Chronic HIV encephalitis — II. clinical aspects

Abstract

Combined medical, neurological, and serological investigations were carried out in 59 patients infected with human immunodeficiency virus (HIV). In stage I clinical and neuropsychiatric testing did not reveal evidence for HIV encephalitis as diagnosed by local antibody production in CSF. Neuropsychiatric abnormalities, brain atrophy, memory and cognitive impairment reliably indicated HIV encephalitis in later stages. The commonest symptoms were cerebellar and brainstem signs, followed by dementia. Epileptic fits and hemiparesis always were associated with cerebral toxoplasmosis. A polyneuropathy was frequently found but other causes have to be considered.

Chronic interleukin‐6 exposure alters metabotropic glutamate receptor‐activated calcium signalling in cerebellar Purkinje neurons

“…Disruptions of mGluR‐activated Purkinje neuron processes such as LTD are likely to result in alterations in information processing within the cerebellar cortex, thus disrupting the subsequent output of the cerebellum to descending motor systems. Disturbances of cerebellar function are manifested primarily as symptoms of discoordinated movement and ataxia, which are common to both IL‐6 transgenic mice and a number of neurological disorders with elevated CNS IL‐6 expression, including AIDS dementia complex (Poser et al ., 1988; Graus et al ., 1990), Alzheimer's disease (Aikawa et al ., 1985; Vakili & Muller, 1987), systemic lupus erythematosus (Tuchman et al ., 1983; Singh et al ., 1988) and multiple sclerosis (Aikawa et al ., 1985; Vergani et al ., 1988; Davie et al ., 1995). Our results suggest that elevated levels of IL‐6 in these conditions could be an important contributing factor to the disturbances in cerebellar function.…”

“…An effect of chronic IL‐6 exposure on mGluR‐activated intracellular Ca 2+ signalling has not been reported. However, such an effect could contribute to cerebellar dysfunction observed in conditions associated with elevated levels of IL‐6 in the CNS (Aikawa et al ., 1985; Poser et al ., 1988; Graus et al ., 1990; Davie et al ., 1995). Thus, in the present study we used the cultured cerebellar Purkinje neuron model to determine the effects of chronic IL‐6 on intracellular Ca 2+ signalling mediated through the activation of mGluRs.…”