Sexual abuse in children and adolescents with intellectual disability.

The present authors conducted a study of the occurrence of victimization and the perpetration of sexual abuse among 43 in-patients with intellectual disability aged between 9 and 21 years who were admitted to a child and adolescent psychiatric in-patient department over a period of 5 years. A retrospective case-note review was employed that explored the nature and severity of abuse in relation to the age, gender and level of disability. The prevalence of abuse or abusive behaviour, i.e. 14% of 300 admissions, did not change over time. In 13 out of the 43 cases, the issue of sexual abuse was identified after admission. Victimization alone occurred in 21 cases, perpetration alone in six cases, and both victimization and perpetration in 16 cases. Fifty per cent of the victims had been abused by a member of their close or extended family. Most cases (62%) were adolescents. There was only one instance of a victim being abused by a female. However, there were five girls who were perpetrators, all of whom had previously been victims. By contrast, 11 out of the 17 male perpetrators had been victims. Despite difficulties of disclosure, it was possible to establish that severely disabled patients had suffered sexual abuse. The present data support theories which (1) recognize gender differences in sexual abuse patterns and (2) have a developmental perspective, incorporating the influence of adolescence.

Path integration following temporal lobectomy in humans.

Path integration, a component of spatial navigation, is the process used to determine position information on the basis of information about distance and direction travelled derived from self-motion cues. Following on from studies in the animal literature that seem to support the role of the hippocampal formation in path integration, this facility was investigated in humans with focal brain lesions. Thirty-three neurosurgical patients (17 left temporal lobectomy, LTL; 16 right temporal lobectomy, RTL) and 16 controls were tested on a number of blindfolded tasks designed to investigate path integration and on a number of additional control tasks (assessing mental rotation and left-right orientation). In a test of the ability to compute a homing vector, the subjects had to return to the start after being led along a route consisting of two distances and one turn. Patients with RTL only were impaired at estimating the turn required to return to the start. On a second task, route reproduction was tested by requiring the subjects to reproduce a route consisting of two distances and one turn; the RTL group only were also impaired at reproducing the turn, but this impairment did not correlate with the homing vector deficit. There were no group differences on tasks where subjects were required to reproduce a single distance or a single turn. The results indicate that path integration is impaired in RTL patients only and suggest that the right temporal lobe plays a role in idiothetic spatial memory.