Toxic and Drug-Related White Matter Diseases of the Brain and Spine

Toxic leukoencephalopathy and myelopathy are common neurologic complications of a wide range of chemotherapeutic and substance abuse agents. During the last decade, there has been a significant change in the profile of white matter toxins, primarily driven by the development and usage of new chemotherapeutic and immunotherapeutic agents and by the continuous increase in illicit drug abuse with contaminants. Neuroimaging in the form of MR imaging forms the cornerstone in the diagnosis of these entities, many of which are reversible and amenable to rapid correction. Chronic white matter changes are also seen with these toxins with gradually progressive clinicoradiological findings.

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.

Disseminating Necrotizing Leukoencephalopathy Associated With Intra-CSF Methotrexate Chemotherapy: A Retrospective Observational Study

BACKGROUND AND OBJECTIVES

Leptomeningeal metastases (LMs) are neoplasms that proliferate to membranes lining the brain and spinal cord. Intra-CSF methotrexate (MTX) chemotherapy is a prevalent treatment option. However, resultant long-term neurotoxicity can lead to irreversible disseminated necrotizing leukoencephalopathy (DNL). This study aims to determine the incidence, characteristics, risk factors, and outcomes of DNL following intra-CSF MTX chemotherapy for LM.

METHODS

We retrospectively reviewed patients with LM who received intra-CSF MTX between 2001 and 2021 at the National Cancer Center of Korea. Patients with a follow-up duration of <3 months and those without follow-up MRI after MTX administration were excluded. The primary outcome was the development of DNL, evaluated based on the clinical and radiologic definitions of DNL. Logistic and Cox proportional regression models were used to assess the risk of DNL in patients with LM receiving intra-CSF MTX chemotherapy.

RESULTS

Of the 577 patients included in the DNL investigation, 13 (2.3%) were identified to have irreversible DNL. The MRI features of DNL typically include necrotic changes in the bilateral anterior temporal region, extensive white matter, and/or brainstem lesions. All patients with DNL experienced fatal clinical course despite MTX cessation. Logistic regression analysis revealed that a cumulative dose of MTX significantly affected DNL occurrence. Multivariable analysis showed that the factor of ≥10 MTX rounds was significant for DNL development after adjusting for route of MTX administration and prior brain radiotherapy (odds ratio 7.32, 95% CI 1.42-37.77 at MTX rounds ≥10 vs < 10). In the Cox proportional hazards model considering time to occurrence of DNL, ≥10 rounds of MTX were identified as an independent predictor of DNL (hazard ratio 12.57, 95% CI 1.62-97.28, p = 0.015), even after adjusting for the synergistic effect of brain radiotherapy.

DISCUSSION

DNL is a rare but fatal complication of intra-CSF MTX chemotherapy, and its progression cannot be prevented despite early recognition. The cumulative dose of intra-CSF MTX was an independent risk factor for DNL occurrence. Thus, intra-CSF MTX treatment for patients with LM should be administered with caution considering the possibility of the cumulative irreversible neurotoxicity.

Clinico-radiological profile, management and follow-up of methotrexate induced neurotoxicity in children with acute lymphoblastic leukemia

Methotrexate-induced neurotoxicity is a well-defined side-effect of high-dose and intrathecal methotrexate with characteristic clinico-radiological findings and transient nature. Our experience in managing this entity in children with acute lymphoblastic leukemia(ALL) is reported here. All children with de novo ALLregistered from January 2016 through December 2021 who developed methotrexate-induced neurotoxicity were included. Of children with ALL treated during the study period, thirty-three experienced methotrexate induced neurotoxicity with an incidence of 1.25%. Stroke-like symptoms(36.36%; 12/33) were the most common clinical manifestation followed by seizures(30.3%, 10/33). Twenty-three patients had radiological features consistent with methotrexate-induced leukoencephalopathy. With emerging evidence, thirty-one patients were re-challenged with methotrexate (IV/IT), of whom 4 patients had recurrence of symptoms. No long-term neurological sequalae were noted in our cohort, despite rechallenging. Therefore in our study, methotrexate induced neurotoxicity is a self-limiting toxicity and methotrexate can be re-challenged safely without compromising theintensity of CNS-directed therapy.

