Leukoencephalopathy and raised brain lactate from heroin vapor inhalation ("chasing the dragon")

Clinical and neuroradiographic features of fentanyl inhalation-induced leukoencephalopathy

A man in his late 40s with no known past medical history was unresponsive for an unknown period of time. Crushed pills and white residue were found on a nearby table. On presentation he was obtunded and unresponsive to verbal commands but withdrawing to painful stimuli. The initial urine drug screen was negative, but a urine fentanyl screen was subsequently positive with a level of 137.3 ng/mL. MRI of the brain showed reduced diffusivity and fluid attenuated inversion recovery (FLAIR) hyperintensity symmetrically in the bilateral supratentorial white matter, cerebellum and globus pallidus. Alternative diagnoses such as infection were considered, but ultimately the history and workup led to a diagnosis of fentanyl-induced leukoencephalopathy. Three days after admission the patient became able to track, respond to voice and follow basic one-step commands. The patient does not recall the mechanism of inhalation. While there are case reports of heroin-induced leukoencephalopathy following inhaled heroin use and many routes of fentanyl, this is the first reported case of a similar phenomenon due to fentanyl inhalation.

Imaging of Drug-Related Vasculopathy

Illicit and recreational drugs, such as cocaine, heroin, amphetamines, and marijuana, can result in drug-related vasculitis or vasculopathy. Similarly, the use of certain antithyroid, oncologic, and immunosuppressive medications for therapeutic purposes can lead to vasculopathy. This in turn may result in significant complications in the central nervous system, including intracranial hemorrhage and stroke. Cocaine abuse can also lead to midline destructive lesions of the sinonasal complex. MR imaging, Vessel Wall imaging, and CT/CTA are valuable imaging tools for the evaluation of patients with suspected drug-induced vasculopathy or vasculitis. This article reviews the pathomechanism, clinical presentation, and imaging findings of vasculopathy related to drug abuse and prescribed medications.

Spongiform leukoencephalopathy unveiled in an autopsy of a drug abuser

Toxic leukoencephalopathy (TLE) is a rare neurological debilitating and fatal condition. It has been previously associated with exposure to leukotoxic offenders such as chemotherapy, cranial radiation, certain drugs, and environmental factors. Currently, it is a commoner white matter syndrome resulting from increased substance abuse, classically by inhaled heroin and other opioids. Herein, we report a case of fatal TLE unveiled in an autopsy of a drug abuser. A 24-year-old male was found dead on the roadside. A day before, he was located in a state of delirium. In this case, the autopsy findings and histopathology characteristics of cerebral cortex involvement particularly directed to speculate the heroine as the principal offender.

Heroin Inhalation Leukoencephalopathy: An Overlooked Entity in the Opioid Epidemic

Heroin inhalation leukoencephalopathy (HIL) is a rare complication of vaporized heroin inhalation leading to white matter degeneration resulting in a range of neurologic disturbances including softened speech, cerebellar ataxia, behavioral changes, cerebellar gait abnormalities, and even respiratory failure resulting in death in the most severe cases. Magnetic resonance imaging (MRI) most commonly demonstrates bilateral hyperintensities affecting the basal ganglia, periventricular white matter, and cerebellum. In this case report, we present a relatively mild case of HIL in a young female patient to describe the characteristic challenges associated with the condition's presentation, diagnosis, and treatment. While healthcare workers everywhere are addressing a complex and ever-changing opioid epidemic, we strive to raise awareness about HIL as only one of a variety of complications resulting from opioid use disorder.

Methamphetamine-induced encephalopathy in the absence of hyperammonemia

BACKGROUND

Methamphetamine is an addictive drug with various effects on the neurotransmitters in the central nervous system. Methamphetamine-induced encephalopathy in the absence of hyperammonemia presents a unique challenge in a clinical setting. Previously published cases of methamphetamine-induced encephalopathy suggested that methamphetamine-induced hepatotoxicity and subsequent hyperammonemia may be the cause of encephalopathy. However, the literature is limited on methamphetamine-induced encephalopathy without hyperammonemia.

CASE

This case presents a disoriented patient with methamphetamine use disorder in acute toxicity, unable to ambulate independently, and poorly responsive to verbal stimuli. The patient was found to have normal ammonia levels.

DISCUSSION

This patient's presentation and laboratory findings, namely normal ammonia levels, suggest a different pathophysiological pathway for methamphetamine-induced encephalopathy. One potential pathway is through the direct action of methamphetamine on the central nervous system through acute disruption of neurotransmitter signaling and disruption of the blood-brain barrier.

CONCLUSION

Further research should be conducted into the prevalence and pathophysiology of methamphetamine-induced encephalopathy in the absence of hyperammonemia.

KEY POINTS

Methamphetamine-induced encephalopathy (MIE) in the absence of hyperammonemia presents a unique challenge in a clinical setting. Previously published cases of MIE suggest that methamphetamine-induced hepatotoxicity and subsequent hyperammonemia may be the cause of encephalopathy. Further research should be conducted into the prevalence and pathophysiology of MIE in the absence of hyperammonemia.

