Efficacy of Botulinum Toxin Type A in Trigeminal Neuralgia in a South Asian Cohort.

INTRODUCTION: The antinociceptive effect of botulinum toxin-A (BTX-A) in trigeminal neuralgia (TN) has been described. We evaluated effects of BTX-A in relieving pain in patients with refractory TN at National Hospital of Sri Lanka. MATERIALS AND METHODS: Pain in patients with TN was assessed using a visual analog from 0 to 10. Three months after commencement of drug therapy with ≥2 drugs including one first-line drug (carbamazepine/oxcarbazepine), pain scores were re-assessed. Twenty-two patients who did not report improvement of ≥50% at 90 days' posttreatment were recruited. They were given adjunct BTX-A directly to the trigger point (if identified) or intradermal. Pain scores were assessed at 10, 20, 30, 60, and 90 days' posttreatment. RESULTS: There was a statistically significant improvement in mean pain scores at 10, 20, 30, 60, and 90 days' posttreatment (5.59 [standard deviation (SD) = 2.7], 5.68 [SD = 2.6], 5.27 [SD = 3.2], 4.77 [SD = 3.7], and 5.32 [SD = 4.0]) compared to pre-BTX-A treatment (7.14, SD = 2.2). Percentage reduction in mean pain score ranged from 20.4% to 33.1%. Maximum response was at day 60 post-BTX-A (50% had ≥50% reduction in pain). No significant difference was found in response with higher doses and injection strategy. CONCLUSION: Consistent statistically significant reductions in pain scores at the aforesaid intervals compared to pretreatment means that there is a place for BTX in refractory TN.

Associations between Lifestyle Factors and Parkinson's Disease in an Urban Sri Lankan Clinic Study.

BACKGROUND: Associations between certain environmental and lifestyle factors and Parkinson's disease (PD) have been reported in several studies, but information on these factors and Parkinson's Disease (PD) in South Asia, is limited. OBJECTIVE: To determine associations between lifestyle factors and PD in an urban clinic-based study in Sri Lanka. METHODS: In this case-control study, demographic and lifestyle factor data (including diet, coffee/tea drinking, smoking, alcohol status) was collected from an unselected cohort of PD patients and age and gender-matched controls attending clinics in Greater Colombo, Sri Lanka. Associations between lifestyle factors and PD status were assessed using Logistic Regression analysis, while links with age of PD onset were explored with Kaplan Meier and Cox Regression survival analyses. Results with p<0.05 were considered to be statistically significant. FINDINGS: Of 229 patients with parkinsonism, 144 had Idiopathic PD using standard diagnostic criteria. Controls numbered 102. Coffee drinkers and smokers were significantly less likely to have PD (coffee, p<0.001; Odds Ratio (OR)=0.264; smoking, p=0.043; OR=0.394). Coffee drinkers were older at PD onset (p<0.001). Similar trends seen with tea drinking were not statistically significant. CONCLUSIONS: This is the first formal study of PD and these lifestyle factors in South Asia. It demonstrates an inverse association between coffee drinking, smoking and PD, and an association between coffee drinking and later age of PD onset. This is in line with other studies done worldwide, suggesting biological associations with global relevance.

Viral aetiologies of acute encephalitis in a hospital-based South Asian population.

BACKGROUND: The aetiological spectrum of acute encephalitis shows inter- and intra-geographical variations. We aimed to identify the viruses that cause infectious encephalitis in Sri Lanka, which represents a South Asian population. METHODS: A cross-sectional study was conducted among 99 patients with encephalitis/meningoencephalitis admitted to two tertiary-care hospitals in Colombo. Cerebrospinal fluid and serum were tested for conventional and emerging encephalitogenic viruses. Specific nucleic acid amplification and antibody assays were used to identify viruses. Plaque reduction neutralization test was done to confirm the diagnosis of West Nile virus (WNV). RESULTS: Patients' age ranged from 1 month to 73 years (mean = 24.91; SD = 21.33) with a male:female ratio of 1.75:1. A viral aetiology was identified in only 27.3%. These included dengue virus (40.7%), Japanese encephalitis virus (25.9%), varicella zoster virus, WNV and probable Epstein Barr virus (11.1% each). None were positive for herpes simplex viruses or cytomegalovirus. Screening for bacterial aetiologies was negative for all patients. There were no distinguishable clinical or laboratory findings between the different viral aetiologies. The case fatality rate was 7%, which was higher among patients with an identified viral aetiology. CONCLUSIONS: A viral aetiology was identified in only about a quarter of patients with encephalitis. Dengue virus accounted for the majority.

