Computerized tomography and neuropsychological assessment in long-term high-dose heroin addicts

Effects of extended abstinence on cognitive functions in tramadol-dependent patients: A cohort study

BACKGROUND

Some pieces of the literature report impaired cognitive functioning in tramadol dependence. Whether extended abstinence improves cognitive functioning or not is not well studied.

AIM

We aimed to measure the change in cognitive functioning following complete abstinence among individuals with tramadol dependence.

METHODS

Eighty-three male tramadol-dependent (TD) and 57 matched healthy controls participated in this study. Cognitive functions were assessed using: The Trail making test (TMT), Wechsler Memory Scale-Revised (WMS-R), and Wechsler Adult Intelligence Scale (WAIS). Patients were assessed in the first week immediately after the end of the in-patient treatment program (T1), and after six months of sustained abstinence (T2).

RESULTS

At T1, the TD group showed deficits on all tested cognitive parameters (visual attention, task switching, working memory, visual memory, verbal memory, verbal knowledge, Verbal IQ, Performance IQ, and Full-Scale IQ) in comparison to the control group. At T2, significant improvements had occurred in all the tested parameters except performance IQ. The cognitive performance of the abstinent individuals at T2 was comparable to the control group for the verbal subsets of WMS-R, Verbal IQ, Performance IQ, and Full-Scale IQ. Nevertheless, it was still worse than the control group in TMT, and all other WMS subsets.

CONCLUSION

tramadol dependence has negative effects on cognitive performance, which improves with extended abstinence.

Discrimination learning in oxycodone-treated nonhuman primates

BACKGROUND

Prescription opioid abuse continues to be a public health concern of epidemic proportions. Notwithstanding the extensive literature regarding opioid action, there has been little systematic research regarding the effects of opioid dependence and withdrawal on aspects of cognition-related behavior in laboratory animals. The present studies examined the effects of the prescription opioid oxycodone on learning processes in nonhuman primates.

METHODS

The ability of subjects to repeatedly learn novel touchscreen-based visual discriminations was examined during three conditions of opioid exposure. Discrimination learning was examined, first, during oxycodone self-administration (3-hr sessions, 0.1 mg/kg/injection) and, next, during non-contingent chronic treatment with oxycodone (10 mg/kg/day). Finally, discrimination learning was re-examined during antagonist-precipitated opioid withdrawal (0.001-0.1 mg/kg naltrexone) and, subsequently, following abrupt discontinuation of oxycodone treatment.

RESULTS

Although motoric behavior was disrupted by oxycodone, neither the development of discrimination learning nor steady-state performance were impaired following oxycodone self-administration or during non-contingent chronic oxycodone treatment. However, discrimination learning was substantially impaired during oxycodone withdrawal, whether elicited by naltrexone or by abrupt oxycodone discontinuation. Moreover, these learning impairments were concordant with autonomic signs of opioid withdrawal.

CONCLUSIONS

Taken together, the present studies indicate that impairment of learning processes can accompany the unconditioned signs of opioid withdrawal.

Neuropsychological functioning in opioid use disorder: A research synthesis and meta-analysis

BACKGROUND

Research has demonstrated that patients with opioid use disorders (OUD; including both opioid abuse and/or dependence) have poorer neuropsychological functioning compared to healthy controls; however, the pattern and robustness of the findings remain unknown.

OBJECTIVES

This study meta-analyzed the results from previous research examining the neuropsychological deficits associated with opioids across 14 neurocognitive domains.

METHOD

Articles comparing patients with OUD to healthy controls were selected based on detailed inclusion/exclusion criteria and variables of interest were coded. In total, 61 studies were selected for the analyses. These consisted of 2580 patients with OUD and 2102 healthy control participants (15.9% female). Drug-related variables were analyzed as potential moderators.

RESULTS

The largest effect size difference in neuropsychological performance was observed in complex psychomotor ability. With the exception of the motor and processing speed domains, which showed no group differences, small-to-medium effect sizes were associated with all neurocognitive domains examined. Meta-regression revealed that increases in the length of abstinence were associated with decreases in effect sizes of the complex psychomotor domain. Additionally, attentional ability predicted effect size differences in executive functioning as well as verbal memory ability. Although the majority of meta-analyzed studies demonstrated significant differences between patients with OUD and controls, the average raw scores for patients with OUD in these studies typically fell within the normal range.

CONCLUSION

The pattern of neuropsychological performance among patients with OUD appears to reflect mild generalized cognitive dysfunction, with a large effect in complex psychomotor abilities.

REVIEW ■ : Long-lasting Effects of Recreational Drugs of Abuse on the Central Nervous System

Although a wealth of knowledge exists regarding the acute pharmacological effects of recreational drugs on the CNS, much less is known about the long-term toxic effects of recreational drugs on the CNS. Recent findings in nonhuman primates treated with amphetamine analogs, such as ±3,4-methylenedioxymetham phetamine (MDMA), indicate that these drugs can produce long-lasting, probably permanent, changes in brain serotonin innervation. Similarly, animals treated with phencyclidine (PCP) and related drugs develop neurodegenerative changes in selected brain regions. It seems clear, then, that some psychoactive drugs have the potential to produce persistent changes in CNS structure and, possibly, function. The goal of this article is to summarize current knowledge regarding the long-term effects of several popular recreational drugs, including MDMA and related amphetamine analogs, cocaine, marijuana, alcohol, PCP, lysergic acid (LSD), and opiates. Gaps in the current knowledge base are identified, and areas ripe for future research efforts are suggested. NEUROSCIENTIST 3:399-411, 1997

An Update of the Review of Neuropsychological Consequences of HIV and Substance Abuse: A Literature Review and Implications for Treatment and Future Research

