T2-weighted hypointensity in the thalami and basal ganglia is a well-known MR finding. Toluene-induced chronic toxic encephalopathy causes cerebellar symptoms and signs such as ataxia, tremors, and nystagmus (14–17). Toluene and xylene poisoning can occur when someone swallows these substances, breathes in their fumes, or when these substances touch the skin. Human studies have reported developmental effects, such as CNS dysfunction, attention deficits, and minor craniofacial and limb anomalies, in the children of pregnant women exposed to high levels of toluene or mixed solvents by inhalation. Little is known about the health risks of most of the contaminants found. Coronal T2-weighted images in the patient who had new-onset epilepsy revealed increased signal intensity and atrophy in the left hippocampus. The effects of toluene on animals are similar to those seen in humans. 2008 Feb;101(2):286-93. doi: 10.1093/toxsci/kfm264. Separate sets of rats were exposed to the toluene via inhalation, at 1,500 ppm and at 10,000 ppm respectively, and via an ingestion (400 mg/kg). Inhalant abuse among adolescents: neurobiological considerations. All patients with diffuse white matter changes had findings of cerebral-cerebellar atrophy and thinning of the corpus callosum. Restricted changes were periventricular white matter alterations without a loss of gray matter-white matter differentiation. Axial T2-weighted MR images (3000/80/2 [TR/TE/NEX]) in a 22-year-old patient who had abused thinner for 11 years. B, Axial T2-weighted (2620/85/2) image at the level of lower medulla oblongata shows symmetric hyperintensity along the spinocerebellar tracts (arrowheads). Its neurobiological effects are, at least in part, mediated by gamma-aminobutyric acid (GABA(A)) receptors. On T2-weighted images in three patients, small, round, nonspecific hyperintense lesions were present in the cerebral white matter; these lesions were similar to those of age-related white matter changes. We also compared differences between those with and those without thalamic hypointensity relative to duration of abuse. Animals were treated as described in Fig. Chronic long term exposure of organic solvents can cause damage to the brain. The regional distribution of toluene in the brain and its effects on the brain catecholamine levels in rats is reported. A P value of less than .05 was selected to indicate a statistically significant difference. We do not capture any email address. Your brain suffers when it is over-exposed to cleaning product fumes. Some have suggested that disruption of the physiologic axonal transport of iron might result in the accumulation of iron in the thalami and basal ganglia. Demyelination, dysmyelination, infarction, and neurodegenerative diseases are reported to cause extrapyramidal iron deposition and hypointensity in the thalami, basal ganglia, and red nuclei on T2-weighted images (29–31). The peripheral cerebral white matter and gray matter-white matter differentiation are preserved. Test was performed on PN 58. Our patients with diffuse white matter changes had abused the substance longer than had patients with restricted changes. Unger et al (11) studied eight cases of chronic toluene encephalopathy. Note that gray matter-white matter differentiation is lost in the anterior part of the left temporal lobe. Toluene is a clear, colorless liquid which becomes a vapor when exposed to air at room temperature. These changes may transform into the diffuse type, together with the development of cerebral atrophy, if the duration of abuse is long enough. And your brain being the organ most vulnerable to even small scale disruptions, it shouldn't be surprising its effects show up there most. 2014 May;104:27-35. doi: 10.1016/j.brainresbull.2014.04.001. However, cranial MR examination had not been performed in the patient. [Long-term effects of recurrent seizures in neonate period on gamma-aminobutyric acid A receptor alpha1 and beta2 subunits expression in adult brain: experiment with rats]. The cause of low T2 signal in the basal ganglia and thalami (see below) is uncertain, and could relate to iron deposition 1. A total of 20 male rabbits were used as control and experimental groups. The current theory "CNS toxicity may be due to the liposolubility of toluene in the neuronal membrane. Animal and human research shows that most inhalants are extremely toxic. Demyelination and gliosis in the cerebral and cerebellar white matter are the histologic changes reported in chronic toluene abusers (5, 6). It is known, that people inhaling toluene for a long time have significant brain damage, including decreased intelligence. The most toxic chemicals detected – formaldehyde, benzene, chloroform and toluene – are not listed on the label. After three basal trials of hot-plate test (A), nicotine (1 mg/kg, ip) was given. Toluene exposure during brain growth spurt and adolescence produces differential effects on N-methyl-D-aspartate receptor-mediated currents in rat hippocampus. RATIONALE: The abused inhalant toluene has potent behavioral effects, but only recently has progress been made in understanding the neurochemical actions that mediate the action of