Acute hemorrhagic leukoencephalitis: neuroimaging features and neuropathologic diagnosis

Emergent Management of Central Nervous System Demyelinating Disorders

OBJECTIVE

This article reviews the various conditions that can present with acute and severe central nervous system demyelination, the broad differential diagnosis of these conditions, the most appropriate diagnostic workup, and the acute treatment regimens to be administered to help achieve the best possible patient outcomes.

LATEST DEVELOPMENTS

The discovery of anti-aquaporin 4 (AQP4) antibodies and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies in the past two decades has revolutionized our understanding of acute demyelinating disorders, their evaluation, and their management.

ESSENTIAL POINTS

Demyelinating disorders comprise a large category of neurologic disorders seen by practicing neurologists. In the majority of cases, patients with these conditions do not require care in an intensive care unit. However, certain disorders may cause severe demyelination that necessitates intensive care unit admission because of numerous simultaneous multifocal lesions, tumefactive lesions, or lesions in certain brain locations that lead to acute severe neurologic dysfunction. Intensive care may be necessary for the management and prevention of complications for patients who have severely altered mental status, rapidly progressive neurologic worsening, elevated intracranial pressure, severe cerebral edema, status epilepticus, or respiratory failure.

Acute hemorrhagic leukoencephalitis following the first dose of BNT162b2 vaccine against SARS-CoV-2: A case report

Acute hemorrhagic leukoencephalitis (AHLE), is a rare inflammatory demyelinating disorder, variant of acute disseminated encephalomyelitis. The diagnosis of AHLE remains challenging due to the rarity of the disease and the lack of a reliable biomarker. We report here a case of a 73-year-old male patient with a progressive, low-grade febrile confusional syndrome 20 days after receiving the first dose of BNT162b2 vaccine against SARS-CoV-2. Evidence indicative of the underlying condition by an extensive panel of imaging (brain magnetic resonance imaging, computed tomography and digital subtraction angiography), laboratory (complete blood count, biochemistry, coagulation, tests for autoimmune or infectious disorders, tumor markers, hormonal levels, cerebrospinal fluid analysis) and electrodiagnostic tests were scarce, and mainly non-specific. Sequential neuroimaging revealed the appearance of extensive T2 lesions (signs of gliosis) along with multiple hemorrhagic lesions at various cortical sites. The patient was treated with corticosteroids, discontinued due to severe adverse effects, and subsequently with sessions of plasmapheresis and monthly intravenous administration of cyclophosphamide. Considering the rapid aggravation of the patient's neurological status, the MRI findings of cortical lesions and the lack of response to any treatment, a biopsy of a frontal lobe lesion was conducted, confirming the presence of confluent, inflammatory-edematous lesions with scattered areas of necrosis and hemorrhage, and ultimately areas of demyelination, thus confirming the diagnosis of AHLE. After more than 5 months of hospitalization the patient was transferred in a primary care facility and remained in a permanent vegetative state until his death, more than 2 years later.

[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.

Two-year follow-up of a young male with possible acute hemorrhagic leukoencephalitis: A case report

RATIONALE

Acute hemorrhagic leukoencephalitis (AHLE) is a rare but fetal fulminant demyelinating disease of unknown etiology. It is commonly regarded as a severe variant of acute demyelinating encephalomyelitis (ADEM). Its rapid clinical deterioration and high mortality appeal to clinicians to attach importance to early diagnosis. Immunosuppressive therapy is the main management to attenuate the autoimmune process, but with varied response and prognosis.

PATIENT CONCERNS

A young male presented with moderate fever, headache and seizures after extraction of impacted teeth, and then deteriorated rapidly to deep coma. Initial magnetic resonance imaging (MRI) revealed multiple plaque-like lesions in bilateral cerebra, right thalamus and pontobulbar region with massive edematous swelling and multifocal small hemorrhagic foci. Inflammatory parameters in the peripheral blood were only mild higher with a pleocytosis in CSF.

DIAGNOSIS

His clinical presentation, laboratory evaluation and radiological features were consistent with a suspected diagnosis of AHLE.

INTERVENTIONS

He underwent pulse corticosteroids initially but failed to respond to it. However, his consciousness improved obviously when he was treated with multiple courses of intravenous injection of immunoglobulin (IVIG) combined with mycophenolate mofetil (MMF).