Neuropyschological dysfunction, ranging from mild cerebral indicators to dementia has been a consistent part of the medical picture of HIV/AIDS. However, advances in medical supervision, particularly as a result of antiretroviral (ARV) treatment, have resulted in some mitigation of the neuropsychological effects of HIV and necessitate re-evaluation of the pattern and nature of HIV-related cognitive or mental deficits. The associated enhancements in morbidity and mortality that have occurred as a result of ARV medication have led to a need for interventions and programs that maintain behaviors that are healthy and stop the resurgence of the risk of HIV transmission. Risk factors such as mental illness and substance use that may have contributed to the initial infection with HIV still need consideration. These risk factors may also increase neuropsychological dysfunction and impact observance of prevention for treatment and recommendations. Explicitly, a better comprehension of the role of substance use on the progression of HIV-related mental decline can enlighten management and evaluation of persons living with HIV with concurrent disorders of substance use. This review provides a summary of the neurophyschology of substance use and HIV and the existing research that has looked at the effects of both substance use and HIV disease on neurophyscological function and suggestions for future research and treatment.

[Reaction time in relation to duration of heroin abuse]

INTRODUCTION

Consequences of heroin abuse include organic damage of cerebral structures. The level of impairments is in a direct and positive relation with the length of heroin abuse.

OBJECTIVE

The aim of this research was the evaluation of the reaction time with heroin addicts with different length of substance abuse.

METHODS

RESEARCH METHOD

90 examinees were divided into three groups with relation to the length of heroin abuse. Data collection included a questionnaire referring to socio-demographic and addictive characteristics. A specially designed programme was used for the evaluation of reaction time to audio/ visual signal.

RESULTS

In relation to the reaction time as overall model, the difference between examinees with different length of heroin abuse can be found on the marginal level of significance (F = 1.69; df = 12; p = 0.07). In visual modality, with the increase of length of heroin abuse leads to a significant prolongation of simple (the first visual sign: F = 3.29; df = 2; p = 0.04) and choice reaction time (the second visual sign: F = 4.97; df = 2; p = 0.00; the third visual sign: F = 3.08; df = 2; p = 0.05). Longer heroin consumption also leads to the prolongation of the simple (the first auditory task: F = 3.41; df = 2; p = 0.04) and the complex auditory reaction time (the second auditory task: F = 5.67; df = 2; p = 0.01; the third auditory task: F = 6.42; df = 2; p = 0.00).

CONCLUSION

Heroin abuse leads to the prolongation of both simple and choice reaction time in visual as well as auditory modality. The average daily dose of opiates was the most important predictor of the abovementioned cognitive dysfunction.

POSTMORTEM CHANGES IN THE CENTRAL NERVOUS SYSTEM AND ADRENAL MEDULLA OF THE HEROIN ADDICTS

This study describes the pathological changes in 20 heroin addicts (12 male and 8 female) autopsied 24 h after sudden death. The central nervous system (including the pituitary body) and the adrenal medulla were studied, along with those from age-matched controls who died from traffic accidents. Immunohistochemistry and histological (Hematoxylin and eosin) observation were performed. Some neuronal cells in every region of the CNS were positive for opioid receptors but these cells were most numerous in the hippocampus. Positive opioid fibers were most abundant in the basal ganglia region. Histopathology indicated coagulative changes of cytoplasm and dissolution of Nissl bodies of neuron. Edema of nerve fibers was frequently demonstrated. Pituitary body showed an evident decrease or even absence of basophils in the pars anterior. The adrenal medulla featured a down regulation of chromaffin granules. Degeneration of CNS neurons and fibers, alterations in hormonal and blood pressure regulation therefore would be the prime targets of heroin addiction in human subjects.

Effects of mild traumatic brain injury cannot be differentiated from substance abuse

PRIMARY OBJECTIVE

Patients involved in litigation relating to mild traumatic brain injury (MTBI) typically undergo a forensic neuropsychological evaluation. However, if cognitive problems are identified, it is difficult to know whether these are related to the MTBI or other factors such as pre- and/or post-injury substance abuse. The purpose of this study was to compare the neuropsychological test performances of 73 patients with acute, uncomplicated MTBIs to a sample of 73 patients from an inpatient substance abuse programme.

METHODS AND PROCEDURES

Patients were perfectly matched on age, education and gender. Ten cognitive measures were used that included the Trail Making Test (TMT) and selected sub-tests from the Wechsler Memory Scale-Revised.

MAIN OUTCOMES AND RESULTS

Patients with MTBI demonstrated poorer performances on Digits Backwards (p < 0.028) and TMTA (p < 0.032). There were no significant differences between the two groups on the remaining cognitive measures. The clinical usefulness of these measures to differentiate between the groups, using discriminant function analysis, was very poor.

CONCLUSIONS

Patients with uncomplicated MTBIs could not be reliably differentiated from patients with substance abuse problems on these measures of concentration, memory and processing speed.