Heroin-Induced Leukoencephalopathy Leading to Locked-In Syndrome: A Case Report

Heroin-induced leukoencephalopathy (HLE) is a rare neurological sequela of heroin use. Heroin can be consumed through different routes such as inhalation, intravenous injection, and snorting. HLE cases have been reported via each route. However, heroin vapor inhalation has a higher rate of HLE and is also known as "chasing the dragon syndrome." We present a 65-year-old male who came unresponsive after heroin intoxication. During the hospital stay, he developed locked-in syndrome secondary to brain damage by HLE sequelae.

Prognosis in substance abuse-related acute toxic leukoencephalopathy: A scoping review

OBJECTIVES

Abuse of opiates, cocaine, and lipophilic inhalants (e.g., toluene) can damage brain myelin and cause acute toxic leukoencephalopathy (TL), but little is known about recovery or prognosis in this condition. In light of the ongoing opiate epidemic in the United States, it is important to understand the natural history of patients who have acute neurological complications from illicit drug exposure. Our aim was to conduct a scoping review of the literature regarding prognosis in described cases of substance abuse-related TL.

METHODS

A strategic search of PubMed, Ovid, Cumulative Index to Nursing, and Allied Health Literature (CINAHL) databases yielded adult cases of acute TL from opiates, cocaine, or inhalants. Cases and case series were eligible for inclusion if they described acute leukoencephalopathy with a clear temporal association with opiate, cocaine, or inhalant abuse. Inclusion was contingent on availability of clinical descriptions until death or ≥ 4 weeks follow-up with neuroimaging consistent with TL.

RESULTS

Among 52 cases from 14 articles, 21 (40.4%) individuals died with mean time to death of 28.2 days; with mean follow-up of 12.8 months, 10 (19.2%) survived with no recovery, 17 (32.7%) had partial recovery, and 4 (7.7%) individuals had full recovery.

CONCLUSION

Substance abuse-related acute TL often has a poor prognosis, but partial or even full recovery is possible in a subgroup of individuals over months to years.

Toxic Spongiform Leukoencephalopathy After Intravenous Heroin Abuse: Unusual But Important Differential Diagnosis of Acute Impairment of Consciousness

Abuse of heroin vapour inhalation known as "chasing the dragon" is associated with toxic spongiform leukoencephalopathy. However, similar clinical and imaging findings may occur also after intravenous heroin abuse. We report on a 32-year-old male suffering from extensive toxic spongiform leukoencephalopathy after intravenous heroin abuse resulting in acute impairment of consciousness and a global state of confusion. MRI disclosed broad and nearly symmetrical diffusion restriction of the supratentorial white matter indicating cytotoxic oedema. In an emergency setting, differential diagnosis of acute impairment of consciousness and broad symmetrical white matter lesions in neuroimaging should also include toxic leukoencephalopathy due to intravenous heroin application.

Leukoencephalopathy due to inhalational and trans-conjunctival heroin abuse: First case report from Pakistan

Introduction

and importance: Heroin-induced leukoencephalopathy (HLE) is a rare illness that causes diffuse white matter destruction, leading to acute or subacute development of neurological signs and symptoms. Physicians must be aware of the likely clinical presentation to properly evaluate and diagnose this clinical entity.

Case presentation

We report the case of a young gentleman who presented with acute stupor following his first instance of heroin vapor inhalation. He later confessed to trans-conjunctival application of the drug as well. His Glasgow Coma Scale (GCS) score improved within four days of admission, however, the neurologic sequalae such as cognitive impairment, spastic paraparesis and urge incontinence only partially resolved at three months. Abnormal white matter hyperintensities with restricted diffusion on brain magnetic resonance imaging and history of heroin abuse led to diagnosis of toxic leukoencephalopathy.

Clinical discussion

Leukoencephalopathy with heroin is mostly observed after inhalation (i.e., “chasing the dragon”) but other routes of abuse have also been reported. Although a large spectrum of presentations exists, altered mental status, cerebellar dysfunction and fecal/urinary incontinence are the most commonly seen presenting features. Anti-oxidant therapy has shown promising results in terms of treatment.

Conclusion

The growing rates of opioid use disorders require physicians to be aware of and counsel the patients regarding dangerous neurological sequelae of these drugs.

•

Heroin-induced leukoencephalopathy (HLE) is a rare entity that can present with neurobehavioral symptoms and focal neurological deficits.

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It is most common after inhalation but trans-conjunctival abuse may cause it as well.

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The growing rates heroin abuse require physicians to be aware of and counsel the patients regarding HLE.

Neuroimaging Pearls from the MDS Congress Video Challenge. Part 2: Acquired Disorders

The MDS Video Challenge continues to be the one of most widely attended sessions at the International Congress. Although the primary focus of this event is the presentation of complex and challenging cases through videos, a number of cases over the years have also presented an unusual or important neuroimaging finding related to the case. We reviewed the previous Video Challenge cases and present here a selection of those cases which incorporated such imaging findings. We have compiled these "imaging pearls" into two anthologies. The first focuses on pearls where the underlying diagnosis was a genetic condition. This second anthology focuses on imaging pearls in cases where the underlying condition was acquired. For each case we present brief clinical details along with neuroimaging findings, the characteristic imaging findings of that disorder and, finally, the differential diagnosis for the imaging findings seen.

