The neuroanatomical basis of slow saccades in spinocerebellar ataxia type 2 (Wadia-subtype).

In a case of spinocerebellar ataxia type 2, Wadia-subtype (SCA2), with slow horizontal saccades, we used parvalbumin immunohistochemistry to identify the omnipause (OPNs) excitatory (EBNs), and inhibitory burst neurons (IBNs) of the saccade generator. Nissl sections was used to measure neuronal diameters, and synaptophysin staining to estimate of synaptic density on the cell somata. Morphometric and synaptic density measurements of the abducens motoneurons were identical in SCA2 and the control. A significant cell loss and reduced synaptic density on somata was found only in the EBN area. We conclude that degeneration of the EBNs is the most likely cause for the slowing of horizontal saccades.

Selective, circuit-wide sparing of floccular connections in hereditary olivopontine cerebellar atrophy with slow saccades.

We present a systems-oriented histopathologic analysis of the ocular motor control circuits in the cerebellum and brainstem from a patient with a hereditary form of olivopontine cerebellar atrophy of the Wadia type, which has a characteristic ocular motor presentation of slow saccades but relative preservation of smooth pursuit and gaze-holding. This differential pattern of clinical involvement is associated with a lobule-specific pattern of cerebellar degeneration. We asked whether these patterns of sparing and degeneration were consistent throughout the associated deep cerebellar and brainstem structures. Specimens were fixed in formalin, embedded in paraffin, and stained for various markers. We found that elements of the floccular and nodular pathways, controlling smooth pursuit and vestibular reflexes, were relatively spared, particularly those structures that are interconnected with the medial regions. Conversely, the elements of the dorsal vermis pathway controlling saccade adaptation were relatively involved. This subregional specificity of degeneration further defines possible areas of investigation for elucidating pathophysiology, testing biomarkers of disease, and developing areas for therapeutic intervention.

Late-onset episodic ataxia type 2 due to an in-frame insertion in CACNA1A.

Episodic ataxia type 2 (EA2) is caused by calcium channel (CACNA1A) mutations and typically begins before age 20 years. The molecular basis of late-onset EA2 is unclear. The authors describe a case of late-onset EA2 associated with the first multiple-base pair insertion in CACNA1A. Molecular expression revealed evidence of impaired calcium channel function, suggesting that genetically induced reduction in calcium channel function may associate with cases of late-onset EA2.

Acute renal failure with neurological involvement in adults associated with measles virus isolation.

BACKGROUND: Three people with clinical manifestations of acute renal failure with neurological involvement of unknown cause were admitted to a hospital in Mumbai, India. We describe clinical presentations and investigations of the cause. METHODS: We analysed case reports and laboratory findings for the patients (age 37-43 years, two men, one woman) that were provided by the clinicians in charge. Serum and cerebrospinal fluid were tested for viral cause by IgM ELISA to Japanese encephalitis, West Nile fever, dengue, and measles. Samples were inoculated in vero-cell culture for virus isolation. The virus isolates were confirmed with indirect immunofluoresence with antimeasles immune sera and mouse monoclonal antibodies to measles HA and F proteins and with neutralisation tests using antimeasles immune sera. FINDINGS: Clinical features were fever, vomiting, oliguria or anuria, bilateral facial weakness, impaired hearing, blindness, proximal and distal areflexic limb paralysis, and respiratory paralysis. No patient had a macropapular rash. Blood urea nitrogen (4.64-27.8 mmol/L) and creatinine (601.1-1105.0 micromol/L) were high, and cerebrospinal fluid contained high concentrations of proteins and pleocytosis. Kidney biopsy samples in two patients showed severe interstitial nephritis. IgM antibodies to measles were found in blood and cerebrospinal fluid. Vero-cell cultures from serum and cerebrospinal fluid of one patient and cerebrospinal fluid of two patients, showed cytopathic effects characteristic of measles. INTERPRETATION: Unusual manifestations of acute renal failure with neurological involvement associated with measles virus in adults presenting without rash was confirmed. Our findings may affect the development of measles-elimination programmes.