Withania somnifera prevents morphine withdrawal-induced decrease in spine density in nucleus accumbens shell of rats: a confocal laser scanning microscopy study

Opiate withdrawal is associated with morphological changes of dopamine neurons in the ventral tegmental area and with reduction of spine density of second-order dendrites of medium size spiny neurons in the nucleus accumbens shell but not core. Withania somnifera has long been used in the Middle East, Africa, and India as a remedy for different conditions and diseases and a growing body of evidence points to its beneficial effects on a number of experimental models of neurological disorders. Recently, many studies focused on the potential neuritic regeneration and synaptic reconstruction properties of its methanolic extract and its constituents (withanolides). This study investigates whether morphine withdrawal-induced spine reduction in the nucleus accumbens is affected by the administration of a Withania somnifera extract. To this end, rats were chronically treated with Withania somnifera extract along with morphine or saline and, upon spontaneous (1 and 3 days) or pharmacologically precipitated withdrawal, their brains were fixed in Golgi-Cox stain for confocal microscopic examination. In a separate group of animals, Withania somnifera extract was administered during three days of spontaneous withdrawal. Withania somnifera extract treatment reduced the severity of the withdrawal syndrome when given during chronic morphine but not during withdrawal. In addition, treatment with Withania somnifera extract during chronic morphine, but not during withdrawal, fully prevented the reduction of spine density in the nucleus accumbens shell in spontaneous and pharmacologically precipitated morphine withdrawal. These results indicate that pretreatment with Withania somnifera extract protects from the structural changes induced by morphine withdrawal potentially providing beneficial effects on the consequences related to this condition.

Heroin prescribing in the “British System” of the mid 1990s: data from the 1995 national survey of community pharmacies in England and Wales

Prescribing heroin in the treatment of addiction has been, until recently, an exclusively UK practice. However, despite international fascination with such prescribing, no recent report exists on the extent or nature of the practice. Furthermore, no data have ever previously been available on dispensing arrangements and geographical localization of heroin-prescribing to addicts. Data are presented on heroin prescriptions being dispensed to addicts in 1995, collected through the national survey of a 1 in 4 sample of the 10 616 community pharmacies in England and Wales. The 64 heroin prescriptions constituted only 1.7% of the 3846 prescriptions for opiates being issued to addicts by regarding community pharmacists, while methadone accounted for 96.0%. Heroin daily doses were more than three times higher than for methadone. Heroin was mainly prescribed in injectable form and, in contrast to methadone prescriptions, was mainly dispensed on a daily basis. Major regional variations in the extent of heroin-prescribing in the United Kingdom have been identified, with these variations appearing to relate to the practice of individual doctors rather than the nature of the local problem.

Neuropsychological consequences of HIV and substance abuse: a literature review and implications for treatment and future research

Neuropsychological dysfunction, ranging from mild cognitive symptoms to dementia has been a consistent part of the clinical picture of HIV/AIDS. However, advances in clinical management, particularly antiretroviral (ARV) treatment, have mitigated the neuropsychological effects of HIV and revised the pattern and nature of cognitive deficits, which are observed in HIV-infected individuals. The attendant improvements in mortality and morbidity have led to a need for programs and interventions that sustain healthy behavior and prevent a resurgence of HIV transmission risk. Psychiatric risk factors, particularly substance use, which often contribute to initial acquisition of HIV, still require attention. These risk factors may also exacerbate neuropsychological dysfunction and compromise adherence to prevention recommendations and treatment. Specifically, a more complete understanding of the effects of substance abuse on the progression of HIV related cognitive decline can inform evaluation and management of HIV seropositives with concurrent substance use disorders. This review provides an overview of the neuropsychology of HIV and substance abuse and the extant research that has examined the effects of both HIV disease and substance use on neuropsychological functioning and implications for treatment and future research.

Impaired response inhibition function in abstinent heroin dependents: an fMRI study

Heroin, like various illicit substances, has a negative impact on the frontal cognitive function after repeated abuse. We used functional magnetic resonance imaging (fMRI) to examine the neural substrates of response inhibition and competition in 18 healthy controls and assess the frontal neurocognition in 30 abstinent heroin dependents (AHD) as they performed a Go/NoGo Association task with reaction times recorded spontaneously. The neural response which was induced by response inhibition was prominent in the midline structure, specifically the bilateral medial prefrontal gyrus and anterior cingulated cortex, as well as the left middle frontal gyrus, insula, bilateral inferior frontal gyrus and limbic system. Unlike drug-naïve controls, only the bilateral superior frontal gyrus and left middle frontal gyrus were activated in AHD. Furthermore, the RT of AHD was significantly longer than that of controls. The results suggest that: (1) the ACC, mPFC and inferior frontal lobe play an important role in response inhibition and competition; (2) heroin dependents had an impaired response inhibition function that lasted even months into abstinence, which indicates that the negative effect of heroin on the inhibitory function still continues in early protracted withdrawal state.

Comparability of Neuropsychological Test Profiles in Patients with Chronic Substance Abuse and Mild Traumatic Brain Injury

The purpose of this study was to compare 104 patients with acute uncomplicated mild traumatic brain injury (MTBI) to a sample of 104 patients from an inpatient substance abuse program to determine whether these patients could be differentiated by their pattern of relative cognitive strengths and weaknesses. Patients were matched on age, education, and gender. Eight cognitive measures were used that included tests of attention, memory, and processing speed. There were no statistically significant differences between the two groups on any of the cognitive measures. Using a two-step cluster analysis procedure (i.e., hierarchical and k-means analyses), seven common profiles were identified. There was no significant difference in the proportions of patients from the MTBI or substance abuse group in each of the seven profiles. These results show that patients with uncomplicated MTBIs could not be reliably differentiated from patients with substance abuse problems on these cognitive measures. This is of particular concern for clinicians evaluating the neuropsychological effects of MTBI in individuals with a comorbid history of substance abuse.