OUTCOMES

The patient regained consciousness gradually on day 180 and was in minimally conscious state (MCS) during the two-year follow-up.

LESSONS

AHLE presents distinctly from classical ADEM, and the situation may pose a diagnostic challenge. Clinicians should be vigilant in recognizing AHLE because of its rapid clinical deterioration and high mortality. We highlight the critical role of multimodal MRI, particularly susceptibility-weighted imaging (SWI) in the diagnosis of AHLE if cerebral biopsies are unavailable. Multiple courses of IVIG with MMF may be effective when early single pulse of corticosteroids fails. Individual who survives the initial insult may carry relatively good prognosis.

Acute Hemorrhagic Leukoencephalitis (AHLE): A Comprehensive Review on Causes, Symptoms, Link with COVID-19, Diagnosis, and Treatment

Acute hemorrhagic leukoencephalitis (AHLE), also called Hurst disease, is a rare demyelinating disease of the central nervous system (CNS) marked by rapid progression and acute inflammation of the white matter. Due to the correlation in their suspected postinfectious autoimmune pathogenesis, it is regarded as the most severe form of acute disseminated encephalomyelitis (ADEM). Because this clinical scenario has a high mortality rate, aggressive and immediate treatment is required. Although the exact cause of AHLE is unknown, it usually occurs after a bacterial or viral infection, or, less frequently, after a measles or rabies vaccination. AHLE has been reported in patients with coronavirus disease 2019 (COVID-19) as a rare but serious neurological complication. However, due to the lack of evidence-based diagnostic criteria, diagnosis is difficult. The small number of cases described in the literature, which most likely reflects underreporting and/or low incidence, necessitates greater public awareness. Increased clinical suspicion and early imaging identification of this entity may allow clinicians to pursue more aggressive treatment options, potentially reducing fatal outcomes. This study focuses on symptoms and causes of AHLE, difference between AHLE and ADME, diagnosis and treatment of AHLE, and its link with COVID-19.

Postinfectious coronavirus disease 2019 hemorrhagic cerebellitis: illustrative case

BACKGROUND

Conditions that can mimic posterior fossa tumors are rare. Their identification is crucial to avoid unnecessary surgical intervention, especially when prompt initiation of medical therapy is critical.

OBSERVATIONS

The authors presented a case of pseudotumoral hemorrhagic cerebellitis in a 3-year-old boy who presented initially with headache, persistent vomiting, and decreased level of consciousness 9 weeks after severe acute respiratory syndrome coronavirus 2 infection. Magnetic resonance imaging showed a left cerebellar hemorrhagic mass–like lesion with edema and mild hydrocephalus. The patient responded to high-dose steroids and was discharged 2 weeks later with complete recovery.

LESSONS

When evaluating patients with possible tumor syndromes, it is important to also consider rarer inflammatory syndromes that can masquerade as neoplasms. Postinfectious hemorrhagic cerebellitis is one such syndrome.

Paediatric acute haemorrhagic leukoencephalitis

We report a case of a preschool age girl, previously healthy, referred to our hospital on ventilatory support with a history of vomiting, headache, and rapid neurological worsening within 24 hours in the form of seizures, encephalopathy and loss of consciousness. On presentation, she was deeply comatose with dilated non-reactive pupils, absent brainstem reflexes and flaccid quadriplegia. Diagnosis of acute haemorrhagic leukoencephalitis was considered based on laboratory and neuroimaging findings. MRI of the brain showed fluffy white matter hyperintensities and microhaemorrhages in bilateral cerebral hemispheres and thalami. Aggressive treatment with methylprednisolone, plasmapheresis and intravenous immunoglobulin showed dramatic improvement with no neurological sequelae. Our case is unique in a way that despite the hyperacute onset and rapid deterioration, with a fulminant course in the intensive care unit, the child recovered dramatically with aggressive management.

Case Report: Minimal Neurological Deficit of Two Adult Patients With Weston-Hurst Syndrome Due to Early Craniectomy: Case Series and Review of Literature on Craniectomy

Objectives: We describe two new cases of acute hemorrhagic leucoencephalitis (AHLE), who survived with minimal sequelae due to early measures against increased intracranial pressure, particularly craniotomy. The recently published literature review on treatment and outcome of AHLE was further examined for the effect of craniotomy.

