Cerebellar Leukoencephalopathy following Fentanyl Intoxication. A case report and review of the literature.

The opioid crisis has become a significant public health concern in recent years. Although respiratory depression and overdose are the most reported side effects of fentanyl, there have been rare cases of cerebellar leukoencephalopathy (CLE) following fentanyl intoxication. A 29-year-old man with a history of opioid use disorder and intravenous drug use presented to the emergency room with significant ataxia and dysarthria following fentanyl intoxication. According to the patient, the symptoms began four days prior after "chasing the dragon" with "pure fentanyl", and he reported experiencing nausea and dizziness, particularly during ambulation. Neurological examination revealed a positive Romberg test, ataxia, and delayed speech. Brain magnetic resonance imaging (MRI) indicated there was toxic degeneration of the cerebellar white matter that extended into the posterior limbs of the internal capsule. Urine drug screening was positive for opioids, making fentanyl-induced cerebellar leukoencephalopathy the most likely diagnosis in this case. This case of opioid-induced CLE underscores the critical significance of early recognition, which is vital for enhancing a patient's recovery and averting the development of severe neurological complications.