Radiological Characteristics of Extraocular Muscles in Myasthenia Gravis Patients with Ocular Manifestations: A Case-Control Study.

PURPOSE: To analyze radiological characteristics of the extraocular muscles (EOMs) in myasthenia gravis (MG) patients with ocular manifestations. PATIENTS AND METHODS: This retrospective case-control study included all MG cases with ocular manifestations, who attended a neuro-ophthalmology clinic at a university hospital, Bangkok, from April 2009 to June 2018. They experienced double vision and ophthalmoplegia. Control participants had normal eye movements. Orbital scans were thoroughly reviewed. We measured muscle thickness (MT) of the superior rectus, inferior rectus, medial rectus and lateral rectus muscles in both eyes using magnetic resonance imaging or computed tomography scan. The sum of the muscle thickness at all sites was calculated (MTsum). Comparisons of the mean MT of each muscle type and the mean MTsum between the MG and control groups were performed by using Student's t-test. MRI signal intensities of the EOMs were also recorded. RESULTS: Twenty MG cases and 20 controls were included in the study. The mean MTsum was 23.7 (standard deviation 4.8) mm in the MG group and 32.6 (3.5) mm in the controls. There were statistically significant differences between the two groups with respect to the mean MT and mean MTsum (p <0.001). In the MG group, there was a negative correlation between the MTsum and disease duration (p= 0.03). By using coronal T2-weighted orbital MRI with fat suppression (T2W/FS), the most frequent finding was isointensity with central hypointensity of the EOMs in the MG group. CONCLUSION: Atrophic EOMs were frequently found in the MG group, particularly in chronic cases. Isointensity with central hypointensity of EOMs on T2W/FS was also common in the MG group. These findings highlight the importance of muscle involvement in MG and may be helpful for clinical decision-making.

Clinical Characteristics of HIV-Associated Optic Neuritis.

INTRODUCTION: Acute optic neuritis (ON) has been increasingly reported in patients infected with human immunodeficiency virus (HIV). We aimed to describe clinical characteristics of HIV-infected patients with ON. MATERIALS AND METHODS: This observational retrospective study was performed from January 2008 to January 2016 in a university hospital in Bangkok, Thailand. Demographic data and clinical manifestations were retrospectively reviewed. RESULTS: We included 10 HIV-infected patients and divided them into two groups: infectious and non-infectious ON. There were six patients in the infectious ON group (five males, mean age 33.6 years, median CD4 cell counts during ON episodes 36.5 cells/µL, high viral loads, median initial visual acuity [VA] 1.7, median VA difference [initial VA - follow-up VA] 0). Four patients developed cryptococcal meningitis and 2 developed neuro-syphilis. They were treated with amphotericin B plus fluconazole and penicillin G sodium, respectively. There were four patients in the non-infectious ON group (two males, mean age 44.3 years, median CD4 cell count during acute ON 157.5 cells/µL, undetectable viral loads, median initial VA 1.3, and median VA difference 1.2). They were given corticosteroid treatments. There were no statistically significant differences between the two groups with respect to age, sex, and initial VA. There were statistically significant differences in median VA difference and median CD4 cell counts between the two groups (p=0.02 and 0.03, respectively). There was a significant correlation between CD4 counts and duration in three non-infectious ON patients treated with antiretroviral therapy (ART, p<0.001). DISCUSSION: Patients with infectious ON had low initial CD4 counts and high viral loads. Patients with non-infectious ON had increasing CD4 cell counts and undetectable HIV viral load following ART. The findings are highly suggestive of immune reconstitution inflammatory syndrome. The CD4 cell counts and viral loads may help to identify the type of acute ON in HIV-infected patients and establish proper therapies.

Etiologies of Acute Optic Neuritis in Thailand: An Observational Study of 171 Patients.

PURPOSE: To analyze the demographic patterns, clinical characteristics and etiologies of acute optic neuritis (ON). METHODS: This retrospective observational study included patients with acute ON who presented to a university hospital in Bangkok, Thailand, between January 2010 and March 2020. The demographic details, clinical characteristics and etiologies of acute ON were evaluated. RESULTS: A total of 171 patients were included in the study (78.4% [n=134] female; mean age 45 years [standard deviation 15.4 years]; 32.2% [n=55] bilateral involvement). The most common type of acute ON was idiopathic (51.5%), followed by neuromyelitis optica spectrum disorder (NMOSD, 30.9%), other autoimmune disorders (9.9%), myelin oligodendrocyte glycoprotein antibody-associated disorder (MOGAD, 5.3%), multiple sclerosis (MS, 1.8%), and postinfection (0.6%). In the other autoimmune disorders group, 2 patients developed systemic lupus erythematosus (1.2%), 2 Sjogren's syndrome (1.2%), 1 RA (0.6%), 1 anti-NMDAR (0.6%), 3 anti-Jo1 (1.8%), 2 c-ANCA (1.2%), 1 anti-centromere (0.6%), and 5 nonspecific autoimmune disorders (2.9%). In the idiopathic group, 38.6% developed single isolated ON, 1.8% relapsing isolated ON and 11.1% chronic relapsing inflammatory optic neuropathy. CONCLUSION: The most common form of acute ON in this study, similar to other Asian countries, was idiopathic. Idiopathic-ON shared some phenotypes with NMOSD and MOGAD. We also reported patients with anti-NMDAR, anti-Jo1, c-ANCA and anti-centromere disorders. Improvements in antibody detection have widened the range of possible etiologies of acute ON. The study highlighted the important role of antibodies in creating effective treatments in the future.

