The neuropathology of cocaine abuse

Acute Toxic Cerebellar Leukoencephalopathy in an Eight-Year-Old Child Following Illicit Fentanyl and Cocaine Ingestion: A Case Report of Full Clinical Recovery

During the current opioid epidemic, the number of children with illicit toxic ingestions is increasing. Children presenting with altered mental status and neurologic, particularly cerebellar symptoms of unclear etiology, should be considered to undergo brain imaging as well as toxicology screening to not miss the possible complication of acute toxic leukoencephalopathy. We report the case of an eight-year-old child who presented with somnolence and respiratory depression of unclear etiology, responding profoundly to naloxone, quickly raising concern for drug ingestion. The toxicology screen was positive for fentanyl, cocaine metabolites, caffeine, and diphenhydramine, but not available until day 3 of the hospital stay. In the interim, head CT and brain MRI findings revealed concerning bilateral cerebellar hypodensities, suggestive of opioid-induced leukoencephalopathy. This condition has been described as potentially malignant and fatal, but very few cases of this pathology have been described in children so far. Fortunately, all neurological symptoms in our patient, including altered mental status, respiratory depression, atactic gait, blurry vision, and lower extremity pain, completely resolved within five days of presentation and the patient seemingly underwent a full clinical recovery without residual symptoms. Awareness and prompt recognition of acute toxic leukoencephalopathy in children presenting with altered mental status or neurological symptoms of unclear etiology is of utmost importance to prevent deterioration and optimize treatment, especially during times of a worsening opioid epidemic in our country.

Astrocytes modulate cerebral blood flow and neuronal response to cocaine in prefrontal cortex

Cocaine affects both cerebral blood vessels and neuronal activity in brain. Cocaine can also disrupt astrocytes, which modulate neurovascular coupling-a process that regulates cerebral hemodynamics in response to neuronal activation. However, separating neuronal and astrocytic effects from cocaine's direct vasoactive effects has been challenging, partially due to limitations of neuroimaging techniques able to differentiate vascular from neuronal and glial effects at high temporal and spatial resolutions. Here, we used a newly-developed multi-channel fluorescence and optical coherence Doppler microscope (fl-ODM) that allows for simultaneous measurements of neuronal and astrocytic activities (reflected by the intracellular calcium changes in neurons Ca2+N and astrocytes Ca2+A, respectively) alongside their vascular interactions in vivo to address this challenge. Using green and red genetically-encoded Ca2+ indicators differentially expressed in astrocytes and neurons, fl-ODM enabled concomitant imaging of large-scale astrocytic and neuronal Ca2+ fluorescence and 3D cerebral blood flow velocity (CBFv) in vascular networks in the mouse cortex. We assessed cocaine's effects in the prefrontal cortex (PFC) and found that the CBFv changes triggered by cocaine were temporally correlated with astrocytic Ca2+A activity. Chemogenetic inhibition of astrocytes during the baseline state resulted in blood vessel dilation and CBFv increases but did not affect neuronal activity, suggesting modulation of spontaneous blood vessel's vascular tone by astrocytes. Chemogenetic inhibition of astrocytes during a cocaine challenge prevented its vasoconstricting effects alongside the CBFv decreases, but it also attenuated the neuronal Ca2+N increases triggered by cocaine. These results document a role of astrocytes both in regulating vascular tone and consequently blood flow, at baseline and for modulating the vasoconstricting and neuronal activation responses to cocaine in the PFC. Strategies to inhibit astrocytic activity could offer promise for ameliorating vascular and neuronal toxicity from cocaine misuse.

Traumatic Aneurysm Involving the Posterior Communicating Artery

Traumatic intracranial aneurysms (TICAs) are rare, accounting for less than 1% of all intracranial aneurysms. However, they are associated with a mortality rate of over 50%. The case presented herein focuses on a posterior communicating artery TICA caused by violent aggression. A 41-year-old man with massive subarachnoid hemorrhage (SAH), on admission to hospital, had a CT angiography that showed a ruptured left posterior communicating artery aneurysm with continuous blood loss and underwent neurosurgical cooling. The CT scan also showed fractures of the mandible, mastoid and left styloid process, as well as brain contusions caused by blows and kicks. Despite medical treatment and surgery, after four days, he died. The assault dynamics were recorded by a camera in the bar. The damage was caused by kicks to the neck and head. The forensic neuropathological examination showed the primary injury (SAH, subdural hemorrhage, cerebral contusions, head-neck fractures), as well as secondary damage following the attack (cerebral infarcts, edema, supratentorial hernia, midbrain hemorrhage). The coil was intact and well positioned. In this case, circumstantial information, medical records, and the type of injury could shed light on the mechanism of the production of a TICA. In addition, the CT angiography and histological investigations helped to distinguish a recent and traumatic aneurysm from a pre-existing one. Following precise steps, the study of aneurysms can be helpful in clarifying their traumatic origin even when the victim was taking drugs. The aim of this study is also to share the diagnostic process that we used in the forensic field for the assessment of suspected traumatic aneurysms.

