation of various types of dementia. Among these techniques 123I-meta-iodobenzylguanidine (MIBG) uptake was reported to have benefit in distinguishing DLB from AD. The authors study the role of MIBG as a tool for differentiation of DLB, AD and VAD. METHOD: Patients with dementia were recruited to the study by DSMIIIR criteria. Diagnosis of each dementia type was made by standard clinical criteria. Brain imagings and 131I-MIBG uptake were performed in all the studied patients. RESULTS: Five DLB, 3 AD and 3 VAD patients were clinically diagnosed. The heart/mediastinum (H/M) ratio in 4 out of 5 in DLB was significantly lower than H/M ratio in patients with AD and VAD. AD patients had the highest uptake of MIBG MIBG uptake of VAD patients was in the range between AD and DLB but the values were close to the AD group. CONCLUSIONS: 131I-MIBG is helpful in differentiating DLB from AD.

Long-term effectiveness of acetazolamide on permanent weakness in hyperkalemic periodic paralysis.

Acetazolamide is commonly used as an empirical treatment for inherited periodic paralyses although some patients may develop deleterious effects. We report a 65 year-old man with hyperkalemic periodic paralysis and late-onset permanent weakness in association with the common T704M mutation in α-subunit, skeletal muscle voltage-gated sodium channel gene. He rapidly recovered from weakness after acetazolamide treatment. Magnetic resonance imaging of thighs comparing pre- and post-treatment revealed a significant increase in muscle bulk. The patient has been without any type of weakness for over 6 years. This data show the remarkable benefit of acetazolamide on permanent weakness of hyperkalemic periodic paralysis in association with the T704M mutation.

Prevalence, clinical features and treatment outcomes of patients with myasthenia gravis positive for antibodies to muscle-specific kinase in Thailand.

A small but variable subgroup of patients with myasthenia gravis (MG) who have antibodies to muscle-specific kinase (MuSKAb-MG) can present with distinct phenotypes and are often treatment-resistant. The prevalence, clinical phenotypes and outcomes of treatment of patients with MuSKAb-MG in Thailand were determined. Eight (16.3%) of the 49 patients with generalized MG who were negative for acetylcholine receptor antibodies (AChRAb) were positive for muscle-specific kinase antibodies. Most patients had predominant oculobulbar features and respiratory failure occurred in three. At follow up, three out of the seven patients who underwent thymectomy were in complete stable remission and four had improved and were on reduced immunosuppression medication, suggesting a possible benefit of thymectomy.

Electrophysiological and immunological study in myasthenia gravis: diagnostic sensitivity and correlation.

OBJECTIVE: To determine the diagnostic sensitivity of repetitive nerve stimulation (RNS), single fiber electromyography (SFEMG) and acetylcholine receptor antibody (AChRAb) in myasthenia gravis (MG), and to compare the degree of SFEMG abnormality between ocular and generalized MG and between seronegative and seropositive patients. METHODS: The sensitivities of RNS, SFEMG and AChRAb were estimated. SFEMG abnormality was compared between ocular and generalized MG and between seronegative and seropositive patients. RESULTS: Abnormal RNS, abnormal SFEMG and AChRAb were detected in 62%, 93% and 38% of 42 ocular, and 80%, 99% and 73% of 70 generalized cases, respectively. The degree of SFEMG abnormality was significantly greater in the generalized than ocular patients and was significantly greater in the seropositive than seronegative patients in both extensor digitorum communis and orbicularis oculi muscles. CONCLUSION: SFEMG is a very sensitive and useful test for MG. A correlation between SFEMG abnormality and clinical phenotype or severity and between SFEMG abnormality and AChRAb seropositivity was demonstrated. SIGNIFICANCE: The sensitivities of RNS, SFEMG and AChRAb in the diagnosis of MG were documented. The differences in severity between the ocular and generalized MG and between the seronegative and seropositive MG were confirmed and quantitatively determined by SFEMG.