Acute myelopathy selectively involving lumbar anterior horns following intranasal insufflation of ecstasy and heroin

Substance Use and the Nervous System

OBJECTIVE

This article informs and updates the practicing neurologist on the current landscape of known neurologic injuries linked to the use of illicit drugs, focusing on emerging agents.

LATEST DEVELOPMENTS

Synthetic opioids such as fentanyl and similar derivatives have exploded in prevalence, becoming the leading cause of overdose fatalities. The higher potency of synthetic opioids compared with semisynthetic and nonsynthetic opiates poses an increased risk for unintentional overdose when found as an adulterant in other illicit drug supplies such as heroin. Conversely, misinformation about the risk of symptomatic exposure to fentanyl through casual contact with the skin and ambient air has led to misdirected fear and stigma that threatens to impede valid harm-reduction measures for fentanyl users at risk of actual overdose. Finally, during the COVID-19 pandemic, overdose rates and deaths continued to climb, especially among those who use opioids and methamphetamine.

ESSENTIAL POINTS

A variety of potential neurologic effects and injuries can occur with illicit drug use owing to the diverse properties and mechanisms of action of the various classes. Many high-risk agents are not detected on standard drug screens, including so-called designer drugs, and the practicing neurologist is best served by recognizing the clinical features of the traditional toxidrome and other potential idiosyncratic effects of various illicit agents.

Metabolic and Toxic Myelopathies

Metabolic and toxic causes of myelopathy form a heterogeneous group of disorders. In this review, we discuss the causes of metabolic and toxic myelopathies with respect to clinical presentation, pathophysiology, diagnostic testing, treatment, and prognosis. This review is organized by temporal course (hyperacute, acute, subacute, and chronic) and etiology (e.g., nutritional deficiency, toxic exposure). Broadly, the myelopathies associated with dietary toxins (neurolathyrism, konzo) and decompression sickness present suddenly (hyperacute). The myelopathies associated with heroin use and electrical injury present over hours to days (acutely). Most nutritional deficiencies (cobalamin, folate, copper) and toxic substances (nitrous oxide, zinc, organophosphates, clioquinol) cause a myelopathy of subacute onset. Vitamin E deficiency and hepatic myelopathy cause a chronic myelopathy. Radiation- and intrathecal chemotherapy-induced myelopathy can cause a transient and/or a progressive syndrome. For many metabolic and toxic causes of myelopathy, clinical deficits may stabilize or improve with rapid identification and treatment. Familiarity with these disorders is therefore essential.

The Emerging Role of Inhaled Heroin in the Opioid Epidemic: A Review

Importance

Opioid addiction affects approximately 2.4 million Americans. Nearly 1 million individuals, including a growing subset of 21 000 minors, abuse heroin. Its annual cost within the United States amounts to $51 billion. Inhaled heroin use represents a global phenomenon and is approaching epidemic levels east of the Mississippi River as well as among urban youth. Chasing the dragon (CTD) by heating heroin and inhaling its fumes is particularly concerning, because this method of heroin usage has greater availability, greater ease of administration, and impressive intensity of subjective experience (high) compared with sniffing or snorting, although it also has a safer infectious profile compared with heroin injection. This is relevant owing to peculiar and often catastrophic brain complications. Following the American Medical Association Opioid Task Force mandate, we contribute a description of the pharmacology, pathophysiology, clinical spectrum, neuroimaging, and neuropathology of CTD leukoencephalopathy, as distinct from other heroin abuse modalities.

Observations

The unique spectrum of CTD-associated health outcomes includes an aggressive toxic leukoencephalopathy with pathognomonic neuropathologic features, along with sporadic instances of movement disorders and hydrocephalus. Clinical CTD severity is predominantly moderate at admission, frequently unmodified at discharge, and largely improved in the long term. Mild cases survive with minor sequelae, while moderate to severe presentations might deteriorate and progress to death. Other methods of heroin use may complicate with stroke, seizure, obstructive hydrocephalus, and (uncharacteristically) leukoencephalopathy.

Conclusions and Relevance

The distinct pharmacology of CTD correlates with its specific clinical and radiological features and prompts grave concern for potential morbidity and long-term disability costs. Proposed diagnostic criteria and standardized reporting would ameliorate the limitations of CTD literature and facilitate patient selection for a coenzyme Q10 therapeutic trial.

Outcomes associated with hospital admissions for accidental opioid overdose in British Columbia: a retrospective cohort study

OBJECTIVES

To study the association between accidental opioid overdose and neurological, respiratory, cardiac and other serious adverse events and whether risk of these adverse events was elevated during hospital readmissions compared with initial admissions.

DESIGN

Retrospective cohort study.

