Rare anoxic brain injury sequela of delayed posthypoxic leukoencephalopathy due to recreational drug overdose with benzodiazepines

A case report of long-term effects of Delayed post-hypoxic leukoencephalopathy (DPHL) following benzodiazepine overdose

Objective: We report a neuropsychological evaluation for a 39-year-old, right-handed, white female who 8 years ago developed delayed post-hypoxic leukoencephalopathy (DPHL), a rare demyelinating syndrome, two-weeks following an anoxic brain injury due to an overdose from benzodiazepines. Methods: An extensive record review documenting her medical timeline and treatment over the last 8 years was conducted using the available EMR system, which also included both EEG and neuroimaging data. Eight years post injury, a comprehensive neuropsychological battery was administered with corrected normative data for age, race, education, and other demographic factors when available. Collected data was compared with other case reports of DPHL. Results: The neuropsychological profile indicated difficulties across multiple cognitive domains that appeared driven by executive dysfunction, likely related to fronto-subcorto-striatal dysfunction. Conclusion: As a rare disease, the process by which DPHL occurs is not fully understood. Our results revealed similar findings in the literature for learning and memory, attention, processing speed, and executive functions. This is discussed in the context of available neuroimaging while highlighting the value of comprehensive neuropsychological assessment in DPHL even years post-injury.

Association between toxic drug events and encephalopathy in British Columbia, Canada: a cross-sectional analysis

BACKGROUND

Encephalopathy can occur from a non-fatal toxic drug event (overdose) which results in a partial or complete loss of oxygen to the brain, or due to long-term substance use issues. It can be categorized as a non-traumatic acquired brain injury or toxic encephalopathy. In the context of the drug toxicity crisis in British Columbia (BC), Canada, measuring the co-occurrence of encephalopathy and drug toxicity is challenging due to lack of standardized screening. We aimed to estimate the prevalence of encephalopathy among people who experienced a toxic drug event and examine the association between toxic drug events and encephalopathy.

METHODS

Using a 20% random sample of BC residents from administrative health data, we conducted a cross-sectional analysis. Toxic drug events were identified using the BC Provincial Overdose Cohort definition and encephalopathy was identified using ICD codes from hospitalization, emergency department, and primary care records between January 1st 2015 and December 31st 2019. Unadjusted and adjusted log-binomial regression models were employed to estimate the risk of encephalopathy among people who had a toxic drug event compared to people who did not experience a toxic drug event.

RESULTS

Among people with encephalopathy, 14.6% (n = 54) had one or more drug toxicity events between 2015 and 2019. After adjusting for sex, age, and mental illness, people who experienced drug toxicity were 15.3 times (95% CI = 11.3, 20.7) more likely to have encephalopathy compared to people who did not experience a drug toxicity event. People who were 40 years and older, male, and had a mental illness were at increased risk of encephalopathy.

CONCLUSIONS

There is a need for collaboration between community members, health care providers, and key stakeholders to develop a standardized approach to define, screen, and detect neurocognitive injury related to drug toxicity.

Delayed post-hypoxic leukoencephalopathy following alcohol consumption and cardiopulmonary arrest

Delayed post hypoxic leukoencephalopathy (DPHL) is a rare consequence of hypoxic brain injury that occurs several days to weeks following an initial hypoxic insult. Most of the previously published cases occur in the setting of drug overdoses or carbon monoxide poisoning, where the incidence of DPHL is as high as 3%. Our case depicts a patient with delayed hypoxic brain injury following cardiac arrest with cardiopulmonary resuscitation. Initial neuroimaging was normal, and a repeat MRI scan six days later revealed DWI changes consistent with DPHL. Our patient remained comatose throughout his clinical course until his eventual death nine days after the initial incident. The autopsy confirmed hypoxic-ischemic brain injury with co-existent Wernicke's encephalopathy, a known consequence of alcohol use disorder. This case outlines the clinical course of DPHL accompanied by the unique neuroimaging features that distinguish it from conventional hypoxic-ischemic brain injury.