The mystery of the cerebellum: clues from experimental and clinical observations

Abstract The cerebellum has a striking homogeneous cytoarchitecture and participates in both motor and non-motor domains. Indeed, a wealth of evidence from neuroanatomical, electrophysiological, neuroimaging and clinical studies has substantially modified our traditional view on the cerebellum as a sole calibrator of sensorimotor functions. Despite the major advances of the last four decades of cerebellar research, outstanding questions remain regarding the mechanisms and functions of the cerebellar circuitry. We discuss major clues from both experimental and clinical studies, with a focus on rodent models in fear behaviour, on the role of the cerebellum in motor control, on cerebellar contributions to timing and our appraisal of the pathogenesis of cerebellar tremor. The cerebellum occupies a central position to optimize behaviour, motor control, timing procedures and to prevent body oscillations. More than ever, the cerebellum is now considered as a major actor on the scene of disorders affecting the CNS, extending from motor disorders to cognitive and affective disorders. However, the respective roles of the mossy fibres, the climbing fibres, cerebellar cortex and cerebellar nuclei remains unknown or partially known at best in most cases. Research is now moving towards a better definition of the roles of cerebellar modules and microzones. This will impact on the management of cerebellar disorders

Efeitos do trabalho sobre a saúde de adolescentes Effects of work on the health of adolescents

O estudo analisa conseqüências do trabalho para as condições de vida, saúde e desenvolvimento psicossocial de adolescentes. Participaram do estudo 354 estudantes de 14 a 18 anos, do ensino médio, período noturno. A análise das representações foi realizada a partir da coleta de evocações livres. Os dados sobre sono foram obtidos por meio de questionários, sobre auto-percepções acerca das condições de vida e trabalho, sintomas de saúde e doenças. A análise de dados foi realizada com o software EVOC 2000 e SPSS. Constataram-se diferenças significativas na duração média de sono entre os adolescentes: os trabalhadores relataram menores médias de duração de sono. Entre os trabalhadores, referiram dormir menos os que sentem sono no trabalho e nas aulas, têm maiores exigências psicológicas no trabalho, ganham acima de 1 salário mínimo mensal, jornadas acima de 6 horas diárias ou acima de 20 horas semanais, trabalham em local barulhento e com presença de gases e vapores. As representações do trabalho entre os jovens apontam contradição entre o seu reconhecimento como valor moral positivo para o desenvolvimento psicossocial e a construção da identidade, e as conseqüências negativas decorrentes da exposição a cargas físicas e psicológicas precocemente.<br>This study evaluated life and work conditions and their impact on the health and psychological development of adolescents. A number of 354 high school students, 14 to 18 years old, studying during evening period took part in this study. Data were collected using free evocation technique and questionnaires. Data on sleep during the weekdays were obtained using questionnaires, filled out by students regarding life and work conditions, health symptoms and illness. Data were analyzed with software EVOC 2000 for the social representations, and T-Student, ANOVA, Mann-Whitney e Kruskal-Wallis tests were employed for analyze health and sleep conditions. Differences were found among worker students who reported shorter mean sleep durations and: males, feeling sleepy at work and classes, referring to tougher psychological demands at work, working as salesperson, earning more than 1 minimum monthly wage, working more than 6 hours per day or 20 hours per week, working in noisy environment or polluted with gases and vapors. The representation of work among teen workers point a contradiction between recognizing work as a moral positive value to psychosocial development and identity construction, and the negative consequences due to precocious exposure to physical and psychological workloads

Phenomenology, psychiatric comorbidity and family history in referred preschool children with obsessive-compulsive disorder

<p>Abstract</p> <p>Objective</p> <p>The study aimed to investigate phenomenology, psychiatric comorbidity, and family history of obsessive-compulsive disorder (OCD) in a clinical sample of normally developing preschool children with OCD.</p> <p>Method</p> <p>Subjects in this study were recruited from a clinical sample of preschool children (under 72 months of age) who were referred to a university clinic. Subjects with a normal developmental history and significant impairment related to OCD symptoms were included in the study. Children’s Yale-Brown Obsessive-Compulsive Scale was used to assess OCD symptoms. Each subject was assessed for comorbid DSM-IV psychiatric disorders using a semi-structured interview. Parents were evaluated for lifetime history of OCD in individual sessions.</p> <p>Results</p> <p>Fifteen boys and ten girls (age range: 28 to 69 months; 54.12±9.08 months) were included. Mean age of onset of OCD was 35.64±13.42 months. All subjects received at least one comorbid diagnosis. The most frequent comorbid disorders were non-OCD anxiety disorders (n=17; 68.0%), attention-deficit hyperactivity disorder (ADHD) (n=15; 60.0%), oppositional defiant disorder (ODD) (n=12; 48.0%), and tic disorders (n=6; 24.0%). Mean number of comorbid disorders was 3.65 and 2.35 for boys and girls, respectively. At least one parent received lifetime OCD diagnosis in 68 percent of the subjects.</p> <p>Conclusions</p> <p>The results indicated that OCD in referred preschool children is more common in males, highly comorbid with other psychiatric disorders, and associated with high rates of family history of OCD. Given the high rates of comorbidity and family history, OCD should be considered in referred preschool children with disruptive behavior disorders and/or with family history of OCD.</p