Dynamic 3D imaging of cerebral blood flow in awake mice using self-supervised-learning-enhanced optical coherence Doppler tomography

Cerebral blood flow (CBF) is widely used to assess brain function. However, most preclinical CBF studies have been performed under anesthesia, which confounds findings. High spatiotemporal-resolution CBF imaging of awake animals is challenging due to motion artifacts and background noise, particularly for Doppler-based flow imaging. Here, we report ultrahigh-resolution optical coherence Doppler tomography (µODT) for 3D imaging of CBF velocity (CBFv) dynamics in awake mice by developing self-supervised deep-learning for effective image denoising and motion-artifact removal. We compare cortical CBFv in awake vs. anesthetized mice and their dynamic responses in arteriolar, venular and capillary networks to acute cocaine (1 mg/kg, i.v.), a highly addictive drug associated with neurovascular toxicity. Compared with awake, isoflurane (2-2.5%) induces vasodilation and increases CBFv within 2-4 min, whereas dexmedetomidine (0.025 mg/kg, i.p.) does not change vessel diameters nor flow. Acute cocaine decreases CBFv to the same extent in dexmedetomidine and awake states, whereas decreases are larger under isoflurane, suggesting that isoflurane-induced vasodilation might have facilitated detection of cocaine-induced vasoconstriction. Awake mice after chronic cocaine show severe vasoconstriction, CBFv decreases and vascular adaptations with extended diving arteriolar/venular vessels that prioritize blood supply to deeper cortical capillaries. The 3D imaging platform we present provides a powerful tool to study dynamic changes in vessel diameters and morphology alongside CBFv networks in the brain of awake animals that can advance our understanding of the effects of drugs and disease conditions (ischemia, tumors, wound healing).

Cocaine's cerebrovascular vasoconstriction is associated with astrocytic Ca2+ increase in mice

Human and animal studies have reported widespread reductions in cerebral blood flow associated with chronic cocaine exposures. However, the molecular and cellular mechanisms underlying cerebral blood flow reductions are not well understood. Here, by combining a multimodal imaging platform with a genetically encoded calcium indicator, we simultaneously measured the effects of acute cocaine on neuronal and astrocytic activity, tissue oxygenation, hemodynamics and vascular diameter changes in the mouse cerebral cortex. Our results showed that cocaine constricted blood vessels (measured by vessel diameter Φ changes), decreasing cerebral total blood volume (HbT) and temporally reducing tissue oxygenation. Cellular imaging showed that the mean astrocytic Ca2+ dependent fluorescence [Formula: see text] increase in response to cocaine was weaker but longer lasting than the mean neuronal Ca2+ dependent fluorescence [Formula: see text] changes. Interestingly, while cocaine-induced [Formula: see text] increase was temporally correlated with tissue oxygenation change, the [Formula: see text] elevation after cocaine was in temporal correspondence with the long-lasting decrease in arterial blood volumes. To determine whether the temporal association between astrocytic activation and cocaine induced vasoconstriction reflected a causal association we inhibited astrocytic Ca2+ using GFAP-DREADD(Gi). Inhibition of astrocytes attenuated the vasoconstriction resulting from cocaine, providing evidence that astrocytes play a critical role in cocaine's vasoconstrictive effects in the brain. These results indicate that neurons and astrocytes play different roles in mediating neurovascular coupling in response to cocaine. Our findings implicate neuronal activation as the main driver of the short-lasting reduction in tissue oxygenation and astrocyte long-lasting activation as the driver of the persistent vasoconstriction with cocaine. Understanding the cellular and vascular interaction induced by cocaine will be helpful for future putative treatments to reduce cerebrovascular pathology from cocaine use.

Trends in characteristics of the recipients of new prescription stimulants between years 2010 and 2020 in the United States: An observational cohort study

BACKGROUND

Stimulant prescriptions increased by 250% in the United States from 2006-2016 while diagnoses for ADHD minimally increased. There is insufficient data regarding who may be the recipients of these new stimulant prescriptions and safety of stimulants have come under scrutiny in some populations. We aim to describe trends in stimulant prescriptions across biopsychosocial patient level factors between 2010 and 2020.

METHODS

We applied a retrospective observational cohort design utilizing electronic health records from 52 healthcare organizations sourced from the TriNetX research network database in the United States. We assessed new stimulant prescriptions across biopsychosocial variables for recipients of prescriptions. We utilized linear regression to assess longitudinal trends of all participants and also conducted an age stratified logistic regression analysis.

