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.