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Dose-dependent impact of vaporized cannabis on the neural correlates of monitoring of action errors and divergent thinking in regular cannabis users

Background: Vasculitis neuropathy is an emergency disease of
peripheral nervous system.
Objective: The aim of this study was to assess the utility of
erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)
as a predictor of necrotizing vasculitis in vasculitis neuropathy.
Patients and Methods/Material and Methods: We searched the
medical records of 24 patients undergoing the sural nerve biopsy at
our Hospital between April 2015 and December 2016, and assessed
the clinicopathological features of 10 patients (9 women, 1 men,
56 years, age at biopsy) whose biopsied samples were diagnosed as
vasculitis neuropathy. We also investigated clinical and serological
proles including ESR, CRP and anti-neutrophil cytoplasmic antibody
(ANCA) in those patients. The specimens of biopsy were divided
into two portions. The rst portion was xed in formalin solution,
embedded in parafn, and stained with haematoxylin and eosin. The
second was xed in glutaraldehyde, embedded in epoxy resin, and
assessed in toluidine blue-stained semi-thin sections.
Results: The clinical diagnoses of 10 patients were eosinophilic
granulomatosis with polyangitis (n=5), microscopic polyangitis
(n=1), polyarteritis nodosa (n= 1), Sjogrens syndrome (n = 1)
and others (n=2), respectively. ANCA was positive in 2 patients. The
biopsy ndings of perivascular cell invasion were seen in 10 patients,
whereas necrotizing vasculitis was detected in only 3 patients. ESR
levels were signicantly elevated in all the 3 cases (more than 120 in
2, 102 mm/hr in 1), whereas CRP levels were diversely distributed in
those cases (21.2, 3.5 and 2.6 mg/dl).
Conclusion: ESR levels might be more useful than those of CRP for a
predictor of necrotizing vasculitis in vasculitis neuropathy.
Dose-dependent impact of vaporized cannabis on the neural
correlates of monitoring of action errors and divergent thinking
in regular cannabis users
M. Kowal
, H. van Steenbergen
, L. Colzato
, A. Hazekamp
, N. van der
, M. Manaï
, J. Durieux
, B. Hommel
Bedrocan International,
Research & Development, Veendam, The Netherlands;
Leiden University,
Institute of Psychology, Leiden, The Netherlands;
Leiden University
Medical Center, Psychiatry, Leiden, The Netherlands
Background: Data is lacking on how delta-9-tetrahydrocannabinol
(THC), the main psychoactive compound found in cannabis, affects
information processing.
Objective: To investigate the effects of cannabis on the amplitudes of
two event-related potentials associated with the cognitive processing
of errorsthe error-related negativity (ERN) and error positivity (Pe),
and performance on measures of divergent and convergent thinking.
Patients and Methods/Material and Methods: The study adopted a
between-subjects, double-blind, placebo-controlled design. It investi-
gated the effects of administering a low (5.5 mg THC) or high dose
(22 mg THC) of vaporized cannabis vs. placebo to a sample of 55 regular
cannabis users (using cannabis minimally 4 times a week, for at least
2 years). Error monitoring was assessed in the context of a Flanker Task,
while divergent and convergent thinking was measured by the Alternate
Uses Task (AUT) and Remote Associates Task (RAT), respectively.
Results: Participants in the high-dose condition showed a signi-
cantly reduced ERN, compared to placebo. Both the high- and low-
dose groups displayed a diminished Pe amplitude, as compared to
placebo. Moreover, the high-dose group demonstrated signicantly
worse performance on the AUT, compared to both the low-dose and
placebo conditions.
Conclusion: The ndings suggest that even a low dose of cannabis
may alter the neural correlates of error monitoring of regular cannabis
users. Moreover, this effect is more distinct with a high dose. In
addition, the results suggest that a high dose of cannabis impairs
divergent thinking. Furthermore, the study demonstrated the effec-
tiveness of new clinical tools available for researchers working with
cannabis and cannabinoids.
Actual problems of chronic brain ischemia
S. Krokhmal
, I. Dolgova
, V. Baturin
, M. Hibirtova
, N. Kalashyants
F. Shamasurova
Stavropol State Medical University, Neurology-
Neurosurgery and Medical Genetics, Stavropol, Russia;
Stavropol State
Medical University, Clibical Pharmacology, Stavropol, Russia
Background: Chronic cerebral ischemia (CCI) leading cause of
persistent disability and mortality of patients in Russia and around
the world, including in people of working age.
Objective: To evaluate the clinical manifestation of CCI determine
their severity.
Patients and Methods/Material and Methods: A total of 20 patients
of CCI. All patients suffered from hypertensive patients. Dened
clinical syndromes, cognitive and psycho-emotional disorders. Cogni-
tive disorder was assessed using the test clock drawing, the mini-
mental state examination. Psycho-emotional status carried out with
the help of Taylor anxiety Scale score.
Results: Vestibular in 11 (55%) people, Insomnia in 5 (25%) and
asthenia in 4 (20%) people, Mild cognitive impairment is identied in
6 (30%), Moderate cognitive impairment in 14 (70%) people. The
anxiety result of Taylor Scale in 7 (35%) patients revealed an average
of anxiety, while 13 (65%) people high levels of anxiety.
Conclusion: The core clinical picture CCI make cognitive impairment.
Severity of which dependson the duration of thepresence of risk factors
and their timely prevention. Additional inuence have the clinical
manifestations and the state of psycho-emotional status. Early diagnosis
of the cognitive disorder has a great socio economic importance.
