CSF oligoclonal bands, immunoglobulins, and viral antibodies in progressive myoclonus epilepsy

Progressive myoclonic ataxia with intrathecal immune activation in six patients

In six patients with slowly progressive sporadic cerebellar ataxia and cortical multifocal action myoclonus, cerebrospinal fluid (CSF) IgG index was persistently very high (1.2-6.7) and numerous oligoclonal bands were detected. Progressive cognitive impairment and MRI cerebellar and cerebral atrophy were observed. No serum antibodies were found. Various degenerative, metabolic, inflammatory and systemic diseases were excluded. The cerebellum may be the main target of a degenerative or immune process and releases antigens that, enhancing a compartmentalised (auto)immune response, as suggested by the persistent intrathecal activation, could lead to further cerebellar damage. As the frequency of CSF oligoclonal banding in myoclonic ataxia is unknown, our patients' disease might represent a hitherto unreported entity or a subset of progressive myoclonic ataxia.

Epilepsy and the immune system: is there a link?

The concept that the immune system plays a role in the epileptogenic process of some epileptic syndromes was first proposed more than 20 years ago. Since then, numerous studies have reported on the existence of a variety of immunological alterations in epileptic patients, on the observation of favourable responses of refractory epilepsy syndromes to immunomodulatory treatment, and on the association of certain well-known immune-mediated disease states with epilepsy. This review comprehensively recapitulates the currently available evidence supporting or arguing against the possible involvement of the immune system in the pathogenesis of certain types of epilepsy. It is concluded that an abundance of facts is in support of this concept and that further studies should be directed at substantiating the pathogenic significance of (auto)immune responses in certain types of epilepsy. Current progress in the functional and molecular immunological research techniques will indisputably contribute to the elucidation of this link.

Unusual imaging findings in progressive myoclonus epilepsy

We describe a patient with progressive myoclonus epilepsy (PME), white matter hyperintensities in the corpus callosum, cerebral hemispheres, and left cerebral peduncle on magnetic resonance imaging (MRI), and positive oligoclonal bands. A phosphorus magnetic resonance spectrum was compatible with mitochondrial dysfunction. Abnormal white matter signals are not a feature of the known PME syndromes, although they occur in Leber's hereditary optic neuropathy (LHON). These abnormalities oriented the diagnosis toward mitochondrial disease.

Intrathecal immune activation in three patients with progressive myoclonic ataxia

Three patients displaying a clinical picture of progressively evolving multifocal action myoclonus and cerebellar ataxia showed a marked intrathecal immune activation, which was persistent over a 2- to 5-year time span in the two serially investigated patients. A thorough search for metabolic, toxic, infectious, or degenerative causes of myoclonus was unsuccessful. The presence of intrathecal immune activation in at least a subgroup of patients with the clinical features of progressive myoclonic ataxia suggests the possibility of immune-mediated damage within the central nervous system in this condition.

Cerebrospinal fluid examinations in cryptogenic West and Lennox-Gastaut syndrome before and after intravenous immunoglobulin administration

Before and after administration of intravenous immunoglobulin (IVIg), cerebrospinal fluid (CSF) was examined in a homogeneous group of 15 patients with cryptogenic types of West syndrome (WS) and Lennox-Gastaut syndrome (LGS). The purpose of the present CSF study was: (i) to elucidate possible etiological factors and consequences of these severe forms of epilepsy, and (ii) to elucidate mechanisms of action and adverse effects of IVIg. Hypotheses concerning etiological factors like central nervous system infections, neuroimmunological disorders, or disturbances in neurotransmitter metabolites could not be confirmed. These normal CSF findings are in accordance with the concept of a cryptogenic etiology of the epilepsies in the reported patients. Nor could we confirm hypotheses concerning seizure consequences, such as increased blood-CSF permeability, increased markers of brain cell destruction, or increased metabolic components. Following IVIg administration in these patients, all with an on the whole undisturbed blood-CSF barrier permeability as measured by Q albumin, the CSF IgG concentrations increased significantly and proportionally to the Q albumin level. No signs of adverse effects of IVIg such as aseptic meningoencephalitis were found in 165 infusions of IVIg performed in the 15 children.

Virus antibodies in the cerebrospinal fluid of multiple sclerosis patients detected with ELISA tests

The enzyme-linked immunosorbent assay (ELISA) was used to determine levels of specific IgG antibodies against measles, rubella, vaccinia, corona (OC43) and mumps viruses in cerebrospinal fluid (CSF) and serum of 18 patients with clinically definite multiple sclerosis (MS), 8 patients with optic neuritis (ON), 27 patients with other neurological disease (OND), and 88 control subjects without central nervous system disease. Serum antibody levels were not significantly different between the four groups. Differences in the frequency and levels of CSF antibodies between the four groups were observed. Control patients had serum/CSF antibody ratios from 2.0 to 3.0 (log) with an average of 2.5 corresponding to a 320-fold difference between serum and CSF antibody levels. MS patients had ratios from 1.1 to 2.1 with an average of 1.6. The average was 2.0 for the ON patients. The average for the OND patients was similar to the controls. The altered serum/CSF ratios for several viruses within an individual patient was similar. These results suggest that nonspecific immunostimulation is responsible for the increased levels of CSF virus antibodies.

Progressive myoclonus epilepsy is not accompanied by humoral immune response within the central nervous system

CSF and serum from five patients with progressive myoclonus epilepsy taken on two occasions with about one month's interval were examined for intrathecal humoral immune response. The CSF IgG and IgA index values were normal, and no oligoclonal bands were detectable by agarose electrophoresis or polyacrylamide isoelectric focusing (IEF). Immunofixation of IEF separated IgG with four different viruses as possible antigens, and autoradiography did not reveal any intrathecal antibody production. In contradiction to previous reports, no evidence was obtained for a local humoral immune response in progressive myoclonus epilepsy.

The significance of abnormal immune responses in patients with multiple sclerosis

Early diagnosis of multiple sclerosis (MS) may be assisted by tests for the abnormal immune responses of the central nervous system (CNS) including oligoclonal IgG bands in the cerebrospinal fluid (CSF), increased CNS IgG synthesis, increased CNS antibody synthesis against multiple viruses and increased numbers of enlarged lymphoid cells in the CSF. Alterations in immunological responses are important in the pathogenesis of MS. Further studies are needed, however, to identify the antigen(s) and/or antibodies responsible for oligoclonal IgG in the CSF of MS patients. Also, the cause(s) for the other immunological abnormalities with diagnostic importance need to be identified. The increased synthesis of antibodies against multiple unrelated viruses suggests generalized alteration in the immune regulatory system. The etiology of MS might be multifactorial involving abnormal immunological responses, possibly precipitated by infectious agents acquired during childhood by genetically susceptible individuals. The immunological responses including alterations in myelin basic protein concentration, antimyelin antibody and immune complex activities in CSF, and in vitro stimulation, suppression and migration inhibition of blood lymphocytes appear to correlate with stage of MS and severity of CNS damage. Some of the tests may become useful in estimating the prognosis of the disease. Longitudinal studies are needed to clarify the sensitivity of the diagnostic and prognostic immunological tests and etiological significance of these abnormalities in MS.