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.

FOLFIRI-bevacizumab-induced acute toxic leukoencephalopathy

INTRODUCTION

Acute toxic leukoencephalopathy (ATL) is a rare complication of cancer treatment, with symptoms varying from mild cognitive impairment to coma. Recognition and management of ATL are important because in most cases, the cessation of the responsible agent is essential.

CASE REPORT

We report a case of a 57-year-old male with relapsed right colon cancer who had multiple steps of chemotherapy, admitted to the emergency department (ED) with confusion and inability to talk, 4 days after FOLFIRI and bevacizumab treatment. To exclude cerebrovascular events cranial computed tomography and diffusion-weighted magnetic resonance imaging were evaluated. There was bilateral and symmetric diffusion restriction on white matter, which was consistent with ATL.

MANAGEMENT AND OUTCOME

Supportive treatment such as optimization of blood pressure and metabolic control was applied since there is no specific treatment for ATL other than cessation of the responsible agents. 12 days after the admission to the ED his neurologic symptoms were normalized and there was no diffusion restriction on control imaging.

DISCUSSION

ATL is a rare complication of cancer treatment and responsible agents are increasing in number due to the development of cancer treatment. ATL is associated with drugs that are used frequently such as 5-fluorouracil. ATL is mostly reversible, but the progression of neurologic symptoms was also reported. The diagnosis and cessation of the responsible agent are important in management.

[Characteristics and management of leukoencephalopathy in leukemia treatment]

Central nervous system relapse prevention through intrathecal and intravenous methotrexate (MTX) administration is a crucial aspect of treatment in acute lymphoblastic leukemia. However, neurotoxicity-induced leukoencephalopathy is a significant concern. Neurological symptoms associated with MTX can appear as subacute leukoencephalopathies, which manifest as a stroke-like syndrome, consisting of paralysis, seizures, consciousness disturbances, and dysarthria. These symptoms persist for a few days, presenting with fluctuating severity and location. Characteristic findings in bilateral white matter are observed on diffusion-weighted magnetic resonance imaging. Symptoms typically improve naturally within a few days although supportive therapy remains the primary treatment. The efficacy of drug administration is not established. Therapy should be continued if clinical improvements are achieved following the initial neurological event regarding MTX re-administrations after symptom improvement. However, careful consideration is required for each patient because symptoms may reoccur or persist and long-term effects remained unclear.

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.

Two Cases Comparing the Presentations and Outcomes of Heroin-induced Toxic Leukoencephalopathy

Heroin-induced toxic leukoencephalopathy (TLE) is an uncommon condition that presents with nonspecific and variable neuropsychiatric findings. It may result in satisfactory recovery or death. Traditionally referred to as "chasing the dragon" syndrome and associated with inhalation of pyrolyzed heroin, recent publications have reported forms of the syndrome associated with noninhaled heroin. We report 2 cases of heroin-induced TLE associated with noninhaled routes of administration and a well-documented history of opioid use disorder. The patient in the first case presented with moderate to severe symptoms. Magnetic resonance imaging of the brain revealed increased T2 and fluid-attenuated inversion recovery signals bilaterally throughout subcortical and periventricular white matter. She survived with significant cognitive issues at discharge from which she adequately recovered by 11-month follow up. The patient in the second case presented with severe symptoms. Magnetic resonance imaging of the brain showed diffuse abnormal increased T2 and fluid-attenuated inversion recovery signals in the white matter of the centrum semiovale and corona radiata. The patient died within 3 weeks of presentation. Both cases illustrate the underrecognition of the form of TLE associated with noninhaled heroin and the difficulties involved in confirming recent heroin use that likely delayed the diagnosis. Further, noninhaled heroin-induced TLE can present with specific signs and symptoms that may help clinicians delineate it from the inhaled form. Given the ongoing opioid epidemic, early and accurate recognition of this condition is of paramount importance.