FINDINGS

There was an increase in stimulants to people categorized as white (OR 1.24 CI 1.20-1.28), female (OR 1.28 CI 1.23-1.31), and to those with diagnosed anxiety disorders (OR 1.39 CI 1.35-1.44) as well as obesity (OR 1.34 CI 1.28-1.41). The average age of recipients increased throughout the study, and among people sixty-five and older, there was an increase in prescriptions to people with multiple cardiovascular risk factors.

INTERPRETATION

Prescription stimulant dispensing may have liberalized during the study period in some demographics as a greater number of new prescriptions were dispensed to individuals with risk of adverse outcomes (i.e. older individuals, obese individuals, and geriatric patients with CV risk factors) between 2010 and 2020. Similar trends in prescription medications were witnessed through the opioid epidemic and warrant attention given concerning trends with illicit stimulants. Additional research that investigates patient and provider motivation for stimulant prescriptions, as well as risk perception of stimulants, may be warranted.

FUNDING

This study was made possible by institutional resources at Penn State Hershey Medical Center.

Ca2+ channel blockade reduces cocaine's vasoconstriction and neurotoxicity in the prefrontal cortex

Cocaine profoundly affects both cerebral blood vessels and neuronal activity in the brain. The vasoconstrictive effects of cocaine, concurrently with its effects on neuronal [Ca²⁺]_i accumulation are likely to jeopardize neuronal tissue that in the prefrontal cortex (PFC) could contribute to impaired self-regulation and compulsive cocaine consumption. Here we used optical imaging to study the cerebrovascular and neuronal effects of acute cocaine (1 mg/kg i.v.) and to examine whether selective blockade of L-type Ca²⁺ channels by Nifedipine (NIF) (0.5 mg/kg i.v.) would alleviate cocaine's effects on hemodynamics (measured with cerebral blood volume, HbT), oxygenation (measured with oxygenated hemoglobin, HbO₂) and neuronal [Ca²⁺]_i, which were concomitantly measured in the PFC of naive rats. Our results show that in the PFC acute cocaine significantly reduced flow delivery (HbT), increased neuronal [Ca²⁺]_i accumulation and profoundly reduced tissue oxygenation (HbO₂) and these effects were significantly attenuated by NIF pretreatment. They also show that cocaine-induced vasoconstriction is distinct from its increase of neuronal [Ca²⁺]_i accumulation though both of them contribute to hypoxemia and both effects were attenuated by NIF. These results provide evidence that blockade of voltage-gated L-type Ca²⁺ channels might be beneficial in preventing vasoconstriction and neurotoxic effects of cocaine and give support for further clinical investigations to determine their value in reducing cocaine's neurotoxicity in cocaine use disorders.

Delayed cerebral ischemia causing cortical blindness due to repeat cocaine use weeks subsequent to aneurysmal subarachnoid hemorrhage

Cocaine is a known vasoactive drug associated with poor clinical outcomes and high in-hospital mortality related to aneurysmal subarachnoid hemorrhage; however, the association of prior cocaine use with the incidence of vasospasm and delayed cerebral ischemia remains controversial. We report a case of a 42-year-old male with a history of active cocaine use who presented with a severe headache. Imaging demonstrated diffuse cisternal subarachnoid hemorrhage due to a ruptured basilar apex aneurysm, which was successfully treated with endovascular coil embolization. Despite expedited endovascular treatment and an initially benign clinical course, he suffered from delayed cerebral ischemia resulting in cortical blindness due to bilateral posterior cerebral artery vasospasm secondary to repeat cocaine use weeks after his initial ictus. To our knowledge, the present case is the first to describe delayed cerebral ischemia resulting in a severe neurologic deficit due to repeat cocaine use weeks subsequent to aneurysm rupture. We review the current literature on the association of cocaine use with the incidence of vasospasm and delayed cerebral ischemia as well as the effects of cocaine on the cerebrovasculature.

