Encephalitis Of Unknown Aetiology Research Articles

Ecological and clinical evidence of the establishment of West Nile virus in a large urban area in Europe, Berlin, Germany, 2021 to 2022.

BackgroundWest Nile virus (WNV), found in Berlin in birds since 2018 and humans since 2019, is a mosquito-borne virus that can manifest in humans as West Nile fever (WNF) or neuroinvasive disease (WNND). However, human WNV infections and associated disease are likely underdiagnosed.AimWe aimed to identify and genetically characterise WNV infections in humans and mosquitoes in Berlin.MethodsWe investigated acute WNV infection cases reported to the State Office for Health and Social Affairs Berlin in 2021 and analysed cerebrospinal fluid (CSF) samples from patients with encephalitis of unknown aetiology (n=489) for the presence of WNV. Mosquitoes were trapped at identified potential exposure sites of cases and examined for WNV infection.ResultsWest Nile virus was isolated and sequenced from a blood donor with WNF, a symptomatic patient with WNND and a WNND case retrospectively identified from testing CSF. All cases occurred in 2021 and had no history of travel 14 days prior to symptom onset (incubation period of the disease). We detected WNV in Culex pipiens mosquitoes sampled at the exposure site of one case in 2021, and in 2022. Genome analyses revealed a monophyletic Berlin-specific virus clade in which two enzootic mosquito-associated variants can be delineated based on tree topology and presence of single nucleotide variants. Both variants have highly identical counterparts in human cases indicating local acquisition of infection.ConclusionOur study provides evidence that autochthonous WNV lineage 2 infections occurred in Berlin and the virus has established an endemic maintenance cycle.

Polymorphism of autoimmune encephalitis

This review analyses the current understanding and diagnostic approaches to the management of patients with autoimmune encephalitis. Cellular and synaptic targets, involved in the pathological process in autoimmune encephalitis, are described. The presence of clinical and immunological differences in the pathology is emphasized: on the one hand, non-structural damage to the nervous system is combined with the subacute development of cognitive impairment, epileptic and psychopathological syndromes, which, on the other hand, are associated with polymorphic immunological heterogeneity. The algorithm for clinical and laboratory diagnosis is described, based on our own clinical observations of three patients. The first patient was diagnosed with a cross-autoimmune syndrome with a combination of Hodgkin’s lymphoma and anti-NMDA encephalitis, probably triggered by the reactivation of the Epstein–Barr virus with a fatal outcome. The second patient was diagnosed with autoimmune anti-LGI1 limbic encephalitis, and the third patient was seronegative to the available immunological antigens. The authors note the need to rethink the concept of ‘encephalitis of unknown aetiology’ and its transformation into ‘autoimmune encephalitis’ with the immunological diagnosis of three antigens (NMDA, LGI1, CASPR2). Considering the rarity of the disease, the high probability of initial admission to an infectious diseases or psychiatric hospital, it is worthwhile to explore this problem more widely at various research forums and to create a comprehensive, interdisciplinary approach to the diagnosis of this disease in the Russian Federation.

First reported cases of anti-NMDA receptor encephalitis in Vietnamese adolescents and adults

IntroductionAnti-NMDA receptor encephalitis is increasingly recognised as an important differential diagnosis in patients with encephalitis of unknown aetiology. We report the first case series of patients diagnosed in Vietnam. MethodsSamples of CSF from patients with presumed encephalitis but negative microbiological investigations, who exhibited dyskinesia, autonomic instability or psychosis were tested for antibodies against the NR1 subunit of the glutamate (type-NMDA) receptor using an indirect immunofluorescence assay. ResultsOf 99 patients admitted with all-cause encephalitis over an 18month period, 9.1% (n=9 patients, 5 female, median age 28years) had confirmed NMDAR encephalitis. All patients were admitted from one mental health hospital, and the incidence may therefore be an underestimate. Common features included reduction in speech (n=9), catatonia (n=9), convulsions (n=7), dyskinesia (n=9), rigidity (n=9) and autonomic dysfunction (n=7). Aside from a modest lymphocytic pleocytosis, routine CSF analysis was usually normal. No female patient had ovarian teratoma detected by abdominal ultrasound. Most patients were treated with high dose corticosteroids, and one patient received intravenous immunoglobulin. The median duration of hospitalization was 75days and no patient died during admission. ConclusionsAnti-NMDA receptor encephalitis is an important differential diagnosis to consider for patients presenting with acute onset psychiatric symptoms, who develop ensuing seizures, movement or autonomic disorder in Vietnam. A stronger evidence base for management and access to second line immunotherapy agents may help to reduce morbidity from this disease.