Involuntary Emotional Expression Disorder in a Patient With Toluene Leukoencephalopathy

OBJECTIVE

Inhalant users may develop toluene leukoencephalopathy, a devastating neuropsychiatric disorder. We present a case of toluene-induced damage to the corticospinal and the corticonuclear tracts, which presented with involuntary emotional expression disorder.

METHODS

Case study of a 20-year-old man with a 3-year history of frequent solvent abuse was admitted to the Neuropsychiatry Unit of the National Institute of Neurology and Neurosurgery because "he could not speak or walk" but would keep "laughing and crying without reason".

RESULTS

Neuropsychiatric examination revealed pathological laughter and crying, facial and speech apraxia, a bilateral pyramidal syndrome, and lack of control of urinary sphincter. Magnetic resonance imaging revealed a highly selective bilateral damage to the pyramidal system and the somatosensory pathway. SPECT imaging showed left fronto-parietal hypoperfusion.

CONCLUSIONS

This document provides support for the understanding of involuntary emotional expression disorders as a differential diagnosis in the clinical practice of psychiatrists, as well as the functional anatomy of these conditions.

Methotrexate-induced Leukoencephalopathy: A Rare but Life-threatening Toxicity

Methotrexate (MTX), an anti-metabolite, is part of various chemotherapy regimens to treat acute lymphoblastic leukemia (ALL) and certain non-Hodgkin's lymphomas (NHLs). It is the major drug used in central nervous system (CNS) prophylaxis. Besides, its common hepatic, pulmonary, and hematologic toxicities, it has been implicated in the development of toxic leukoencephalopathy. Here, we present a case of a 19-year female, diagnosed with T-ALL. She was managed with UK ALL 2011 regimen B induction as a standard of care and intrathecal MTX as CNS prophylaxis. She tolerated induction well; however, during the second block of consolidation, she started developing lower limb weakness, inability to stand, unilateral weakness and aphasia. Her condition worsened rapidly over the next 24 hours leading to paraplegia and ultimately quadriplegia. Within 48 hours from onset of symptoms, she had lost all her motor functions, potentially leading to impending apnoea. We placed her on mechanical ventilation. MRI brain showed drug (MTX)-induced leukoencephalopathy (LE). In most cases, recovery starts within 5-7 days and by the 3rd week, majority have usually recovered. However, cases of irreversible neurologic damage and late-onset chronic toxicities have been reported. Key Words: Methotrexate, Leukoencephalopathy, Chemotherapy, Leukemias.

Capecitabine-induced leukoencephalopathy in a patient with triple-negative breast cancer: A case report and review of the literature

INTRODUCTION

Capecitabine is an orally administered prodrug that converts preferentially to 5-fluorouracil within tumors, resulting in enhanced concentrations of 5-fluorouracil in tumor tissue. The use of capecitabine has shown efficacy in the metastatic setting for breast cancer, and more recently, efficacy as adjuvant therapy for triple-negative breast cancer (TNBC). Capecitabine has been shown to be well tolerated with minimal side effects, but the incidence of leukoencephalopathy is rare with a risk of less than one percent.

CASE REPORT

We report on a 34-year-old female patient with left TNBC, moderately differentiated, stage IIB that experienced symptoms of neurotoxicity following initiation of adjuvant chemotherapy with capecitabine.

MANAGEMENT AND OUTCOME

Naranjo Algorithm Assessment score of nine indicated patient had drug-induced leukoencephalopathy leading to discontinuation of capecitabine and resolution of the neurotoxicity symptoms.

DISCUSSION

Early detection of capecitabine-induced neurotoxicity by magnetic resonance imaging is crucial as symptoms may be reversible to the condition that capecitabine is immediately discontinued.

Reversible leukoencephalopathy caused by 2 rodenticides bromadiolone and fluoroacetamide: A case report and literature review

RATIONALE

With the easy access, rodenticide poisoning has been a public health problem in many countries. Characteristics of central nervous system (CNS) lesions induced by rodenticides are scarcely reported.

PATIENT CONCERNS

We presented a case of a 40-year-old man with seizure and consciousness disorder, coagulation dysfunction, and symmetric lesions in white matter and corpus callosum.

