[Weston-Hurst syndrome. A case report and literature review]

Background

Acute disseminated encephalomyelitis is an autoimmune and demyelinating disease. It is rare in adults. It has 3 main variants. One of them is Weston-Hurst syndrome, also called acute hemorrhagic leukoencephalitis. The objective was to share the experience in the diagnostic and therapeutic approach of this rare disease, as well as make a review of the current bibliography, in order to collaborate in the knowledge of this disease.

Clinical case

27-year-old woman, with a viral respiratory infection 2 weeks prior to the development of a neurological syndrome characterized by paresthesia, motor deficit, status epilepticus and acute encephalopathy, progressing rapidly to coma, with evidence in MRI of diffuse hemorrhagic lesions in cerebral white matter with demyelination and peripheral edema. It was administered steroid treatment for 5 days, with improvement of symptoms, but with motor and sensory deficits persisting.

Conclusion

Acute disseminated encephalomyelitis and its variants are rare entities, with an important range of differential diagnosis, which must be identified and quickly treated to avoid their lethal or disabling outcome.

[Acute hemorrhagic leukoencephalitis with a subacute onset]

Acute hemorrhagic leukoencephalitis (AHLE), also called Hurst's encephalitis, is a rare demyelinating disease of the central nervous system characterized by rapid progression and acute inflammation of the white matter of the brain and spinal cord. AHLE is currently considered as a rare, most severe variant of acute disseminated encephalomyelitis. Clinically AHLE is characterized by a fulminant course with a rapid development of encephalopathy and multifocal neurological symptoms. AHLE is associated with high mortality rate that requires immediate and aggressive treatment initiation. This article describes a case of AHLE with an atypical course, a subacute form, which is extremely rarely described in the literature, with the progressive symptoms' development over several months. Due to delayed treatment initiation, unfortunately, a fatal outcome has been observed. Subsequent histological examination of the autopsy material confirmed the presence of a subacute form of AHLE in the patient.

Roles of Nucleoporin RanBP2/Nup358 in Acute Necrotizing Encephalopathy Type 1 (ANE1) and Viral Infection

Ran Binding Protein 2 (RanBP2 or Nucleoporin358) is one of the main components of the cytoplasmic filaments of the nuclear pore complex. Mutations in the RANBP2 gene are associated with acute necrotizing encephalopathy type 1 (ANE1), a rare condition where patients experience a sharp rise in cytokine production in response to viral infection and undergo hyperinflammation, seizures, coma, and a high rate of mortality. Despite this, it remains unclear howRanBP2 and its ANE1-associated mutations contribute to pathology. Mounting evidence has shown that RanBP2 interacts with distinct viruses to regulate viral infection. In addition, RanBP2 may regulate innate immune response pathways. This review summarizes recent advances in our understanding of how mutations in RANBP2 contribute to ANE1 and discusses how RanBP2 interacts with distinct viruses and affects viral infection. Recent findings indicate that RanBP2 might be an important therapeutic target, not only in the suppression of ANE1-driven cytokine storms, but also to combat hyperinflammation in response to viral infections.

Non-fatal acute haemorrhagic leukoencephalitis following snake bite: A case report

Acute haemorrhagic leukoencephalitis (AHL) is a fulminant inflammatory disease of cerebral white matter, characterised by demyelination and haemorrhagic necrosis. The outcome is usually fatal with only few survivors. An unusual presentation of a 44-year-old South Indian farmer who developed AHL following a snake bite is reported. Though the initial brain imaging showed extensive involvement of the white matter with multiple haemorrhagic foci, the patient improved spontaneously with no specific therapy. A repeat magnetic resonance imaging of the brain 28 days after the snake bite confirmed radiological improvement.

A 7-year-old boy dying of acute encephalopathy

A 7 year old Chinese boy died of a rapidly progressive encephalopathy after influenza infection. MRI showed bilateral and symmetrical lesions including the thalamus and brainstem tegmentum. The pathology of necrosis and vasculopathy were in keeping with acute necrotizing encephalopathy (ANE). ANE was first described in Japan and carries a high mortality and morbidity. A vasculopathy with breakdown of the blood-brain-barrier was incriminated but the pathogenesis remained obscure and autopsy studies have been limited. A review of the literature showed only nine postmortem reports in the acute stage. Symmetrical brain necrosis always involved the thalamus followed by the tegmentum of the pons and other regions. Exudative vasculopathy was commonly observed and often accompanied by endothelial cell necrosis. In the present case there was inflammatory fibrinoid vasculitis which has not been previously described.

