Murray Valley encephalitis, 1974: clinical features

Of the 58 patients who developed Murray Valley encephalitis (MVE) during 1974, 22 were admitted to Fairfield Hospital, Melbourne. The patients were of all ages, but the disease was most common in children. Calculations suggest that the incubation period of MVE is from one to four weeks. The severity of brain damage varies considerably; 11 patients recovered almost completely, seven had severe residual damage and four patients died. There are no special features which distinguish MVE from any other form of encephalitis. The survival of five of eight patients who required artificial respiration suggests that patients with suspected MVE should be transported at an early stage to a hospital where artificial respiration is available if necessary. There is no evidence that infection with the MVE virus can cause clinical manifestations of a disease other than acute encephalitis.     

Isolated retrograde amnesia following viral encephalitis

We describe a patient who presented with isolated retrograde amnesia of 2-year duration after recovery from viral encephalitis. The patient was a 29-year-old right-handed male dentist and was admitted to our hospital with a complaint of generalized convulsion. Cerebrospinal fluid (CSF) showed mononuclear pleocytosis. Neuroradiological examinations (X-ray CT, MRI and 123I-IMP SPECT) revealed no significant abnormality. Immunological method showed no specific increase of viral antibody titers. However, with a tentative diagnosis of viral encephalitis, administration of acyclovir was started. After 3 weeks he became comprehensive, and several kinds of neuropsychological tests were performed. His intelligence and immediate memory were normal, and his procedural memory of dentist was intact. On the other hand, he could not recall any information about events, both personal and public, occurred within 2 years before the onset of present illness. His autobiographical memory disorder was also demonstrated using a series of weekly comic. In isolated retrograde amnesia following viral encephalitis like this case, memory of relatively short time duration, acquired prior to the onset of present illness, tend to be disturbed.     

Fatal encephalitis caused by concomitant infection with tick-borne encephalitis virus and Borrelia burgdorferi

We describe a 38-year-old farmer from the southwestern archipelago of Finland where both tick-borne encephalitis (TBE) virus and Borrelia burgdorferi are endemic. He presented with fever and headache, developed severe meningoencephalitis in 3 days, and, after 1 month, died without regaining consciousness. High titers of IgG and IgM antibodies to TBE virus were present in both serum and CSF. Serology for Borrelia was negative. Autopsy revealed necrotizing encephalitis and myelitis with involvement of the dorsal root ganglion. With use of polymerase chain reaction tests, segments of two separate genes of B. burgdorferi were amplified from the patient's CSF. This case demonstrates that the possibility of dual infection should be considered for patients residing in geographic areas where Ixodes ticks may carry both the TBE virus and B. burgdorferi. We believe that the most severe damage in this case was caused by TBE virus rather than by B. burgdorferi. Nevertheless, the coinfection might have contributed to the fatal outcome that has not been previously observed in Finnish patients with TBE.     

Cytomegalovirus encephalitis

PURPOSE: To review the pathologic and clinical features of and establish the frequency of cytomegalovirus encephalitis in adults and to review the methods available for diagnosis and treatment. DATA SOURCE: MEDLINE search of all English-language articles from January 1965 to August 1995. STUDY SELECTION: Articles dealing with cytomegalovirus infection of the brain in adults. We also reviewed all unselected autopsies of these populations to establish the frequency of cytomegalovirus encephalitis in recipients of organ transplants and in patients infected with the human immunodeficiency virus (HIV). DATA EXTRACTION: Epidemiologic and pathologic characteristics, clinical manifestations, diagnostic methods, pathogenetic mechanisms, and use of anticytomegalovirus treatments. DATA SYNTHESIS: Of 676 patients receiving a diagnosis of cytomegalovirus encephalitis, 574 (85%) were infected with HIV, 81 (12%) had other causes of immunosuppression, and 21 (3%) were otherwise healthy. Cytomegalovirus encephalitis was confirmed during autopsy in 12% of HIV-infected patients and 2% of transplant recipients. The most common lesion was microglial nodule encephalitis, but the clinical findings corresponding to this pathologic entity are not well defined. In contrast, the pathologic entity of cytomegalovirus ventriculoencephalitis, found almost exclusively in patients with advanced HIV infection, has distinct clinical features that allow recognition even in patients with HIV encephalopathy. Polymerase chain reaction has been shown to be useful for diagnosis of cytomegalovirus encephalitis. CONCLUSIONS: Cytomegalovirus encephalitis is an important opportunistic infection in HIV-infected patients but is rarely recognized in other groups. Cytomegalovirus ventriculoencephalitis has emerged as a unique entity in patients with advanced HIV infection. Recent developments in diagnostic techniques allow early recognition and may make more aggressive approaches to therapy possible.     