Methods: We present two cases from our institution. The outcome of 44 cases from the literature was defined either as good (no deficit, minimal deficit/no daily help) or poor outcome (severe deficit/disabled, death). Patients with purely infratentorial lesions (n = 9) were excluded. Fisher's exact test was applied.

Results: Two cases are presented: A 43-year-old woman with rapidly progressive aphasia and right hemiparesis due to a huge left frontal white matter lesion with rim contrast enhancement. Pathology was consistent with AHLE. The second case was a 56-year-old woman with rapidly progressive aphasia and right hemiparesis. Cranial MRI showed a huge left temporo-occipital white matter lesion with typical morphology for AHLE. Both patients received craniotomy within the first 24 h and consequent immunosuppressive-immunomodulatory treatment and survived with minimal deficits. Out of 35 supratentorial reported AHLE cases, seven patients received decompressive craniotomy. Comparing all supratentorial cases, patients who received craniotomy were more likely to have a good outcome (71 vs. 29%).

Conclusion: Due to early control of the intracranial pressure, particularly due to early craniotomy; diagnosis per biopsy; and immediate start of immunosuppressive-immunomodulatory therapies (cortisone pulse, plasma exchanges), both patients survived with minimal sequelae. Craniotomy plays an important role and should be considered early on in patients with probable AHLE.

A Case Series of Acute Hemorrhagic Leukoencephalitis

ABSTRACT

Acute hemorrhagic leukoencephalitis (AHL) is an acute, hemorrhagic demyelinating disease thought to be caused by an immune-mediated process. Acute hemorrhagic leukoencephalitis is both diagnostically challenging and fatal in the majority of cases. We present two cases of AHL unexpectedly diagnosed at autopsy. These cases demonstrate the often nonspecific and challenging nature of AHL clinical presentation, review neuropathological mimics, and emphasize the importance of considering this diagnosis in the forensic setting.

Acute Hemorrhagic Encephalitis Related to COVID-19

PURPOSE OF REVIEW

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the most critical public health challenge in recent history. In this report, we present a case of suspected acute hemorrhagic encephalitis with bilateral intracranial hemorrhages associated with coronavirus disease 2019 (COVID-19) infection.

RECENT FINDINGS

A 48-year-old female COVID-19-positive patient developed acute changes in her neurologic status. A head CT with CT angiography demonstrated extensive bilateral parietal and occipital intraparenchymal hemorrhage with intraventricular extension and acute hydrocephalus. The patient was treated with an external ventricular drain, and a CSF sample was tested for SARS-CoV-2 but was found to be negative.

SUMMARY

The underlying mechanism for developing acute hemorrhagic encephalitis in viral illnesses may be autoimmune in nature and warrants further investigation. The initial neurologic presentation of COVID-19-related hemorrhagic encephalitis is altered level of consciousness, which may prompt further neurologic examination and imaging to exclude this feature.

Extensive cerebellar involvement and cognitive impairment in COVID-19-associated acute necrotizing encephalopathy

Neurological complications of the newly appeared severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are increasingly recognized. Here, we report a case of a young male presenting with a clinical and neuroimaging scenario of an acute necrotizing encephalopathy related to the coronavirus disease 2019 (COVID-19). This case is notable by its distinct pattern of magnetic resonance imaging findings of an extensive involvement of the cerebellum, and emergence of cognitive and behavioral impairment.

Pseudotumoral lesion as a manifestation of acute hemorrhagic leukoencephalitis (Weston-Hurst syndrome)

A case of acute hemorrhagic encephalomyelitis whose first manifestation was a pseudotumoral lesion in the corpus callosum is presented. The patient had an acute headache accompanied by visual hallucinations and subsequently developed convulsive status epilepticus. The initial CT scan showed a lesion with a pseudotumoral aspect in the splenius of the corpus callosum. Multiple microbleeds in the same location associated with vasogenic edema were seen in the MRI. A brain biopsy was necessary to obtain an accurate diagnosis. Corticosteroid management resulted in only a partial response. Weston Hurst syndrome is a variant of acute disseminated encephalomyelitis (ADEM) with an unfavorable prognosis.