Association of type IV spinal muscular atrophy (SMA) with myoclonic epilepsy within a single family.

BACKGROUND: Spinal muscular atrophies (SMAs) are a group of disorders characterized by degeneration of the anterior horn cells in the spinal cord and motor nuclei in the lower brainstem. It is transmitted by autosomal recessive inheritance and most of these conditions are linked to SMN gene. Even if the clinical picture is mainly dominated by the diffuse muscular atrophy, some patients can also show atypical clinical features such as myoclonic epilepsy ("SMA plus"), which may be related to other genes. In particular, the association of SMA and progressive myoclonic epilepsy (PME) has been previously described. CASE PRESENTATION: We present a case of two brothers with late onset SMA associated with a unique form of non progressive myoclonic epilepsy without cognitive impairment or ataxia. They had identical clinical and electrophysiological features. CONCLUSIONS: The association of SMA with myoclonic epilepsy may constitute a separate and genetically independent syndrome with unique clinical and electrophysiological findings. Collection of similar cases with genetic studies is needed to define the phenotype clearly and to identify new genes and molecular pathogenetic mechanisms involved in this condition.

Clinical and serological study of myasthenia gravis using both radioimmunoprecipitation and cell-based assays in a South Asian population.

BACKGROUND: Identification of autoantibodies has defined distinct clinico-immuno-pathological subtypes of myasthenia gravis (MG) such as AChR-antibody-positive-MG and MuSK-antibody-positive-MG. The use of more sensitive assays such as the cell-based assay (CBA) is expected to reduce the proportion of seronegative-MG. We studied the seroprevalence of AChR and MuSK antibodies using both radioimmunoprecipitation (RIA) and CBA amongst MG patients in Sri Lanka and related their antibody status to their clinical subtypes and severity. METHODS: 113 patients with MG attending Neurology units in the district of Colombo were studied. Clinical data were obtained using an interviewer-administered questionnaire and medical records. The severity of MG was assessed according to MGFA clinical grading. RIA and CBA were used to detect serum AChR and MuSK antibodies. Patients with other neurological diseases were recruited as controls. RESULTS: We detected either AChRAb (85%) or MuSKAb (6.2%) in 91.2% of MG patients. Complementing the RIA with the CBA improved the diagnostic power of detecting AChRAbs by 21% and MuSKAbs by 77%. The clinical characteristics and the occurrence of thymic pathology were similar to other populations except for a male preponderance (1.5:1). The AChRAb titer appeared to parallel the clinical severity. Seven of 11 (63.6%) patients with AChRAb-negative generalized MG had MuSK-MG. CONCLUSIONS: Clinical characteristics of MG in Sri Lanka are similar to other populations. Complementing the RIA with CBA increases the diagnostic power of detecting pathogenic autoantibodies.

Toxic encephalopathy due to colchicine--Gloriosa superba poisoning.

Gloriosa superba, a flowering plant widespread in South and Southeast Asia, is implicated in many cases of self-poisoning. Colchicine is concentrated in the seeds and tubers and this mediates its toxicity. We describe a 28-year-old woman who developed delayed encephalopathy after eating G superba tubers. MR scan of brain showed bilateral symmetrical T2 basal ganglia hyperintensities in the caudate and lentiform nuclei. The delay in onset of encephalopathy is attributable to a direct-effect colchicine, probably mediated through its effect on microtubular transport.

Neurological manifestations of dengue: a cross sectional study.