toluene in the brain. Clipboard, Search History, and several other advanced features are temporarily unavailable. Intensive treatment is necessary to prevent death. Some investigators have suggested that iron deposition and the partition of toluene into the lipids of cell membranes explain this finding (8, 11). METHODS: We studied the neurologic signs, symptoms, and cranial MR findings in 41 patients who chronically abused thinner, a toluene-containing solvent. Demyelination and gliosis are the histopathologic changes underlying these white matter lesions on cranial MR images (5, 6). Two neuroradiologists (K.A., S.S.) independently interpreted images. Distribution of clinical and MR imaging findings with respect to the duration of toluene abuse. Disorders of the muscles, cardiovascular effects, renal tubular damage, and su… 1. Human studies have reported developmental effects, such as CNS dysfunction, attention deficits, and minor craniofacial and limb anomalies, in the children of pregnant women exposed to high levels of toluene or mixed solvents by inhalation. Only one of our patients (2%) had epilepsy and findings of mesial temporal sclerosis at cranial examination. © 2020 by the American Society of Neuroradiology | Print ISSN: 0195-6108 Online ISSN: 1936-959X. So Erika Sabbath, a research fellow at the Harvard School of Public Health and … effects such as reductions in thinking, memory, and muscular abilities, as well as some losses in hearing and color vision. Stupor, delirium, and drowsiness give way to seizures and coma. BACKGROUND AND PURPOSE: Chronic abuse of toluene by inhalation causes variable white matter changes and thalamic hypointensity on T2-weighted MR images. Available evidence suggests that toluene inhalation alters dopamine (DA) neurotransmission, but toluene's mechanism of action is unknown. The seizure sensitivity induced by bicuculline (a GABA(A) receptor antagonist), methyl beta-carboline-3-carboxylate (inverse agonists of the GABA(A)/benzodiazepine receptor) but not 3-mercaptopropionic acid (a glutamate decarboxylase inhibitor) was enhanced by toluene exposure. Toluene is typically used in a mixture with other solvents and chemicals such as paint pigments. Chronic toluene exposures at less than 200 ppm have been associated with headache, fatigue, and nausea. The widths of the cerebral sulci are normal. The partition of toluene into brain lipids might cause thalamic hypointensity after a limiting dosage is reached. Unger et al also designed an experimental model to determine the source of thalamic hypointensity. Enter multiple addresses on separate lines or separate them with commas. Toluene is degraded into benzoic acid by oxidation and is conjugated with glycine to form hippuric acid in the liver. White matter changes are multifocal in the restricted type, but alterations in the diffuse type are widespread, causing loss of gray matter-white matter differentiation. The deposition of iron due to demyelination and axonal loss is the most probable mechanism for the thalamic hypointensity found in solvent abusers. DO NOT use it to treat or manage an actual poison exposure. The objective was to test whether oxidative stress plays a role in the adverse effects caused by toluene exposure, and if so, if effects are age-dependent. Effects of toluene exposure during the brain growth spurt on basal and nicotine-induced antinociception in the hot-plate test. Fluid accumulates in the lungs compromising breathing; there is poor oxygen absorption from the air. Toxicol Lett. Symmetric hypointensity in the thalami and basal ganglia on T2-weighted cranial MR images is also reported in chronic solvent abuse (8, 10, 11). White matter lesions in chronic solvent encephalopathy were classified as restricted, diffuse, or intermediate, according to the extent of signal intensity changes (8) revealed by MR imaging. All patients with thalamic hypointensity had cerebral-cerebellar atrophy. No patient with thalamic hypointensity had abused thinner for less than 5 years. Today, organic solvents contained in industrial and domestic products are the most commonly abused volatile substances. Total aconitase activity was increased by toluene in frontal cortex and cerebellum at 12 and 24 months, respectively. Xiong et al (7) and Yamanouchi et al (8) described white matter changes in the centrum semiovale, posterior limb of the internal capsule, the ventral part of pons, the cerebellar peduncles, and the cerebellar white matter on cranial MR images in patients who chronically abuse toluene. The main effect of toluene is on the brain and nervous system, but animals exposed to moderate or high levels of toluene also show harmful effects in their liver, kidneys, and lungs and impaired immune function. Cranial T2-weighted MR images in 19 patients (46%) revealed high-signal-intensity white matter changes. Long-term and intense exposure to toluene vapors in humans who abuse spray paint and related substances has led to the recognition that toluene has a severe impact on central nervous system myelin. The pattern of white matter changes is compatible with that of the restricted type. 2009 Sep;34(10):2296-304. doi: 10.1038/npp.2009.57. A, High