Acute Hemorrhagic Leukoencephalitis: A Case and Systematic Review of the Literature

Objectives: To present a patient with acute hemorrhagic leukoencephalitis (AHLE) and a systematic review of the literature analyzing diagnostic procedures, treatment, and outcomes of AHLE.

Methods: PubMed and Cochrane databases were screened. Papers published since 01/01/2000 describing adult patients are reported according to the PRISMA-guidelines.

Results: A 59-year old male with rapidly developing coma and cerebral biopsy changes compatible with AHLE is presented followed by 43 case reports from the literature including males in 67% and a mean age of 38 years. Mortality was 47%. Infectious pathogens were reported in 35%, preexisting autoimmune diseases were identified in 12%. Neuroimaging revealed uni- or bihemispheric lesions in 65% and isolated lesions of the cerebellum, pons, medulla oblongata or the spinal cord without concomitant hemispheric involvement in 16%. Analysis of the cerebrospinal fluid showed an increased protein level in 87%, elevated white blood cells in 65%, and erythrocytes in 39%. Histology (reported in 58%) supported the diagnosis of AHLE in all cases. Glucocorticoids were used most commonly (97%), followed by plasmapheresis (26%), and intravenous immunoglobulins (12%), without a clear temporal relationship between treatment and the patients' clinical course.

Conclusions: Although mortality was lower than previously reported, AHLE remains a life-threatening neurologic emergency with high mortality. Diagnosis is challenging as the level of evidence regarding the diagnostic yield of clinical, neuroimaging and laboratory characteristics remains low. Hence, clinicians are urged to heighten their awareness and to prompt cerebral biopsies in the context of rapidly progressive neurologic decline of unknown origin with the concurrence of the compiled characteristics. Future studies need to focus on treatment characteristics and their effects on course and outcome.

Weston-Hurst syndrome with acute hemorrhagic cerebellitis

Weston-Hurst syndrome is an exceptional variant of ADEM characterized by brain hemorrhages. Lesions are usually supratentorial and death is a usual outcome. We report a cerebellar Weston-Hurst syndrome early treated by craniectomy, steroids and plasma exchange. This is the first case of infratentorial Weston-Hurst syndrome associated with a favorable outcome.

Sudden Death of a Young Man by Acute Hemorrhagic Leukoencephalitis

We report a case of acute hemorrhagic leukoencephalitis in an adult man with a prodrome of "feeling unwell" two days prior to this death. At autopsy, external examination revealed minor external injuries including contusions on the scalp and left thigh and abrasions on the forehead and right eyebrow. Gross examination of the brain after coronal sectioning revealed multiple petechial hemorrhages in the white matter in the cerebral hemispheres, corpus callosum, basal ganglia, brainstem, and cerebellum. Microscopic examination of these lesions revealed demyelination, hemorrhage, and necrosis with fibrin exudation in a perivenular distribution with radial extension into the white matter. The remainder of the autopsy was unremarkable. This case highlights the death of a young man by a rare fatal complication of a natural disease only identified by a singular set of gross and microscopic findings at autopsy in circumstances that would otherwise suggest a nonnatural death. The case demonstrates the importance of a thorough autopsy in settings where the clinical history, scene, and circumstances may be misleading or absent.

Finding a Balance between Protection and Pathology: The Dual Role of Perforin in Human Disease

Perforin is critical for controlling viral infection and tumor surveillance. Clinically, mutations in perforin are viewed as unfavorable, as lack of this pore-forming protein results in lethal, childhood disease, familial hemophagocytic lymphohistiocytosis type 2 (FHL 2). However, many mutations in the coding region of PRF1 are not yet associated with disease. Animal models of viral-associated blood–brain barrier (BBB) disruption and experimental cerebral malaria (ECM) have identified perforin as critical for inducing pathologic central nervous system CNS vascular permeability. This review focuses on the role of perforin in both protecting and promoting human disease. It concludes with a novel hypothesis that diversity observed in the PRF1 gene may be an example of selective advantage that protects an individual from perforin-mediated pathology, such as BBB disruption.

