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

Abstract

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.

Uncommon Causes of Nontraumatic Intracerebral Hemorrhage

“…25 Unlike acute disseminated encephalomyelitis, which touches mostly a pediatric population, AHLE mostly occurs in young adults with a male predominance. 26 In AHLE, patients initially present with mild neurological deficits followed by a fulminant neurological deterioration that often leads to coma/death in about 1 week from the time of onset. 26 ANE, a postinfectious inflammatory condition that occurs a few days after a viral infection (primarily influenza and parainfluenza 26 ) is characterized by symmetrical micro-hemorrhagic necrosis centered on the thalami, without macroscopic hematoma.…”

Emergent Management of Central Nervous System Demyelinating Disorders

“…Like ADEM, it is often associated with a prior infectious illness, typically an upper respiratory infection. Recently, acute hemorrhagic leukoencephalopathy has been associated with COVID-19 in several case reports 45 . Brain lesions are often larger than those seen in ADEM and have evidence of petechial hemorrhage on susceptibility-weighted MRI (notably, petechial hemorrhage is an atypical finding of tumefactive demyelination in general) ( figure 9-7 46 ).…”

“…Recently, acute hemorrhagic leukoencephalopathy has been associated with COVID-19 in several case reports. 45 Brain lesions are often larger than those seen in ADEM and have evidence of petechial hemorrhage on susceptibility-weighted MRI (notably, petechial hemorrhage is an atypical finding of tumefactive demyelination in general) (FIGURE 9-7 46 ). Pathology is characterized by hemorrhagic lesions with small vessel necrosis and infiltrates of neutrophils and macrophages, in contrast to classic ADEM, which shows perivascular demyelination with lymphocytic infiltration.…”

Acute Hemorrhagic Encephalomyelitis in the Context of MOG Antibody-Associated Disease. Comment on Chen et al. Rapid Progressive Fatal Acute Hemorrhagic Encephalomyelitis. Diagnostics 2023, 13, 2481

“…Acute hemorrhagic encephalomyelitis (AHEM), also known as acute hemorrhagic leukoencephalitis or Hurst disease, is an extremely rare demyelinating disorder characterized by distinctive clinical features, diagnostic complexity, and limited treatment options [1][2][3]. This disease has a predilection for affecting adults, particularly males, more frequently than children [1][2][3].…”

“…Acute hemorrhagic encephalomyelitis (AHEM), also known as acute hemorrhagic leukoencephalitis or Hurst disease, is an extremely rare demyelinating disorder characterized by distinctive clinical features, diagnostic complexity, and limited treatment options [1][2][3]. This disease has a predilection for affecting adults, particularly males, more frequently than children [1][2][3]. It typically presents suddenly with hyperacute or acute symptoms, leading to rapid neurological deterioration with severe manifestations, including altered consciousness, seizures, and, in some cases, a coma [1,3].…”