Clinical spectrum and prognostic factors of acute necrotizing encephalopathy in children

This study was conducted to investigate the etiology, the clinical characteristics and prognosis of acute necrotizing encephalopathy (ANE) in Korean children. Six children (1 yr to 7 yr) patients with ANE were enrolled. They were diagnosed by clinical and radiological characteristics and their clinical data were retrospectively analyzed. In a search of clinically plausible causes, brain MRI in all patients, mitochondrial DNA studies for mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes (MELAS) and myoclonus epilepsy and ragged red fibers (MERRF) in four patients, and genomic typing on HLA DRB/HLA DQB genes in three patients were performed. All had precedent illnesses and the main initial symptoms included mental change (83%), seizures (50%), and focal deficits (50%). MRI revealed increased T2 signal density in the bilateral thalami and/or the brainstem in all patients. Mitochodrial DNA studies for MELAS and MERRF were negative in those children and HLA-DRB1*1401, HLA-DRB3*0202, and HLA-DQB1*0502 seemed to be significant. A high dose steroid was given to all patients, which seemed to be partly effective except for 2 patients. In conclusion, ANE is relatively rare, but can result in serious neurological complication in children. Early detection and appropriate treatment may lead to a better neurological outcome.

Use of therapeutic plasma exchange in the management of acute hemorrhagic leukoencephalitis: a case report and review of the literature

BACKGROUND

Acute hemorrhagic leukoencephalitis (AHLE) is a rare, fatal, central nervous demyelinating disease characterized by a rapid fulminant clinical course. Successful management requires early diagnosis, aggressive management of cerebral edema, and immunosuppression. Therapeutic plasma exchange (TPE) is infrequently used and commences after initial management fails.

CASE REPORT

A 31-year-old man presented with right arm weakness, whose symptoms rapidly progressed to hemiplegia and aphasia. The patient was initially managed with glucocorticosteroids. Decompressive craniotomy and brain biopsies were performed when his intracranial pressure increased. Brain biopsy findings were consistent with AHLE. Mycoplasma pneumonia immunoglobulin G and immunoglobulin M serologies revealed recent infection. Despite surgical and medical management, he decompensated on Day 11, and TPE was initiated. The patient received a total of 10 TPE treatments. On the fourth day of TPE treatment, he was extubated. Twenty-one days after TPE began, he was ambulating with near normal muscle strength and was discharged. Four months after initial presentation, the patient has normal strength and is working full-time.

CONCLUSIONS

AHLE has a fulminant course requiring accurate and rapid diagnosis. Successful therapy requires aggressive management of intracranial pressure and immunosuppression. Two other reports of AHLE document successful management with TPE. Each of these patients survived with minimal neurologic impairments. Given the likely immune-mediated nature of this disease, combined treatment of steroids, surgery, and TPE may lead to shorter hospital stays and improved neurologic outcomes. Clinical studies are needed to further study the effect of TPE on neurologic outcome in AHLE.

Transplacental infection of Coxsackievirus B3 pathological findings in the fetus

Coxsackievirus intrauterine infection has been documented mostly on the basis of indirect evidence of transplacental transmission, with neonatal manifestations ranging from asymptomatic infection to meningoencephalitis, myocarditis, and generalized sepsis. This is the first report of prenatal findings and fetoplacental pathology in a third trimester fetus with coxsackie B3 transplacental infection confirmed by molecular techniques. Prenatal ultrasound detected severe reduction of fetal movements at the 27th week. Late onset fetal akinesia deformation sequence with mild arthrogryposis, necrotic meningoencephalitis with vascular calcifications, interstitial pneumonitis, mild myocardial hypertrophy, and chronic monocytic placental villitis were the cardinal findings at fetal autopsy following interruption of the pregnancy.

[Hurst acute haemorrhagic leukoencephalitis: MRI findings]

A case of autopsy-proven acute hemorrhagic leukoencephalitis is reported. Early magnetic resonance imaging showed extensive bilateral asymmetrical demyelinating lesions and foci of microhemorrhage sparing the cortex ribbon. Fulminant disease culminated in coma and death within twenty-four hours. A comprehensive correlation between pathological findings of acute haemorrhagic leukoencephalitis and both classical and advanced neuroimaging findings is provided.

Severe Necrotizing Encephalitis in a Yorkshire Terrier: Topographic and Immunohistochemical Study

Necrotizing encephalitis of the Yorkshire terrier is a chronic non-suppurative encephalitis that was reported in approximately 15 cases worldwide. We report the case of a 10-year-old female Yorkshire terrier with gross evidence of severe cortical degeneration and necrosis. Microscopically, affected areas were mainly located in the cortical white matter and in the mesencephalon without implication of the cerebellum. Cavitation necrosis, demyelination, gemistocytic astrocytosis, marked perivascular lymphocytic cuffing with a diffuse lymphocytic/histiocytic/gitter cell infiltration characterized the lesions. Immunohistochemical analysis identified the major infiltration of T lymphocytes and macrophages with implication of some cytotoxic lymphocytes and IgG-producing plasma cells; depositions of IgG in the affected white matter were also observed. Specific stains did not reveal fungal, protozoal or bacterial organisms and reverse transcriptase-polymerase chain reaction analysis for distemper virus was also negative. The lympho-histiocytic inflammation suggests a T-cell-mediated and a delayed-type immune reaction as a possible pathogenic mechanism for this brain disorder.

Acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated inflammatory disorder of the CNS characterized by a widespread demyelination that predominantly involves the white matter of the brain and spinal cord. The condition is usually precipitated by a viral infection or vaccination. The presenting features include an acute encephalopathy with multifocal neurologic signs and deficits. Children are preferentially affected. In the absence of specific biologic markers, the diagnosis of ADEM is still based on the clinical and radiologic features. Although ADEM usually has a monophasic course, recurrent or multiphasic forms have been reported, raising diagnostic difficulties in distinguishing these cases from multiple sclerosis (MS). The International Pediatric MS Study Group proposes uniform definitions for ADEM and its variants. We discuss some of the difficulties in the interpretation of available literature due to the different terms and definitions used. In addition, this review summarizes current knowledge of the main aspects of ADEM, including its clinical and radiologic diagnostic features, epidemiology, pathogenesis, and outcome. An overview of ADEM treatment in children is provided. Finally, the controversies surrounding pediatric MS and ADEM are addressed.

Acute necrotizing encephalopathy of childhood in non-Asian patients: report of three cases and literature review

Acute necrotizing encephalopathy of childhood is a novel type of parainfectious encephalopathy with a racial and geographic predilection, rarely reported from other than East Asian areas. The objective was to describe the clinical, imaging, and other laboratory findings of non-Asian patients with acute necrotizing encephalopathy. Data were collected from three patients diagnosed in Athens over a 4-year period plus 16 cases reported from other European and North American countries. One of the Greek children died, and the other two had a normal outcome. A neuropathologic examination in the fatal case showed edematous necrosis without inflammatory, reactive, or proliferative changes. Data from Greek and other non-Asian patients support the homogeneity of the disease worldwide.

Influenza a-associated acute necrotizing encephalopathy

Acute inflammatory processes of the brain tissue and meninges caused by viruses are relatively common and may be caused by a number of different viral agents. The specific etiological agent is not identified in many instances. Most cases completely recover. The prognosis depends upon the severity of the clinical illness, the specific etiology, and the age of the child. Acute necrotizing encephalopathy (ANE) is an important clinical type of encephalitis. In recent years, many cases of ANE caused by influenza A virus infection have been reported from different Eastern and European countries. In this paper we describe a young child with influenza A-associated ANE.

Magnetic resonance imaging and pathologic findings associated with necrotizing encephalitis in two Yorkshire terriers

Two young adult Yorkshire terriers had neurologic signs consistent with forebrain and brainstem involvement or forebrain involvement alone. On magnetic resonance imaging studies there were asymmetric bilateral lesions mainly in the cerebral cortex, and in the diencephalon. These areas were hyperintense on T2-weighted and FLAIR images, but hypointense or isointense on T1-weighted images. Lesions had a varying degree of contrast enhancement. Areas which were isointense on T1-weighted images had no contrast enhancement or only foci of contrast enhancement. Lesions with hypointensity in T1-weighted images had no enhancement or more frequently ring-like enhancement around the lesion. Necrotizing encephalitis was confirmed pathohistologically in both dogs. The degree of contrast enhancement appeared to be related to the degree of lymphohistiocytic inflammation on histologic examination.

Serial MR imaging findings of acute hemorrhagic leukoencephalitis: a case report

We report a patient with acute hemorrhagic leukoencephalitis with a focus on serial MR imaging findings. Initial MR imaging of a 42-year-old woman revealed a 2.5-cm focal nonhemorrhagic lesion in the left thalamus and internal capsule. Twenty-four days later, fever and altered consciousness developed, and MR imaging showed huge masslike lesions in both frontal lobes, mainly involving the white matter and the genu of the corpus callosum, with massive edematous swelling that contained multifocal small hemorrhages. Most lesions showed high apparent diffusion coefficient value with peripheral small areas of low apparent diffusion coefficient. On follow-up MR imaging obtained 49 days after initial MR imaging, the lesions progressed with increase in extent and development of rim-enhancing necrosis, despite steroid therapy. Following stereotactic biopsy and subsequent high-dose steroid treatment, the patient recovered with some neurologic sequelae. MR imaging obtained at 72 and 126 days revealed residual necrosis and cerebromalacia in the both frontal lobes.