Spongiform leukoencephalopathy: A unique case of biopsy confirmed leukoencephalopathy secondary to toxic, non-inflammatory exposure

Toxin-induced leukoencephalopathy is a rare neurological condition that has been previously associated with intracranial radiation, chemotherapy, drugs of abuse, and environmental exposures. Herein, we present a patient with brain-biopsy proven toxin-induced leukoencephalopathy, likely secondary to multiple environmental offenders including insecticides and non-Food and Drug Administration approved anabolic steroids, opioids, and benzodiazepines. A 60-year-old man presented to our service as a direct transfer from an outside facility for evaluation of a rapidly progressive neuropsychiatric decline. Extensive workup with blood work, cerebrospinal fluid analysis, paraneoplastic panel, serial magnetic resonance imaging brain with and without contrast, and electroencephalograms were unrevealing. Magnetic resonance imaging brain showed diffuse confluent white matter disease, which was non-specific. The patient was treated with high-dose methylprednisolone and trials of intravenous immunoglobulin without any significant improvement. Finally, a brain biopsy was performed, and pathology confirmed a spongiform leukoencephalopathy, favoring a toxin-related etiology. The diagnosis of toxin-induced leukoencephalopathy should be considered in patients with steep neuropsychiatric decline and associated diffuse white matter disease. Diagnosis relies heavily on history of exposure, clinical presentation, imaging findings, and ultimately, histopathology from brain biopsy. The recognition of the clinical presentation is important to pursue the appropriate diagnostic workup and treatment.

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.

Heroin-Induced Leukoencephalopathy

Heroin-induced leukoencephalopathy (HLE) is a rare but potentially debilitating and sometimes fatal neurological disorder. Despite the widely practiced heroin use via different routes and modalities, the syndrome is said to be rare and mostly associated with inhaling rather than injecting or snorting practices. We reviewed the literature to address the latest diagnostic, therapeutic, and prognostic measures related to the condition. Here, we present a case of a 35-year-old male who admitted to inhaling heroin 18 days ago and has been experiencing ongoing neurological symptoms for the past 17 days. Imaging was consistent with extensive white matter disease at multiple levels and different anatomical regions. Although there is no known cure for HLE, the patient benefited, somewhat, from antioxidants and physical rehabilitation.

Does a hypoxic injury from a non-fatal overdose lead to an Alzheimer Disease?

Long term consequence of non-fatal overdose in people who use opioids are not well understood. The intermittent exposure to non-fatal overdose leads to a tauopathy that is often accompanied by abrogated neuroprotective response, abnormal amyloid processing and other pathologies. The scope and limitations of available literature are discussed including neuropathologies associated with opioid and overdose exposures, contributing comorbidities and proteinopathies. Contrasting postmortem data of overdose victims with animal models of opioid neuropathologies and hypoxic injury paints a picture distinct from other proteinopathies as well as effects of moderate opioid exposure. Furthermore the reported biochemical changes and potential targets for therapeutic intervention were mapped pointing to underlying imbalance between tau kinases and phosphatases that is characteristic of Alzheimer Disease.

Toxic Leukoencephalopathy due to Inhalational Heroin Abuse

Heroin-induced spongiform leukoencephalopathy (HSLE) is a rare condition that is strongly associated with heroin vapor inhalation which has become a popular method among heroin addicts because it poses a less immediate danger to the user and makes the drug much easier to use. We present a case of a 22-year-old male who presented with dysarthria and cerebellar symptoms starting, after 3 months of heroin inhalation. Diagnosis was confirmed to be HSLE after extensive diagnostic testing. HSLE is a rare complication of which the pathogenesis is poorly understood. Clinical history and characteristic findings on magnetic resonance imaging (diffuse, symmetric T2-hyperintensity, and diffusion restriction in frontal, parietal, occipital lobs, basal ganglia, and superior cerebellum) are diagnostic; however, care should be taken to exclude other etiologies. Treatment is primarily supportive; however, there is anecdotal evidence that coenzyme Q10 may be of benefit. The growing number of victims of the opioid crisis requires that physicians be aware of and counsel patients on the devastating neurological complications that can occur with abuse of these drugs.

An Atypical Presentation of Heroin Inhalation Induced Leukoencephalopathy (Chasing the Dragon)

Heroin leukoencephalopathy is associated with 'Chasing the dragon,' which is a heroin vapour inhalation method that is different from smoking or sniffing heroin. The clinical presentation ranges from mild to severe disease. Mild disease is characterized by inattentiveness and ataxia. In moderate diseases, extrapyramidal symptoms predominate, and finally, severe disease is characterized by generalized motor impairment, with death occurring in two-third of cases. We now report a rare presentation of the disease in a 60-year-old female with a past medical history of heroin abuse who presented to ED with signs and symptoms of confusion and restlessness. MRI brain without contrast showed diffuse symmetric increased intensity signals throughout the white matter. Electroencephalogram (EEG) revealed mild diffuse slowing with no lateralization. The patient was started on Vitamin E and was transferred to a rehab facility with following up neurology as an outpatient.

