1,720,968 research outputs found
Dose-dependent effect of risperidone treatment in a case of 22q13.3 deletion syndrome.
No full textWe describe a 18-year-old female with 22q13.3 deletion syndrome characterized by an alteration of SHANK3/PROSAP2 and severe mental retardation, intense psychomotor agitation and aggressive behaviour. When the patient was given risperidone, different therapeutic results were observed: at a 6 mg dose, risperidone had no therapeutic effect and the patient's behavioural problems increased; at a low dose (1mg), risperidone treatment resulted in rapid improvement of mood and behaviour. Recent findings suggest that risperidone exerts dose-dependent effects on Glu receptors in developing rats. An altered preset of the glutamate receptors, due to the presence of a haploinsufficiency of SHANK3/PROSAP2, could explain the different results of risperidone therapy observed in our patient with 22q13.3 deletion syndrome
Neuroleptic treatments and overflow movements in schizophrenia: are they independent?
No full textNeurological soft signs (NSS) are minor neurological abnormalities that can be revealed by a clinical examination focused on sensory and motor information processing. NSS include overflow movements (OMs), which are defined as involuntary movements that may accompany the production of voluntary movements. OM is generally considered to be a characteristic feature of schizophrenia. White matter abnormalities might be involved in the pathogenesis of OMs. Dopamine receptors play a role in oligodendrocytes development. There is a direct link between antipsychotic agents that bind to dopamine receptors on oligodendrocytes and the development of oligodendrocytes and myelin formation. In this paper, we review the current knowledge of the effects of antipsychotic agents on NSS in schizophrenic patients. As a result of this critical review we hypothesize that the neuroleptic actions described in this paper could explain why antipsychotic agents have no effect on the resolution of NSS in patients with schizophrenia
Overflow movements and white matter abnormalities in ADHD
Get PDFMultiple motor abnormalities have been identified in some children with Attention Deficit/Hyperactivity Disorder (ADHD). These include persistence of overflow movements, impaired timing of motor responses and deficits in fine motor abilities. Motor overflow is defined as co-movement of body parts not specifically needed to efficiently complete a task. The presence of age-inappropriate overflow may reflect immaturity of the cortical systems involved in automatic motor inhibition. Theories on overflow movements consistently implicate impairments in white matter (WM) tracts, including the corpus callosum. WM connections might be altered selectively in brain networks and thus influence motor behaviours. We reviewed the scientific contributions on overflow movements and WM abnormalities in ADHD. They suggest that WM abnormalities in motor/premotor circuits, which are important for motor response inhibition, might be responsible for overflow movements in patients with ADHD
Neurological soft signs, but not theory of mind and emotion recognition deficit distinguished children with ADHD from healthy control
No full textAttention Deficit Hyperactivity Disorder (ADHD) is associated with social cognition impairment, executive dysfunction and motor abnormalities, consisting in the persistence of neurological soft signs (NSS). Theory of mind (ToM) and emotion recognition (ER) deficit of children with ADHD have been interpreted as a consequence of their executive dysfunction, particularly inhibitory control deficit. To our knowledge, there are not studies that evaluate the possible correlation between the ToM and ER deficit and NSS in the population with ADHD, while this association has been studied in other psychiatric disorders, such as schizophrenia. Therefore, the aim of this study was to evaluate ToM and ER and NSS in a sample of 23 drug-naïve children with ADHD and a sample of 20 healthy children and the possible correlation between social cognition dysfunction and NSS in ADHD. Our findings suggest that ToM and ER dysfunction is not a constant feature in the population with ADHD, while NSS confirmed as a markers of atypical neurodevelopment and predictors of the severity of functional impairment in children with ADHD
Dopamine dysfunction in 22q11 deletion syndrome: possible cause of motor symptoms
No full text22q11 Deletion syndrome (22q11DS) is a neurogenetic disorder, resulting from a hemizygous microdeletion on the long arm of chromosome 22. In 22q11DS, the phenotypic expression is highly variable. Approximately one-third of all individuals with 22q11DS develop schizophrenia-like psychotic disorder. Among the genes in the deleted region, catechol-O-methyltransferase (COMT) has a particular relevance for psychiatric disorders: lower COMT enzymatic activity decreases the clearance of dopamine (DA), yielding higher levels of catecholamines in the central nervous system. Deficits in myelinogenesis and dysfunctions in the DA system could justify the white matter abnormalities in motor/premotor circuits described in 22q11DS. The alterations in DA could determine the high incidence of psychiatric disorders and the presence of neurological soft signs in 22q11DS. Neurological soft signs are defined as non-normative performance on an examination of motor and sensory tasks without focal neurological deficits. COMT haploinsufficiency, DA dysfunction, and white matter abnormalities may contribute toward the presence of neurological soft signs in 22q11DS
Motor examination in children with Attention-deficit/hyperactivity Disorder and Asperger Syndrome
No full textEvaluating whether motor skills could differentiate drug-naive subjects with two neurodevelopmental disorders: Attention-Deficit Hyperactivity Disorder (ADHD) and Asperger Syndrome (AS)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