Brain stem encephalitis in childhood

OBJECTIVE: To present two cases of post-infectious encephalitis of the brain stem (ETC) in infancy, which is very infrequent at this age. CLINICAL CASES: Two patients aged 4 months and 9 months respectively had a previous history of a catarrhal illness a few days before the onset of encephalitis. The clinical condition was of subacute onset and torpid course, characterized by ataxia, reduced level of consciousness, involvement of the pyramidal tracts and paralysis of the cranial nerves. No significant information for the diagnosis of either case was obtained from CT. MR showed lesions at the level of the pons. However, the MR image did not correspond in seventy to the clinical condition. The clinical courses of the two patients were different. One case recovered with no sequelae. In the other case the cranial nerves and gait did not return to normal. CONCLUSIONS: In our experience, ETC is rarely seen in infancy. A high degree of suspicion and early treatment of ETC caused by the herpes simplex virus is necessary, since there is usually a high mortality or serious neurological sequelae.     

Failure of acyclovir sodium therapy in herpes simplex encephalitis

Herpes simplex encephalitis is an important disease characterized by focal haemorrhagic necrosis of the temporal and frontal lobes of the brain. The mortality rate may be as high as 70% of untreated cases. Isolation of the virus from brain tissue is the most reliable means of diagnosis. Although some non-invasive diagnostic modalities have been investigated, none is as reliable as brain tissue sampling. Despite acceptance that acyclovir sodium is the most effective drug for treatment, there is not a consensus on the dosage and duration of the antiviral therapy because some patients fail to respond and sometimes there is recurrence following therapy. We report a case of encephalitis in a previously normal host who died after a 13-day course of acyclovir therapy with isolation of HSV-type 1 from the brain post mortem.     

Acute encephalitis and bacterial meningitis in children in Aichi Prefecture (1984-1993)

A survey was performed of acute encephalitis and bacterial meningitis in infancy and childhood from 1984 to 1993 using a questionnaire directed to departments of pediatrics in large hospitals in Aichi prefecture. The case records for 391 patients with acute encephalitis including related diseases and 328 patients with bacterial meningitis were obtained from 63 hospitals. Of 391 patients with acute encephalitis, 224 were male and 167 were female. Of 328 patients with bacterial meningitis, 200 were male and 128 were female. Sex ratio were 1.3, 1.6 respectively. Of the patients, 52.4% of encephalitis and 84.8% of meningitis were under 4 years of age and 0 year olds made up 53.7% of the latter. The causes of these diseases were confirmed in 38.7% and 82.9% of the encephalitis and meningitis patients, respectively, etiologically. In encephalitis, rubella virus was the most frequent with 29 cases, followed by measles virus (27 cases), herpes simplex virus (24) and varicella-zostervirus (19). In meningitis H. influenzae (95 cases), S. pneumoniae (56), Group B streptococcus (41) and E. coli (27) were frequently diagnosed. These diseases showed respective patterns of age distribution and clinical course, and moreover, the increases in their onset were clearly related to the prevalence of causal infections. Therefore, the results of this study should be utilized in the development of administrative measures for prevention of these diseases.     

