[Herpetic meningoencephalitis in the elderly. Apropos of 13 cases]

Diagnostic yield of cerebral imaging in patients with acute confusion

OBJECTIVE

Acute confusion (AC) is a frequent reason for hospital admission in elderly patients. Although in majority of cases the cause is a systemic disorder (e.g., dehydration or septicaemia), patients are frequently subjected to cerebral imaging. This study was undertaken to find clinical predictors of normal cerebral computed tomography (CCT) or magnetic resonance imaging (MRI) scans in AC.

METHODS

Retrospective study of 294 patients admitted with AC of unknown origin, of whom 178 received cerebral imaging.

RESULTS

The rate of pathological imaging studies was 14%. The best single predictor of a normal brain scan was the absence of focal signs. Patients without focal abnormalities and either fever or dehydration had a probability of 0.96 of having a normal CCT or MRI. In demented patients without focal signs, the predictive value for a normal brain scan was 0.98, and if either patients with drowsiness were excluded or the existence of fever or dehydration was added as a selection criterion, all patients had normal scans.

CONCLUSIONS

Patients with AC without focal signs and with either evidence for a medical aetiology of delirium or prediagnosed dementia are at a very low risk of having focal lesions in their CCT or MRI.

Neuropsychological sequelae of acute-onset sporadic viral encephalitis

Acute encephalitis is an inflammation of the brain parenchyma. In the USA, by estimation, 20,000 cases occur every year. A variety of cognitive deficits may persist after the acute stage, and they are often the sole cause of disability. Recent literature demonstrates the heterogeneity of both amnestic disorders and the outcome following encephalitis. Herpes simplex virus is the most commonly recognised single aetiology of sporadic encephalitis and it may be the cause of the most severe symptoms. Antiviral medication, however, seems to have improved the cognitive outcome when compared to the historical, untreated cases. The cognitive sequelae following herpes simplex virus encephalitis (HSVE) are best known and most commonly described, e.g., in textbooks, but they do not represent the typical symptomatology of encephalitis in general. Much less is unfortunately known about other types of encephalitis, those that account perhaps up to 80% of all cases, where both mild and severe defects have been observed. This article summarises the current knowledge.

Skin infections and infestations in geriatric patients

Geriatric patients develop infections, but many have a different appearance from what usually is expected. The difference depends on the age and immune status of the patient and the virulence of the organism. Differences may make recognition more difficult. Therapy may require different doses. Examples of the more common infections are detailed in this article.

[Details of meningitis in the elderly]

PURPOSE

Elderly patients being more at risk for infections than younger people, this study was aimed at defining the epidemiological and clinical features of meningitis in this population, with the objective of improving diagnosis and management.

METHODS

Over a period of 10 years, all cases admitted to an infectious diseases unit for acute meningitis were reviewed. Patients infected by human immunodeficiency virus (HIV), fungi meningitis, and who were younger than 15 years of age were excluded from the study. According to age, two groups were constituted (group A: < 65 years and group B: > or = 65 years) and compared.

RESULTS

One hundred fifty-two patients were included in the study: 110 (72.4%) in group A (29 with bacterial and 81 with viral meningitis) and 42 (26.7%) in group B (32 with bacterial and ten with viral meningitis); the mean age was, respectively, 32.7 +/- 12.9 years (range: 15-61 years) and 75.9 +/- 7.6 years (range: 65-94 years). Diagnosis was less frequently evoked in the elderly (n = 11; 26%) than in younger patients (n = 78; 71%) (P < 0.001). Streptococcus pneumoniae, Listeria monocytogenes, and herpes simplex virus were the three most common causal agents in group B. Confusion was the most common symptom among the elderly (88 vs. 17%; P < 0.001). The mortality rate was more important in group B than in group A (11.9 vs. 2.7%; P = 0.04).

CONCLUSIONS

Diagnosis of acute meningitis is difficult and must be evoked in the presence of any new neurologic sign. Cranial computerized tomography should not delay lumbar puncture, except in the presence of focal neurologic symptoms. Antimicrobial therapy takes into account the bacterial epidemiology.

Cognitive outcome in acute sporadic encephalitis

Acute encephalitis is an inflammation of the brain parenchyma. In the United States, 20,000 cases occur yearly. A variety of cognitive deficits, often the sole cause of disability, may persist after the acute stage. Still, infectious diseases tend to be covered only briefly in neuropsychological handbooks. Recent literature demonstrates the heterogeneity of both amnestic disorders and the outcome following encephalitides. Herpes Simplex virus (HSV), the most common single etiology of sporadic encephalitis, usually causes the most severe symptoms. Modern antiviral medication, however, seems to improve the cognitive outcome. Much less is known about non-HSV encephalitides, where both mild and severe defects have been observed. This article summarizes the current knowledge and also calls upon a more active neuropsychological research in the area.