Acute necrotizing encephalopathy in caucasian children: two cases and review of the literature

Acute necrotizing encephalopathy is a fulminant neurologic disease seen predominantly in Japan and Taiwan. We present two cases diagnosed at a Canadian center within the same year in Caucasian children. Both were previously well, developed an acute viral illness with fever and vomiting, and progressed to brain death within 2 to 4 days. Neuroimaging and postmortem examination demonstrated the unique features of bilateral and severe necrosis of deep gray- and subcortical white-matter structures. The first case was associated with extensive, but transient, hepatic involvement, recent varicella and rotavirus infections, and detailed metabolic studies, including mitochondrial functional analysis, were normal. The second case tested positive for influenza A infection, whereas evidence of liver damage was lacking. Both children demonstrated early lymphopenia and myocardial necrosis, two features not previously associated with acute necrotizing encephalopathy. These cases are unique in their occurrence in non-Japanese children and are among the first published reports in Canada.

Acute necrotizing encephalopathy in Korean infants and children: imaging findings and diverse clinical outcome

Objective

The purpose of our study was to describe acute necrotizing encephalopathy in Korean infants and children, and we sought to evaluate the prognostic factors.

Materials and Methods

Acute necrotizing encephalopathy was diagnosed in 14 Korean infants and children. We retrospectively analyzed the neuroimaging findings including the follow-up changes. The clinical course of the disease was graded, and we evaluated prognostic factors including age, serum level of the aminotransferase, hemorrhage, and localized atrophy of the brain.

Results

This encephalopathy predominantly affected the bilateral thalami (n=14), pons (n=12), and midbrain (n=10) in a symmetrical pattern. Hemorrhage was observed in eight patients (57%). On the follow-up images (n=12), the brain lesions were reduced in extent for all patients, and generalized atrophy was seen in six patients. Localized tissue loss was observed in five patients and a complete resolution occurred for one patient. All the patients survived and two recovered completely; mild (n=6) to severe (n=6) neurological deficits persisted in the remaining 12 patients. The significant prognostic factors identified in this study were the presence of hemorrhage (p = 0.009) and localized atrophy (p = 0.015).

Conclusion

Acute necrotizing encephalopathy in Korean patients showed the characteristic patterns of the post-infectious encephalopathy as described in the literature. The high survival rate and the relatively favorable clinical course observed for the present study suggest a more diverse spectrum of disease severity than was previously described. The presence of hemorrhage and localized tissue loss on MR images may suggest a poor prognosis.

Acute hemorrhagic leukoencephalitis (Hurst's disease) linked to Epstein-Barr virus infection

A 16-year-old girl presented signs of a common cold in combination with a hemolytic crisis. Within 3 days, she developed reduced consciousness and hemiparesis subsequently followed by coma. CT and MRI scans revealed evidence for raised intracranial pressure and an extensive inflammatory process extending from the brain stem up to the thalamus. The patient died within 3 weeks after onset of first symptoms of intracranial pressure despite maximum intensive care. Neuropathological examination revealed disseminated necrotic lesions and perivascular hemorrhages characteristic for acute hemorrhagic leukoencephalitis (Hurst's disease), mainly of the brain stem, diencephalon and cerebellum. Serological results, in situ hybridization and PCR analysis demonstrated an acute Epstein-Barr virus (EBV) infection of the central nervous system. To our knowledge, this is the first reported case of Hurst's disease linked to EBV.

Leukoencephalitis associated with selective viral replication in the brain of a pony with experimental chronic equine infectious anemia virus infection

Neurologic disease occurs sporadically in horses infected with the equine infectious anemia virus (EIAV). This report describes a case of clinically severe neurologic disease in a pony experimentally infected with EIAV. This pony did not have fever or anemia, which are the characteristic clinical signs of disease. The histopathologic changes were characterized as lymphohistiocytic periventricular leukoencephalitis. Polymerase chain reaction and in situ hybridization data showed that the brain lesions were directly associated with viral replication and that high-level viral replication occurred selectively within the lesion and not in other tissues. These findings suggest that EIAV-associated neurologic disease is the direct result of viral replication.

Evidence of axonal damage in human acute demyelinating diseases

Substantial axon damage, detected by immunostaining for beta amyloid precursor protein (betaAPP) has been demonstrated in acute demyelinating lesions in multiple sclerosis.

AIMS

The present study aimed to determine if this was also the case in the other human acute demyelinating diseases, acute hemorrhagic leucoencephalitis (AHLE), acute disseminated encephalomyelitis (ADEM) and central pontine myelinolysis (CPM).

METHODS

BetaAPP immunostaining was used as a marker of axonal damage in autopsy material from these conditions.