Proposal of diagnostic criteria for human cysticercosis and neurocysticercosis.

Taenia solium cysticercosis is a major public health problem in several areas of the world. While the disease has a recognized etiologic agent, its definitive histological diagnosis is not possible in most cases because this parasite tends to lodge in cerebral tissues where routine biopsy is not feasible. Therefore, the diagnosis of human cysticercosis (and neurocysticercosis) should rest on the proper interpretation of the patients' symptoms together with data provided by radiological studies and immunologic tests for the detection of anticysticercal antibodies. Unfortunately, the pleomorphism of this parasitic disease creates confusion when non-specific clinical, radiological, or immunologic criteria alone are used to detect cases among populations or to diagnose hospitalized patients with neurological manifestations. We propose a chart of diagnostic criteria for human cysticercosis that objectively permit clinicians and health care workers to evaluate clinical, radiological, immunologic, and epidemiologic data of patients. The chart uses four degrees of criteria: absolute, major, minor, and epidemiologic, that were selected on the basis of their individual diagnostic strength. Interpretation of such criteria will result in three categories of diagnostic certainty: definitive, probable and possible, according to the likelihood that cysticercosis is present in a given person.

Autosomal recessive hereditary sensory neuropathy with spastic paraplegia.

Five patients are described with a progressive sensory neuropathy in association with a spastic paraplegia and a mutilating lower limb acropathy. Disease onset was in childhood. Two pairs of siblings were both the offspring of normal consanguinous parents, suggesting autosomal recessive inheritance. The fifth case was sporadic; her parents were normal and non-consanguinous. Nerve biopsy in three patients showed an axonopathy with a loss of myelinated nerve fibres of all diameters and also of unmyelinated axons. In combination with the previous report by Cavanagh et al. (Brain 1979; 102: 79-94), the present patients establish the existence of an autosomal recessive form of hereditary sensory neuropathy with spastic paraplegia. There have been previous descriptions of a dominantly inherited form.

IgM deposits at nodes of Ranvier in a patient with amyotrophic lateral sclerosis, anti-GM1 antibodies, and multifocal motor conduction block.

We studied a patient with amyotrophic lateral sclerosis, multifocal motor conduction block, and IgM anti-GM1 antibodies. A sural nerve biopsy demonstrated deposits of IgM at nodes of Ranvier by direct immunofluorescence. The deposits were granular and located in the nodal gap between adjacent myelin internodes, and in some instances, they extended along the surface of the paranodal myelin sheath. When injected into rat sciatic nerve, the serum IgM bound to the nodes of Ranvier, and the binding activity was removed by preincubation with GM1. These observations suggest that anti-GM1 antibodies may have caused motor dysfunction by binding to the nodal and paranodal regions of peripheral nerve.

Multiple sclerosis is prevalent in the Zoroastrians (Parsis) of India.

Using Schumacher's classification, we determined the prevalence rate of clinically definite multiple sclerosis (MS) in the distinct but tiny Zoroastrian (largely Parsi) community in the adjacent cities of Bombay (latitude, 18.55 degrees) and Poona (Pune). On prevalence day, 16 clinically definite cases of MS were counted, 14 in Bombay and 2 in Poona, from a total Zoroastrian population of 50,053 and 3,399, respectively. The crude prevalence ratio was 26 per 100,000 for Bombay and 58 per 100,000 for Poona. The age-adjusted prevalence ratio for Bombay was 24 per 100,000, with 95% confidence limits of 13.1 to 40.3. These are much higher than the low rates believed to be prevalent in India, and are comparable with those found in parts of Europe and the United States.

Prevalence of multiple sclerosis in the Parsis of Bombay.

