ABSTRACT
OBJECTIVE: To examine the relationship between the degree of handedness and hemispheric language dominance in patients with epilepsy. METHODS: The authors examined the relationship between degree of handedness and hemispheric language dominance in 174 epilepsy surgery candidates using the intracarotid amobarbital procedure and results from a modified version of the Edinburgh Handedness Inventory. RESULTS: The incidence of atypical language dominance increased linearly with the degree of left-handedness, from 9% in strong right-handers (laterality quotient [LQ] = +100) to 46% in ambidextrous individuals and 69% in strong left-handers (LQ = -100). CONCLUSIONS: The incidence of atypical language dominance depends not only on the direction but also on the degree of handedness. In addition, direction of language dominance varies with hemisphere of seizure focus and degree of handedness. A familial history of sinistrality may have an additional effect on the likelihood of atypical dominance.
Subject(s)
Brain Mapping , Brain/physiopathology , Dominance, Cerebral , Epilepsy/physiopathology , Evoked Potentials , Language , Verbal Behavior , Adolescent , Adult , Aged , Child , Child, Preschool , Epilepsy/diagnosis , Female , Functional Laterality , Humans , Male , Middle Aged , Statistics as TopicABSTRACT
The goals of this work were to: (1) determine the prevalence of clinically significant obsessive-compulsive (OC) symptoms in patients with temporal lobe epilepsy (TLE), (2) characterize the differences in self-reported OC symptoms in patients with TLE and a normative control group, and (3) compare the severity of OC symptoms in right and left hemisphere TLE patients. Patients with TLE (n=30) were administered the Obsessive-Compulsive Inventory (OCI). As a group, patients with TLE had a higher prevalence of OC symptoms than the nonpatient normative sample. In addition, TLE patients exhibited elevated scores on all but 3 of the 16 OCI scales and subscales. There were no reliable differences in OC symptoms in patients with right versus left hemisphere seizure foci, although the right hemisphere patients tended to score higher on both scales of the OCI.
Subject(s)
Epilepsy, Temporal Lobe/complications , Epilepsy, Temporal Lobe/epidemiology , Obsessive-Compulsive Disorder/complications , Obsessive-Compulsive Disorder/epidemiology , Adolescent , Adult , Female , Functional Laterality/physiology , Humans , Male , Middle Aged , Neuropsychological Tests , Prevalence , Psychiatric Status Rating Scales , Reproducibility of ResultsABSTRACT
Fronto-cerebellar circuitry is implicated in word production. Data suggest that the cerebellum is involved in word search, whereas the prefrontal cortex underlies the selection of words from among competing alternatives. We explored the role of search and selection processes in word production deficits in schizophrenia patients. In Experiment 1, patients were impaired in a verb generation task under both high and low selection conditions but were more impaired in the high selection condition. In Experiment 2, when the difficulty level of search and selection conditions was equated in a word stem completion task, patients were only impaired in the search condition. Word search deficits underlie word production problems in schizophrenia, and may involve fronto-cerebellar dysfunction.