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.

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.

Cocaine-induced toxic leucoencephalopathy with complete clinical recovery

A 45-year-old man, a regular cocaine user, presented with confusion and unusual behaviour to the emergency room. On examination he was unable to perform simple tasks or follow commands. He was treated for possible central nervous system infection. MRI of the brain showed multiple bilateral T2 hyperintense periventricular and deep white matter foci, best appreciated on FLAIR with contrast enhancement. He continued deteriorating, eventually becoming catatonic with extensor posturing and increased tone, requiring intensive therapy unit management. Repeat MRIs were also noted to show worsening changes. He was treated for a presumed inflammatory leucoencephalopathy with intravenous methylprednisolone, immunoglobulins, as well as plasmapheresis. After 2 weeks, the patient started to show clinical improvement with eventual transfer to a rehabilitation hospital. A year after his first presentation, the patient scored 30 out of 30 on the MMSE and his neurological examination was normal.

Different routes of heroin intake cause various heroin-induced leukoencephalopathies

OBJECTIVE

Toxic leukoencephalopathy is a rare but critical neurological disorder in heroin abusers. Our aim is to compare the clinical manifestations, brain MRIs and prognoses of heroin-induced leukoencephalopathy by different intake routes.

METHODS

We present two patients with toxic leukoencephalopathy caused by intravenous (IV) injection of heroin and 48 additional cases from systematic reviews of the literature published between 1994 and 2018.

RESULTS

Among the 50 heroin abusers who developed leukoencephalopathy, inhalation was the most popular route (60%), followed by IV injection (30%) and snorting (10%). Mental changes, mutism and urine/fecal incontinence were the major symptoms in patients who IV injected heroin, while cerebellar ataxia and dysarthria were more common among those who inhaled heroin. Delayed-onset encephalopathy uniquely occurred in those who IV injected heroin, whereas progressive encephalopathy was more commonly observed in those who inhaled heroin. Clinical improvement was observed in 60% of patients, the overall mortality rate was 12%, and higher mortality was observed in patients who used the inhalation route (16.7%). The hallmarks on the MRIs of those who inhaled heroin were posterior to anterior involvement of the cerebral white matter and lesions in the posterior limbs of the internal capsules, cerebellum and brainstem. In contrast, those who IV injected heroin had more frequent lesions in the subcortical U fibers and the genu of the internal capsules.

CONCLUSION

These data could help physicians make an early diagnosis and predict prognosis and suggest that prompt antioxidative or symptomatic treatments might reduce the long-term consequences and mortality of heroin-induced leukoencephalopathy.

13C Pyruvate Transport Across the Blood-Brain Barrier in Preclinical Hyperpolarised MRI

Hyperpolarised MRI with Dynamic Nuclear Polarisation overcomes the fundamental thermodynamic limitations of conventional magnetic resonance, and is translating to human studies with several early-phase clinical trials in progress including early reports that demonstrate the utility of the technique to observe lactate production in human brain cancer patients. Owing to the fundamental coupling of metabolism and tissue function, metabolic neuroimaging with hyperpolarised [1-13C]pyruvate has the potential to be revolutionary in numerous neurological disorders (e.g. brain tumour, ischemic stroke, and multiple sclerosis). Through the use of [1-13C]pyruvate and ethyl-[1-13C]pyruvate in naïve brain, a rodent model of metastasis to the brain, or porcine brain subjected to mannitol osmotic shock, we show that pyruvate transport across the blood-brain barrier of anaesthetised animals is rate-limiting. We show through use of a well-characterised rat model of brain metastasis that the appearance of hyperpolarized [1-13C]lactate production corresponds to the point of blood-brain barrier breakdown in the disease. With the more lipophilic ethyl-[1-13C]pyruvate, we observe pyruvate production endogenously throughout the entire brain and lactate production only in the region of disease. In the in vivo porcine brain we show that mannitol shock permeabilises the blood-brain barrier sufficiently for a dramatic 90-fold increase in pyruvate transport and conversion to lactate in the brain, which is otherwise not resolvable. This suggests that earlier reports of whole-brain metabolism in anaesthetised animals may be confounded by partial volume effects and not informative enough for translational studies. Issues relating to pyruvate transport and partial volume effects must therefore be considered in pre-clinical studies investigating neuro-metabolism in anaesthetised animals, and we additionally note that these same techniques may provide a distinct biomarker of blood-brain barrier permeability in future studies.

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.

Heroin-induced toxic leukoencephalopathy – “chasing the dragon” in South Africa

Purpose

In South Africa, many illicit drugs have only recently been introduced and drug-related complications are often new to treating physicians. Heroin-induced leukoencephalopathy has been reported elsewhere in patients who inhale heated heroin vapors, a method known as “chasing the dragon.” The purpose of this paper is to present two patients, known to have inhaled heroin a few weeks prior to presenting with progressive neurological deficits.

Design/methodology/approach

Case presentations: two young males presented independently within eight weeks of one another with progressive slurring of speech, incoordination and weakness of the limbs over a period of two to three weeks. Both were known heroin addicts, and were known to one another, and both had inhaled heroin prior to the onset of symptoms.

