Methadone-induced encephalopathy: a case series and literature review

Severe cerebral edema related to oral methadone: A case report and literature review

Introduction

Opioids are widely used for pain management, and increased intracranial pressure (ICP) has been evidenced in some cases. We reported a patient with severe cerebral edema after initiating methadone and its complete resolution upon discontinuing the medication. Additionally, a review of the literature is made.

Case report

A 53-year-old woman patient with a history of systemic lupus erythematosus developed mechanic chronic lower back pain, refractory to conventional treatments. She presented improvement with oxycodone. She withdrew this medication due to a lack of supplies in her country (Colombia) and showed withdrawal symptoms. She consulted the emergency department, where oral methadone was started and symptom control was achieved. Three days after admission, she presented intense headaches and emesis. A brain CT scan was performed in which severe cerebral edema was appreciated. Methadone was discontinued, and neurological symptoms quickly disappeared. A follow-up brain CT scan was performed later, finding full resolution of the edema.

Conclusion

A case of severe cerebral edema associated with the initiation of oral methadone and its rapid resolution without neurological sequelae after its withdrawal is presented, clinicians must be attentive to this adverse event.

Toxic leukoencephalopathy versus delayed post-hypoxic leukoencephalopathy after oral morphine sulphate overdose

Toxic leukoencephalopathy (TLE) is a rare pathology caused by various substances including opioids (notably heroin), immunosuppressants, chemotherapy agents, cocaine, alcohol and carbon monoxide. However, although heroin is metabolised by the body into morphine, there is a striking paucity in cases of primary oral morphine-induced TLE, especially in the adult population. We present the case of a man in his 40s admitted to hospital in respiratory depression with a Glasgow Coma Scale (GCS) score of 6 after taking an overdose of oral morphine sulphate. Following a complete recovery to baseline, he was then readmitted with an acute deterioration in his neurobehavioural condition. Initial investigations returned normal but MRI showed changes characteristic for TLE.In cases of opioid toxicity such as ours, TLE is difficult to differentiate from delayed post-hypoxic leukoencephalopathy, due to their similar clinical presentation, disease progression and radiological manifestation. We explore how clinicians can approach this diagnostic uncertainty.

A case of posterior reversible encephalopathy syndrome during endoscopic retrograde cholangiopancreatography after anesthesia

Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder that occurs following cerebral vasogenic edema. It has diverse clinical presentations from headache and vomiting to seizure and mental status alteration. Herein, we report a 54-year-old woman with no prior disease who developed PRES in the parieto-occipital lobes and brain stem after a second attempt endoscopic retrograde cholangiopancreatography (ERCP). To our knowledge, no case of PRES during ERCP has been reported to date. This case reminds us of unusual complications that are likely to occur after ERCP. It is believed that blood pressure fluctuations and anesthetic medications, fentanyl in particular, were the main precipitating factors causing the syndrome in the current case. Even if there is no specific treatment for this condition, a diagnosis is critical to start supportive treatment.

Neurocognitive impairments and brain abnormalities resulting from opioid-related overdoses: A systematic review

BACKGROUND

Non-fatal opioid-related overdoses have increased significantly over the past two decades and there have been increasing reports of brain injuries and/or neurocognitive impairments following overdose events. Limited preclinical research suggests that opioid overdoses may cause brain injury; however, little is known about such injuries in humans. The purpose this systematic review is to summarize existing studies on neurocognitive impairments and/or brain abnormalities associated with an opioid-related overdose in humans.

METHODS

PubMed, Web of Science, Ovid MEDLINE and PsyINFO were searched, without year restrictions, and identified 3099 articles. An additional 24 articles were identified by reviewing references. Articles were included if they were published in English, reported study findings in humans, included individuals 18 years of age or older, and reported an objective measure of neurocognitive impairments and/or brain abnormalities resulting from an opioid-related overdose. Six domains of bias (selection, performance, attrition, detection (two dimensions) and reporting were evaluated and themes were summarized.

RESULTS

Seventy-nine journal articles, published between 1973-2020, were included in the review. More than half of the articles were case reports (n = 44) and there were 11 cohort studies, 18 case series, and 6 case-control studies. All of the studies were categorized as at-risk of bias, few controlled for confounding factors, and methodological differences made direct comparisons difficult. Less than half of the studies reported toxicology results confirming an opioid-related overdose; 64.6 % reported brain MRI results and 27.8 % reported results of neuropsychological testing. Only two studies had within subject comparative data to document changes in the brain possibly associated with an overdose. Despite these limitations, existing publications suggest that brain injuries and neurocognitive impairments are associated with opioid overdose. Additional research is needed to establish the incidence of overdose-related brain injuries and the potential impact on functioning, as well as engagement in treatment of substance use disorders.

CONCLUSIONS

Respiratory depression is a defining characteristic of opioid overdose and prolonged cerebral hypoxia may cause brain injuries and/or neurocognitive impairments. The onset, characteristics, and duration of such injuries is variable and additional research is needed to understand their clinical implications.

A case report of toxic leukoencephalopathy induced by metronidazole in a woman with surgical site infection

Metronidazole may rarely cause encephalopathy and neuropathy. In this study, we report a 30-year-old post-partum, ex-addicted female with leukoencephalopathy due to metronidazole.