signal intensity is seen in the centrum semiovale (arrows) on both sides. Symmetric hyperintensity exists in the posterior limbs of the internal capsule (arrowheads). Toluene is the major component of organic industrial solvents that is thought to cause the neurotoxicity seen in solvent abusers (3, 4). All patients with abnormal white matter changes on cranial MR images had neurologic symptoms and signs. However, all of our patients abused the same substance. No studies are currently available on the effects of long-term exposure to white spitit but two such studies are available on jet fuel. Separate sets of rats were exposed to the toluene via inhalation, at 1,500 ppm and at 10,000 ppm respectively, and via an ingestion (400 mg/kg). T2-weighted images also showed increased signal intensity in the cerebellar white matter (15 patients [37%]), internal capsule (13 patients [32%]), and brain stem and upper cervical cord (11 patients [27%]) (Fig 2A and B). Given these three exposure conditions, the values of The purpose of our study was to investigate the associations of the development of white matter changes and thalamic hypointensity on T2-weighted images with patient age at onset of abuse and duration of solvent abuse. We also grouped patients according to age at which abuse began: those who started when they were younger than 12 years and those who started when they were older than 12 years, because 12 years was the mean age at onset of abuse. National Center for Biotechnology Information, Unable to load your collection due to an error, Unable to load your delegates due to an error. Liquid thinner, an organic solvent used in painting, was the substance abused by all of our patients. Yamanouchi et al (8) also suggested that restricted white matter changes might be an early stage of diffuse white matter changes. A, Axial T2-weighted (2620/85/2 [TR/TE/NEX]) image at the level of the brain stem shows a hyperintense lesion in the anterolateral part of pons (arrowhead). Also, only 20% of our patients with restricted changes had findings of atrophy on MR images, although all patients with diffuse white matter changes had cerebral atrophy. Animals were treated as described in Fig. Epub 2011 Jun 24. USA.gov. NLM toluene also causes irritation of the upper respiratory tract and eyes, sore throat, dizziness, and headache. Early caffeine exposure: transient and long-term consequences on brain excitability. | 1. This disrupts your normal brain activity. Markers of oxidative damage reflected changes in oxidative stress. Cerebral and cerebellar atrophy, multifocal or diffuse white matter changes, and loss of demarcation between cortex and white matter are cranial MR imaging findings in chronic toluene encephalopathy (6–9). Contrary to this hypothesis, T2-weighted images in 51% of our patients did not reveal thalamic hypointensity, although the daily thinner consumption in our patients reached the plateau in their 3rd year of abuse. Unlike Yamonouchi et al, we used the diffuse classification for both the diffuse and intermediate types they described. And your brain being the organ most vulnerable to even small scale disruptions, it shouldn't be surprising its effects show up there most. The significant association between the development of thalamic hypointensity and the duration of abuse suggests that thalamic hypointensity develops as a result of a chronic abuse. 2011 Sep 10;205(3):336-40. doi: 10.1016/j.toxlet.2011.06.026. | For example, toluene exposure increased NQO 1 activity at 4 and 12 mos in FC and Cb but only at 24 mos in Hip. With all sequences, a 192–256 × 200–256 matrix and a 180–225 × 200–225-mm field of view were used. Effects of toluene exposure during the brain growth spurt on basal and nicotine-induced antinociception in the hot-plate test. We could not calculate the daily dosage of inhaled toluene and thereby test its association with the development of thalamic hypointensity, which was a limitation of our study. Please enable it to take advantage of the complete set of features! The dopamine system has been shown to play a role in the rewarding effects of nearly all drugs of abuse. Chronic long term exposure of organic solvents can cause damage to the brain. Mean duration of abuse was 4.6 years (range, 1–11 years). All patients underwent a detailed neurologic examination before undergoing cranial MR imaging. 33, no. The NIDA-funded team demonstrated that toluene causes one of its typical behavioral effects in rats, locomotor stimulation—increased roaming—by enhancing dopamine activity in the brain's pleasure center, the nucleus accumbens (NAc). The relative abundance of the mRNAs encoding various subunits of GABA(A) receptor (alpha1, alpha2, alpha4, alpha5, alpha6, beta2, beta3, gamma2S, gamma2L) was examined in four brain regions (hippocampus, striatum, cortex, and cerebellum) by semiquantitative reverse transcription-PCR. Brain cells die and lead to brain damage. The deposition of iron caused by demyelination and axonal loss seems to be the most probable mechanism for thalamic hypointensity on T2-weighted images in toluene-containing solvent abuse. 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