SETTING

Population-based study using linked administrative data in British Columbia, Canada.

PARTICIPANTS

The primary analysis included 2433 patients with 2554 admissions for accidental opioid overdose between 2006 and 2015, including 121 readmissions within 1 year of initial admission. The secondary analysis included 538 patients discharged following a total of 552 accidental opioid overdose hospitalizations and 11 040 matched controls from a cohort of patients with ≥180 days of prescription opioid use.

OUTCOME MEASURES

The primary outcome was encephalopathy; secondary outcomes were adult respiratory distress syndrome, respiratory failure, pulmonary haemorrhage, aspiration pneumonia, cardiac arrest, ventricular arrhythmia, heart failure, rhabdomyolysis, paraplegia or tetraplegia, acute renal failure, death, a composite outcome of encephalopathy or any secondary outcome and total serious adverse events (all-cause hospitalisation or death). We analysed these outcomes using generalised linear models with a logistic link function.

RESULTS

3% of accidental opioid overdose admissions included encephalopathy and 25% included one or more adverse events (composite outcome). We found no evidence of increased risk of encephalopathy (OR 0.57; 95% CI 0.13 to 2.49) or other outcomes during readmissions versus initial admissions. In the secondary analysis, <5 patients in each cohort experienced encephalopathy. Risk of the composite outcome (OR 2.15; 95% CI 1.48 to 3.12) and all-cause mortality (OR 2.13; 95% CI 1.18 to 3.86) were higher for patients in the year following overdose relative to controls.

CONCLUSIONS

We found no evidence that risk of encephalopathy or other adverse events was higher in readmissions compared with initial admissions for accidental opioid overdose. Risk of serious morbidity and mortality may be elevated in the year following an accidental opioid overdose.

Acute extensive myelopathy after single heroin and cocaine exposure in a patient with toxicological evidence of long-term drug abstinence

Heroin-related myelopathy is an uncommon but often devastating complication of heroin intake. It is usually reported in individuals exposed to intravenous heroin after a variable drug-free period, leading to acute and complete spinal cord injury with poor long-term outcome. We describe an original case of acute longitudinally extensive transverse myelopathy following single heroin and cocaine intravenous exposure after a long period of abstinence confirmed by toxicological hair and retrospective urine drug analysis. This case could provide new insights in the understanding of this rare neurological complication.

Neurotoxicology and drug-related disorders

Neuropsychiatric disorders caused by toxic substances pose a great diagnostic challenge due to the large variety of changes caused in the central and peripheral nervous system. The pathogenetic mechanisms at work are multifaceted and partly not solved. In human drug abusers (cannabis, opiates, cocaine, amphetamines, methamphetamine and "designer drugs"), a broad spectrum of central nervous system alterations are observed including infarction, intracerebral and subarachnoidal hemorrhage, hypoxic-ischemic leukoencephalopathy, infections, neuronal loss, specific astroglial and microglial reaction patterns, and vascular changes, including the endothelial cell as well as the basal lamina.

The prevalence and correlates of buprenorphine inhalation amongst opioid substitution treatment (OST) clients in Australia

BACKGROUND

Diversion and injection of buprenorphine (Subutex(®)) and buprenorphine-naloxone (Suboxone(®)) have been well documented. Recent international research and local anecdotal evidence suggest that these medications are also used by other routes of administration, including smoking and snorting.

METHODS

A cross-sectional sample of 440 opioid substitution treatment (OST) clients was recruited through pharmacies and clinics in three Australian jurisdictions, and interviewed face-to-face using a structured questionnaire. Eligible participants were those aged 18 or over, who had resided in their home state for at least six months, and had been in their current treatment episode for at least 4 weeks. We compared differences in characteristics between clients who had ever inhaled (smoked or snorted) buprenorphine (including buprenorphine-naloxone) and other OST clients. Logistic regression was used to identify correlates of buprenorphine inhalation. Sixty-eight clients who had never used buprenorphine were excluded from analysis.

RESULTS

Sixty-five clients (18%) reported having ever inhaled buprenorphine, with Subutex(®) smoking being most common, reported by 50 clients (77%). In multivariable logistic regression, those who reported ever inhaling buprenorphine were significantly more likely to: be aged 35 or younger, have ever been in prison and have ever injected buprenorphine. Clients from New South Wales and Victoria were significantly less likely to have ever inhaled buprenorphine than those from South Australia.

CONCLUSIONS

Our data indicates that the inhalation of buprenorphine has occurred in a significant minority of Australian OST clients. The motivations, contexts and potential health consequences of buprenorphine use by these atypical routes of administration, particularly in a correctional setting, warrant further exploration.