Findings

The patients presented with a pancerebellar syndrome with marked bilateral upper motor neuron signs. CT scans showed diffuse symmetrical hypodense lesions involving the cerebral and cerebellar white matter with normal CSF. Both patients deteriorated neurologically, became cardiovascularly unstable and demised. Postmortem in one of the patients showed a prominent spongiform leukoencephalopathy consistent with reports of heroin-inhalation injury to the brain.

Research limitations/implications

Toxic leukoencephalopathy due to heroin vapor inhalation was first described in the Netherlands in 1982. It has not been reported to occur with other modes of heroin use; an unknown toxin contained in heroin pyrolysate which forms when heroin is heated, may be causative. Brain MRI typically shows diffuse, symmetrical white matter hyperintensities on T2 and fluid-attenuated inversion recovery sequences in the cerebellum, posterior cerebrum and posterior limbs of the internal capsule with a posterior-anterior gradient. Pathologically, spongiform degeneration with relative sparing of subcortical U-fibers is seen. No treatment has been proven effective, but antioxidants and Vitamin E may be beneficial. Mortality is high at 23-48 percent.

Practical implications

This report emphasizes that spongiform leukoencephalopathy as a rare consequence of inhaling heroin vapors does occur in South Africa and clinicians should consider this disorder in their differential diagnosis of acutely developing leukoencephalopathy.

Social implications

An awareness program regarding this grave condition is planned.

Originality/value

The cardiovascular complications of patients inhaling heroin vapor has not been highlighted previously. These are the first patients from Africa described with this condition. A toxic component appears likely.

MRI in Chemotherapy induced Leukoencephalopathy: Report of Two Cases and Radiologist's Perspective

Leukoencephalopathy is a progressive white matter disease primarily caused due to myelin damage by a variety of factors. Chemotherapy for oncological treatment is an uncommon but important cause of potentially reversible leukoencephalopathy. In current radiological setting, conventional and diffusion weighted MRI play a significant role in early and accurate detection of this entity. We are hereby presenting MRI evaluation of two cases of methotrexate and 5-fluorouracil induced toxic leukoencephalopathy.

Psychosis After Switch in Opioid Maintenance Agonist and Risperidone-Induced Pisa Syndrome: Two Critical Incidents in Dual Diagnosis Treatment

BACKGROUND AND AIMS

Dual diagnosis commonly occurs among patients with an opioid use disorder. Treatment is ideally performed in an integrated fashion. We present a case that illustrates the complex and challenging psychiatric and medical therapy of such patients in the light of the literature.

CASE DESCRIPTION

We report on a 56-year-old patient with schizophrenia and opioid dependence who experienced both risperidone-induced Pisa syndrome and, 3 years later, acute psychosis after switching the opioid substitution medication from methadone to slow-release oral morphine due to QT prolongation.

CONCLUSIONS

With the current availability of a diversity of substitution opioids in Switzerland (methadone, buprenorphine, diacetylmorphine, sustained-release oral morphine), studies on differential effectiveness of these agents in opioid-dependent subpopulations with selective comorbidity profiles are desirable. The same is true for further investigation of the involvement of the opioid receptor system in schizophrenia. In clinical practice, any alteration of opioid medication in patients with dual diagnosis and a history of schizophrenia should be accompanied by close observation for psychotic symptoms.

Multifocal leukoencephalopathy in cocaine users: a report of two cases and review of the literature

Background

Cocaine abuse is associated with several mechanisms of brain injury including ischemic, hemorrhagic and metabolic. Recently two case reports of leukoencephalopathy in cocaine users implicated a commonly used cocaine adulterant, levamisole. One well-documented adverse effect of levamisole, when used alone as antihelminthic or immunomodulatory drug, is multifocal inflammatory leukoencephalopathy. Therefore, immune mechanisms may also contribute to cocaine-induced brain injury.

Case presentations

Two cocaine users with multifocal leukoencephalopathy, treated with steroids and plasmapheresis, are described. The first is a 25-year-old man who presented with unilateral motor and sensory impairment progressing to bilateral deficits, dysphagia, dysarthria and confusion over several days. Serial MRI showed increasing abnormal FLAIR signal lesions with patchy restricted diffusion and heterogenous enhancement deep in the right and left hemispheres, including periventricular white matter as well as in the pons and cerebellar peduncle. The second patient is a 41-year-old woman who presented with confusion and impaired balance. MRI showed bilateral periventricular FLAIR lesions with scattered restricted diffusion and subtle gadolinium enhancement of some of the lesions. She initially stabilized with supportive care only, but after further cocaine use was re-admitted six weeks later with marked neurological deterioration and MRI showed prominent worsening of the lesions. Both patients received steroid and plasma exchange and showed substantial improvement clinically and on imaging, which was sustained during out-patient follow-up.

Conclusion

Multifocal leukoencephalopathy associated with cocaine use may have an inflammatory/immune basis, possibly related to levamisole contamination, at least in some patients. Three cases, including the present two, have been described wherein good neurological improvement was seen in association with steroid treatment. However, in the absence of appropriate clinical trials, it remains unknown whether immunotherapy is truly beneficial for these patients.