DIAGNOSIS

He was diagnosed with rodenticide poisoning due to bromadiolone and fluoroacetamide.

INTERVENTIONS

He was treated with vitamin K, hemoperfusion, acetamide, and calcium gluconate.

OUTCOMES

His leukoencephalopathy was reversed rapidly with the improvement of clinical symptoms.

LESSONS

This report presented the impact of rodenticide poisoning on CNS and the dynamic changes of brain lesions, and highlighted the importance of timely targeted treatments.

Tocilizumab-induced Leukoencephalopathy with a Reversible Clinical Course

Tocilizumab (TCZ; Actemra/RoActemra) is an anti-interleukin (IL)-6 receptor antibody for the treatment of rheumatoid arthritis (RA) and other autoimmune diseases and cytokine storms. The present case is a 63-year-old female well-controlled RA patient, who presented with a progressive cognitive impairment after 34 months of TCZ administration. Brain magnetic resonance imaging (MRI) showed leukencephalopathy with a lactic acid peak in magnetic resonance spectroscopy (MRS), a decreased blood flow in single photon emission computed tomography (SPECT), and a decreased accumulation in fluorodeoxyglucose positron emission tomography (FDG-PET). The discontinuation of TCZ improved her cognitive function and brain MRI findings at 3 months after drug cessation. The present case suggests that TCZ may sometimes cause leukoencephalopathy after long-term administration, and thus the early discontinuation of TCZ is recommended to achieve a good prognosis.

Toxic leukoencephalopathy-When a Boxer's fracture requires an MRI and LP

This case report describes a young patient presenting to the ED with altered mental status several days after being diagnosed with a Boxer's fracture and ultimately discovered to have toxic leukoencephalopathy. We review the clinical features in his presentation leading to his diagnosis, as well as MRI imaging findings frequently found in his condition.

Long-term leukoencephalopathy and neurocognitive functioning in childhood sarcoma patients treated with high-dose intravenous chemotherapy

PURPOSE

Knowledge is limited regarding the prevalence and persistence of chemotherapy-induced leukoencephalopathy in childhood sarcoma patients. This study explored the presence, clinical relevance, and potential risk factors of leukoencephalopathy in childhood bone and soft tissue sarcoma survivors, treated with intravenous chemotherapy.

METHODS

We acquired cross-sectional neurocognitive data in adult survivors (n = 34) (median age at diagnosis [AaD] = 13.32 years, age range = 16-35 years) and healthy age-matched controls (n = 34). Additionally, magnetic resonance imaging included T2-weighted FLAIR (leukoencephalopathy Fazekas rating), multiexponential T2 relaxation (MET2), and multishell diffusion MRI to estimate myelin integrity-related metrics and fluid movement restrictions. Finally, chemotherapy subgroups (methotrexate, alkylating agents, or combination), AaD, and Apoε and MTHFRC677T polymorphisms were explored as potential risk factors for leukoencephalopathy.

RESULTS

At the group level, quality of life, working memory, processing speed, and visual memory were significantly lower in patients compared to controls. Furthermore, long-term leukoencephalopathy was observed in 27.2% of the childhood sarcoma survivors, which was related to attentional processing speed. Lesions were related to diffusion-derived, but not to myelin-sensitive metrics. A significant interaction effect between AaD and chemotherapy group demonstrated more lesions in case of high-dose methotrexate (HD-MTX) (F = 3.434, P = .047). However, patients treated with alkylating agents (without HD-MTX) also showed lesions in younger patients. Genetic predictors were nonsignificant.

CONCLUSION AND IMPLICATION

This study suggests long-term leukoencephalopathy with possibly underlying changes in vasculature, inflammation, or axonal injury, but not necessarily long-term demyelination. Such lesions could affect processing speed, and as such long-term daily life functioning of these patients.