Weston-Hurst syndrome: a rare fulminant form of acute disseminated encephalomyelitis (ADEM)

A 25-year-old Pakistani woman presented to the emergency department with a 2-day history of rapidly progressive tetraplegia followed by sudden loss of consciousness. This was preceded by an upper respiratory tract infection. On examination, she was deeply comatose with a GCS of 3/15 and intact brainstem reflexes. She was in respiratory distress, and an endotracheal tube had been passed. She had flaccid quadriplegia with depressed deep tendon reflexes and upgoing plantar response. Her MRI brain with contrast showed extensive brainstem involvement with haemorrhagic foci along with signal changes in the corpus callosum. The patient was put on a respirator. She was given IV methyl prednisolone, and later on 5 sessions of plasmapheresis were performed. After 3 months, the patient gradually recovered and started communicating. Her motor power had improved to 2/5 in her arms and 1/5 in the lower extremities. She was then discharged for further rehabilitation at home.

Acute hemorrhagic leukoencephalomyelitis in a man with viral myocarditis

We report a case of acute hemorrhagic leukoencephalomyelitis in a man with viral myocarditis. A 48-year-old previously healthy male was found dead in his locked apartment. At autopsy he was found to be malnourished, and his lungs showed gross evidence of bilateral pneumonia with abscess formation and bullous emphysema. Multiple petechial hemorrhages were observed in the brain and mainly involved white matter in the cerebral hemispheres including the corpus callosum and internal capsule, as well as the cerebellum, brainstem, and spinal cord. Microscopy of the brain and spinal cord revealed perivenular hemorrhages, central microthrombi in venules with fibrin exudation into the subcortical white matter, and early perivenular demyelination associated with scanty mixed cellular infiltrates. Other microscopic features included widespread diffuse viral myocarditis, extensive suppurative bronchopneumonia, and chronic bronchitis. This case illustrates the death of a man with a rare fatal disease associated with two other potentially lethal diseases. The case also illustrates the importance of a holistic approach when determining the cause of death, especially when there are competing causes of death.

Acute hemorrhagic leukoencephalopathy associated with influenza A (H1N1) virus

BACKGROUND

Acute hemorrhagic leukoencephalopathy (AHLE) is a rare condition associated with H1N1. In this condition the infection triggers an autoimmune response which results in perivascular demyelination and hemorrhage in the brain parenchyma.

METHODS

We report a case of a patient who developed brain edema and herniation as a result of AHLE.

RESULTS

A 27-year-old presented to a community hospital with fever, dyspnea, and malaise and was found to have H1N1-associated pneumonia. Despite treatment he progressed to acute respiratory distress syndrome and required mechanical ventilation. Due to failure on conventional ventilation, he was transferred to our hospital and was placed on high-frequency oscillatory ventilation. He was showing improvement until day 6 of transfer to our hospital when he was suddenly noted to have a rise in his blood pressure followed by hypotension. The following morning he was noted to have non-reactive pupils and was declared brain dead. Autopsy of the brain was consistent with AHLE.

CONCLUSIONS

This case emphasizes the importance of awareness of this disease. The non-specific signs and symptoms, and the use of sedatives, make diagnosis challenging in the early stages of this disease. If suspected early, appropriate imaging can aid in the diagnosis. Treatment with immunosuppressive agents and plasmapheresis may prevent rapid progression and death. This is the first published case of AHLE in association with H1N1 that has been confirmed pathologically.

Fulminant form of acute disseminated encephalomyelitis in a child treated with mild hypothermia

We describe the case of a 3-year-old boy diagnosed with the fulminant form of acute disseminated encephalomyelitis (ADEM). He developed general fatigue, fever, drowsiness and difficulty in walking. He had extensive multiple high-intensity lesions in the white matter of the cerebrum and cerebellum, which are typical findings of ADEM. He became comatose and developed decerebrate rigidity with severe brain edema despite high-dose methylprednisolone therapy, and then was subjected to mild hypothermia therapy, and given i.v. immunoglobulin. The patient recovered remarkably with the sequela of only mild action tremor. The patient was considered to have acute hemorrhagic leukoencephalitis (AHLE), an extremely severe form of ADEM, in terms of the rapidly deteriorating clinical course and neuroimaging features. It was speculated that AHLE and ADEM might be a continuous disease spectrum. It is considered that the severe brain edema associated with ADEM or AHLE is a suitable indication for mild hypothermia therapy.