Long-term outcome of acute encephalitis of unknown aetiology in adults

AbstractEncephalitis is caused by a variety of conditions, including infections of the brain by a wide range of pathogens. A substantial number of cases of encephalitis defy all attempts at identifying a specific cause. Little is known about the long-term prognosis in patients with encephalitis of unknown aetiology, which complicates their management during the acute illness. To learn more about the prognosis of patients with encephalitis of unknown aetiology, patients in whom no aetiology could be identified were examined in a large, single-centre encephalitis cohort. In addition to analysing the clinical data of the acute illness, surviving patients were assessed by telephone interview a minimum of 2 years after the acute illness by applying a standardized test battery. Of the patients with encephalitis who qualified for inclusion (n = 203), 39 patients (19.2%) had encephalitis of unknown aetiology. The case fatality in these patients was 12.8%. Among the survivors, 53% suffered from various neurological sequelae, most often attention and sensory deficits. Among the features at presentation that were associated with adverse outcome were older age, increased C-reactive protein, coma and a high percentage of polymorphonuclear cells in the cerebrospinal fluid. In conclusion, the outcome in an unselected cohort of patients with encephalitis of unknown aetiology was marked by substantial case fatality and by long-term neurological deficits in approximately one-half of the surviving patients. Certain features on admission predicted an unfavourable outcome.

Encefalitis por Rickettsia conorii sin exantema

Mediterranean boutonneuse fever, caused by Rickettsia conorii, is an endemic disease in the Mediterranean area. The serious forms of the disease, which include encephalitis, are infrequent but are associated with a high mortality rate. Diagnostic suspicion is backed up by the development of exanthema. We report the case of a patient who developed encephalitis caused by Rickettsia conorii without exanthema. Clinical case. A 27 year old woman who had nauseas, headache, fever, abdominal upset and generalised pain during the days before being admitted to hospital. On the day she was admitted, she noticed reduced strength in the left limbs, together with numbness and pins and needles in the left side of the body. In the casualty department she presented tonic seizures in the left extremities and later generalised tonic clonic seizures. Exploration showed facial paresis and 4/5 hemiparesis on the left side. Complementary tests carried out in casualty, including cerebrospinal fluid (CSF), did not reveal any significant findings. She was admitted after a loading dose of phenytoin. After 48 hours she presented fever and repeated complex partial seizures. A new CSF analysis was normal. She was treated with valproate, clonazepam, ceftriaxone, doxycycline and acyclovir. An electroencephalogram (EEG) showed theta activity in the left centroparietal areas and slow delta waves in the right temporal regions. Magnetic resonance imaging (MRI) of the brain showed contrast enhancement in the meninges. 24 later, due to the frequency of the seizures, phenobarbital and methylprednisolone were added, which enabled the seizures to be controlled. The posterior brain MRI revealed a right parasylvian lesion. Serological Rickettsia conorii IgM +, IgG 1/256 was administered. After eight months, she has presented no seizures or neurological deficit. There are cases of encephalitis from Rickettsia conorii that can present without exanthema. This means that in endemic areas early treatment with doxycycline could be advisable when faced with encephalitis of unknown aetiology, bearing in mind the high mortality rate that occurs when no early treatment is administered and the good tolerance to doxycycline.

Stereotaxic brain biopsy in AIDS patients: does it contribute to patient management?

The authors analysed all cases of brain biopsy done in AIDS or HIV+patients at the Department of Clinical Neurosciences, Western General Hospital, Edinburgh, during the period 1989-92 to determine the clinical utility of the procedure. Thirteen lesions were biopsied revealing toxoplasmosis in five, lymphoma in four, progressive multifocal leucoencephalopathy in three, HIV encephalitis in two and encephalitis of unknown aetiology in one. One biopsy specimen contained abnormal tissue but was non-diagnostic. The median survival after biopsy was only 7 weeks, but preoperative immunological (median CD4 count 45) and clinical status of the patients were poor. Although the impact of tissue diagnosis on patient survival was minimal it did enable modification of drug therapy. The authors preliminary experience with biopsy in AIDS patients suggests that the diagnostic information obtained is of limited value in prolonging the lives of patients in poor immunological status, but may be useful in refining medical therapies for toxoplasmosis and progressive multifocal leucoencephalopathy. Whether biopsy should be performed earlier in the course of cerebral disease in an effort to prolong survival time remains unclear.

Acute viral encephalitis: its diagnosis and outcome.

Sixty patients with acute viral encephalitis admitted to The London Hospital in the last fifteen years have been reviewed. These consisted of 12 patients with known viral infection, 29 patients with acute viral infection of undetermined type, and 19 patients in whom an encephalitic illness followed a viral infection (post-infection encephalitis). The patients with primary viral encephalitis presented with an inflammatory brain disorder, including headaches and fever, and developed focal or diffuse neurological signs. Patients with post-infection encephalitis, usually following a 'flu'-like illness, presented with an acute neurological disturbance. The results of investigations, including virological studies, CSF examination, electroencephalography and neuroradiology, are described. Biopsy or autopsy material was available in 11 patients and these pathological findings supported the clinical classification of these patients. The mortality was highest in patients with herpes simplex virus encephalitis and lowest in patients with post-infection encephalitis. A considerable morbidity was found, not only in patients with primary viral encephalitis, but also in patients with encephalitis of unknown aetiology and post-infection encephalitis.