RESULTS

Axonal damage was detected in all these conditions. Its extent varied within and between them. Axonal damage was largely confined to tissue adjacent to veins and venules in AHLE and ADEM but was unrelated to proximity to these vessels in CPM.

CONCLUSION

Substantial axon damage occurs in fatal cases of AHLE, ADEM and CPM.

Acute haemorrhagic encephalomyelitis (AHEM): MRI findings

Acute disseminated encephalomyelitis (ADEM) comprises a group of demyelinating disorders of the CNS, of which a haemorrhagic variant indicates the most severe clinical course (AHEM). It is supposed to be caused by an overshooting immunological response following an infection or a vaccination. Restricted diffusion of protons could be demonstrated using DW-MRI in a case of rapidly progressive disease with additional haemorrhage. Hence, the addition of DWI adds to the diagnostic power of MRI in the setting of post-infectious demyelinating disorders of the CNS.

Acute fatal necrotizing hemorrhagic encephalitis caused by Epstein-Barr virus in a young adult immunocompetent man

Epstein-Barr Virus (EBV) encephalitis is a rare (<1%) and generally self-limited disease with few sequelae. This neurological complication has been reported almost exclusively in the course of acute primary infection and in paediatric patients. We describe a case of a young adult immunocompetent man who developed an acute fatal necrotizing haemorrhagic encephalitis as the only manifestation of an acute EBV infection. EBV-DNA was tested positive in several CSF samples by qualitative and quantitative PCR. Serological profile showed: absence of IgM against Viral Capsid Antigen (VCA) in three different consecutive samples, presence of IgG against VCA and IgG seroconversion for Epstein Barr Nuclear Antigen (EBNA). EBV-DNA was detected by qualitative PCR in autoptic brain material. Clinical course was not influenced by antiviral therapy with acyclovir. In conclusion to our knowledge, this is the only case of acute necrotizing haemorrhagic EBV encephalitis with a fatal outcome, in an adult immunocompetent man.

Relationship between lobar intracerebral hemorrhage and leukoencephalopathy associated with cerebral amyloid angiopathy: clinicopathological study of 64 Japanese patients

Cerebral amyloid angiopathy (CAA) has two major clinical manifestations: intracerebral hemorrhages and ischemic lesions. Among these, the lobar type of intracerebral hemorrhage (ICH) is a well-known clinical manifestation, while the CAA-related diffuse deep white matter degeneration known as leukoencephalopathy is thought to be rare. The characteristics of CAA-related leukoencephalopathy are still incompletely understood, and the relationship between lobar ICH and leukoencephalopathy in patients with CAA has not been properly clarified. The main purpose of this study is to elucidate the clinical and histopathological features of CAA-related lobar ICH and leukoencephalopathy in order to determine whether the degree of deep white matter degeneration parallels the severity of CAA-associated vasculopathies that lead to vascular wall rupture. We studied 64 Japanese patients with histopathologically proven amyloid beta protein (A beta) type CAA presenting with lobar ICH (52 biopsy and 12 autopsy). In this study, a total of 106 hematomas were observed. CAA-related cerebral hemorrhages tend to occur recurrently and multifocally. Multiple simultaneous labor hemorrhages occasionally developed (9.4%). CAA-related ICH in the sixth decade was not rare (14.1%). Although most patients suffered relapsing and/or multiple severe ICH, no patient in our series presented with diffuse leukoencephalopathy. In conclusion, A beta type cerebrovascular amyloid deposition causes recurrent, multifocal, and often multiple simultaneous ICH even in relatively younger elderly patients, but rarely produces diffuse leukoencephalopathy. This suggests that CAA-associated vasculopathies that cause vascular wall rupture do not always lead to ischemic deep white matter degeneration, and that there may be another unknown pathogenetic mechanism producing the latter CAA-related white matter lesion.

Autosomal dominant acute necrotizing encephalopathy

OBJECTIVE

To define the clinical and biochemical abnormalities of an autosomal dominant form of acute encephalopathy.

METHODS

The clinical details of 11 affected family members in comparison with 63 unaffected relatives were analyzed.

RESULTS

Affected children become comatose after onset of a febrile illness. Outcomes include full recovery, permanent neurologic impairment, and death. Recurrences produce more severe impairments. Lesions of necrotizing encephalopathy of the thalamus and brainstem are present on autopsy and MRI. Oxidative phosphorylation of intact mitochondria from a muscle biopsy shows loose coupling. Unaffected family members, including obligate carriers, share no clinical characteristics, demonstrating incomplete penetrance.

CONCLUSIONS

Characteristic pathology and MRI findings define this disorder of autosomal dominant acute encephalopathy. Leigh syndrome and sporadic acute necrotizing encephalopathy share similarities but are distinct.