Histologic Changes In Recreational Drug Misuse

Use of recreational drugs is associated with a number of histologic changes. These may be related to the method of administration or due to systemic effects of the drugs. This paper reviews the histopathological features seen following recreational drug use. With injection, there may be local effects from abscess formation and systemic effects may result in amyloidosis. Injections have been associated with necrotizing fasciitis, anthrax, and clostridial infections. Systemic effects include infective endocarditis, with the risk of embolization, and abscesses may be seen in organs in the absence of infective endocarditis. Viral complications of injection include hepatitis and human immunodeficiency virus (HIV) infection. Injecting crushed tablets can result in intravascular granulomata in the lungs. Smoking drugs is associated with intraalveolar changes, including blackand brown-pigmented macrophages in crack cocaine and cannabis smoking, respectively. Snorting may result in intraalveolar granulomata forming when crush tablets are used and there may be systemic granulomata. Stimulants are associated with cardiovascular and cerebrovascular pathology, including contraction band necrosis and myocardial fibrosis, as well as coronary artery dissection. Stimulants may cause hyperpyrexia and rhabdomyolysis, which may be associated with changes in multiple organs including myoglobin casts in the kidney. Opioids cause respiratory depression and this can be associated with inhalational pneumonia and hypoxia in other organs if there is resuscitation and a period of survival. Ketamine use has been associated with changes in the urothelium and the liver. This paper reviews histology changes that may be seen in drug-related deaths using illustrative cases.

Vascular disease in cocaine addiction

Cocaine, a powerful vasoconstrictor, induces immune responses including cytokine elevations. Chronic cocaine use is associated with functional brain impairments potentially mediated by vascular pathology. Although the Crack-Cocaine epidemic has declined, its vascular consequences are increasingly becoming evident among individuals with cocaine use disorder of that period, now aging. Paradoxically, during the period when prevention efforts could make a difference, this population receives psychosocial treatment at best. We review major postmortem and in vitro studies documenting cocaine-induced vascular toxicity. PubMed and Academic Search Complete were used with relevant terms. Findings consist of the major mechanisms of cocaine-induced vasoconstriction, endothelial dysfunction, and accelerated atherosclerosis, emphasizing acute, chronic, and secondary effects of cocaine. The etiology underlying cocaine's acute and chronic vascular effects is multifactorial, spanning hypertension, impaired homeostasis and platelet function, thrombosis, thromboembolism, and alterations in blood flow. Early detection of vascular disease in cocaine addiction by multimodality imaging is discussed. Treatment may be similar to indications in patients with traditional risk-factors, with few exceptions such as enhanced supportive care and use of benzodiazepines and phentolamine for sedation, and avoiding β-blockers. Given the vascular toxicity cocaine induces, further compounded by smoking and alcohol comorbidity, and interacting with aging of the crack generation, there is a public health imperative to identify pre-symptomatic markers of vascular impairments in cocaine addiction and employ preventive treatment to reduce silent disease progression.

Changes in regional cerebral blood flow are associated with endothelial dysfunction markers in cocaine-dependent patients under recent abstinence

OBJECTIVES

Cocaine is a known risk factor for several vascular ischemic events. The underlying mechanisms leading to the complications are not fully understood, although thrombus formation and accelerated atherosclerosis are prominent findings. Evidence of endothelial dysfunction (ED), a key phenomenon in the pathogenesis of atherogenesis, has been demonstrated in cocaine-dependent individuals. Abnormal regional cerebral blood flow (rCBF) is a common finding among chronic cocaine users. The aim of this study was to evaluate whether brain perfusion changes were associated with ED markers in cocaine-dependent individuals.

METHODS

Circulating endothelial cells (CECs), soluble intercellular cell adhesion molecule, and the chemokine regulated on activation normal T cells expressed and secreted were measured in 27 DSM-IV (Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition) cocaine-dependents patients. Regional cerebral blood flow was assessed using single-photon emission computed tomography at baseline (after recent cocaine consumption) and after 4 weeks of strict abstinence under standard benzodiazepine or antipsychotic therapy. We used statistical parametric mapping analysis to evaluate the covariates.

RESULTS

Endothelial cell damage/activation markers were significantly higher in cocaine-dependent individuals after recent consumption and were reduced after 1-month abstinence (P < 0.05). Global rCBF exhibited no significant difference between baseline and after abstinence. When regional perfusion was analyzed in association with ED covariates, significant differences were observed in bilateral cortical areas, including the limbic lobes.

CONCLUSIONS

We demonstrated an association between systemic ED markers and rCBF in cocaine-dependent patients. These findings suggest that vascular injury may play a role in the pathogenesis of abnormal rCBF.