Chronic morphine selectively impairs cued fear extinction in rats: implications for anxiety disorders associated with opiate use

Previous studies have shown that opioid transmission plays an important role in learning and memory. However, little is known about the course of opiate-associated learning and memory deficits after cessation of chronic opiate use in a behavioral animal model. In the present study, we examined the effects of chronic morphine on fear extinction, an important preclinical model for behavior therapy of human anxiety disorders. Rats were administrated subcutaneously morphine hydrochloride or saline twice per day for continuous 10 days. Rats received a cued or contextual fear conditioning session 7 days after the last morphine injection. During subsequent days, rats received four cued or contextual extinction sessions (one session per day). Percent freezing was assessed during all phases of training. Chronic morphine did not affect the acquisition of cued fear response or the initial encoding of extinction memory within each session, but produced an impairment in the between-session extinction. However, the same morphine treatment schedule did not affect the acquisition or extinction of contextual fear response. These results suggest that the effects of chronic morphine on memory for fear extinction are complex. Chronic morphine selectively impairs extinction of cued fear response. This deficit in fear extinction may be one of those critical components that contribute to the high prevalence of anxiety disorders in opiate addicts.

Neurocognitive characterizations of Russian heroin addicts without a significant history of other drug use

Research on the neurocognitive characteristics of heroin addiction is sparse and studies that do exist include polydrug abusers; thus, they are unable to distinguish neurocognitive effects of heroin from those of other drugs. To identify neurocognitive correlates specific to heroin addiction, the present study was conducted in St. Petersburg, Russia where individuals typically abuse and/or become addicted to only one substance, generally alcohol or heroin. Heroin addicts were recruited from an inpatient treatment facility in St. Petersburg. Three comparison groups included alcoholics, addicts who used both alcohol and heroin, and non-abusers. Psychiatric, background, and drug history evaluations were administered after detoxification to screen for exclusion criteria and characterize the sample. Executive Cognitive Functions (ECF) that largely activate areas of the prefrontal cortex and its circuitry measured include complex visual pattern recognition (Paired Associates Learning), working memory (Delayed Matching to Sample), problem solving (Stockings of Cambridge), executive decision making (Cambridge Decision Making Task), cognitive flexibility (Stroop Color-Word Task) and response shifting (Stop Change Task). In many respects, the heroin addicts were similar to alcohol and alcohol+heroin dependent groups in neurocognitive deficits relative to controls. The primary finding was that heroin addicts exhibited significantly more disadvantageous decision making and longer deliberation times while making risky decisions than the other groups. Because the nature and degree of recovery from drug abuse are likely a function of the type or pattern of neurocognitive impairment, differential drug effects must be considered.

Neuropsychological Consequences of Opiate Use

Approximately 3.7 million individuals have used heroin and other opiate substances in their lifetime. Despite increasing knowledge of the effects of heroin, it remains the most abused opiate and use among adults has recently increased. The empirical literature examining the neurocognitive effects of acute and chronic opioid use remains limited; however, findings to date suggest that the use of opiates has both acute and long-term effects on cognitive performance. Neuropsychological data indicate deficits in attention, concentration, recall, visuospatial skills and psychomotor speed with both acute and chronic opioid use. The long-term effects of opiate use appear to have the greatest impact on executive functions, including the ability to shift cognitive set and inhibit inappropriate response tendencies. Factors that contribute to addiction and recovery are also discussed, as it is difficult to disentangle the effects of opiate use on cognitive performance from other factors that may affect neurobehavioral measures.

Neuropsychological functioning in opiate-dependent subjects receiving and following methadone maintenance treatment

OBJECTIVE

An accumulating body of research suggests that former heroin abusers in methadone maintenance therapy (MMT) exhibit deficits in cognitive function. Whether these deficits are present in former methadone maintained patients following discontinuation of MMT is unknown. This study tests the hypothesis that former heroin users who have detoxified from methadone maintenance therapy and are drug-free have less pronounced cognitive impairment than patients continuing long-term MMT.

METHOD

A series of neuropsychological tests were administered to three groups of subjects: 29 former heroin addicts receiving methadone maintenance treatment, 27 former heroin addicts withdrawn from all opiates, and 29 healthy controls without a history of drug dependence. Testing included Wechsler Adult Intelligence Scale-Revised Vocabulary Test, the Stroop Color-Word Test, the Controlled Oral Word Association Test, the Benton Visual Retention Test, and a Substance Use Inventory.

FINDINGS

Both methadone-maintained and abstinent subject groups performed worse than controls on tasks that measured verbal function, visual-spatial analysis and memory, and resistance to distractibility. Abstinent subjects performed worse than their methadone maintained counterparts on tests measuring visual memory and construct formation. Cognitive impairment did not correlate with any index of drug use.

CONCLUSIONS

We confirmed previous findings of neuropsychological impairment in long-term MMT recipients. Both patients receiving MMT and former heroin users in prolonged abstinence exhibited a similar degree of cognitive impairment. Cognitive dysfunction in patients receiving methadone maintenance may not resolve following methadone detoxification.

Neuroimaging in drug and substance abuse part II: opioids and solvents

The central nervous system is one of the primary targets for the detrimental effects of drugs of abuse. Diagnostic imaging, especially MRI, plays an important role in the detection of complications associated with drug abuse. We present the imaging findings associated with the abuse of opioids and other morphine derivatives, as well, as solvents. Of the morphine derivatives, heroin is the most commonly abused. Several CNS pathologic effects have been described in association with its abuse. These include neurovascular complications such as microvascular ischemic changes or ischemic stroke. A rare form of leukoencephalopathy has been described in those abusers who inhale heroin vapors. Other neurologic complications include atrophy and various infectious processes. Solvent inhalation is a common practice among adolescents and young adults secondary to its ease of access and low cost. The most important component of industrial solvents is toluene. Complications of toluene abuse may be either acute, showing no neuroradiological changes, or chronic, characterized by cerebral and cerebellar demyelination as well as atrophy.