Measles inclusion-body encephalitis in a child with treated acute lymphoblastic leukaemia

A child with acute lymphoblastic leukaemia, being treated in the UKALL II Trial, had while in remission an attack of measles and made a normal recovery. Four months later she developed an acute encephalopathy and died within two weeks. The brain showed mild inflammatory features and widespread inclusion bodies in neurones and glial cells. Immunofluorescence proved an infection with measles virus. Similar cases have been called SSPE; reasons are given for preferring the term "measles inclusion-body encephalitis".     

Human cytomegalovirus (HCMV) encephalitis in an immunocompetent young person and diagnostic reliability of HCMV DNA PCR using cerebrospinal fluid of nonimmunosuppressed patients

Human cytomegalovirus (HCMV) encephalitis in adult nonimmunosuppressed patients has rarely been reported. We have diagnosed HCMV encephalitis in an anti-HCMV immunoglobulin G-negative, nonimmunosuppressed young woman by HCMV DNA PCR and virus isolation from cerebrospinal fluid (CSF). At the same time, HCMV antigen and HCMV DNA could be demonstrated in peripheral blood leukocytes, and the virus was isolated in fibroblast cultures. After 22 days of acute illness, the virus disappeared from the CSF. Remarkably, the patient did not generate detectable anti-HCMV antibodies within 5 months after the beginning of illness. To investigate the significance of HCMV DNA detection in CSF, samples of CSF, blood cells, and serum from 35 nonimmunosuppressed patients with various neurological disorders (but no herpes simplex virus central nervous system [CNS] disease) were tested for HCMV DNA, antigen, and antibodies. Eleven of these patients were found to be positive for virus DNA and/or antigen in peripheral blood leukocytes. Additionally, HCMV DNA was detected in the CSF of two patients with noninflammatory CNS diseases. A causative role of HCMV in the CNS diseases of these two patients was not evident. In summary, HCMV DNA amplification from CSF samples is a very suitable method to verify HCMV-associated encephalitis, but it should be taken into consideration that there are few cases of positive PCR with DNA from CSF without any known clinical correlative.     

Single-photon emission CT findings in acute Japanese encephalitis

PURPOSE: To determine the usefulness of single-photon emission CT (SPECT) in the diagnosis of acute Japanese encephalitis (JE). METHODS: We examined 10 patients (six men and four women; mean age, 69 years) with viral encephalitis. We divided the cases into two groups: the JE group (n = 4) and the non-JE group (n = 6; two with herpes simplex encephalitis and four with encephalitis of unknown origin). All cases were investigated with 99mTc-hexamethylpropyleneamine oxime (HMPAO) SPECT within 15 days after the onset of symptoms. Two patients in the JE group were also examinated by SPECT at a later stage. In all cases MR imaging was performed after the SPECT study. RESULTS: In the acute stage, all patients in the JE group showed a marked increase of HMPAO uptake that matched the hyperintense area observed on MR images in the thalami and putamina bilaterally. Follow-up SPECT studies of two patients with JE revealed a decrease of HMPAO deposition in the areas of high uptake. None of the patients in the non-JE group had an increased accumulation of HMPAO in the thalami or the putamina. CONCLUSIONS: SPECT is helpful in differentiating JE from herpes simplex encephalitis and other types of encephalitis. SPECT may be useful as a diagnostic tool in the early stages of JE.     