Cranial window implantation on mouse cortex to study microvascular change induced by cocaine

Cocaine-induced stroke is among the most serious medical complications associated with cocaine's abuse. However, the extent to which chronic cocaine may induce silent microischemia predisposing the cerebral tissue to neurotoxicity has not been investigated; in part, because of limitations of current neuroimaging tools, that is, lack of high spatiotemporal resolution and sensitivity to simultaneously measure cerebral blood flow (CBF) in vessels of different calibers quantitatively and over a large field of view (FOV). Optical coherence tomography (OCT) technique allows us to image three dimensional (3D) cerebrovascular network (including artery, vein, and capillary), and provides high resolution angiography of the cerebral vasculature and quantitative CBF velocity (CBFv) within the individual vessels in the network. In order to monitor the neurovascular changes from an in vivo brain along with the chronic cocaine exposure, we have developed an approach of implanting a cranial window on mouse brain to achieve long-term cortical imaging. The cranial window was implanted on sensorimotor cortex area in two animal groups, i.e., control group [saline treatment, ~0.1 cc/10 g/day, intraperitoneal injection (i.p.)] and chronic cocaine group (cocaine treatment, 30 mg/kg/day i.p.). After implantation, the cortex of individual animal was periodically imaged by OCT and stereoscope to provide angiography and quantitative CBFv of the cerebral vascular network, as well as the surface imaging of the brain. We have observed vascular hemodynamic changes (i.e., CBFv changes) induced by the cranial preparation in both animal groups, including the inflammatory response of brain shortly after the surgery (i.e., <5 days) followed by wound-healing process (i.e., >5 days) in the brain. Importantly, by comparing with the control animals, the surgical-related vascular physiology changes in the cortex can be calibrated, so that the cocaine-induced hemodynamic changes in the neurovasculature can be determined in the cocaine animals. Our results demonstrate that this methodology can be used to explore the neurovascular functional changes induced by the brain diseases such as drug addiction.

Headache in chronic cocaine users: A cross-sectional study

Background

Headache is one of the most common symptoms after cocaine use.

Methods

We investigated headache frequency and characteristics and the correlation between headache and acute cocaine intake in a cross-sectional study in a consecutive series of chronic cocaine users.

Results

Participation rate was 94.1%. Of the 80 subjects enrolled, 72 (90%) reported current headaches, in most cases migraine or probable migraine without aura. Of these 72, 29 (40.3%) had a headache history, whereas 43 (59.7%) reported de novo headache after beginning to use cocaine. After acute cocaine use, a large percentage of users reported headache attacks: 86.2% of previous headache sufferers (migraine or probable migraine without aura in all cases) and 93% of de novo headache sufferers (migraine/probable migraine without aura = 35; episodic tension-type headache = three patients; cocaine-induced headache= two patients). Most subjects reported that when they used cocaine headaches worsened.

Conclusion

Chronic cocaine use frequently seems to worsen or induce headache with migraine or migraine-like characteristics, probably owing to a serotoninergic and dopaminergic system impairment. In headache sufferers, especially those with migraine headaches, clinicians should enquire into possible cocaine use.

Neuropathology of substance use disorders

Addictions to licit and illicit drugs are chronic relapsing brain disorders that affect circuits that regulate reward, motivation, memory, and decision-making. Drug-induced pathological changes in these brain regions are associated with characteristic enduring behaviors that continue despite adverse biopsychosocial consequences. Repeated exposure to these substances leads to egocentric behaviors that focus on obtaining the drug by any means and on taking the drug under adverse psychosocial and medical conditions. Addiction also includes craving for the substances and, in some cases, involvement in risky behaviors that can cause death. These patterns of behaviors are associated with specific cognitive disturbances and neuroimaging evidence for brain dysfunctions in a diverse population of drug addicts. Postmortem studies have also revealed significant biochemical and/or structural abnormalities in some addicted individuals. The present review provides a summary of the evidence that has accumulated over the past few years to implicate brain dysfunctions in the varied manifestations of drug addiction. We thus review data on cerebrovascular alterations, brain structural abnormalities, and postmortem studies of patients who abuse cannabis, cocaine, amphetamines, heroin, and "bath salts". We also discuss potential molecular, biochemical, and cellular bases for the varied clinical presentations of these patients. Elucidation of the biological bases of addiction will help to develop better therapeutic approaches to these patient populations.

Sex-dependent changes in brain CB1R expression and functionality and immune CB2R expression as a consequence of maternal deprivation and adolescent cocaine exposure

Early life stress has been associated with several psychiatric disorders, including drug addiction. Actually, maternal deprivation (MD) alters the endocannabinoid system, which participates in motivation and reward for drugs, including cocaine. At youth, the rate of cocaine abuse is alarmingly increasing. Herein, we have investigated the consequences of MD and/or adolescent cocaine exposure in brain CB1Rs and CB2Rs in immune tissues. Control and maternally deprived (24h on postnatal day, pnd, 9) male and female Wistar rats were administered cocaine (8mg/kg/day) or saline during adolescence (pnd 28-42). At adulthood, [(3)H]-CP-55,940 autoradiographic binding was employed for the analysis of CB1R density and CP-55,940-stimulated [(35)S]-GTPgammaS binding for CB1R functionality; CB2R expression was analyzed by Western blotting. Sex differences in CB1R expression and functionality were found, and MD induced important and enduring sex-dependent changes. In addition, the plastic changes induced by adolescent cocaine administration in brain CB1Rs were differentially influenced by early life events. MD increased spleen CB2R expression while adolescent cocaine administration attenuated this effect; cocaine exposure also diminished CB2R expression in bone marrow. Present findings provide evidence for changes in brain CB1R expression and functionality and immune CB2R expression as a consequence of early life stress and adolescent cocaine exposure, and indicate functional interactions between both treatments, which in many regions differ between males and females.