Evaluation of Retinal Nerve Fiber Layer and Ganglion Cell Layer Thickness in Alzheimer's Disease Using Optical Coherence Tomography.

OBJECTIVE: To evaluate the feasibility of using optical coherence tomography (OCT) for the detection of Alzheimer's disease (AD), by measuring the thickness of the retinal nerve fiber layer (RNFL) and the ganglion cell layer and inner plexiform layer (GCL-IPL). MATERIAL AND METHODS: This was a single-center, cross-sectional study. The study included 29 patients with AD (mean age ± standard deviation: 75.61 ± 6.24 years) and 29 healthy age- and sex-matched controls. All participants underwent cognitive evaluations using the Montreal Cognitive Assessment test. Measurements of the RNFL thickness, as well as GCL-IPL thickness, were obtained for all participants using OCT. Both RNFL and GCL-IPL parameters were adjusted for best-corrected visual acuity, hypertension, diabetes and dyslipidemia. RESULTS: The mean RNFL thickness was significantly thinner in the AD group than in the control group (85.24 and 90.68 µm, respectively, adjusted P=0.014). The superior quadrant was thinner in the AD group (adjusted P=0.033). The thicknesses did not differ significantly between groups for the other quadrants. The mean GCL-IPL thickness in the AD (68.81 µm) was significantly thinner than that in the controls (76.42 µm) (adjusted P=0.014). Overall, there was a negative correlation between age and mean RNFL; and between age and GCL-IPL thickness (r=-0.338, P=0.010 and r=-0.346, P=0.008, respectively). CONCLUSION: The mean RNFL and GCL-IPL thicknesses were thinner in the AD group than in the control group. These findings suggest that RNFL and GCL-IPL thickness may be biological markers for AD.

Infectious causes of encephalitis and meningoencephalitis in Thailand, 2003-2005.

Acute encephalitis is a severe neurologic syndrome. Determining etiology from among ≈100 possible agents is difficult. To identify infectious etiologies of encephalitis in Thailand, we conducted surveillance in 7 hospitals during July 2003-August 2005 and selected patients with acute onset of brain dysfunction with fever or hypothermia and with abnormalities seen on neuroimages or electroencephalograms or with cerebrospinal fluid pleocytosis. Blood and cerebrospinal fluid were tested for >30 pathogens. Among 149 case-patients, median age was 12 (range 0-83) years, 84 (56%) were male, and 15 (10%) died. Etiology was confirmed or probable for 54 (36%) and possible or unknown for 95 (64%). Among confirmed or probable etiologies, the leading pathogens were Japanese encephalitis virus, enteroviruses, and Orientia tsutsugamushi. No samples were positive for chikungunya, Nipah, or West Nile viruses; Bartonella henselae; or malaria parasites. Although a broad range of infectious agents was identified, the etiology of most cases remains unknown.

Identification of stroke mimics among clinically diagnosed acute strokes.

BACKGROUND: Stroke is a clinically syndrome of a sudden onset of neurological deficit in a vascular cause. Stroke mimics is the non-vascular disorders with stroke-like clinical symptoms. It is important to distinguish true stroke from mimics since treatment plan may differ OBJECTIVE: To determine the incidence of the stroke mimics and identify their etiologies. MATERIAL AND METHOD: All non-contrast head CT of the patients with clinically diagnosed stroke who immediately received imaging upon arrival at the emergency department of the university hospital were retrospectively reviewed in 12-month period between January 1 and December 31, 2008. Medical records, laboratory results, MRI, and 6-month clinical follow-up records were reviewed for final diagnosis. RESULTS: Seven hundred four patients were included in this study, including 363 (51.5%) men and 341 (48.5%) women with range in age from 24 to 108 years. Amongst those, 417 (59.2%) were ischemic stroke, 80 (11.40%) were hemorrhagic stroke, 186 (26.4%) were stroke-mimics, and 21 (3%) were inconclusive. The etiologies among stroke-mimics were metabolic/intoxication (35, 18.8%), sepsis (28, 15.0%), seizure (21, 11.3%), syncope (20, 10.8%), subdural hemorrhage (14, 7.5%), vertigo (11, 6.0%), brain tumor (10, 5.30%), central nervous system infection (5, 2.7%), others (26, 14.0%), and unspecified (16, 8.6%). CONCLUSION: Incidence rates and etiologies of the stroke mimics were similar to the western reports. However the frequency of each mimic was not.