Multifocal leukoencephalopathy in cocaine users: a report of two cases and review of the literature

BACKGROUND

Cocaine abuse is associated with several mechanisms of brain injury including ischemic, hemorrhagic and metabolic. Recently two case reports of leukoencephalopathy in cocaine users implicated a commonly used cocaine adulterant, levamisole. One well-documented adverse effect of levamisole, when used alone as antihelminthic or immunomodulatory drug, is multifocal inflammatory leukoencephalopathy. Therefore, immune mechanisms may also contribute to cocaine-induced brain injury.

CASE PRESENTATIONS

Two cocaine users with multifocal leukoencephalopathy, treated with steroids and plasmapheresis, are described. The first is a 25-year-old man who presented with unilateral motor and sensory impairment progressing to bilateral deficits, dysphagia, dysarthria and confusion over several days. Serial MRI showed increasing abnormal FLAIR signal lesions with patchy restricted diffusion and heterogenous enhancement deep in the right and left hemispheres, including periventricular white matter as well as in the pons and cerebellar peduncle. The second patient is a 41-year-old woman who presented with confusion and impaired balance. MRI showed bilateral periventricular FLAIR lesions with scattered restricted diffusion and subtle gadolinium enhancement of some of the lesions. She initially stabilized with supportive care only, but after further cocaine use was re-admitted six weeks later with marked neurological deterioration and MRI showed prominent worsening of the lesions. Both patients received steroid and plasma exchange and showed substantial improvement clinically and on imaging, which was sustained during out-patient follow-up.

CONCLUSION

Multifocal leukoencephalopathy associated with cocaine use may have an inflammatory/immune basis, possibly related to levamisole contamination, at least in some patients. Three cases, including the present two, have been described wherein good neurological improvement was seen in association with steroid treatment. However, in the absence of appropriate clinical trials, it remains unknown whether immunotherapy is truly beneficial for these patients.

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.

Catatonia after cerebral hypoxia: do the usual treatments apply?

BACKGROUND

Neurologic deterioration occurring days to weeks after a cerebral hypoxic event accompanied by diffuse white matter demyelination is called delayed posthypoxic leukoencephalopathy (DPHL). Manifestations of DPHL are diverse and include dementia, gait disturbance, incontinence, pyramidal tract signs, parkinsonism, chorea, mood and thought disorders, akinetic mutism, and rarely catatonia.

METHODS

We report a case of malignant catatonia in a patient diagnosed with DPHL that was refractory to electroconvulsive therapy (ECT) and review the literature on catatonia in DPHL.

RESULTS

The patient was a 56-year-old woman with schizoaffective disorder who was admitted with catatonia 2 weeks after hospitalization for drug overdose and respiratory failure. Her catatonic symptoms did not respond to treatment of lorazepam, amantadine, methylphenidate, or 10 sessions of bilateral ECT at maximum energy. Repeat magnetic resonance imaging revealed extensive periventricular white matter lesions not present on admission scans, and she was diagnosed with DPHL.

DISCUSSION

No treatment for DPHL has been proven to be widely effective. Hyperbaric oxygen treatments may reduce the rate of development, and symptom improvement has been reported with stimulants and other psychotropic agents. Review of literature reveals rare success with GABAergic agents for catatonia after cerebral hypoxia and no cases successfully treated with ECT. There are 7 case reports of neurologic decompensation during ECT treatment after a cerebral hypoxic event.

CONCLUSION

Caution is advised when considering ECT for catatonia when delayed sequelae of cerebral hypoxia are on the differential diagnosis, as there is a dearth of evidence to support this treatment approach.

Toxic Leukoencephalopathy in the Intensive Care Unit

In this article, we report two cases of acute toxic leukoencephalopathy to highlight this acute clinicoradiological syndrome as an important, although uncommon, consideration in the undifferentiated comatose patient who fails to wake following drug overdose or has unexplained neurology with a history of drug exposure. We then review the current literature and discuss potential differential diagnoses in this setting, along with proposed treatments for this condition. The cases presented demonstrate a more fulminant onset than previously well-defined acute toxic leukoencephalopathy subtypes and highlight the prognostic importance of magnetic resonance imaging in diagnosing a condition from which significant functional recovery seems possible.

'Chasing the dragon': new knowledge for an old practice

Heroin administration by "chasing the dragon," whereby the user places freebase heroin on aluminum foil, heats it below with a flame, and inhales the pyrolysate through a straw, can be associated with the rare development of a delayed-onset spongiform leukoencephalopathy. We report the case of a 46-year-old woman with a psychiatric diagnosis of depression and heroin dependence by "chasing the dragon" admitted with features of altered mental status and later development of catatonia, abulia, and akinetic mutism. A brain magnetic resonance image evidenced bilateral symmetric high-signal lesions in the white matter of the cerebrum and cerebellum on T2-weighted images compatible with toxic leukoencephalopathy. The patient's condition resolved after a hospital stay of 2 months with supportive treatment. Acute onset of neurobehavioral changes, including confusion, apathy, and cerebellar signs in a person with exposure to heroin, should prompt one to consider toxic leukoencephalopathy as a cause of presentation.