Subdural hematoma occurrence: comparison between ethanol and cocaine use at death

OBJECTIVE

The objective of this study was to show that, in a medical examiner population, ethanol intoxication is associated with an increase in the occurrence of subdural hematoma (SDH), whereas the presence of cocaine is not associated with an increase in the occurrence of SDH.

DESIGN

This was a retrospective evaluation of 967 SDH including the investigative information, autopsy, and toxicological findings derived from 18,314 medical examiner cases over 8 years.

RESULTS

Subdural hematoma is found in 7% to 9% of cases with either no ethanol or less than 100 mg/dL of ethanol. Subdural hematoma is found in 18% of cases with ethanol levels of greater than 100 mg/dL. Subdural hematoma is found in 11% of cases negative for cocaine, whereas SDH is found in 9% of cases with any form of cocaine present at death.

[Ischemic strokes in young adults and illegal drugs]

One out of four ischemic strokes in France occurs in adults under 65 years old. About a third of them remain unexplained even after an extensive etiological assessment. A large part of these unexplained strokes could be linked to illegal drug abuse, and 10 % are estimated to be directly linked to illegal drugs in some international studies. The most frequently incriminated recreational drug remains cocaine, via several mechanisms. However, several other illegal drugs, some very commonly used such as cannabis, are suspected to have an important role in neurovascular diseases. In this article, we reviewed the epidemiological, pathophysiological and clinical studies, published in the international literature over the past 30 years. The drug-caused stroke epidemiology needs to be more precisely studied, as well as the underlying mechanisms depending on each drug. This is a public health issue that affects an economically active population, as stroke is the first cause of acquired handicap in adults.

Cocaine-induced intracerebral hemorrhage in a patient with cerebral amyloid angiopathy

Intracerebral hemorrhage (ICH) is a well-recognized complication of recreational cocaine use. The precise mechanism of the cocaine-induced hemorrhagic event is unclear, although multiple factors have been implicated. We report a case of a 62-year-old woman who suffered left parieto-occipital ICH with herniation and death, following a cocaine binge. Microscopic examination also revealed extensive cerebral amyloid angiopathy (CAA) in the vicinity of the hemorrhage. We additionally studied brain tissue in eight subjects between ages of 60 and 80 who were positive for cocaine metabolites at autopsy; of these, none had vascular amyloid-β deposits by immunohistochemistry. Whereas we found no evidence that chronic cocaine use is a risk factor for CAA, given the age-associated nature of CAA and the aging population using cocaine, CAA-induced hemorrhage in the setting of cocaine use may be more common than recognized. This is the first reported case of CAA-associated ICH precipitated by cocaine.

Amnestic effect of cocaine after the termination of its stimulant action

The effects of cocaine on memory are controversial. Furthermore, the psychostimulant action of cocaine can be a critical issue in the interpretation of its effects on learning/memory models. The effects of a single administration of cocaine on memory were investigated during the presence of its motor stimulating effect or just after its termination. The plus-maze discriminative avoidance task (PM-DAT) was used because it provides simultaneous information about memory, anxiety and motor activity. In Experiment I, mice received saline, 7.5, 10, 15 or 30 mg/kg cocaine 5 min before the training session. In Experiment II, mice were trained 30 min after the injection of saline, 7.5, 10, 15 or 30 mg/kg cocaine. In Experiment III, mice received 30 mg/kg cocaine 30 min pre-training and pre-test. In Experiment IV, mice received 30 mg/kg cocaine immediately post-training. Tests were always conducted 24 h following the training session. Given 5 min before training, cocaine promoted a motor stimulant effect at the highest dose during the training session but did not impair memory. When cocaine was injected 30 min pre-training, the drug did not modify motor activity, but produced marked amnestic effects at all doses tested. This amnesia induced by cocaine given 30 min pre-training was not related to a state-dependent learning because it was not abolished by pre-test administration of the drug. Post-training cocaine administration did not induce memory deficits either. Our results suggest that the post-stimulant phase is the critical moment for cocaine-induced memory deficit in a discriminative task in mice.

An analysis of cocaine powder in the Netherlands: content and health hazards due to adulterants

AIMS

To report on trends in the content and adulterants present in street cocaine (powder) in the Netherlands and to describe the associated health hazards.