[Acute infantile bilateral thalamic necrosis]

INTRODUCTION

Acute necrotizing encephalitis is a clinical entity recently described in previously healthy Japanese children. Following a respiratory or gastrointestinal infection of a viral nature, these patients present a sudden deterioration in the level of consciousness. Since neuroimaging shows a bilateral thalamic disorder in all cases, the name infantile bilateral thalamic necrosis has been put forward to refer to this affection.

CASE REPORT

We report the case of an 11 month old Spanish patient who was brought into the hospital with disconnection from the surroundings and hypertonia in the upper extremities, within the context of a febrile gastrointestinal picture. Blood sample analysis revealed haemoconcentration and metabolic acidosis, although it did not suggest an infection. The computerised tomography scan of the brain showed a striking hypodensity of both thalami. The initial hypertonia was followed by a generalised hypotonia, accompanied by haemodynamic and respiratory deterioration. The patient died 40 hours after admission.

CONCLUSIONS

Acute necrotizing encephalitis was initially described in Japanese children but in recent years isolated cases have also been reported in the Western world. In the case of the patient we have described, one of the most outstanding points is that evolution was unfavourable in spite of mechanical ventilation and the use of inotropic drugs, together with the clinical state of brain death that occurred on the second day after admission. Since neuroimaging showed a selective disorder of the thalami in all cases, and the fact it is an entity that affects small children, it seems more appropriate to use the term acute infantile thalamic necrosis

Detection of infectious agents in brain of patients with acute hemorrhagic leukoencephalitis

Acute hemorrhagic leukoencephalitis (AHL) is a rare and usually fatal disorder characterized clinically by an acute onset of neurologic abnormalities. It may occur in association with a viral illness or vaccination. Radiology and brain biopsy are essential for the diagnosis. The etiology of AHL is unclear. We postulated that viral/bacterial infection might be responsible, directly or through an immune-mediated mechanism, for this acute inflammatory myelinopathy. Fifteen cases of AHL were studied. Infectious agents, including varicella zoster virus (VZV), herpes simplex virus (HSV), human herpes virus-6 (HHV-6), cytomegalovirus, Epstein-Barr virus, and Mycoplasma, were investigated in brain specimens using the polymerase chain reaction (PCR), reverse transcriptase (RT)-PCR, and immunohistochemistry. Using PCR, HSV DNA was found in four cases, VZV DNA in two, and HHV-6 DNA in one. Among the control cases, two were HSV DNA positive. Further investigation to detect HSV RNA and antigens in HSV DNA-positive cases revealed that two cases with AHL were both HSV RNA and antigen positive. AHL is a hyperacute disease, which is considered the most acute form of acute disseminated encephalomyelitis (ADEM). Our findings suggests that a viral infection may be implicated in its pathogenesis, most likely through an indirect mechanism; however, as only a few cases of this rare disease were examined, statistical significance was not achieved. As a number of patients with disorders of the ADEM group may progress to develop multiple sclerosis (MS), we argue that an organism that has produced the former may remain in the brain tissue and be subsequently involved in the production of a self-sustained disorder such as MS.

Acute onset of hemorrhagic leukoencephalomyelitis (Hurst) in the spinal cord

Acute hemorrhagic leukoencephalomyelitis is considered to be a rare autoimmune disorder. The present case, a 34-year-old male, developed non-specific symptoms 3 weeks after surgical removal of his meniscus and following an inconspicuous infection of the upper respiratory tract. The spinal cord was the first to be affected, followed by symptoms of headache, nausea and fever which reached 39.4 degrees C. Autopsy revealed acute hemorrhagic leukoencephalomyelitis with marked involvement of the spinal cord. Diagnosis was established by histopathological examination of the brain and spinal cord. This is the first description of the onset of this disease in the spinal cord.

[Weston Hurst acute haemorrhagic leukoencephalitis. Neuropathological study of one case]

INTRODUCTION

Acute hemorrhagic leukoencephalitis (AHL), or Hurst disease is a rare, usually fatal, disease, probably due to an autoimmune cross reaction against myelin antigens present in the central nervous system, and which forms a spectrum of post infeccious demyelinating diseases with acute disseminated encephalomyelitis.

CASE REPORT

The patient was a 21 year old female who presented with an acute encephalopathy and generalized seizures following a 15 day febrile syndrome attributed to amygdalitis; a laboratory work up, including CSF, was non diagnostic, and a brain CT scan revealed diffuse cerebral edema. After 12 days the patient died from nosocomial pneumonia and multi organ failure; neuropathological examination of the brain confirmed the diagnosis of Hurst acute hemorrhagic leukoencephalitis, with a weak perilesional inflammatory reaction, unlike the usual picture in AHL.