Malignant cerebellar edema in three-year-old girl following accidental opioid ingestion and fentanyl administration

A three-year-old girl was found altered with an unknown timeline. Gas chromatography mass spectrometry was positive for hydromorphone, dihydrocodeine, and hydrocodone. Initial computed tomography and magnetic resonance imaging suggested a malignant cerebellar edema not confined to a vascular distribution. She received fentanyl boluses on hospital days 0 and 1 before receiving a continuous infusion on day 1. On day 3, she had an episode of acute hypertension and bradycardia. Emergent computed tomography showed an evolving hydrocephalus and similar diffuse edema throughout both cerebellar hemispheres. External ventricular drain was placed to relieve the increased intracranial pressure. Following drain placement and fentanyl discontinuation, the patient recovered, though not without fine- and gross-motor deficits at the four-month follow-up. Our case adds to a handful of case reports of opioid toxicity in pediatric patients that present as toxic leukoencephalopathy. Though the mechanism is poorly understood, it has been suggested to be a consequence of the neurotoxic effects of the drug, which has particular affinity for µ opioid receptors-the primary opioid receptor found in the cerebellum. Clinicians would do well to recognize that this syndrome is primarily caused by direct toxicity rather than ischemia. This case adds insight by suggesting that lipophilic opioid analgesics may worsen this neurotoxicity. When intervening with mechanical ventilation, clinicians should consider avoiding lipophilic opioid drugs for analgesia until the pathogenesis of cerebellar edema is better understood.

The Impact of Persistent Leukoencephalopathy on Brain White Matter Microstructure in Long-Term Survivors of Acute Lymphoblastic Leukemia Treated with Chemotherapy Only

BACKGROUND AND PURPOSE

Survivors of acute lymphoblastic leukemia are at risk for neurocognitive deficits and leukoencephalopathy. We performed a longitudinal assessment of leukoencephalopathy and its associations with long-term brain microstructural white matter integrity and neurocognitive outcomes in survivors of childhood acute lymphoblastic leukemia treated on a modern chemotherapy-only protocol.

MATERIALS AND METHODS

One hundred seventy-three survivors of acute lymphoblastic leukemia (49% female), treated on a chemotherapy-only protocol, underwent brain MR imaging during active therapy and repeat imaging and neurocognitive testing at follow-up (median, 13.5 years of age; interquartile range, 10.7-17.6 years; median time since diagnosis, 7.5 years; interquartile range, 6.3-9.1 years). Persistence of leukoencephalopathy was examined in relation to demographic and treatment data and to brain DTI in major fiber tracts and neurocognitive testing at follow-up.

RESULTS

Leukoencephalopathy was found in 52 of 173 long-term survivors (30.0%) and persisted in 41 of 52 (78.8%) who developed it during therapy. DTI parameters were associated with leukoencephalopathy in multiple brain regions, including the corona radiata (fractional anisotropy, P = .001; mean diffusivity, P < .001), superior longitudinal fasciculi (fractional anisotropy, P = .02; mean diffusivity, P < .001), and superior fronto-occipital fasciculi (fractional anisotropy, P = .006; mean diffusivity, P < .001). Mean diffusivity was associated with neurocognitive impairment including in the genu of the corpus callosum (P = .04), corona radiata (P = .02), and superior fronto-occipital fasciculi (P = .02).

CONCLUSIONS

Leukoencephalopathy during active therapy and neurocognitive impairment at long-term follow-up are associated with microstructural white matter integrity. DTI may be more sensitive than standard MR imaging for detection of clinically consequential white matter abnormalities in childhood acute lymphoblastic leukemia survivors treated with chemotherapy and in children undergoing treatment.

Acute and sub-acute neurological toxicity in children treated for acute lymphoblastic leukemia

Eighty percent of children with acute lymphoblastic leukemia (ALL) survive with current treatments. Neurotoxicity is an infrequent adverse event. We describe clinical presentations of neurological toxicity, phases of treatment when these adverse events were more frequent and patients ́ outcome. From January-1995 to December-2015, 1379 ALL cases were admitted. Neurotoxicity was diagnosed in 49 patients (3.6%) and classified according to neurological syndromes. Medical records, laboratory-tests and images were reviewed. The diagnosed syndromes were: a) Methotrexate-leukoencephalopathy (MLE) (35.4%); b) Cerebral-venous-sinus thrombosis following L-Asparaginase administration (26.5%); c) Vincristine-induced-vocal-cord paralysis (VVCP) (14.2%); d) Stroke-associated vasospasm (14%), after high-dose methotrexate e) Severe polyneuropathy (6.1%); f) Methotrexate myelopathy (2%); and g) Pseudotumor-cerebri (2%) associated with corticosteroid therapy. Neurotoxicity was diagnosed during induction in 55% of cases. We conclude that MLE was the most frequent syndrome. VVCP was observed in infants and Down patients. Seizure was the most common symptom and toxicity occurred mainly during induction phase.