Poliomyelitis-like illness due to Japanese encephalitis virus

BACKGROUND: Acute flaccid paralysis remains common among Vietnamese children despite a pronounced fall in the incidence of poliomyelitis. METHODS: During 1995, all 22 children presenting with acute flaccid paralysis to a referral centre in Ho Chi Minh City, Vietnam, had virological cultures and antibody measurements done on serum, cerebrospinal fluid, and faeces. A year later the children were reassessed and electrophysiological studies were done. FINDINGS: Wild poliovirus type 1 was isolated from the faeces of only one patient, and non-polio enteroviruses from three patients. 12 (55%) of the 22 children with acute flaccid paralysis had evidence of acute Japanese encephalitis virus (JEV) infection, compared with only one (1%) of 88 age-matched hospital controls (children with diphtheria; p<0.0001). Compared with JEV-negative patients, weakness in JEV-infected children was more rapid in onset, tended to be asymmetrical, but was less likely to involve the arms. All 12 children with JEV infection were febrile at the onset of weakness, seven had acute retention of urine, and ten had CSF pleiocytosis. Seven of eight JEV-negative patients met the case-definition of Guillain-Barré syndrome, compared with only one of 12 JEV-positive children. At follow-up, patients with JEV infection had greater disability and were more likely to have muscle wasting than were JEV-negative children. Nerve conduction and electromyographic studies indicated damage to the anterior horn cells. INTERPRETATION: JEV causes an acute flaccid paralysis in children that has similar clinical and pathological features to poliomyelitis. In endemic areas, children with acute flaccid paralysis should be investigated for evidence of JEV infection.     

Photoperiodic modulation of monoamines and amino-acids involved in the control of prolactin and LH secretion in the ewe: evidence for a regulation of tyrosine hydroxylase activity

The aim of this study was to analyse medico-legal autopsy rates among Norwegian citizens who died in the two northernmost counties of Norway during the 20-year period 1973-1992. Medico-legal autopsy rate was defined as the number of medico-legal autopsies divided by the total number of deaths. The rates were calculated according to year of death, manner of death, sex, age, police district and county. The material included 1539 medico-legal autopsies. In the total 20-year period 37.9% (n = 1113) of the violent deaths and 1.2% (n = 426) of the natural deaths were subjected to medico-legal autopsy. The annual rates increased gradually up to 1987. In the last 5-year period 51.7% of the violent deaths and 2.1% of the natural deaths were subjected to medico-legal autopsy. Among violent deaths in this period the medico-legal autopsy rates were: suicides 65.7%, motor vehicle traffic accidents 58.3%, falls 8.6%, and other violent deaths 77.1%. Females dying after a fall and due to natural causes were significantly less frequently than males subjected to medico-legal autopsy. These two categories of death also revealed a significant decrease in autopsy rate with increasing age (age group 0-29, 30-59 and > or = 60 years) in each 5-year period. In cases of violent death the medico-legal autopsy rate according to police district varied from 24.1% to 88.9% in the last 5-year period. In conclusion, medico-legal autopsy rates depended on manner of death, sex, age and police district, besides changes in legislation.     

Anterior opercular syndrome, caused by herpes simplex encephalitis

Bilateral frontal and parietal opercular lesions cause a syndrome characterized by paralysis of the masticatory, facial, pharyngeal, and tongue muscles (the anterior opercular syndrome). The anterior opercular syndrome can occur in patients with herpes simplex encephalitis (HSE), but in most of these patients the diagnosis of HSE was not confirmed. We describe the anterior opercular syndrome in four patients with HSE. In two of these patients, the anterior opercular syndrome dominated the clinical picture, but in the other two patients it was overshadowed by other manifestations of HSE. The diagnosis of HSE was confirmed by detection of herpes simplex virus (HSV) DNA in the CSF (two patients), culture of the HSV from a brain biopsy (one patient), and elevated HSV antibody titers in the CSF (one patient). Our patients made a partial recovery. Acute onset of weakness of masticatory, facial, pharyngeal, and glossal muscles, accompanied by fever, headache, and partial motor seizures of the face should suggest HSE.     