Complaints of heroin-maintained patients: A survey of symptoms ascribed to diacetylmorphine

Prescribing of injectable diacetylmorphine (DAM) for heroin dependence has raised concerns about its safety. In light of various reports by heroin-maintained patients of DAM-related adverse events, and previously established unwanted effects of opioids in pain management, we undertook a survey in February 2001 of a random sample of 132 (127 participated) of 1061 patients prescribed DAM in Switzerland at that time. The purpose was to document the prevalence rates of a list of unintended symptoms experienced and attributed to DAM by patients. To assess symptom complaints and other data, staff administered a six-page self-report questionnaire. The patients ascribed numerous symptoms to DAM, with the best-known being the most frequently reported (e.g. skin itching, sweating, constipation). Among potentially more problematic complaints ranged irregular menses, cognitive deficits, muscle twitches, labored breathing, pains in the cardiac region, and temporary paralysis of limbs. In the absence of a control group, however, these may also be due to other factors, such as expectation, co-medication, concomitant substance use or co-morbidity. This pilot study emphasizes the necessity of rigorous assessment of the true rates, types, severity and preventability of such complications, especially given the current efforts to establish heroin maintenance as an optional treatment for heroin dependence.

Cognitive function during early abstinence from opioid dependence: a comparison to age, gender, and verbal intelligence matched controls

BACKGROUND

Individuals with opioid dependence have cognitive deficits during abuse period in attention, working memory, episodic memory, and executive function. After protracted abstinence consistent cognitive deficit has been found only in executive function. However, few studies have explored cognitive function during first weeks of abstinence. The purpose of this study was to study cognitive function of individuals with opioid dependence during early abstinence. It was hypothesized that cognitive deficits are pronounced immediately after peak withdrawal symptoms have passed and then partially recover.

METHODS

Fifteen patients with opioid dependence and fifteen controls matched for, age, gender, and verbal intelligence were tested with a cognitive test battery When patients performed worse than controls correlations between cognitive performance and days of withdrawal, duration of opioid abuse, duration of any substance abuse, or opioid withdrawal symptom inventory score (Short Opiate Withdrawal Scale) were analyzed.

RESULTS

Early abstinent opioid dependent patients performed statistically significantly worse than controls in tests measuring complex working memory, executive function, and fluid intelligence. Their complex working memory and fluid intelligence performances correlated statistically significantly with days of withdrawal.

CONCLUSION

The results indicate a rather general neurocognitive deficit in higher order cognition. It is suggested that cognitive deficit during early abstinence from opioid dependence is related to withdrawal induced neural dysregulation in the prefrontal cortex and is partly transient.

Magnetic resonance imaging of severe, long-term, opiate-abuse patients without neurologic symptoms may show enlarged cerebrospinal spaces but no signs of brain pathology of vascular origin

BACKGROUND

Recreational drug abuse is one of the most important risk factors for stroke in young adults. Abuse of opiates may lead to severe acute neurologic problems due to ischemia or hemorrhage. In contrast, their minor effects on brain structures are not well established. We evaluated brain magnetic resonance images (MRI) of opiate-dependent subjects who had no major neurologic symptoms or psychiatric disorder.

METHODS

Seventeen opiate-dependent patients and 17 controls underwent 1.5 T MRI. Any abnormalities in signal intensity of the brain were recorded. Areas of vermis, corpus callosum, and midline internal skull surface (MISS) were measured from midline sagittal slice. To evaluate size of cortical sulci, sylvian fissures, and ventricles, axial images were compared with standard sets of reference images. In addition, bifrontal and sylvian-fissure ratios were measured.

RESULTS

Only one patient had a small subcortical post-traumatic lesion; otherwise, gray and white matter showed normal signal intensities. Opiate-dependent subjects had significantly wider sylvian fissures (p=0.008, Mann-Whitney U) and larger ventricles (p=0.04) than controls. Bifrontal and sylvian-fissure ratios were significantly higher in patient group than in controls (p=0.013 and p=0.005, respectively).

CONCLUSIONS

No signs of brain pathology of vascular origin were found. From the clinical point of view, we want to emphasize that in the first acute neurologic attack of opiate-dependent patients, any abnormal signal intensity in MRI is most probably associated with the patient's current situation. Sylvian fissures and ventricles were wider in opiate-dependent subjects than in controls, which may be related to brain atrophy located especially in frontal and temporal lobes.

Neuropsychological correlates of opioid dependence and withdrawal

Severity of opioid dependence, and performance on two successive runs of the Wisconsin Card Sorting Test (WCST), were assessed in 39 right-handed male and female methadone patients who had been randomly assigned to either a recently dosed (n=21) or 24 hr abstinent (n=18) condition. Results indicated that severity of opioid dependence was positively correlated with perseverative responses and errors on the second run of the WCST, p<.05. Further, controlling for the effect of dependence severity, patients in early methadone withdrawal made selectively more perseverative responses and errors than did recently dosed patients, p<.05, with no difference on nonperseverative errors. Findings were consistent with the hypothesis that opioid dependence, like alcoholism and cocaine addiction, is associated with disruption of executive cognitive functions mediated by the prefrontal cortex.

Demographic effects on the Trail Making Test in narcotic/other opiate abusers

Demographic effects on the Trail Making Test (TMT), a test often used to screen for cognitive impairments, were examined in a sample of narcotic/other opiate abusers in drug abuse treatment programs. A sample was drawn from the Drug Abuse Treatment Outcome Study (DATOS). The DATOS was a naturalistic, prospective cohort study that collected data from 1991 through 1993 in 96 programs within 11 cities in the United States. The number of narcotic/other opiate abusers' scores available for analysis was 191. Data were analyzed to determine the effects of sex, ethnicity, age, and education on the two parts of the TMT in this sample of narcotic/other opiate abusers. The variables of age and education level were statistically significantly related to TMT parts A and B, and ethnicity was statistically significant for part B of the TMT. R-square values for overall models were moderate (A = .34, B = .24), suggesting that demographic effects on the TMT are moderate.