Delayed-onset movement disorder and encephalopathy after oxycodone ingestion

We present the case of a 14-year-old girl with a biphasic course after oxycodone ingestion. Clinically, she had a rapid return to baseline after initial ingestion and presented a week later with new-onset ballism, akathisia, and encephalopathy. Neuroimaging demonstrated bilateral globi pallidi and cerebellar lesions with a relative decrease of metabolite peaks on magnetic resonance spectroscopy. Her movement disorder was treated successfully with valproic acid and clonidine. Her cognitive functioning returned to baseline 3 months after ingestion.

Toxic leukoencephalopathies

Leukoencephalopathy is a syndrome of neurologic deficits, including alteration of mental status, caused by pathologic changes in the cerebral white matter. The term, toxic leukoencephalopathy, encompasses a wide variety of exposures and clinical presentations. The diagnosis in these Frontiers in Clinical Neurotoxicology syndromes is made by careful attention to the history, clinical features, and radiologic findings. This article details three of the best-defined toxic leukoencephalopathies: delayed posthypoxic leukoencephalopathy, including delayed neurologic sequelae after carbon monoxide poisoning; heroin inhalation leukoencephalopathy; and posterior reversible encephalopathy syndrome.

Heroin activates Bim via c-Jun N-terminal kinase/c-Jun pathway to mediate neuronal apoptosis

Heroin is reported to cause spongiform leukoencephalopathy (SLE) in heroin addicts and the exact mechanism has not yet been identified. In the present study, we found that heroin could induce apoptosis of primary cultured cerebellar granule cells (CGCs) and Bim was upregulated both transcriptionally and post transcriptionally during CGCs apoptosis. Upregulated Bim translocated to mitochondria and Bax was activated under heroin treatment. Genetic knockdown of Bim using lentiviruses significantly prevented neuronal apoptosis induced by heroin. Meanwhile, c-Jun N-terminal kinase (JNK)/c-Jun pathway was activated in heroin-induced apoptosis. Bim was demonstrated as a downstream target of JNK/c-Jun pathway in this process because pharmacological inhibition of JNK reduced the levels of Bim mRNA and protein. These results indicate that Bim plays a critical role in the neurotoxic process by heroin and JNK/c-Jun pathway acts upstream of Bim in regulating heroin-induced neuronal death. This represents a detailed mechanism of heroin-induced neuronal apoptosis and may provide a new and effective strategy to treat heroin-induced addiction and SLE.

Heroin spongiform leukoencephalopathy (HSLE)

PURPOSE

An increasing number of heroin addicts-especially young and first-time users-prefer inhaling the drug to intravenous injection. A rare complication of inhaling heroin is the development of a spongiform leukoencephalopathy (HSLE).

METHODS

Pathological background, symptoms, imaging, and therapeutical options are discussed on the basis of an example case.

RESULTS

Pathophysiologically, a dysfunction of the oligodendrocyte mitochondria is suspected. Three distinct stages based on key symptoms are defined. Patients may remain in one stage, or pass through two, or all three stages. Magnetic resonance imaging (MRI) is necessary for diagnosis. There are few therapeutical options. Antioxidants and coenzyme Q may be beneficial. The disorder is self-limiting in the majority of cases. Complications such as hydrocephalus and diffuse cerebellar swelling may, however, require neurosurgical intervention.

CONCLUSIONS

HSLE is a rare occurrence in patients with heroin abuse. The number of undetected cases in drug-related deaths may be high. Clinical appearance may be easily mistaken for withdrawal symptoms.

Protective Effect of Bacoside-A against Morphine-Induced Oxidative Stress in Rats

In the present study, we investigated the protective effect of bacoside-A the active principle isolated from the plant Bacopa monniera against oxidative damage induced by morphine in rat brain. Morphine intoxicated rats received 10-160 mg/kg b.w. of morphine hydrochloride intraperitoneally for 21 days. Bacoside-A pretreated rats were administered with bacoside-A (10 mg/kg b.w/day) orally, 2 h before the injection of morphine for 21 days. Pretreatment with bacoside-A has shown to possess a significant protective role against morphine induced brain oxidative damage in the antioxidant status (total reduced glutathione, superoxide dismutase, catalase, glutathione peroxidase and lipid peroxidation) and membrane bound ATP-ases(Na⁺/K⁺ATPase. Ca²⁺ and Mg²⁺ ATPases) activities in rat. The results of the present study indicate that bacoside-A protects the brain from oxidative stress induced by morphine.

Traumatic white matter injury and toxic leukoencephalopathies

White matter injury may be secondary to a range of neurodegenerative disorders, such as the common dementing disorders of the elderly, or may be a consequence of specific white matter disorders, such as multiple sclerosis and the rare leukodystrophies. This article will focus on two relatively common primary groups of disorders of the white matter, traumatic white matter injury and toxic leukoencephalopathies. Traumatic axonal injury may be focal or diffuse, and is associated with a clinical spectrum ranging from concussion through to coma and death. The molecular mechanisms underlying axonal degeneration secondary to traumatic axonal degeneration are being elucidated and may give an insight into potential therapeutic targets. Toxic leukoencephalopathy may be secondary to exposure to a wide range of compounds, including chemotherapeutic drugs. These toxins may produce white matter injury through a range of mechanisms, and the potential toxic effects of compounds need to be considered when assessing a patient with a nonspecific leukoencephalopathy.

