Hippocampal involvement due to heroin inhalation--"chasing the dragon"

Area of Science:

• Neurology
• Toxicology
• Radiology

Background:

• Toxic leukoencephalopathy is a neurological condition resulting from exposure to various toxic agents.
• Heroin vapor inhalation, often termed 'chasing the dragon,' is known to cause a specific neurological syndrome.
• Magnetic Resonance (MR) imaging is crucial for diagnosing and characterizing these toxic effects on the brain.

Observation:

• A patient presenting with altered sensorium after engaging in heroin vapor abuse was evaluated.
• Brain MR imaging revealed characteristic symmetrical T2 hyperintensities.
• These hyperintensities were predominantly observed in the cerebellum and hippocampi.

Findings:

• The patient experienced initial improvement following the toxic exposure.
• Delayed involvement of the bilateral basal ganglia led to the development of spasticity in all limbs.
• This case is the first to report bilateral hippocampal involvement in the context of heroin vapor abuse.

Implications:

• This case underscores the diverse and potentially delayed neurological sequelae of heroin vapor abuse.
• It highlights the importance of considering toxic leukoencephalopathy in patients with relevant exposure history and neurological symptoms.
• The findings expand the understanding of the neuroanatomical patterns associated with 'chasing the dragon,' particularly the hippocampal and basal ganglia involvement.