Frontocortical N-acetylaspartate reduction associated with long-term i.v. heroin use

To examine possible metabolic frontal lobe alterations in i.v. heroin-dependent patients with different histories of concomitant substance use, N-acetylaspartate (NAA), a putative marker of neuronal viability, was measured by (1)H-MRS. Compared with controls, NAA levels in patients were reduced by 7% in gray matter (p = 0.015) but not in white matter. To what extent comorbid conditions or substance use, including alcohol, contributed to these frontocortical metabolic changes remains to be elucidated.

Spongiform leucoencephalopathy following intravenous heroin abuse: radiological and histopathological findings

A case of spongiform leucoencephalopathy in a known intravenous heroin abuser is presented. To our knowledge, this is the only case of heroin-related spongiform leucoencephalopathy reported in Australia. The relationship to intravenous rather than inhaled heroin is particularly unusual with only one other possible case documented in the literature. The imaging and histopathological findings are described.

Neurobehavioural consequences of substance abuse and HIV infection

Although our understanding of how human immunodeficiency virus (HIV)-related neurobehavioural deficits develop is nascent and preliminary, some clues have emerged which may clarify lingering uncertainties. In particular, HIV seems to yield brain dysfunction by mediating pathological changes upon neuronal function. HIV also compromises immunological integrity, thereby resulting in secondary infections that may further increase brain dysfunction. Notably, many individuals with HIV tend to be current or past abusers of drugs, and, in some cases, their drug use may have actually presented a pathway for initial HIV infection. Similar to HIV, many drugs tend to yield pathological changes upon neuronal function. Further paralleling HIV, some drugs seem to compromise immune function, which in turn may yield secondary detrimental effects upon the brain. Yet, despite the relatively high comorbidity rates of HIV infection and substance abuse, few investigations have addressed the potential interaction between these two factors upon neurobehavioural status. Towards this end, the present paper reviews the existing literature concerning neuropsychological effects of HIV and substance use, and suggests potential mechanisms whereby substance use may potentiate and exacerbate the onset and severity of neurobehavioural abnormalities in HIV infection.

The neuropathology of heroin abuse

A broad spectrum of neuropathologic changes are encountered in the brains of heroin abusers. The main findings are due to infections, either due to bacterial spread from bacterial endocarditis, mycoses, or from HIV-1 infection. Other complications include hypoxic-ischemic changes with cerebral edema, ischemic neuronal damage and neuronal loss, which are assumed to occur under conditions of prolonged heroin-induced respiratory depression, stroke due to, for example, thromboembolism, vasculitis, septic emboli, hypotension, and positional vascular compression. Myelopathy is believed to be the result of an isolated vascular accident within the spinal cord due to an as yet unknown mechanism. A distinct entity, spongiform leukoencephalopathy, has been described mainly after inhalation of pre-heated heroin. A lipophilic toxin-induced process was considered to be due to contaminants and to be induced or enhanced by cerebral hypoxia, but a definite toxin could not be identified. At the cellular level, abnormalities in signal transduction systems and changes of various receptor densities have been reported. The exact etiology of the different neuropathological alterations associated with heroin abuse is still unclear, but may also be related to additional substances used as adulterants.

Cerebral phosphorus metabolite abnormalities in opiate-dependent polydrug abusers in methadone maintenance

This study evaluated cerebral phosphorus metabolites in opiate-dependent polydrug abusers in methadone maintenance therapy (MMT) and determined whether metabolite profiles differed based on treatment duration. Phosphorus magnetic resonance spectroscopy (31P-MRS) data were acquired with the ISIS volume localization method from a 50-mm thick axial brain slice through the orbitofrontal and occipital cortices. Study subjects included 15 MMT subjects, seven having undergone treatment for an average of 39 +/- 23 weeks (mean +/- S.D.) and eight having undergone treatment for 137 +/- 53 weeks, as well as an age matched comparison group (n = 16). The methadone dose administered on the study day averaged 70.5 +/- 17.1 mg and was statistically equivalent in short- and long-term subgroups. MMT subjects (n = 15) differed from control subjects in percent phosphocreatine (%PCr) levels (-13%), and in both phosphomonoester (%PME, +13%) and phosphodiester (%PDE, +10%) levels, which likely reflect abnormalities in energy and phospholipid metabolism, respectively. There were no sex effects or group by sex interaction effects on these measures. In short-term MMT treatment subjects, abnormal %PCr (-18%), %PME (+20%) and %PDE (+17%) levels were found compared with control subjects. The only metabolite abnormality detected in long-term MMT subjects was decreased %PCr (-9%), in spite of continued illicit drug abuse. From these data, we conclude that polydrug abusers in MMT have 31P-MRS results consistent with abnormal brain metabolism and phospholipid balance. The nearly normal metabolite profile in long-term MMT subjects suggests that prolonged MMT may be associated with improved neurochemistry.