DISCUSSION

AHL should be a part of the differential diagnosis of acute encephalopathic diseases, particularly if preceded by systemic infections. The atypical laboratory findings, and the impossibilty of performing a brain MRI were obstacles to the diagnosis in this case. The relative paucity of the perivascular infiltrate is an atypical finding, and could be due to apoptotic clearance of the inflammatory cells, as has been described in other autoimmune demyelinating diseases.

Imaging and pathology in pediatric neurological disorders

Radiologic and pathologic findings correlate well in many pediatric neurologic disorders. However, there are some exceptions. Radiologic techniques are unable to visualize or identify pathologic changes in some diseases (e.g. status marmoratus and subdural fluid collection), whereas pathologic examination fails to clarify the histologic substrate of radiologic abnormalities in other conditions (e.g. Fukuyama-type congenital muscular dystrophy and neurofibromatosis type 1). Although studies to solve these issues have met with practical difficulties, important progress has recently been made on some disorders such as Fukuyama-type congenital muscular dystrophy and acute necrotizing encephalopathy.

Posterior leukoencephalopathy in a girl with acute haemorrhagic leukoencephalitis

In children, posterior leukoencephalopathy is frequently associated with hypertensive encephalopathy, anticancer chemotherapy, treatment with immunosuppressive drugs in patients with organ transplantation, transfusion or human immunodeficiency virus infection. Posterior leukoencephalopathy in these children appears as a complicating illness and resolves once precipitating factor (e.g. cancer chemotherapy) is removed. Here we are reporting a fatal case of acute haemorrhatic leukoencephalitis in a 13 year old girl, imaging abnormalities are also suggestive of posterior leukoencephalopathy. Posterior leukoencephalopathy in our patient possibly, is a part of post-infectious haemorrhagic leukoencephalitis, rather than because of ischaemia or cerebral oedema secondary either to abrupt increase in blood pressure or following administration of immunosuppressive drugs.

Acute hemorrhagic leukoencephalitis in male sibs

Male siblings developed acute hemorrhagic leukoencephalitis (AHL) at age five months and eight months, respectively. This rare condition has not been reported in individuals less than two years of age or with a recurrence in the family. The diagnosis was based on neuropathologic features after ruling out potentially mimicking conditions. Genetic counseling of early onset AHL should include the possibility of recurrence in siblings.

Post-infectious central and peripheral nervous system diseases complicating Mycoplasma pneumoniae infection. Report of three cases and review of the literature

Three patients with a central and peripheral nervous system disease complicating a Mycoplasma pneumoniae (M. pn.) infection are presented. Patient 1 suffered from bilateral optic neuritis as well as acute Guillain-Barré syndrome recovering after plasmapheresis. The two other patients suffered from severe haemorrhagic leukoencephalitis (Hurst) which only could be contained by aggressive decompressive craniectomy with duraplasty. All three illnesses were clearly shown to be associated with M. pn. infection. Our three patients represent the full scale of central nervous (CNS) (cerebral and myelitic) as well as peripheral nervous system (PNS) (GBS, optic neuritis) manifestation of a disease caused by the same pathogenetic - post-infectious - mechanism; pathogenic CNS and PNS epitopes might be shared in post-infectious neurological disease following M. pn. infection.

Acute necrotizing encephalopathy presenting as a basal ganglia syndrome

Acute necrotizing encephalopathy is a relatively new disease. The characteristic clinical findings are of febrile illness followed by rapid deterioration in mental status and seizures. The hallmark of the disease is multifocal bilateral symmetric lesions affecting the thalamus, hypothalamus, brainstem tegmentum, cerebral white matter, and cerebellum. The etiology is unknown, but immune-mediated mechanism was suggested. We present a 12-year-old previously healthy girl who developed increased sleepiness progressing to stupor and coma. Magnetic resonance imaging (MRI) of the brain showed the characteristic findings previously described in acute necrotizing encephalopathy. Her mental status improved dramatically with steroid treatment, and the MRI findings resolved completely within 6 months. Following the acute illness, she developed a complex neuropsychiatric disorder consistent with basal ganglia syndrome.

Varicella-associated acute necrotizing encephalopathy with a good prognosis

A patient with acute necrotizing encephalophathy (ANE) following varicella infection with a good prognosis is reported. A somatosensory evoked magnetic field (SEF) study using a 37-channel-magnetoencephalography system demonstrated normal latency and strength of the first component (N20m) elicited by median nerve stimulation, despite bilateral symmetrical thalamic lesions on MRI. The normal SEF findings and the good prognosis suggested a reversible breakdown of the blood-brain barrier, and an edematous process as the brain pathology. Furthermore, our results support the idea of distinct generators for the three earliest cortical SEF components (N20m, P30m, N45m).