'Khatatonia' - cathinone-induced hypertensive encephalopathy

Khat consumption is an under-recognised cause of hypertensive encephalopathy and intraparenchymal brain haemorrhage. We report the radiological findings of extensive periventricular, subcortical and brain stem white matter pathology of a patient who had consumed excessive amounts of Khat. The Khat plant contains cathinone, an amphetamine-like alkaloid which has been associated with chronic hypertensive end-organ damage, but is seldom considered a cause of cerebrovascular events in northern Europe.

Rat white matter injury model induced by endothelin-1 injection: technical modification and pathological evaluation

White matter injury is an important cause of functional disability of the brain. We comprehensively analyzed a modified endothelin-1 (ET‑1) injection-induced white matter injury model in the rat which is very valuable for investigating the underlying mechanisms of subcortical ischemic stroke. ET-1 was stereotactically injected into the internal capsule of the rat. To avoid complications with leakage of ET-1 into the lateral ventricle, the safest trajectory angle to the target was established. Rats with white matter injury were extensively evaluated for structural changes and functional sequelae, using motor function tests, magnetic resonance (MR) imaging, histopathology evolution, volume estimation of the lesion, and neuroanatomical identification of affected neurons using the retrograde tracer hydroxystilbamidine. Optimization of the trajectory of the ET-1 injection needle provided excellent survival rate. MR imaging visualized the white matter injury 2 days after surgery. Motor function deficit appeared temporarily after the operation. Histological studies confirmed damage of axons and myelin sheaths followed by inflammatory reaction and gliosis similar to lacunar infarction, with lesion volume of less than 1% of the whole brain. Hydroxystilbamidine injected into the lesion revealed wide spatial distribution of the affected neuronal population. Compared with prior ET-1 injection models, this method induced standardized amount of white matter damage and temporary motor function deficit in a reproducible and safe manner. The present model is valuable for studying the pathophysiology of not only ischemia, but a broader set of white matter damage conditions in the lissencephalic brain.

[Delayed posthypoxic leucoencephalopathy after suicide attempt with opioids]

Delayed posthypoxic leucoencephalopathy (DPHL) is a rare condition with manifestation of neurological and neuropsychological symptoms, following an acute hypoxic condition with an intermittent recovery period of four weeks. MRI findings show symmetric subcortical white matter lesions. We present a patient admitted with symptoms and brain MRI-scan consistent with DPHL. Four weeks prior the patient had tried to commit suicide with opioids. DPHL should be considered in patients with subacute onset of neurological and neuropsychological symptoms after an acute hypoxic condition of the brain.

Capecitabine-induced leukoencephalopathy involving the bilateral corticospinal tracts

An 80 year old lady with a history of metastatic sigmoid carcinoma presented with expressive dysphasia and unsteady gait 4 days after commencement of adjuvant capecitabine chemotherapy. MRI demonstrated restricted diffusion and T2/FLAIR hyperintensity involving the course of the bilateral corticospinal tracts, the corpus callosum and the middle cerebellar peduncles. Discontinuation of chemotherapy lead to symptom resolution in 2 days; repeat MRI at 2 months demonstrated reversal of the diffusion changes and improvement of the previous T2W/FLAIR hyperintensity. This report describes the first case of capecitabine induced leukoencephalopathy causing restricted diffusion along the corticospinal tracts, which should be differentiated from other entities that involve the corticospinal tracts (i.e. amyotrophic lateral sclerosis (ALS), primary lateral sclerosis (PLS), hypoglycemic coma, etc.).