The role of neurology specialists in cases of emergency calls by
home care patients
M. Kunimoto
, Y. Nagashima
, Y. Osawa
Kunimoto Life Support Clinic,
Neurology, Yokohama, Japan;
Funabashi Municipal Rehabilitation
Hospital, Rehabilitation, Chiba, Japan
Background: Presently, home care medicine is often performed in
Japan. As neurology specialists might increasingly engage in this
mode of care, we examined how often home care situations prove
Abstracts / Journal of the Neurological Sciences 381 (2017) 561756614
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Anterior cingulate cortex (ACC) is a part of the brain's limbic system. Classically, this region has been related to affect, on the basis of lesion studies in humans and in animals. In the late 1980s, neuroimaging research indicated that ACC was active in many studies of cognition. The findings from EEG studies of a focal area of negativity in scalp electrodes following an error response led to the idea that ACC might be the brain's error detection and correction device. In this article, these various findings are reviewed in relation to the idea that ACC is a part of a circuit involved in a form of attention that serves to regulate both cognitive and emotional processing. Neuroimaging studies showing that separate areas of ACC are involved in cognition and emotion are discussed and related to results showing that the error negativity is influenced by affect and motivation. In addition, the development of the emotional and cognitive roles of ACC are discussed, and how the success of this regulation in controlling responses might be correlated with cingulate size. Finally, some theories are considered about how the different subdivisions of ACC might interact with other cortical structures as a part of the circuits involved in the regulation of mental and emotional activity.
The authors present a unified account of 2 neural systems concerned with the development and expression of adaptive behaviors: a mesencephalic dopamine system for reinforcement learning and a "generic" error-processing system associated with the anterior cingulate cortex. The existence of the error-processing system has been inferred from the error-related negativity (ERN), a component. of the event-related brain potential elicited when human participants commit errors in reaction-time tasks. The authors propose that the ERN is generated when a negative reinforcement learning signal is conveyed to the anterior cingulate cortex via the mesencephalic dopamine system and that this signal is used by the anterior cingulate cortex to modify performance on the task at hand. They provide support for this proposal using both computational modeling and psychophysiological experimentation.
Rationale An increase in the potency of the cannabis cigarettes has been observed over the past three decades. Objectives In this study, we aimed to establish the impact of Δ9-tetrahydrocannabinol (THC) on the rating of subjective effects (intensity and duration of the effects), up to 23 % THC potency (69 mg THC) among recreational users. Methods Recreational users (N = 24) smoked cannabis cigarettes with four doses of THC (placebo 29, 49 and 69 mg of THC) on four separate test days in a randomized, double-blind, placebo-controlled, crossover study. The participants filled in three different questionnaires measuring subjective effects during the exposure up to 8 h post-smoking. The ‘high’ feeling, heart rate, blood pressure and THC serum concentrations were also regularly recorded during these 8 h. Results THC significantly increased the high feeling, dizziness, dry-mouthed feeling, palpitations, impaired memory and concentration, and ‘down’, ‘sedated’ and ‘anxious’ feelings. In addition, THC significantly decreased alertness, contentment and calmness. A cubic relationship was observed between ‘feeling the drug’ and ‘wanting more’. The THC-induced decrease in ‘feeling stimulated’ and increase in anxiety lasted up to 8 h post-smoking. Sedation at 8 h post-smoking was increased by a factor of 5.7 with the highest THC dose, compared to the placebo. Conclusions This study shows a strong effect of cannabis containing high percentages of THC on the rating of subjective effects. Regular users and forensic toxicologists should be aware that the THC-induced increase in ‘feeling sedated’ continues longer with a 69 mg THC dose than with a 29 mg THC dose.
Successful goal-directed behavior critically depends on performance monitoring, a set of cognitive and affective functions determining whether adaptive control is needed and, if so, which type and magnitude is required. Knowledge of the brain structures involved in such a process has grown enormously, although the time course of performance-monitoring (PM) activity remains poorly understood. Here, we review evidence from EEG recordings in humans and show that monitored events elicit a rather uniform sequence of cortical activity reflecting the detection, accumulation, and weighting of evidence for the necessity to adapt and (re)act. We link the EEG findings with invasive and pharmacological findings and evaluate the neurobiological plausibility of current theories of PM.
The influence of cannabis on mental health receives growing scientific and political attention. An increasing demand for treatment of cannabis dependence has refueled the discussion about the addictive potential of cannabis. A key feature of all addictive drugs is the ability to increase synaptic dopamine levels in the striatum, a mechanism involved in their rewarding and motivating effects. However, it is currently unknown if cannabis can stimulate striatal dopamine neurotransmission in humans. Here we show that Δ9- tetrahydrocannabinol (THC), the main psychoactive component in cannabis, induces dopamine release in the human striatum. Using the dopamine D2/D 3 receptor tracer [11C]raclopride and positron emission tomography in seven healthy subjects, we demonstrate that THC inhalation reduces [11C]raclopride binding in the ventral striatum and the precommissural dorsal putamen but not in other striatal subregions. This is consistent with an increase in dopamine levels in these regions. These results suggest that THC shares a potentially addictive property with other drugs of abuse. Further, it implies that the endogenous cannabinoid system is involved in regulating striatal dopamine release. This allows new directions in research on the effects of THC in neuropsychiatric disorders, such as schizophrenia.
In many response time tasks, people slow down after they make an error. This phenomenon of post-error slowing (PES) is thought to reflect an increase in response caution, that is, a heightening of response thresholds in order to increase the probability of a correct response at the expense of response speed. In many empirical studies, PES is quantified as the difference in response time (RT) between post-error trials and post-correct trials. Here we demonstrate that this standard measurement method is prone to contamination by global fluctuations in performance over the course of an experiment. Diffusion model simulations show how global fluctuations in performance can cause either spurious detection of PES or masking of PES. Both confounds are highly undesirable and can be eliminated by a simple solution: quantify PES as the difference in RT between post-error trials and the associated pre-error trials. Experimental data are used as an empirical illustration.