CD8 T cell-initiated blood-brain barrier disruption is independent of neutrophil support

Blood-brain barrier (BBB) disruption is a common feature of numerous neurologic disorders. A fundamental question in these diseases is the extent inflammatory immune cells contribute to CNS vascular permeability. We have previously shown that CD8 T cells play a critical role in initiating BBB disruption in the peptide-induced fatal syndrome model developed by our laboratory. However, myelomonocytic cells such as neutrophils have also been implicated in promoting CNS vascular permeability and functional deficit in murine models of neuroinflammatory disease. For this reason, we evaluated neutrophil depletion in a murine model of CD8 T cell-initiated BBB disruption by employing traditionally used anti-granulocyte receptor-1 mAb RB6-8C5 and Ly-6G-specific mAb 1A8. We report that CNS-infiltrating antiviral CD8 T cells express high levels of granulocyte receptor-1 protein and are depleted by treatment with RB6-8C5. Mice treated with RB6-8C5, but not 1A8, display: 1) intact BBB tight junction proteins; 2) reduced CNS vascular permeability visible by gadolinium-enhanced T1-weighted magnetic resonance imaging; and 3) preservation of motor function. These studies demonstrate that traditional methods of neutrophil depletion with RB6-8C5 are broadly immune ablating. Our data also provide evidence that CD8 T cells initiate disruption of BBB tight junction proteins and CNS vascular permeability in the absence of neutrophil support.

A hematopoietic contribution to microhemorrhage formation during antiviral CD8 T cell-initiated blood-brain barrier disruption

Background

The extent to which susceptibility to brain hemorrhage is derived from blood-derived factors or stromal tissue remains largely unknown. We have developed an inducible model of CD8 T cell-initiated blood-brain barrier (BBB) disruption using a variation of the Theiler's murine encephalomyelitis virus (TMEV) model of multiple sclerosis. This peptide-induced fatal syndrome (PIFS) model results in severe central nervous system (CNS) vascular permeability and death in the C57BL/6 mouse strain, but not in the 129 SvIm mouse strain, despite the two strains' having indistinguishable CD8 T-cell responses. Therefore, we hypothesize that hematopoietic factors contribute to susceptibility to brain hemorrhage, CNS vascular permeability and death following induction of PIFS.

Methods

PIFS was induced by intravenous injection of VP2_121-130 peptide at 7 days post-TMEV infection. We then investigated brain inflammation, astrocyte activation, vascular permeability, functional deficit and microhemorrhage formation using T2*-weighted magnetic resonance imaging (MRI) in C57BL/6 and 129 SvIm mice. To investigate the contribution of hematopoietic cells in this model, hemorrhage-resistant 129 SvIm mice were reconstituted with C57BL/6 or autologous 129 SvIm bone marrow. Gadolinium-enhanced, T1-weighted MRI was used to visualize the extent of CNS vascular permeability after bone marrow transfer.

Results

C57BL/6 and 129 SvIm mice had similar inflammation in the CNS during acute infection. After administration of VP2_121-130 peptide, however, C57BL/6 mice had increased astrocyte activation, CNS vascular permeability, microhemorrhage formation and functional deficits compared to 129 SvIm mice. The 129 SvIm mice reconstituted with C57BL/6 but not autologous bone marrow had increased microhemorrhage formation as measured by T2*-weighted MRI, exhibited a profound increase in CNS vascular permeability as measured by three-dimensional volumetric analysis of gadolinium-enhanced, T1-weighted MRI, and became moribund in this model system.

Conclusion

C57BL/6 mice are highly susceptible to microhemorrhage formation, severe CNS vascular permeability and morbidity compared to the 129 SvIm mouse. This susceptibility is transferable with the bone marrow compartment, demonstrating that hematopoietic factors are responsible for the onset of brain microhemorrhage and vascular permeability in immune-mediated fatal BBB disruption.