We carried out a door-to-door-survey to screen a community of 14,010 people (Parsis living in colonies in Bombay, India) for possible neurologic diseases, and used defined diagnostic criteria to evaluate people who tested positive on the screening survey. There were three clinically definite cases of multiple sclerosis (21/100,000). This is the first prevalence survey for multiple sclerosis in a large developing country.

Radiation necrosis causing failure of automatic ventilation during sleep with central sleep apnea.

A patient operated upon for a midline cerebellar hemangioblastoma developed failure of automatic respiration during sleep, together with central sleep apnea syndrome, approximately two years after receiving radiation therapy to the brain. Clinical and CT scan findings were compatible with a diagnosis of radiation necrosis as the cause of his abnormal respiratory control.

SMON as seen from Bombay.

Clioquinol is still consumed in India in considerable amounts but no new case reports have appeared since 1977. A review is made for a regional neurotoxicology group of an enquiry that we conducted in Bombay to gather information regarding SMON, spanning the period of 1967 to 1976. Nine patients were diagnosed with a variable degree of confidence as suffering from SMON, two from a retrospective search and seven after a prospective watch for the disease. Myelopathy with predominant more distal dysesthesia was seen more often than the full-blown picture of SMON. The peripheral neuropathy component (N) diagnosed clinically or electrophysiologically was seen only once. Pyramidal tract disturbances and resulting spasticity was as striking as posterior column disorder and sensory ataxia. Subacute myelopathy was seen in six patients, optico-myelopathy in two, and myeloneuropathy only once. It was clear that clioquinol has potential neurotoxicity, but no definitive explanation was forthcoming about the vast difference in the prevalence of SMON as reported from Japan and seen by us in Bombay.

A study of the neurological disorder associated with acute haemorrhagic conjunctivitis due to enterovirus 70.

Ninety cases of the neurological manifestations associated with acute haemorrhagic conjunctivitis caused by Enterovirus 70 (EV 70) are reported. The patients were seen during the widespread epidemics in 1971 and 1981. Male adults were predominantly affected by a "polio-like" paralysis of the limbs and/or cranial nerves. Root pains were often complained of early in the disease. In the absence of a necropsy, clinical and neurophysiological examinations helped to localise the lesions. Significant antibody titres against EV 70 were demonstrated in the serum and more relevantly in the CSF. Though other viruses can cause sporadic and epidemic conjunctivitis and similar paralysis independently, the combination of a haemorrhagic conjunctivitis and a neurological disease mostly simulating poliomyelitis is caused by EV 70 alone. It is therefore suggested that this combination be called "Enterovirus 70 disease". Because of its neurovirulence, it is important to identify this virus at the very beginning of an epidemic of conjunctivitis, so as to limit its spread by strict public health measures.

Polio-like motor paralysis associated with acute hemorrhagic conjunctivitis in an outbreak in 1981 in Bombay, India: clinical and serologic studies.

High and rising neutralizing antibody titers (NATs) to enterovirus type 70 (EV70) were detected in the serum and cerebrospinal fluid (CSF) of patients with polio-like motor paralysis accompanying acute hemorrhagic conjunctivitis (AHC) in an outbreak of AHC in 1981 in Bombay, India. Fifty-four (88.5%) of 61 patients with AHC with or without neurologic disease had serum NATs of greater than or equal to 1:16, and some paired sera from these patients showed significant increases in NAT. Serum from noninfected control subjects had no significant neutralizing antibody to EV70. Thirty-six (94.7%) of 38 CSF specimens from 30 patients with spinal or a combination of spinal and cranial motor paralysis associated with AHC had NATs ranging from 1:2 to 1:256. No neutralizing antibody was found in CSF specimens from patients with AHC alone or in those from non-infected control subjects, and a reduced ratio of serum NAT to CSF NAT was detected in patients with neurologic disease. Therefore, it is highly likely that intrathecal synthesis of antibody occurred in response to direct invasion of the central nervous system by EV70. The results represent strong laboratory evidence of the neurovirulence of EV70.