Schizophrenia, substance use, and brain morphology

The high rate of comorbid substance abuse in schizophrenia and the consistently poor outcome of this comorbidity are well established findings in the research literature. However, the reasons for the high rate of comorbidity are not adequately understood, and the question of why some patients with schizophrenia abuse substances and others do not remains unanswered. There is widespread agreement about the clinical heterogeneity of schizophrenia, and there is some evidence suggesting that the heterogeneous clinical presentation may reflect a parallel underlying heterogeneity of brain morphology. We were interested in examining the possibility that the high rate of substance abuse and the characteristically poor outcome may be associated with the underlying brain morphology. Our hypothesis was that study subjects with schizophrenia and substance abuse would have higher rates of gross brain abnormalities than subjects with only schizophrenia. In an attempt to explore this possibility, we looked at qualitative differences in magnetic resonance imaging scans for a large sample (n = 176) of schizophrenia patients. In the group of patients who abused both alcohol and drugs, we found the rate of gross brain abnormalities to be slightly less than half the rate found among the patients with no history of alcohol or substance abuse (8 vs. 19). Although these results are not statistically significant, they reflect a trend that is compatible with previous findings, suggesting that substance abuse history may be accompanied by less impairment in certain areas, which in turn may be reflected in a better premorbid adjustment. However, our findings are not compatible with previous findings that show substance abuse to be associated with more severe symptoms and a poorer outcome in schizophrenia.

Cerebral CT findings in male opioid-dependent patients: stereological, planimetric and linear measurements

Cerebrospinal fluid (CSF) space enlargement has been demonstrated in substance-related disorders like alcohol and cocaine dependence. Experimental animal studies showed a reduction in shape and size of mesolimbic dopaminergic neurons after chronic morphine administration. Other studies indicated a change of neurofilament and glial fibrillary acid proteins after chronic opiate administration. Furthermore, frequent overdosing and toxicological effects of 'street'-heroin may lead to CSF space enlargement in opioid dependence. In our study the pericortical and ventricular CSF space of 21 male opioid-dependent patients was compared with an age- and sex-matched normal control group. Considering serious problems with ratio and proportion measures, we used a battery of linear (cella media index, Huckman number, frontal horn index), planimetric (cortical atrophy score) and stereological volumetric measures in order to detect differences in cranial computerized tomography scans. We found a significant ventricular and cortical volume loss of the brain in opioid-dependent patients. A higher degree of frontal lobe volume loss seemed to be associated with a shorter period of abstinence before relapse. However, the etiology of volume loss of the brain in opioid-dependent patients is still unclear, but experimental animal studies provide some evidence that long-term, chronic opiate exposure is associated with visible changes of specific structures in the brain.

Early neuropsychological impairment in HIV-seropositive intravenous drug users: evidence from the Italian Multicentre Neuropsychological HIV Study

The aim of the Italian Multicentre Neuropsychological HIV Study is to assess the prevalence and natural history of cognitive deficit in intravenous drug users (i.v.DUs) during the asymptomatic phase of HIV infection. The study is currently being conducted in four centres (Napoli, Benevento, Verona and Pavia) whose catchment areas are characterized by different levels of prevalence of HIV infection. Cognitive evaluation is being performed by means of a standardized neuropsychological test battery. A total of 251 subjects (167 males and 84 females) have been recruited in the cross-sectional phase of the study, including 75 asymptomatic HIV-seropositive i.v.DUs (HIV+/i.v.DUs), 97 HIV-seronegative i.v.DUs (HIV-/i.v.DUs) and 79 non-i.v.DU seronegative controls matched to i.v.DUs with regard to sex, age and educational level. The prevalence of global cognitive impairment (performance at least 1.5 standard deviations worse than the average of the control group, on at least two out of five tests) was significantly higher in HIV+/i.v.DUs than in either HIV-/i.v.DUs (22.7% vs. 8.2%; P < 0.01) or healthy controls (22.7% vs. 2.5%; P < 0.001). The difference between HIV-/i.v.DUs and healthy controls was not statistically significant (8.2% vs. 2.5%; P = 0.19). The results of this study lend further support to the 'cerebral reserve' model. The cerebral reserve could indeed be reduced in i.v.DUs as a consequence of chronic exposure to the substance of abuse, so that these subjects become more vulnerable to direct and indirect neurotoxic effects of HIV.

Leucoencephalopathy after inhalation of heroin: a case report

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Cerebral perfusion in early and late opiate withdrawal: a technetium-99m-HMPAO SPECT study

The purpose of this study was to determine if cerebral blood flow (CBF) alterations are associated with discontinuation of heroin in chronic heroin users, and whether these alterations are reversible during abstinence. Ten physically healthy opioid-dependent males, hospitalized on an inpatient drug rehabilitation unit, were studied. Each patient had an initial single photon emission computed tomographic (SPECT) scan with the radiotracer technetium-99m-d,l-hexamethylpropyleneamine oxime (99mTc-HMPAO) 1 week after opiate discontinuation and a repeat scan 2 weeks later. The initial scans in 9 of the 10 subjects demonstrated significant, often discrete, perfusion defects, especially in the frontal, parietal, and temporal cortices. Two weeks later, repeat brain perfusion SPECT scans showed improvement in all nine subjects who had abnormal scans. Comparisons of the first scan with the second scan showed an increase in cortical uptake on the repeat SPECT study. All subjects had normal computed tomographic or magnetic resonance imaging scans. The results of this preliminary study suggest that the chronic use of opiates, like chronic use of cocaine, results in perfusion abnormalities without corresponding abnormalities on imaging studies of cerebral anatomy and morphology. This study also documents that these perfusion defects are partially reversible with short-term abstinence.

The elderly and the use of illicit drugs: sociological and epidemiological considerations

Debates over the prevalence of elderly illicit drug addicts in the population divert our attention from this group as a viable study population. Due to their decelerated lifestyle, low crime rates, and our attitudes toward the elderly as nonstreet drug users, they are likely to remain hidden from the public eye. This paper reviews past trends in drug misuse among the elderly, the lifestyle of those addicted to drugs, the complications associated with drug misuse and aging, and the problems that the elderly face with traditional treatment programs. Given our aging society, is the study of elderly street addicts and users an important area of concern?