Acute hemorrhagic leukoencephalitis: a critical entity for forensic pathologists to recognize

Acute hemorrhagic leukoencephalopathy (AHLE) is a rare, acute disorder characterized by perivenular demyelination and diffuse hemorrhagic necrosis of the central nervous system. AHLE is thought to represent a hyperacute form of acute disseminated encephalomyelitis. AHLE is associated with a greater morbidity and mortality and, fortunately, is much less common than acute disseminated encephalomyelitis. Since most cases of AHLE result in patient demise, forensic pathologists should be cognizant of this entity and consider it in their differential diagnosis.Here we describe an interesting case of a previously healthy 11-year-old boy who initially complained of vague gastroenteritis-like symptoms while visiting a mountain lake. The boy's symptoms evolved to include severe headache and dizziness, necessitating a visit to a rural emergency department. He presented with focal neurologic findings, and head computed tomography (CT) scan confirmed thalamic edema. Cerebrospinal fluid analysis was suggestive of infectious etiology, and multiple empiric therapies were initiated. He was transferred to our institution, and his clinical status continued to worsen. Given the poor prognosis, the family requested withdrawal of supportive care. On day 14 of symptoms the boy succumbed to his illness. An autopsy was requested to further characterize the proximate cause of death.AHLE often presents with abrupt onset of fever, neck stiffness, seizure, and/or focal neurologic signs several days following a viral illness or vaccination. Thus, AHLE can clinically mimic a direct central nervous system infection or a toxic ingestion. AHLE has a very poor prognosis, with rapid deterioration and death usually occurring within days to one week after onset of symptoms. The cause for AHLE is unclear. An autoimmune pathophysiology is likely, with immune cross-reactivity between myelin basic protein moieties and various infectious agent antigens. Treatment for AHLE is not well-established; some authors describe in recent literature that a combination of immunosuppressant medications and/or therapeutic plasma exchange may be of benefit in treating AHLE.

Atypical acute hemorrhagic leukoencephalitis (Hurst's disease) presenting with focal hemorrhagic brainstem lesion

BACKGROUND

Acute hemorrhagic leukoencephalitis (AHL; Hurst's disease) is a rare, severe, inflammatory CNS disease that is typically diffuse, multifocal and associated with petechial hemorrhage. The objective of this study is to report the clinical, radiologic, and pathologic findings in a fatal AHL case with focal brainstem involvement and gross hemorrhage.

METHODS

Patient evaluation in a tertiary neurointensive care unit with serial brain magnetic resonance imaging (MRI) and neuropathological examination on autopsy were performed.

RESULTS

The patient presented with mild, then rapidly worsening, brainstem impairment to a locked-in syndrome. Brain MRI demonstrated an isolated gadolinium enhancing brainstem lesion that enlarged dramatically over weeks and was associated with gross hemorrhage and necrosis. The patient died despite aggressive treatment with intravenous corticosteroids and plasma exchange. Autopsy demonstrated the isolated severe necrotic lesion consistent with AHL.

CONCLUSIONS

AHL may present as a solitary brainstem lesion with gross hemorrhage and should be considered in patients with isolated enhancing brainstem lesions. AHL may be fatal even despite early, aggressive immunomodulatory therapy.

Hemorrhage in posterior reversible encephalopathy syndrome: imaging and clinical features

BACKGROUND AND PURPOSE

Hemorrhage is known to occur in posterior reversible encephalopathy syndrome (PRES), but the characteristics have not been analyzed in detail. The purpose of this study was to evaluate the imaging and clinical features of hemorrhage in PRES.

MATERIALS AND METHODS

Retrospective assessment of 151 patients with PRES was performed, and 23 patients were identified who had intracranial hemorrhage at toxicity. Hemorrhage types were identified and tabulated, including minute focal hemorrhages (<5 mm), sulcal subarachnoid hemorrhage, and focal hematoma. Clinical features of hemorrhage and nonhemorrhage PRES groups were evaluated, including toxicity blood pressure, coagulation profile/platelet counts, coagulation-altering medication, and clinical conditions associated with PRES. Toxicity mean arterial pressure (MAP) groups were defined as normal (<106 mm Hg), mildly hypertensive (106-116 mm Hg), or severely hypertensive (>116 mm Hg).