DESIGN AND PARTICIPANTS

Drug consumers handed in samples of cocaine powder from 1999 to 2007 for analysis. Reports were compiled of users' experiences with the samples received.

MEASUREMENTS AND ANALYSIS

Linear regression analysis was used to assess the trend in adulterated cocaine powder across the study period, and comparison of reported adverse effects of adulterated with those of unadulterated cocaine by Fisher's exact test.

FINDINGS

There has been a statistically significant upward trend in the occurrence of adulterated cocaine powder over the years. Adulterated cocaine was associated more frequently with reported adverse effects than unadulterated cocaine. Phenacetin, hydroxyzine and diltiazem appeared to be three adulterants contributing to these adverse effects.

CONCLUSIONS

An increase in adulterants was detected in the analysed cocaine powder between 1999 and 2007. This increase is associated with relatively more adverse effects with cocaine use. The cardiac and hallucinatory effects that were reported more frequently are not understood clearly. Adverse effects are likely to be due to several factors, including interactions of adulterants with cocaine and the route of administration.

Quantification of cocaine-induced cortical blood flow changes using laser speckle contrast imaging and Doppler optical coherence tomography

We present a dual-imaging technique combining laser speckle contrast imaging and spectral-domain Doppler optical coherence tomography to enable quantitative characterization of local cerebral blood flow (CBF) changes in rat cortex in response to drug stimulus (e.g., cocaine) at high spatiotemporal resolutions. To examine the utility of this new technique, animal experiments were performed to study the influences of anesthetic regimes (e.g., isoflurane, alpha-chloralose) on the pharmadynamic effects of acute cocaine challenge. The results showed that cocaine-evoked CBF patterns (e.g., increases in alpha-chloralose and decreases in isoflurane regimes) were quantitatively characterized, thus rendering it a potentially useful tool for imaging studies of brain functions.

Early retinal vascular abnormalities in African-American cocaine users

PURPOSE

To investigate whether cocaine use is associated with early retinal vascular abnormalities.

DESIGN

Population-based cross-sectional study.

METHODS

SETTINGS

Inner-city neighborhoods in Baltimore, Maryland.

STUDY POPULATION

Sixty-eight participants were recruited from an ongoing observational study, investigating cardiovascular complications of human immunodeficiency virus (HIV) infection and cocaine use in African Americans aged between 25 and 54 years. Those with hypertension and known cardiovascular/cerebrovascular diseases were excluded.

OBSERVATION PROCEDURES

Ophthalmoscopic examinations and fundus photography of the retinas of these subjects were performed after pupillary dilation. The largest angle of arterial bifurcation (LAAB), central retinal artery equivalent (CRAE), and central retinal vein equivalent (CRVE) were measured by single-masked fundus image examiners.

MAIN OUTCOME MEASURES

LAAB, CRAE, and CRVE.

RESULTS

Among the 68 study subjects, 52 (76.5%) were chronic cocaine users and 16 (23.5%) were non-cocaine users. Univariate and multivariate analyses indicated that the LAAB was associated with age and duration of cocaine use of more than 10 years. The LAAB was also inversely associated with very low-density lipoproteins levels. Multivariate analysis indicated a positive association between CRVE and cocaine use. CRAE was also associated with intravenous injection. We confirmed that CRAE was inversely associated with age. HIV infection was not found to be associated with any retinal vascular parameters.

CONCLUSIONS

Cocaine use is associated with increased retinal arterial branching angle and venular caliber. The retinal vascular changes provided the first evidence that cocaine use has an effect on the retinal vascular system.

Neurotoxic profiles of HIV, psychostimulant drugs of abuse, and their concerted effect on the brain: current status of dopamine system vulnerability in NeuroAIDS

There are roughly 30-40 million HIV-infected individuals in the world as of December 2007, and drug abuse directly contributes to one-third of all HIV infections in the United States. Antiretroviral therapy has increased the lifespan of HIV-seropositives, but CNS function often remains diminished, effectively decreasing quality of life. A modest proportion may develop HIV-associated dementia, the severity and progression of which is increased with drug abuse. HIV and drugs of abuse in the CNS target subcortical brain structures and DA systems in particular. This toxicity is mediated by a number of neurotoxic mechanisms, including but not limited to, aberrant immune response and oxidative stress. Therefore, novel therapeutic strategies must be developed that can address a wide variety of disparate neurotoxic mechanisms and apoptotic cascades. This paper reviews the research pertaining to the where, what, and how of HIV and cocaine/methamphetamine toxicity in the CNS. Specifically, where these toxins most affect the brain, what aspects of the virus are neurotoxic, and how these toxins mediate neurotoxicity.

