Toxic leukoencephalopathies

Toxic Leukoencephalopathy After "Chasing the Dragon" With a Non-Heroin Opioid

In the United States, the rate of opioid use increases each year. With this, users are engaging in more non-traditional methods of usage. "Chasing the dragon" is a term used to describe opioid inhalation, where the user heats the opioid and then inhales the smoke. While this method of usage is typically associated with a quicker high and fewer adverse effects, it can also lead to toxic leukoencephalopathy (TLE). TLE is defined as a structural alteration of the brain's white matter due to toxic exposure, such as heroin. A 57-year-old woman with a history of polysubstance abuse was admitted to the hospital after weeks of erratic behavior. At presentation, her urine drug screen was found to be positive for oxycodone (which was prescribed to her) and fentanyl. A brain MRI was eventually done, which showed a periventricular leukoencephalopathy characteristic of opioid inhalation. Traditionally, opioid-related TLE is due to heroin, and patients are found to have very dramatic motor issues. As this patient did not report a history of heroin use and did not present with significant motor deficits, this report highlights the need to maintain a level of suspicion for TLE. As levels of opioid use continue to rise, it is likely that many presentations like that of the patient outlined in this report will be seen.

Posterior Reversible Encephalopathy Syndrome (PRES) in a Patient with Opioid Use Disorder

Posterior Reversible Encephalopathy Syndrome (PRES) is a characteristic clinical radiographic syndrome with diffuse structural alteration of cerebral white matter secondary to myelin damage with diverse and multifactorial etiologies. It can present with acutely altered mentation, somnolence or occasionally stupor, vision impairment, seizures, and sudden or chronic headaches that are not focal. The pathophysiology remains unclear, but mechanisms involving endothelial injury and dysregulation of cerebral autoregulation have been purported. We report the case of a 36-year-old male with a history of heroin use disorder, who was admitted to our hospital for opioid withdrawal. CT head without contrast and MRI with and without gadolinium showed significant white matter disease in both cerebral hemispheres and cerebellum. He was diagnosed with Posterior Reversible Encephalopathy Syndrome secondary to heroin use and managed on the medical floor in collaboration with the neurology team. His clinical symptoms improved and he was discharged after six weeks. To our knowledge, this case did not present with the risk factors for PRES reported in the literature. For patients with heroin use disorder who present with an altered mental status, PRES should be highly suspected. The diagnosis and management require collaboration between psychiatry and neurology.

Mimicking a Psychiatric Disorder: Heroin-Induced Leukoencephalopathy

Toxic leukoencephalopathy is a rare cause of encephalopathy. We describe two cases of toxic leukoencephalopathy associated with opiate abuse where they were misdiagnosed and admitted to the psychiatric ward. In our case series, both patients presented with behavioral changes, restlessness, pressured speech, and cognitive impairment for which they were initially labeled as psychiatric patients and were treated as such. However, after an extensive workup to elucidate the etiology of alteration in mental status, toxic leukoencephalopathy associated with heroin abuse was found to be the culprit in both cases. Toxic leukoencephalopathy is a rare condition that can be caused by inhalation of heroin. Clinically, it may present with confusion, behavioral changes, extrapyramidal symptoms, generalized motor deficit, unresponsiveness and even death. Our cases highlight the importance of recognizing the psychiatric presentation of toxic leukoencephalopathy.

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.

Chasing the wrong dragon: A new presentation of heroin-induced toxic leukoencephalopathy mimicking anoxic brain injury

Toxic leukoencephalopathy associated with heroin inhalation has been extensively described in the literature. This syndrome is characterized by progressive motor symptoms and dysautonomia that develop over weeks to months. We present three cases of abrupt-onset inhaled heroin-associated toxic leukoencephalopathy, a previously undescribed entity. These likely represent a subset of "found down" patients with acute neurologic changes not attributable to hypoxemic encephalopathy. All three had magnetic resonance imaging findings characteristic of toxic leukoencephalopathy, which has a relatively favorable prognosis. Prolonged unresponsiveness in patients "found down" after heroin overdose is often attributed to hypoxic brain injury. Brain magnetic resonance imaging is not generally included as part of routine workup. It should, however, be considered in patients with suspected inhaled heroin use due to the relatively favorable prognosis of toxic leukoencephalopathy. This is especially relevant in the setting of the current opioid epidemic and related increase in overdose-related intensive care unit admissions. The result may have significant impact on decisions about therapeutic options or continuation of care.

Delayed posthypoxic leukoencephalopathy: a case series and review of the literature

BACKGROUND

Delayed posthypoxic leukoencephalopathy (DPHL) is a rare and underrecognized entity where patients manifest a neurological relapse after initial recovery from an acute hypoxic episode. We sought to describe the magnetic resonance imaging (MRI) findings in a group of patients with DPHL and review the available literature.

METHODS

Retrospective case series including patients who presented with neurological and/or psychiatric symptoms after recovery from an acute hypoxic episode. The history and clinical presentation were reviewed from the electronic medical records. MRI scans were evaluated from the picture archiving and communication system. We performed a comprehensive review of the English medical literature for prior published cases of DPHL and describe the key imaging findings that have been reported related to this condition.

RESULTS

A total of five patients were identified, including four patients with respiratory failure due to drug overdoses from benzodiazepines, opioids, and/or barbiturates, and one patient who presented after cardiopulmonary arrest due to pulmonary embolism. All patients showed diffuse, extensive, and confluent white matter signal abnormalities including prominent restricted diffusion, extending to the subcortical white matter and respecting the U-fibers. There was no gyral edema or contrast enhancement. In one case histopathology was available, which highlighted patchy subcortical myelin loss with sparing of U-fibers and demonstrated prominent macrophage/microglial inflammation with extensive axonal damage. Of the other four patients, two were at their neurological baselines and two had persistent neurological deficits at the time of discharge.

CONCLUSIONS

The described constellation of MRI findings is highly suggestive of DPHL in the appropriate clinical setting.

Pyrolysis of drugs of abuse: a comprehensive review

This review summarizes the literature to date relating to pyrolysis and heated vapour ingestion of drugs of abuse. In this context, heating is referred to as smoking or pyrolysis, but these are generic descriptors that encompass numerous methods of vapour generation and inhalation. Depending on the amount of drug used, diluents and contaminants present, heating conditions, and the oxidative/reductive environment, many thermal decomposition products can be formed. In addition to the recognized hazard of rapid onset of pharmacological effects of the parent drug, thermal decomposition products may be pharmacologically active as well as acutely/chronically toxic. For example, several published reports have linked heroin smoking to a form of brain encephalopathy and to the development of movement disorders. Early qualitative studies focusing on the thermal decomposition of drugs have evolved into more complex investigations employing mass spectral identification, confirmation, and elucidation of formation mechanism. In most cases, thermal decomposition begins with cleavage of the weakest bond (often C-N) to generate free radicals that then form the most stable sterically favoured products. Several reports of rearrangements at higher temperatures have been identified and hint at an underlying complexity that arises from the variety of smoking methods and conditions. Given that many designer drugs such as synthetic cannabinoids are ingested primarily through smoking, this issue has taken on new importance.