[Fatal toxic leukoencephalopathy associated with consumption of pasta base of cocaine: Report of three cases]

The prevalence of drug-associated toxic encephalopathy is unknown, but it is an uncommon condition. Toxic leukoencephalopathy was described associated with heroin consumption, it has been less commonly described with the use of cocaine and there are no reports of its association with consumption pasta base of cocaine (PBC). We report two females aged 31 years and a male aged 19 years, consumers of PBC who developed a fatal toxic leukoencephalopathy. They initiated their disease with severe and persistent headache, sequential focal neurologic deficits and a progressive impairment of consciousness that culminated with their death. Laboratory parameters such as blood count, cerebrospinal fluid analyses or infectious biological indices were normal. MRI showed multifocal lesions in brain white matter of both hemispheres confirming the leukoencephalopathy. There was no response to the use of methylprednisolone.

Tobacco Smoke-Induced Brain White Matter Myelin Dysfunction: Potential Co-Factor Role of Smoking in Neurodegeneration

BACKGROUND

Meta-analysis studies showed that smokers have increased risk for developing Alzheimer's disease (AD) compared with non-smokers, and neuroimaging studies revealed that smoking damages white matter structural integrity.

OBJECTIVE

The present study characterizes the effects of side-stream (second hand) cigarette smoke (CS) exposures on the expression of genes that regulate oligodendrocyte myelin-synthesis, maturation, and maintenance and neuroglial functions.

METHODS

Adult male A/J mice were exposed to air (8 weeks; A8), CS (4 or 8 weeks; CS4, CS8), or CS8 followed by 2 weeks recovery (CS8 + R). The frontal lobes were used for histology and qRT-PCR analysis.

RESULTS

Luxol fast blue, Hematoxylin and Eosin stained histological sections revealed CS-associated reductions in myelin staining intensity and narrowing of the corpus callosum. CS exposures broadly decreased mRNA levels of immature and mature oligodendrocyte myelin-associated, neuroglial, and oligodendrocyte-related transcription factors. These effects were more prominent in the CS8 compared with CS4 group, suggesting that molecular abnormalities linked to white matter atrophy and myelin loss worsen with duration of CS exposure. Recovery normalized or upregulated less than 25% of the suppressed genes; in most cases, inhibition of gene expression was either sustained or exacerbated.

CONCLUSION

CS exposures broadly inhibit expression of genes needed for myelin synthesis and maintenance. These adverse effects often were not reversed by short-term CS withdrawal. The results support the hypothesis that smoking contributes to white matter degeneration, and therefore could be a key risk factor for a number of neurodegenerative diseases, including AD.

Intravenous Heroin-Associated Delayed Spongiform Leukoencephalopathy: Case Report and Reviews of the Literature

Heroin-associated spongiform leukoencephalopathy is a rare, and sometimes fatal, condition usually caused by vapor inhalation of heroin. The authors report a 41-year-old man who was diagnosed with delayed spongiform leukoencephalopathy three weeks after injecting heroin intravenously. He had been admitted to another hospital due to acute heroin overdose, which had occurred four hours after intravenous injection of an unknown amount of heroin. His clinical condition showed progressive improvement and he was discharged 12 days after admission. Three weeks after this episode, his cognitive functioning declined. Akinetic mutism, spasticity and hyperreflexia of all extremities were observed. Electroencephalography (EEG) and imaging of the brain showed typical characteristics of spongiform leukoencephalopathy. The three and six-month follow-up of the patient showed clinical improvement and this was corroborated through EEG measures and brain imaging. The discussion summarizes eight previously reported cases of intravenous heroin associated spongiform leukoencephalopathy and compares them to the authors'case.