Cocaine increases the intracellular calcium concentration in brain independently of its cerebrovascular effects

Cocaine abuse increases the risk of life-threatening neurological complications such as strokes and seizures. Although the vasoconstricting properties of cocaine underlie its cerebrovascular effects, the mechanisms underlying its neurotoxicity remain incompletely understood. Here, we use optical techniques to measure cerebral blood volume, hemoglobin oxygenation (S(t)O(2)), and intracellular calcium ([Ca(2+)](i)) to test the hypothesis that cocaine increases [Ca(2+)](i) in the brain. The effects of cocaine were compared with those of methylphenidate, which has similar catecholaminergic effects as cocaine (except for serotonin increases) but no local anesthetic properties, and of lidocaine, which has similar local anesthetic effects as cocaine but is devoid of catecholaminergic actions. To control for the hemodynamic effects of cocaine, we assessed the effects of cocaine in animals in which normal blood pressure was maintained by infusion of phenylephrine, and we also measured the effects of transient hypotension (mimicking that induced by cocaine). We show that cocaine induced significant increases ( approximately 10-15%) in [Ca(2+)](i) that were independent of its hemodynamic effects and of the anesthetic used (isofluorance or alpha-chloralose). Lidocaine but not methylphenidate also induced significant [Ca(2+)](i) increases ( approximately 10-13%). This indicates that cocaine at a dose within the range used by drug users significantly increases the [Ca(2+)](i) in the brain and its local anesthetic, but neither its catecholaminergic nor its hemodynamic actions, underlies this effect. Cocaine-induced [Ca(2+)](i) increases are likely to accentuate the neurotoxic effects from cocaine-induced vasoconstriction and to facilitate the occurrence of seizures from the catecholaminergic effects of cocaine. These findings support the use of calcium channel blockers as a strategy to minimize the neurotoxic effects of cocaine.

Intracranial Aneurysms: an Overview

The outcome of intracranial aneurysms remains disastrous despite progress in diagnosis, management, care, and follow-up. This article discusses the pathology, the etiologies, the epidemiology and the classifications of intracranial aneurysms.

Alterations of the vascular basal lamina in the cerebral cortex in drug abuse: a combined morphometric and immunohistochemical investigation

In drug abusers, white matter hyperintensities, perfusion deficits, and metabolic disturbances are detected by neuroimaging analyses in different brain regions. A specific pattern of involvement or a predominance of a specific brain region cannot be drawn. To examine changes of the cerebral microvasculature as a possible morphological substrate of the neuroimaging findings, brain specimens of 12 polydrug abusers and 8 controls were obtained at autopsy. The basal lamina of blood vessels from the frontal, temporal, parietal, and occipital lobes was analysed by means of immunohistochemistry for collagen type IV. The numerical density of vessels was determined in the gray and white matter, and their staining intensity was rated using a three-point scale. In the gray and white matter of polydrug abusers, the number of vessels showing strong immunoreactivity for collagen type IV was significantly reduced, whereas the number of vessels with mild and moderate immunoreactivity was increased as compared to controls. The total numerical density of vessels was not significantly changed. Our results show a significant reduction in immunoreactivity for collagen type IV in the brains from polydrug abusers compared to controls, which may be due to a thinning of the basal lamina of cerebral vessels. The data of the present study show morphological changes of the basal lamina in the brain of polydrug abusers, which might represent the morphological substrate of a disturbed blood-brain barrier. However, it remains yet to be established if the observed changes are responsible for the alterations seen in different neuroimaging analyses and which drug might be of major pathogenetic significance.

Postmortem toxicology of drugs of abuse

Conducting toxicology on post-mortem specimens provides a number of very significant challenges to the scientist. The range of additional specimens include tissues such as decomposing blood and other tissues, hair, muscle, fat, lung, and even larvae feeding on the host require special techniques to isolate a foreign substance and allow detection without interference from the matrix. A number of drugs of abuse are unstable in the post-mortem environment that requires careful consideration when trying to interpret their significance. Heroin, morphine glucuronides, cocaine and the benzodiazepines are particularly prone to degradation. Moreover, redistributive process can significantly alter the concentration of drugs, particularly those with a higher tissue concentration than the surrounding blood. The designer amphetamines, methadone and other potent opioids will increase their concentration in blood post-mortem. These processes together with the development of tolerance means that no concentration of a drug of abuse can be interpreted in isolation without a thorough examination of the relevant circumstances and after the conduct of a post-mortem to eliminate or corroborate relevant factors that could impact on the drug concentration and the possible effect of a substance on the body. This article reviews particular toxicological issues associated with the more common drugs of abuse such as the amphetamines, cannabinoids, cocaine, opioids and the benzodiazepines.