[A novel adult case of acute necrotizing encephalopathy of childhood with bilateral symmetric thalamic lesions]

This report describes a 46-year-old Japanese woman with bilateral symmetric thalamic necrosis. The unusual radiologic findings are discussed in relation with acute necrotizing encephalopathy (ANE) of childhood, a rare disease proposed by Mizuguchi et al. ANE affects young children and the incidence is highest between 6 and 18 months of ages. There is only one report of an adult case. The acute stage pathology in ANE can be summarized as acute edema and necrosis involving both gray and white matter by local breakdown of the blood-brain barrier. The radiologic findings in our case were similar to those in ANE of childhood. Though the pathogenesis between our adult case and ANE of childhood might be different, severe hypoalbuminea in our case could cause the alteration of permeability of the thalamic vessels, which might accelerate breakdown of the blood-brain barrier in the thalamus.

Leukoencephalopathy with cerebral amyloid angiopathy: a semiquantitative and morphometric study

To investigate changes in caliber of vessels in leukoencephalopathy with cerebral amyloid angiopathy (CAA) we performed a histological and morphometric study of cerebral arteries in this disease. We histologically examined changes in cortico-leptomeningeal arteries in five cases of leukoencephalopathy with CAA and compared their morphometrically determined wall-to-lumen ratio [(external diameter-internal diameter) x 0.5/internal diameter] with those of amyloid-negative arteries to estimate stenotic changes. Additionally, we compared wall-to-lumen ratios of medullary arteries in brains with CAA and white matter lesions (WML) (CAA(+)/WML(+), n = 5), subcortical arteriosclerotic encephalopathy without CAA (CAA(-)/WML(+), n = 7), and neither CAA nor white matter lesions (CAA(-)/WML(-), n = 5). Amyloid-positive arteries had thinned walls and dilated lumens. The external diameter and the wall-to-lumen ratio for amyloid-positive arteries was smaller than for amyloid-negative arteries in CAA(+)/WML(+) brains. There was no significant difference in the external diameters among the three groups. The wall-to-lumen ratio for medullary arteries in CAA(-)/WML(+) brains was significantly greater than for CAA(+)/WML(+) and CAA(-)/WML(-), but there was no significant difference between CAA(+)/WML(+) and CAA(-)/WML(-). Amyloid deposition causes degeneration of the tunica media, resulting in thinning of the wall and dilation of the lumen. The tunica media of small arteries is important in regulation of cerebral blood flow with degeneration causing impairment of cerebrovascular autoregulation in response to blood pressure. This impairment may lead to white matter lesions.

Detection of an autoantibody from Pug dogs with necrotizing encephalitis (Pug dog encephalitis)

An autoantibody against canine brain tissue was detected in the cerebrospinal fluid (CSF) and serum of two Pug dogs (Nos. 1 and 2) by indirect immunofluorescence assay (IFA). Dog No. 1, a 2-year-old male, exhibited severe depression, ataxia, and generalized seizures and died 2 months after the onset of symptoms. Dog No. 2, a 9-month-old male, exhibited severe generalized seizures and died 17 months after the onset of symptoms. Histopathologic examination revealed a moderate to severe multifocal accumulation of lymphocytes, plasma cells, and a few neutrophils in both the gray and white matter of the cerebrum in dog No. 1. In dog No. 2, the cellular infiltrates were mild, but there was a severe, diffuse, and multifocal necrosis in the cerebral cortex with prominent astrocytosis. With the aid of IFA using fluorescein isothiocyanate-labeled antidog IgG goat serum and a confocal imaging system, specific reactions for glial cells were detected in the CSF of these Pug dogs but not in six canine control CSF samples. Double-labeling IFA using CSF from these Pug dogs and a rabbit antiserum against glial fibrillary acidic protein (GFAP) revealed that the autoantibody recognized GFAP-positive astrocytes and their cytoplasmic projections. By immunoblot analysis, the autoantibody from CSF of these Pug dogs recognized two common positive bands at 58 and 54 kd, which corresponded to the molecular mass of human GFAP. The role of this autoantibody for astrocytes is not yet clear. However, if the presence of the autoantibody is a specific feature of Pug dog encephalitis, it will be a useful clinical diagnostic marker and a key to the pathogenesis of this unique canine neurologic disease.

Electron microscopic and immunohistochemical verification of diagnosis in two archival cases recognized as encephalitis necroticans acuta (ENA) on routine examinations

Two archival cases diagnosed 20 years ago on routine neuropathological methods as Encephalitis Necroticans Acuta (ENA) were investigated in EM and by immunohistochemical methods. The previous diagnosis was confirmed only in one case because Herpes simplex virus was found. In the second case the intracellular inclusions visible in ME corresponded to Measles Virus thus previous diagnosis was changed to SSPE.