Methadone-induced acute toxic leukoencephalopathy

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.

Diffuse subcortical white matter injury and bilateral basal ganglia neuronal loss after acute opioid overdose

Opiate intoxication has been associated with life-threatening effects of sympathetic suppression and respiratory depression, but current literature is limited in describing its neurotoxic effects on the central nervous system. Here, we present the case of an otherwise high-functioning adolescent male who was found unresponsive after ingestion of approximately 3-4 fake oxycodone 10-325 mg pills laced with fentanyl. Magnetic resonance imaging showed evidence of diffuse T2 hyperintensities in the corpus callosum and bilateral frontal, parietal, and cerebellum indicative of diffuse white matter injury. In addition, there were distinct areas of restricted diffusion in the bilateral basal ganglia concerning for oxidative stress-mediated neuronal loss. His neurological exam improved with supportive treatment over the course of his hospitalization. Although limited literature has shown leukoencephalopathy to be associated with opioid overdose, we present a case of additional involvement of subcortical gray matter.

The molecular neurobiology and neuropathology of opioid use disorder

The number of people diagnosed with opioid use disorder has skyrocketed as a consequence of the opioid epidemic and the increased prescribing of opioid drugs for chronic pain relief. Opioid use disorder is characterized by loss of control of drug taking, continued drug use in the presence of adverse consequences, and repeated relapses to drug taking even after long periods of abstinence. Patients who suffer from opioid use disorder often present with cognitive deficits that are potentially secondary to structural brain abnormalities that vary according to the chemical composition of the abused opioid. This review details the neurobiological effects of oxycodone, morphine, heroin, methadone, and fentanyl on brain neurocircuitries by presenting the acute and chronic effects of these drugs on the human brain. In addition, we review results of neuroimaging in opioid use disorder patients and/or histological studies from brains of patients who had expired after acute intoxication following long-term use of these drugs. Moreover, we include relevant discussions of the neurobiological mechanisms involved in promoting abnormalities in the brains of opioid-exposed patients. Finally, we discuss how novel strategies could be used to provide pharmacological treatment against opioid use disorder.

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Brain abnormalities caused by opioid intoxication.

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Intoxication of opioids leads to defects in brain neurocircuitries.

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Insight into the molecular mechanisms associated with craving in heroin addicts.

Methadone-induced encephalopathy: a case series and literature review

BACKGROUND

Accidental ingestion or consumption of supra-therapeutic doses of methadone can result in neurological sequelae in humans. We aimed to determine the neurological deficits of methadone-poisoned patients admitted to a referral poisoning hospital using brain magnetic resonance (MR) and diffusion weighted (DW) imaging.

METHODS

In this retrospective study, brain MRIs of the patients admitted to our referral center due to methadone intoxication were reviewed. Methadone intoxication was confirmed based on history, congruent clinical presentation, and confirmatory urine analysis. Each patient had an MRI with Echo planar T1, T2, FLAIR, and DWI and apparent deficient coefficient (ADC) sequences without contrast media. Abnormalities were recorded and categorized based on their anatomic location and sequence.

RESULTS

Ten patients with abnormal MRI findings were identified. Eight had acute- and two had delayed-onset encephalopathy. Imaging findings included bilateral confluent or patchy T2 and FLAIR high signal intensity in cerebral white matter, cerebellar involvement, and bilateral occipito-parietal cortex diffusion restriction in DWI. Internal capsule involvement was identified in two patients while abnormality in globus pallidus and head of caudate nuclei were reported in another. Bilateral cerebral symmetrical confluent white matter signal abnormality with sparing of subcortical U-fibers on T2 and FLAIR sequences were observed in both patients with delayed-onset encephalopathy.

CONCLUSIONS

Acute- and delayed-onset encephalopathies are two rare adverse events detected in methadone-intoxicated patients. Brain MRI findings can be helpful in detection of methadone-induced encephalopathy.

Opioid-induced toxic leukoencephalopathy: A case report and review of the literature

Importance

Reports of toxic leukoencephalopathy (TLE) due to opioids have been extensively documented within the adult literature. There is a paucity of literature with respect to the incidence, complications, and outcomes of TLE in the pediatric population.

Objective

To describe a rare complication of opioid ingestion in the pediatric population and serve as the first large review of published cases of opioid-induced leukoencephalopathy. Thirteen case reports with varying treatments are herein reviewed in addition to our own case. The range of treatment modalities, morbidity and mortality are broad and outcomes secondary to supportive care versus neurosurgical intervention is explored.

Evidence review

All cases of pediatric opioid-induced toxic leukoencephalopathy published on pubmed and google scholar were included in this review.

Findings

We report the case of a 4-year old male surgically treated for acute oxycodone-induced TLE who initially presented with Glascow Coma Scale of 4 and a comatose state for weeks. Over the next several months he recovered with spasticity of all extremities, oral aversion, substantial vision loss, and the ability to speak in short sentences. In addition, we found thirteen other reported cases of opioid-induced leukoencephalopathy reported in the literature. The treatment approaches described range from supportive care alone, to invasive neurosurgical interventions including placement of extraventricular drains, removal of hemorrhagic tissue, and craniectomy. The outcomes of patients with opioid-induced leukoencephalopathy is also variable. Reports demonstrate a range of outcomes that include patients who died to those with no residual neurologic deficits.

Conclusions

This review of reported pediatric cases of opioid-induced leukoencephalopathy highlights the importance of early neurosurgical intervention for prevention of devastating outcomes.