Cognitive impairment after acute encephalitis: comparison of herpes simplex and other aetiologies.

OBJECTIVE: To compare the cognitive defects after acute acyclovir treated herpes simplex encephalitis with those after other types of acute encephalitis. METHODS: Seventy seven consecutive patients between 1985 and 1995 and 29 normal controls were studied. Of the 77 patients without concomitant neurological conditions, 17 had herpes simplex, one virus encephalitis (HSVE group), 27 had some other identified aetiology (non-HSVE group), and in 33 patients the cause was unknown. Acyclovir treatment was started less than four days after the first mental symptoms in 12 of 17 patients with HSVE. A thorough neuropsychological assessment was carried out about one month after the onset. RESULTS: The HSVE group had deficits in verbal memory, verbal-semantic functions, and visuoperceptual functions more often than the non-HSVE group. The risk for cognitive defects was twofold to four-fold in the patients with HSVE compared with the non-HSVE patients. Two (12%) of the patients with HSVE and 12 (44%) of the non-HSVE patients were cognitively intact. Six patients with HSVE (46%) and 17 (89%) non-HSVE patients later returned to work. The lesions on CT or MRI were bilateral only in one patient with HSVE. The defects in the three patients with adenovirus infection were severe and resembled the amnesia after HSVE. Cognitive impairment, not previously reported, was found in encephalitis after rotavirus infection and epidemic nephropathy. CONCLUSION: The recovery in the HSVE group was better than expected based on the medical literature. On the other hand there were surprisingly severe cognitive defects in encephalitis after other viruses. With early acyclovir treatment patients with the least severe HSVE were equivalent to those with non-HSV encephalitis with good outcome whereas those with the most severe non-HSV encephalitis were equivalent to those with HSVE with poor outcome.

Cognitive performance in HIV-1 infection: relationship to severity of disease and brain atrophy.

We examined cognitive performance in 72 HIV-1 infected patients and 34 controls. None of the patients had opportunistic infections or unusual neoplasms of the central nervous system (CNS). Factors other than HIV-1 known to cause cognitive decline were excluded from both groups. Cognitive functioning analysed with special emphasis on the severity of HIV infection was related to neuroradiological and immunological findings. In patients with AIDS-related complex (CDC IVa) or AIDS (CDC IVc,d), a deterioration of memory as well as cognitive speed and flexibility was detected. Furthermore, memory deficits were associated with central cerebral and infratentorial atrophy in those patients, while no association was found between cognitive deficits and immunological abnormalities. Patients at CDC stages II or III showed slight association between altered cognitive speed and flexibility and elevated leukocyte count, suggesting a subclinical CNS disease already at early stages of HIV infection.

Mild brain atrophy in early HIV infection: the lack of association with cognitive deficits and HIV-specific intrathecal immune response.

Brain MRI and/or CT were performed on 72 HIV-infected patients at various stages of the disease, and on 34 controls. The neuroradiological findings were related to duration of the infection, neurological symptoms, and cognitive abnormalities as well as to immunological findings in the CSF and blood. All types of brain atrophy were more severe and more frequent in HIV-infected subjects than in controls. Patients with neurological symptoms, those with advanced HIV infection, and patients with a duration of HIV infection of more than 4 years showed the most severe and most frequent neuroradiological abnormalities, including central and cortical atrophy, brain stem atrophy, and cerebellar atrophy. Subjects with cognitive defects exhibited more severe central atrophy than cognitively intact patients. However, slight brain atrophy and/or parenchymal lesions were found in 57% of cognitively intact HIV-seropositive individuals. Patients with brain atrophy and those with radiologically normal brain, both showed increased intrathecal synthesis of total IgG, and intrathecal HIV-antibody synthesis. However, a declined general immune response and a lowered CSF leukocyte count were seen predominantly in patients with brain atrophy. The results suggest that subcortical, neurologically "silent" areas of brain white matter are an early target of HIV infection.

Microangiopathy with encephalopathy, hearing loss and retinal arteriolar occlusions: two new cases.

Two young women developed encephalopathy, hearing loss and retinal arteriolar occlusions. Their behaviour became immature and cognitive functions were severely impaired. One of the patients underwent brain biopsy, which showed several microinfarcts in both white and grey matter and microangiopathic changes, with thickened arteriolar segments staining intensely for laminin and fibronectin. These findings support the concept of a new type of microangiopathy involving the brain, inner ear and retina.