Delayed hypoxic-ischemic leukoencephalopathy

A 55-year-old female was found unconscious in a ventilated room. She recovered consciousness on the way to the emergency room. Her vital signs were stable. She presented with negativism and poor communication. Physical examination, routine tests, brain CT and electroencephalogram were normal. Urine toxicology was positive for benzodiazepines. Twelve days after, she presented with catatonia and immobility. Additional examinations, including cerebrospinal fluid (CSF) testing and brain CT, were again normal. Risperidone was administered, and psychotherapy intensified. In the third week, the condition worsened, with intense pyramidal signs and decerebration that led to a vegetative state. Brain MRI revealed diffuse leukoencephalopathy. Extensive metabolic and CSF studies were persistently negative. Brain biopsy was compatible with chronic cerebral hypoxia/anoxia. A diagnosis of delayed hypoxic-ischemic leukoencephalopathy was made. Supportive measures were intensified. She was discharged from the hospital after 4 months in a minimally conscious state and was capable of elementary communication and recognising faces.

[Toxic leucoencephalopathy after use of sniffed heroin, an unrecognized form of beneficial evolution]

INTRODUCTION

Serious leukoencephalopathy can be related to heroin injection or inhalation.

OBSERVATION

We report the first case of leukoencephalopathy observed three weeks after a 46-year-old man sniffed heroin. The clinical presentation included cognitive and behaviour disorders, pyramidal irritation and slight gait instability. Blood and cerebrospinal fluid analyse were normal. Brain magnetic resonance imaging showed diffuse, symmetrical supratentorial white matter lesions producing high intense signals on FLAIR and b1000-weighted sequences. Proton spectroscopy revealed an increased rate of cholin, in favour of active demyelinated lesions. Brain biopsy showed intramyelinic oedema with reactive gliosis. After two and a half years, moderate attentional fluctuations and difficulties in initiating activities persisted. Repeated MRI showed a reduction of the leukoencephalopathy.

CONCLUSION

Heroin could be a cause more common than thought of leukoencephalopathy. The clinical and radiological expression and prognosis could be related to the mode of consummation (inhalation, intravenous injection, sniffing). This parameter may modulate severity and localization of brain lesions. More systematic use of MRI for patients with psychiatric symptoms after heroin intoxications could lead to a better evaluation of heroin-related neurotoxicity and potentially improve prevention.

Acute leukoencephalopathy after buprenorphine intoxication in a 2-year-old child

Leukoencephalopathies have been reported after heroin inhalation or ingestion, and buprenorphine injection, but the physiopathology remains unclear. We report here the first case of leukoencephalopathy caused by buprenorphine ingestion in a 2-year-old child who was admitted for coma and fever. Due to technical problems, the toxicology screen was delayed, and infectious disease was first suspected. A brain MRI found bilateral and symmetric white matter damages in the cerebral hemispheres and the cerebellum. Rapid recovery and positive toxicology screen for buprenorphine on day 4 confirmed the diagnosis of acute intoxication.

Imaging of illicit drug use

Illicit drug abuse is a continuing menace of epidemic proportions associated with serious medical and social problems. Drug abuse can have a wide variety of presentations some of which can be life-threatening. The clinical diagnosis can be challenging as the history is usually limited or absent. Radiologists need to be familiar with varied imaging presentations and the related complications of illicit drug abuse to ensure correct diagnosis and appropriate timely treatment. This review will illustrate the imaging spectrum of illicit drug abuse involving several organ systems and also discuss the pathophysiological consequences of drug abuse.

Chasing the dragon - characterizing cases of leukoencephalopathy associated with heroin inhalation in British Columbia

An association between leukoencephalopathy, a disease of the white matter of the brain, and smoking heroin is well recognized. This paper describes 27 cases of leukoencephalopathy identified in two cities in British Columbia, Canada 2001-2006; the largest number of geographically and temporally defined reported cases in North America.

Twenty cases of leukoencephalopathy were identified in and around Vancouver with onset dates December 2001 to July 2003; seven further cases were identified in Victoria September 2005-August 2006. Twenty (74%) of all cases were male, two couples were reported and eleven cases (55%) had Asian ethnicity. One case reported smoking heroin on a single occasion and developed mild symptoms; all other cases were hospitalized. Thirteen (48%) cases died; all had smoked heroin for a minimum of 3 years. Testing of one available heroin sample identified no substance other than common cutting agents.

Although a specific etiology was not identified our study supports the theory of an intermittent exposure to a toxic agent added to the heroin or a combustion by-product. It also suggests a dose response effect rather than genetic predisposition. Collaboration with public health, health professionals, law enforcement and persons who use illegal drugs, will facilitate the early identification of cases to enable timely and complete follow-up including obtaining samples. Testing of implicated heroin samples may allow identification of the contaminant and therefore prevent further cases. It is therefore important to ensure key stakeholders are aware of our findings.