BACKGROUND: Dengue is an infectious disease caused by a virus of the flaviviridae family. It is a multi systemic illness causing considerable morbidity and mortality. A spectrum of neurological manifestations has been associated with dengue. METHODS: This was a descriptive cross sectional study including patients diagnosed with Dengue fever (DF), Dengue with warning signs and severe dengue with neurological sequale presenting to the Institute of Neurology, National Hospital of Sri Lanka from June 2011 to August 2012. All patients underwent serology testing for Dengue IgM in blood and CSF as confirmation of the diagnosis. RESULTS: Seven patients were included. 1/7 had bilateral optic neuritis (ON), 3/7 had a cerebellar syndrome (CS), 2/7 had transverse myelitis (TM) and 1/7 had cranial nerve palsy. The patient with ON had a post-infectious pattern and protracted recovery. All patients with CS had bilateral involvement. All had a self limiting course with complete recovery. Two were associated with acute infection. Both patients with TM had longitudinally extensive disease with one patient experiencing complete recovery. The patient with cranial nerve involvement had isolated 6th nerve palsy. CONCLUSIONS: Neurological manifestations of dengue are diverse. It is important to consider dengue as a cause for the above neurological presentations in hyper endemic territories for the disease.

Spontaneously resolving cerebellar syndrome as a sequelae of dengue viral infection: a case series from Sri Lanka.

Sri Lanka is hyperendemic for dengue viral infection. Dengue has a wide spectrum of neurological manifestations including previously reported Sri Lankan cases with a 6th nerve palsy and a cerebellar syndrome from a co-infection with dengue and Epstein-Barr virus. This series describes a spontaneously resolving cerebellar syndrome following a dengue viral infection. Dengue is potentially an important cause of cerebellar syndromes in countries hyperendemic for the disease; patients need further studies to identify the responsible serotypes.

Idiopathic hypertrophic pachymeningitis presenting with a superficial soft tissue mass.

Idiopathic hypertrophic pachymeningitis (IHP) is a chronic progressive diffuse inflammatory fibrosis of the dura-mater, leading to its diffuse enlargement. The following describes a case of IHP presenting with a superficial soft tissue mass. A 40-year-old female came to hospital with a subcutaneous lump over the left face and frontal headache for 6 months. An excision biopsy revealed chronic inflammation. Magnetic resonance imaging (MRI) of the brain showed left mastoiditis and early dural inflammation of the left temporal region. A few months later, she developed diplopia, complex partial seizures, and retrobulbar neuritis of the left optic nerve. Repeat MRI brain demonstrated meningeal thickening on both sides of the tentorium cerebelli extending to the left tempero-parietal meninges. The meningeal biopsy revealed markedly thickened fibro-connective dural tissue with infiltration of chronic inflammatory cells. There was no evidence of bacterial, fungal, tuberculous or neoplastic infiltration. IHP was diagnosed and steroid therapy initiated. Within weeks, she showed marked clinical improvement. IHP is a diagnosis of exclusion. The absence of underlying infective, neoplastic, or systemic autoimmune disease favors IHP. The above patient had headache, neuro-ophthalmic signs, seizures, which are features of IHP. However, superficial soft tissue involvement is rare.

Chlorpyrifos-induced delayed myelopathy and pure motor neuropathy: a case report.

INTRODUCTION: Organophosphate (OP) poisoning is known to cause delayed neurological manifestations. Chlorpyrifos, an OP, causes a delayed syndrome that is characterized by a motor sensory polyneuropathy. Pure motor neuropathy with intact sensory conduction is rarely documented. Rapidly evolving delayed myelopathy is extremely uncommon. CASE REPORT: A healthy 15-year-old female was admitted to hospital with cholinergic crisis due to ingestion of a large dose of chlorpyrifos (OP). She was treated with atropine and recovered completely without any neurological symptoms or signs. She came to hospital 6 weeks later with upper and lower motor neuron signs involving the lower limbs without sensory loss. By the end of 7 weeks, there was urinary incontinence. At 2-month follow-up, she had progressive spasticity. Electrophysiological studies revealed a pure motor neuropathy. Spine magnetic resonance imaging showed early signs of thoracic cord atrophy. Other causes of myelopathy were excluded. CONCLUSIONS: Chronic neurotoxicity due to OP poisoning is dependent on several factors: chemical composition of the OP, dose systematized, and the administration of anitcholinergics for cholinergic crisis. The pathology of OP-induced delayed neuropathy involves a central-peripheral distal axonopathy. Peripheral distal axonopathy results in a predominantly motor polyneuropathy. Axonopathy of the central nervous system results in myelopathic features that makes for a poorer prognosis.