The prevention of tick-borne encephalitis (author's transl)

Tick-borne encephalitis is one of the most frequently-encountered virus diseases of the central nervous system in Europe. Hence, prophylactic measures for the prevention of tick-borne encephalitis are of particular importance, especially since it is virtually impossible to influence the course of the manifest disease by means of current therapeutic procedures. Moreover, complications (paralysis and other sequelae) are frequent. A recently-developed vaccine (killed virus) is capable of providing easy and long-lasting protection for a large part of the population. The safety and efficacy of the vaccine was proved in 30,000 persons who were vaccinated in a field trial. Wide-scale implementation may be recommended mainly for persons under regular exposure, but also for the protection of people remaining in an endemic area for a short time only. However, if immediate protection of non-immunised persons is required, i.e. persons who discover ticks on their body or who show the presumptive signs of an existing virus infection, passive immunisation with tick-borne encephalitis immune globulin is recommended.     

Causes of death in autosomal dominant polycystic kidney disease

To determine the causes of death in autosomal dominant polycystic kidney disease (ADPKD) patients and to examine whether the extrarenal manifestations of ADPKD influence the causes of death, the medical records of 129 patients who died between 1956 and 1993 were reviewed; 58% of the 129 patients had an autopsy performed. Seventy-seven percent died after reaching ESRD. The mean age at death increased from 51 yr for those who died before 1975 to 59 yr for those who died after 1975, reflecting the introduction of renal replacement therapies. The most common cause of death before 1975 was infection (30%), followed by uremia (28%) and cardiac disease (21%); after 1975, these were cardiac disease (36%) and infection (24%). Infection was equally prevalent before and after 1975, presenting as sepsis in 94% and directly relating to ADPKD in 47% of these patients. Underlying factors for cardiac death were cardiac hypertrophy, seen in 89% of all autopsied patients, and coronary artery disease, seen in 81%. A neurologic event was the cause of death in 12% of patients; these were ruptured intracranial aneurysm in 6%, hypertensive intracranial hemorrhage in 5%, and ischemic stroke in 1%. The mean age of those who died of ruptured intracranial aneurysm was 37 yr. No patient died of renal cancer. Liver cysts were the most common extrarenal manifestation, seen in 70% of the autopsied cases; cysts in other organs were very rare. Colonic diverticula were found in 21%. Thus, the renal and extrarenal manifestations of ADPKD are important contributors to morbidity and mortality.     

Cytokines and other markers of intrathecal immune response in patients with herpes simplex encephalitis

Sequential samples of serum and cerebrospinal fluid (CSF), from 9 patients with herpes simplex encephalitis (HSE), were analyzed for cytokines and soluble cytokine receptors. The response to herpes simplex virus was characterized by a vigorous compartmentalized immune response. The intrathecal response comprised three different phases: an acute stage (first week of illness), characterized by elevated CSF levels of interleukin (IL)-6 and interferon-gamma; an early convalescence stage (weeks 2-6 after onset of disease), associated with peaking levels of tumor necrosis factor-alpha and late markers of the specific T cell-mediated immune response, soluble IL-2 receptor, and soluble CD8 antigen (sCD8); and finally, a late convalescence stage, lasting months to years and associated with persistently increased levels of sCD8 in particular. These findings show the compartmentalization and kinetics of the inflammatory response in HSE and demonstrate persistence of the intrathecal inflammatory process, which may have implications for antiviral and antiinflammatory therapy.     

Ticks, Lyme disease spirochetes, trypanosomes, and antibody to encephalitis viruses in wild birds from coastal Georgia and South Carolina

Ticks and blood samples were collected from wild birds mist-netted on St. Catherine's Island, Georgia, and at the Wedge Plantation in coastal South Carolina in 1994 and 1995. Immature stages of 5 species of ixodid ticks were recovered from 10 of 148 (7%) birds belonging to 6 species in Georgia, whereas 6 ixodid species were recovered from 45 of 259 (17%) birds representing 10 avian species in South Carolina. Borrelia burgdorferi sensu lato was isolated from 27 of 120 (23%) screened ticks (Ixodes scapularis and Ixodes minor) recovered from South Carolina birds, but from none of 16 screened ticks removed from Georgia birds. This spirochete was also isolated from 1 of 97 (1%) birds in South Carolina. In 1995, neither eastern equine encephalitis (EEE) virus nor St. Louis encephalitis (SLE) virus was isolated from any of 218 bird sera screened, but serum neutralizing antibodies were found to EEE virus in 4 of 121 (3%) sera and to SLE virus in 2 of 121 (2%) sera from South Carolina. No antibody to either virus was detected in 51 avian sera screened from Georgia. Trypanosomes (probably Trypanosoma avium) were isolated from 1 of 51 (2%) birds from Georgia and from 13 of 97 (13%) birds from South Carolina. Our data suggest that some wild birds may be reservoir hosts for the Lyme disease spirochete and for encephalitis viruses in coastal Georgia and South Carolina and that migrating birds can disperse immature ticks infected with B. burgdorferi.     