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.

Japanese encephalitis virus remains an important cause of encephalitis in Thailand.

BACKGROUND: Japanese encephalitis virus (JEV) is endemic in Thailand and prevention strategies include vaccination, vector control, and health education. METHODS: Between July 2003 and August 2005, we conducted hospital-based surveillance for encephalitis at seven hospitals in Bangkok and Hat Yai. Serum and cerebrospinal (CSF) specimens were tested for evidence of recent JEV infection by immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) and a plaque reduction neutralization test (PRNT). RESULTS: Of the 147 patients enrolled and tested, 24 (16%) had evidence of acute flavivirus infection: 22 (15%) with JEV and two (1%) with dengue virus. Of the 22 Japanese encephalitis (JE) cases, 10 (46%) were aged ≤ 15 years. The median length of hospital stay was 13 days; one 13-year-old child died. Ten percent of encephalitis patients enrolled in Bangkok hospitals were found to have JEV infection compared to 28% of patients enrolled in hospitals in southern Thailand (p < 0.01). Four (40%) of the 10 children with JE were reported as being vaccinated. CONCLUSIONS: JEV remains an important cause of encephalitis among hospitalized patients in Thailand. The high proportion of JE among encephalitis cases is concerning and additional public health prevention efforts or expanded vaccination may be needed.

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.

Frequencies of spinocerebellar ataxia subtypes in Thailand: window to the population history?

Spinocerebellar ataxias (SCAs) are a heterogeneous group of disorders with almost 30 subtypes. The prevalence and relative frequency of each subtype vary among different populations. In this article, we report the relative frequency of six SCA subtypes in the Thai population and attempt to explain the observed pattern when compared with other populations in this region. We searched for SCA type 1, SCA2, SCA3, SCA6, SCA7 and dentatorubral-pallidoluysian atrophy mutations using GeneScan analysis in 340 patients from 182 families, in which at least one person had a clinical diagnosis of SCA. We analyzed the relative frequencies of SCA subtypes on a family basis, and compared these with the data in the Chinese and Indian populations. SCA3 was found in 19.2% of the patients (Agresti-Coull 95% confidence interval: 14.1-25.6%), SCA1 in 11.5% (7.6-17.1%) and SCA2 in 10.4% (6.7-15.8%). SCA6 was found in three families, with a relative frequency of 1.6% (0.3-5.0%). Compared with the related populations, the Thai SCA3 frequency was less than that of the Chinese, whereas it was higher than that in most of the Indian studies. The reverse is true for the SCA1/SCA2 frequency. A similar study in Singapore, where there was a clear history of population admixture, also showed the frequencies between those of the Chinese and the Indian populations. Although SCA3 was the most common identifiable SCA subtype in Thailand, SCA1 and SCA2 were also relatively common. Our results also supported some degree of admixture with the Indians in the Thai population and justify further study in the area.

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.

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.

Twelve-year changes in vascular risk factors and their associations with mortality in a cohort of 3499 Thais: the Electricity Generating Authority of Thailand Study.

BACKGROUND: Vascular mortality is increasing in economically developing countries such as Thailand but reliable data about the determinants of these changes are few. METHODS: In 1985, male and female employees of the Electricity Generating Authority of Thailand took part in a cardiovascular risk factor survey. In 1997, a follow-up survey was conducted and causes of death were determined for those subjects known to have died. Changes in levels of vascular risk factors over 12 years, and the associations of baseline risk factors with vascular mortality, were calculated. RESULTS: The 1985 survey recruited 3499 volunteers (average age 43 years) of whom 23% were female. In 1997, vital status was determined for 3318 (95%) and 2967 (85%) of the study participants were resurveyed. Mean levels of systolic blood pressure (SBP) and diastolic blood pressure (DBP), body mass index, total cholesterol and high density lipoprotein (HDL) cholesterol all increased over the 12-year follow-up period. Over the same time, the prevalence of diabetes also rose but the proportion of current smokers decreased. Vascular diseases were the most frequent cause of death during follow-up (n = 46), were positively associated with baseline age, SBP, DBP, smoking, diabetes, male sex, and total cholesterol, and were negatively associated with HDL cholesterol. CONCLUSIONS: Levels of most vascular risk factors worsened over the 12-year period between 1985 and 1997. The associations between baseline risk factor levels and vascular mortality were consistent with those observed in other populations. Interventions that control vascular risk factors have the potential to avert much premature vascular disease in Thailand.