[Disease modifying therapies in multiple sclerosis]

The purpose of this section is to introduce the clinical utility of several disease-modifying agents including natalizumab and immunosuppressive treatments that are currently available in Japan, and glatiramer acetate that will be probably available in Japan within a few years. Immunosuppressive therapy has been used to treat multiple sclerosis(MS) for over 30 years based on the hypothesis that MS is a T cell-mediated autoimmune disease. The most commonly used immunosuppressive agents in MS are azathioprine, cyclophosphamide, methotrexate, and mitoxantrone. Like the interferons and glatiramer acetate, immunosuppressive drugs are most efficacious in stages of MS that have an inflammatory component as evidenced by relapses and/or gadolinium-enhancing lesions on MRI or in patients in earlier stages of disease where inflammation predominates over degenerative processes in the CNS. There is no evidence of efficacy in primary progressive MS or later stages of secondary progressive MS. It is appropriate to consider glatiramer acetate for treatment in any patient who has relapsing remitting MS (RRMS), and glatiramer acetate may be helpful in patients with progressive disease. Because of the possibility that natalizumab therapy may be responsible for the increased risk of primary progressive leukoencephalopathy (PML), it is recommended that natalizumab be reserved for use in selected patients with relapsing remitting disease who have failed other therapies either through continued disease activity or medication intolerance, or who have a particularly aggressive initial disease course.

[Early diagnosis of capecitabine-induced acute leukoencephalopathy by using diffusion-weighted MRI]

A 63-year-old woman with colon cancer who was treated with capecitabine as adjuvant chemotherapy presented with vertigo on day 5, and dysarthria and dysphagia on day 7 of the treatment. Diffusion-weighted magnetic resonance imaging of the brain revealed high signal intensity in the corpus callosum and corona radiata. The patient was diagnosed with acute leukoencephalopathy, and the capecitabine treatment was discontinued. Her symptoms recovered immediately. On the basis of these findings, it can be concluded that diffusion-weighted imaging is useful for the early detection and diagnosis of acute leukoencephalopathy.

Delayed leukoencephalopathy after acute carbon monoxide intoxication

Delayed leukoencephalopathy is an uncommon complication of hypoxic-ischemic events of different etiologies, including carbon monoxide intoxication. We present a case of a 40-year-old male patient who was admitted with rapidly progressive neurocognitive and behavioral deficits. There was a history of accidental carbon monoxide intoxication one month before, presenting with loss of consciousness and short hospitalization, followed by a complete clinical recovery. The imaging studies in the delayed phase depicted confluent, symmetric supra-tentorial white matter lesions in keeping with diffuse demyelinization. Restricted diffusion and metabolite abnormalities in magnetic resonance proton spectroscopy were also seen. The diagnosis of CO-mediated delayed post-hypoxic leukoencephalopathy was assumed after exclusion of other mimickers. Hyperbaric oxygen therapy was tentatively performed and the patient had a favorable clinical and radiological evolution.

[Bevacizumab-induced reversible posterior leukoencephalopathy syndrome in a patient with metastatic colorectal cancer]

We report a rare case of a 67-year-old woman with metastatic colorectal cancer whose bevacizumab (B-mab) +m-FOLFOX6 treatment was complicated by reversible posterior leukoencephalopathy syndrome (RPLS). In July 2011, she underwent a right hemicolectomy for cecal carcinoma with peritoneal dissemination; therefore, m-FOLFOX6 was started in September 2011. In November 2011, she was hospitalized to add B-mab to the existing regimen. Subsequently, she developed hypertension on day 4 after the first B-mab infusion, followed by headache, convulsions, and disturbance of consciousness on day 5. T2-weighted and fluid-attenuated inversion recovery (FLAIR) non-enhanced magnetic resonance imaging of the brain revealed bilateral high signal intensities in the posterior lobes. She was diagnosed with RPLS and referred to our department where she was treated with antihypertensives and anticonvulsives. Her symptoms entirely resolved over 12 days. Medical oncologists should be aware that multidrug chemotherapies with B-mab may increase the risk of fatal neurological complications such as RPLS.

[MR imaging late changes of brain after carbon monoxide poisoning--case report]

We present the case of 28 years old patient hospitalized at the Regional Center of Clinical Toxicology in Lublin after carbon monoxide poisoning. The level of carboxyhemoglobin was 33.3%. Because of neurological symptoms MR of brain was performed with normal result. During hospitalization the progression of clinical symptoms was observed and the patient underwent control MR of brain. The result was abnormal and show changes bilaterally in white matter.