Magnetic resonance imaging reveals no ventriculomegaly in polydrug abusers

Previous studies of cerebral structure in substance abusers yielded controversial results, largely due to issues of subject selection and/or limitations of experimental techniques. The purpose of the present study was to assess whether the ventricle-to-brain ratio (VBR), determined volumetrically by magnetic resonance imaging (MRI), differed in polysubstance abusers (n = 10), as compared with age-matched controls (n = 10). Subjects were male volunteers 21-39 years of age. The values of VBR in the polydrug abuse group were not larger than those in control group, nor was there any tendency toward relative ventriculomegaly in the substance abusers. Therefore, the present findings provide no evidence that polysubstance abuse produces abnormalities of gross brain structure in relatively young and physically healthy men.

Quantitative magnetic resonance imaging in heroin- and cocaine-dependent men: a preliminary study

Quantitative magnetic resonance imaging (MRI) of the brain was performed in nine drug-dependent men with a primary diagnosis of opioid and/or cocaine dependence, and 10 age-matched, non-drug-dependent controls. Individuals were screened for the presence of gross cerebral abnormalities before T1 and T2 analyses. Regional T1 and T2 times were calculated on a single 5-mm thick axial slice positioned just below the caudal margin of the lateral ventricles, passing through the caudate and putamen. A voxel of interest (VOI) cursor was placed bilaterally within the putamen, caudate, frontal gray matter, frontal white matter, or posterior white matter. T1 and T2 values were determined for each VOI using an iterative chi 2 minimization program. T1 and T2 relaxation times did not differ significantly between the subject groups in any brain region studied. These results suggest that T1 and T2 relaxation times may not identify microstructural central nervous system changes resulting from chronic opiate and cocaine abuse.

Neuropsychological impairment among intravenous drug users in pre-AIDS stages of HIV infection

While much of the current literature concurs that neuropsychological decline does not occur among gay men in the early stages of HIV infection, there is no comparable body of evidence with regard to seropositive intravenous drug users (IVDU). In this study, 45 seropositive (CDC groups 2, 3, and 4a) IVDU in recovery and 55 seronegative IVDU in recovery were given a complete battery of neuropsychological tests measuring attention, language, visual-motor, memory, and conceptual skills. The groups were not significantly different in age, incidence of childhood and adult head injury, types of drugs used, length of use of cocaine, crack, amphetamines and hallucinogens, overdose history, and length of time in recovery. In addition, groups were statistically corrected for education level and length of heroin use. Results indicate that the seropositive participants scored significantly lower on measures of divided attention, visual short-term memory, graphomotor speed and accuracy, auditory language shortterm memory and abstract concept formation. Further analyses revealed that 18% of participants with Persistent Generalized Lymphadenopathy (CDC group III) and 27% of those with constitutional disease (CDC group IVa) were neuropsychologically impaired, as their performance was two standard deviations or more below the normative mean on two or more measures. These results are similar to the reported performance of gay men with full-blown AIDS in a number of studies. It is hypothesized that because of premorbid neurological insult, the toxic effects of drug abuse on brain tissue, and the immunosuppressive effects of the drugs, subcortical brain cells of IVDU are more vulnerable to the invasion of HIV, and neurological deterioration may occur at earlier stages of HIV Spectrum Disease in IVDU than in gay men.

A scale for estimating the health status of opioid users

The health status of injecting drug users has both clinical and research relevance. In order to evaluate the impact of treatments for opiate dependence on drug users' health status we need valid and reliable instruments which are short and easily administered by non-medical personnel. This paper describes the construction of a brief interviewer administered scale for assessing the current health status of injecting drug users. Data evaluating its reliability and validity are presented which indicate that the scale has excellent psychometric properties.

Brain-associated autoimmune features in heroin addicts: correlation to HIV infection and dementia

We report here on brain associated autoimmune features in opiate-dependent subjects. This study includes 107 (37 HIV + and 70 HIV -) hospitalized heroin-addicted subjects on a methadone maintenance program, and 45 healthy individuals. Human brain S100 protein, neuron specific enolase (NSE), myelin basic protein (MBF), and old tuberculin (OT) were used as antigens in the study. Serum autoantibodies to brain antigens S100, NSE and MBP were detected by ELISA, whereas delayed hypersensitivity skin reactions were evaluated after intradermal injection of S100, NSE, MBP and OT (control brain-irrelevant antigen). In drug-dependent subjects, 68.2% produced anti-S100, 56.1% anti-NSE and 20.5% anti-MBP autoantibodies, while the incidence of autoantibodies in control healthy individuals was 4.4%, 2.2% and 0%, respectively. Occurrence and amount of anti-S100 and anti-NSE autoantibodies were much higher in HIV + than in HIV - heroin-abusing adults. In drug abusers, the incidence of positive delayed hypersensitivity skin reactions were as follows: 67.2% to S100, 51.4% to NSE, 14.9% to MBP, and 94.3% to OT. In control subjects, the occurrence of hypersensitivity reactions to brain antigens was insignificant. Cutaneous reactions were more frequent in HIV - addicts. The incidence of both autoantibodies and delayed skin responses was positively related to the duration of drug abuse, worsening of HIV infection, and dementia. The high incidence of autoantibodies and delayed hypersensitivity skin reactions to S100 and NSE human brain antigens in heroin-abusers indicates that heroin dependence, as well as HIV infection, are associated with a hyperergy towards brain-related autoimmune phenomena. It has been suggested that the brain-associated autoimmune phenomena in HIV + heroin-addicts represent a hyperimmune phase which precedes immunodeficiency that occurs in the further development of HIV infection.