Chemokines and receptors in HIV encephalitis

BACKGROUND: Chemokines are involved in the migration of leukocytes and have been implicated in several inflammatory diseases of the central nervous system. Some of their receptors have been proposed to mediate HIV infection. OBJECTIVE: To determine changes in chemokine and receptor expression in HIV encephalitis, and to determine whether upregulation leads to recruitment of infected monocytes across the blood-brain barrier and participates in HIV neuropathology. METHODS: Immunocytochemistry and double-label immunofluorescent laser confocal microscopy was performed with antibodies to chemokines and their receptors on brain tissues from patients who died with or without HIV encephalitis. In vivo distribution was compared with in vitro cultures of human neuroglial cells. RESULTS: The beta-chemokines monocyte chemotactic protein-1, macrophage inflammatory protein-1alpha, and RANTES were detected on brain macrophages. Their presence was associated with the histopathological signs of HIV encephalitis. The alpha-chemokines IP-10 (10 kDa inflammatory protein) and interleukin-8 were expressed by astrocytes in all tissues, including controls. Presence of the CXC-chemokine receptor (CXCR)-4 was seen on brain macrophages/microglia, neurons, and astrocytes. CC-Chemokine receptor (CCR)-5 was detected only on macrophages/microglia. CCR-3 and CCR-1 were expressed by macrophages and endothelial cells. In vitro studies examining the presence of CCR-3, CCR-5, and CXCR-4 on human brain cell cultures demonstrated abundant neuronal and microglial expression. CONCLUSIONS: Expression of a variety of chemokines and receptors was shown to be increased in HIV encephalitis brain tissues particularly in areas of neuroglial reaction. The expression pattern supported their involvement in the recruitment of inflammatory infiltrates and formation of microglial nodules. Presence of chemokine receptors on neurons may be involved in the pathogenesis of neurologic damage in AIDS patients.     

Encephalitis in ferrets caused by a nonproductive strain of measles virus (D.R.) isolated from patient with subacute sclerosing panencephalitis

A nonproductive, syncytiogenic strain (D.R.) of measles virus, isolated from a patient with subacute sclerosing panencephalitis (SSPE), was inoculated intracerebrally into ferrets in an attempt to induce subacute encephalitis. Inoculation of freeze-thawed syncytia before immunization was the least effective procedure, and inoculation of live syncytia after immunization with measles virus vaccine was the most effective procedure, for induction of subacute or persistent subclinical encephalitis in the animals. After the latter procedure three of five ferrets developed subacute or subclinical encephalitis, whereas ferrets inoculated with live syncytia without prior immunization consistently contracted acute fatal encephalitis in one to two weeks. The subacute encephalitis in ferrets was characterized by high titers of antibody to measles virus in serum. At the time of sacrifice 1.25, 4.5, or 8.0 months after inoculation, brains of the ferrets showed histologic lesions similar to those characteristic of SSPE, and nonproductive syncytiogenic measles virus was recovered from the brains of two of the animals. All three ferrets had greatly increased concentrations of gamma-globulin in their brains and high levels of neutralizing and hemagglutination-inhibiting antibodies to measles virus. Only one of these animals developed clinical signs 1.25 months after inoculation.