Treatment-related fluctuation in Guillain-Barre syndrome.

Guillain-Barre syndrome (GBS) is usually a monophasic illness but relapses occur. A 55-year-old female with hypertension and vitiligo presented with acute inflammatory demyelinating polyradiculoneuropathy. She improved with immunoglobulin treatment started on day 6 of illness, but relapsed on day 14 warranting repeat immunoglobulin therapy. Thereafter recovery was complete. Her relapse was due to treatment-related fluctuation (TRF). TRF is improvement in the GBS disability scale of at least one grade after completion of immunotherapy followed by worsening of the disability scale of at least one grade within the first 2 months after disease onset. Recurrent GBS and chronic inflammatory demyelinating polyradiculoneuropathy were excluded. During the peak of the illness ANA titres were transiently high. The presence of other medical conditions, predominant proximal weakness and the absence of preceding diarrhea are predictors for TRF seen in this patient. Early treatment and evidence of ongoing immune activation have contributed toward TRF.

Adapting the Sniffin' Sticks to diagnose Parkinson's disease in Sri Lanka.

Tests of odor identification might help differentiate Parkinson's disease (PD) from other causes of tremor, but they are culture and language specific and are not currently available for the population of Sri Lanka. We created a Sinhala adaptation of the 16-item identification test from Sniffin' Sticks (SS-16) and applied it to 89 nondemented Sri Lankan PD patients and 100 controls. Twelve of the SS-16 items were correctly identified by at least 50% of the control subjects and were included in a battery, which we called as Colombo SS-12. We used the diagnosis (PD or control) as outcome variable for a logistic regression using age, gender, smoking status and the SS-12 as covariates, and found only the last two were significant covariates. The Colombo SS-12 specificity was 93.0% with a sensitivity of 91.0%, indicating it could be a helpful tool in the diagnosis of PD in Sri Lanka.

MuSK-antibody-positive myasthenia gravis in a South Asian population.

BACKGROUND: MuSK-antibody-positive myasthenia gravis (MuSK-MG) is diagnosed in 0-40% of cases with generalized seronegative MG in different populations. The presence of anti-MuSK antibodies defines a distinct clinico-immuno-pathological subtype of MG. We analysed for the first time the serology and clinical characteristics of MuSK-MG in a South Asian population. METHODS: 113 patients with MG attending Neurology Units in three state hospitals in the district of Colombo, Sri Lanka were studied. AChR antibodies were tested in all patients whilst MuSK antibodies were tested in patients seronegative for AChR antibodies. Sera from patients with other neurological diseases (OND) concurrently attending the same hospitals were obtained as controls. RESULTS: Four of 19 AChRAb-negative generalised MG patients (21%) were positive for MuSKAbs. Two were women and in 3, disease onset was before the age of 30 years. Although 3 of 4 had ocular-bulbar involvement at presentation, none had facial or bulbar muscle wasting. Two of the 4 patients (50%) had developed myasthenic crisis and had required ventilation. A good treatment outcome appears to be related to early commencement of immunosuppressive medication. None of the patients with ocular MG or OND were positive for either AChR or MuSK antibodies. CONCLUSIONS: MuSK-MG is seen in about a fifth of generalised seronegative MG patients in Sri Lanka. The clinical characteristics are consistent with features described in Caucasian MuSK-MG patients.