RESULTS

The overall incidence of hemorrhage was 15.2%, with borderline statistical significance noted between the observed clinical associations (P = .07). Hemorrhage was significantly more common (P = .02) after allogeneic bone marrow transplantation (allo-BMT) than after solid-organ transplantation. The 3 hemorrhage types were noted with equal frequency. A single hemorrhage type was found in 16 patients, with multiple types noted in 7. Patients undergoing therapeutic anticoagulation were statistically more likely to develop hemorrhage (P = .04). No difference in hemorrhage incidence was found among the 3 blood pressure subgroups (range, 14.9%-15.9%).

CONCLUSIONS

Three distinct types of hemorrhage (minute hemorrhage, sulcal subarachnoid hemorrhage, hematoma) were identified in PRES with equal frequency. The greatest hemorrhage frequency was seen after allo-BMT and in patients undergoing therapeutic anticoagulation. Hemorrhage rate was independent of the toxicity blood pressure.

Acute hemorrhagic demyelination in a murine model of multiple sclerosis

Acute hemorrhagic leukoencephalomyelitis (AHLE) is a rare neurological condition characterized by the development of acute hemorrhagic demyelination and high mortality. The pathomechanism of AHLE, as well as potential therapeutic approaches, have remained elusive due to the lack of suitable animal models. We report the first murine model of AHLE using a variation of the Theiler's Murine Encephalitis Virus (TMEV) MS model. During acute TMEV infection, C57BL/6 mice do not normally undergo demyelination. However, when 7 day TMEV infected C57BL/6 mice are intravenously administered the immunodominant CD8 T cell peptide, VP2_121–130, animals develop characteristics of human AHLE based on pathologic, MRI and clinical features including microhemorrhages, increased blood-brain barrier permeability, and demyelination. The animals also develop severe disability as assessed using the rotarod assay. This study demonstrates the development of hemorrhagic demyelination in TMEV infected C57BL/6 mice within 24 hours of inducing this condition through intravenous administration of CD8 T cell restricted peptide. This study is also the first demonstration of rapid demyelination in a TMEV resistant non-demyelinating strain without transgenic alterations or pharmacologically induced immunosuppression.

Neuroimaging of viral infections in infants and young children

Many viral infections can involve the central nervous systems (CNS) of fetuses, neonates, infants, and children. The pathogenesis, patterns of CNS involvement, and species of viral infection may differ in the developing fetus, infant and neonate, and early childhood. Familiarity with the clinical course and imaging appearances of the variable CNS diseases is helpful in making correct differential diagnoses and in prompting timely treatment. This article reviews the clinical courses, pathologic findings, and imaging features of the most common viral infections that may involve the CNS of neonates and infants, including congenital and neonatal CNS viral infections, common CNS viral infections, and parainfectious encephalomyelitis.

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.

Idiopathic inflammatory-demyelinating diseases of the central nervous system

Idiopathic inflammatory-demyelinating diseases (IIDDs) include a broad spectrum of central nervous system disorders that can usually be differentiated on the basis of clinical, imaging, laboratory and pathological findings. However, there can be a considerable overlap between at least some of these disorders, leading to misdiagnoses or diagnostic uncertainty. The relapsing-remitting and secondary progressive forms of multiple sclerosis (MS) are the most common IIDDs. Other MS phenotypes include those with a progressive course from onset (primary progressive and progressive relapsing) or with a benign course continuing for years after onset (benign MS). Uncommon forms of IIDDs can be classified clinically into: (1) fulminant or acute IIDDs, such as the Marburg variant of MS, Baló's concentric sclerosis, Schilder's disease, and acute disseminated encephalomyelitis; (2) monosymptomatic IIDDs, such as those involving the spinal cord (transverse myelitis), optic nerve (optic neuritis) or brainstem and cerebellum; and (3) IIDDs with a restricted topographical distribution, including Devic's neuromyelitis optica, recurrent optic neuritis and relapsing transverse myelitis. Other forms of IIDD, which are classified clinically and radiologically as pseudotumoral, can have different forms of presentation and clinical courses. Although some of these uncommon IIDDs are variants of MS, others probably correspond to different entities. MR imaging of the brain and spine is the imaging technique of choice for diagnosing these disorders, and together with the clinical and laboratory findings can accurately classify them. Precise classification of these disorders may have relevant prognostic and treatment implications, and might be helpful in distinguishing them from tumoral or infectious lesions, avoiding unnecessary aggressive diagnostic or therapeutic procedures.