Acute hemorrhagic leukoencephalitis (AHLE)
General description
Acute hemorrhagic leukoencephalitis (AHLE), also known as Weston-Hurst syndrome or Hurst disease, represents a rare but devastating demyelinating disorder of the central nervous system. This fulminant condition is characterized by rapid neurologic deterioration and carries an exceptionally poor prognosis, with mortality rates ranging from 47% to 70% despite aggressive treatment interventions. AHLE is considered the most severe and hyperacute variant of Acute disseminated encephalomyelitis (ADEM), distinguished by its aggressive clinical course, extensive hemorrhagic white matter lesions, and characteristic pathological features including fibrinoid vascular necrosis and perivascular inflammatory infiltrates.
The clinical presentation of AHLE is distinguished by its catastrophic onset and rapid progression to neurological devastation within hours to days of symptom emergence. Patients typically present with fever, severe headache, neck stiffness, altered mental status, and rapid deterioration of consciousness progressing to coma. The condition predominantly affects young adults, with a mean age of 38 years and a male predominance. While ADEM is more commonly reported in children, AHLE is more frequently observed in adults.
Currently, there are no established diagnostic criteria for AHLE, but this condition should be considered in cases of acute progressive encephalitis of unknown cause.
References
- Grzonka, Pascale, et al. "Acute hemorrhagic leukoencephalitis: a case and systematic review of the literature." Frontiers in neurology 11 (2020): 899.
Cerebral lesion
The white matter lesions in AHLE are distinguished by their extensive bilateral distribution, though asymmetric involvement is common, with uni- or bihemispheric patterns observed. The frontal and parietal white matter regions are most frequently affected. Cerebral swelling is more pronounced than in ADEM, but basal ganglia involvement, which is common in ADEM, is less frequent.
A defining characteristic of AHLE neuroimaging is the presence of multifocal punctate hemorrhages within the white matter lesions, which can be detected using T2*WI sequences or the more sensitive susceptibility-weighted imaging (SWI).