Searching for the neural basis of reserve against memory decline: intellectual enrichment linked to larger hippocampal volume in multiple sclerosis.

BACKGROUND AND PURPOSE: Active engagement in intellectually enriching activities (e.g. reading, hobbies) builds 'reserve' against memory decline in elders and persons with multiple sclerosis (MS), but the neural basis for this protective influence of enrichment is unknown. Herein the neuroanatomical basis of reserve against memory decline in MS patients is investigated. METHODS: Relapse-onset MS patients (N = 187) underwent 3.0 T magnetic resonance imaging of the brain to quantify T2 lesion volume (T2LV) and normalized volumes of total brain, total white, total grey (using SIENAX) and thalamus, caudate, putamen, pallidum, amygdala and hippocampus (using FIRST). Patients completed a survey quantifying their engagement in early life intellectual enrichment (i.e. reading, hobbies). Verbal and visuospatial episodic memory was assessed with neuropsychological tasks in a representative subsample (N = 97). RESULTS: Controlling for demographics and T2LV, intellectual enrichment was specifically linked to larger normalized hippocampal volume (r(p) = 0.213, P = 0.004), with no link to other brain volumes/structures. Moreover, greater intellectual enrichment moderated/attenuated the negative relationship between normalized total brain volume (i.e. overall cerebral atrophy) and normalized hippocampal volume (i.e. hippocampal atrophy; P = 0.001) whereby patients who engaged in more early life intellectual enrichment better maintained hippocampal volume in the face of worse overall cerebral atrophy. Finally, the link between greater intellectual enrichment and better memory was partially mediated through larger hippocampal volume. CONCLUSIONS: These findings support larger hippocampal volume as one key component of the neuroanatomical basis of reserve against memory decline in MS. These findings are consistent with previous literature on experience-dependent neuroplasticity within the hippocampus.

HIV antibody testing: the gap between policy and practice.

In response to recent laws regulating human immunodeficiency virus (HIV) antibody testing practices in all federal hospitals, our university-affiliated Veterans Affairs Hospital instituted several interventions designed to increase appropriate testing. Specific hospital policy requiring restriction of testing to high-risk individuals, provision of pre- and posttest counseling, and documentation of written consent was instituted. In addition, an education campaign to inform physicians of hospital policy and training of counselors as physician extenders was undertaken. To determine the efficacy of these interventions, we reviewed all HIV antibody tests performed during a subsequent six-month period (n = 221). Only 14% of tests met all hospital policy requirements. The decision to test was prompted by identification of a risk factor or other acceptable reason for testing for only 31% of patients. Risk reduction counseling was provided for only 28% of patients. Written consent was documented for 62% of patients. Health care providers on surgical services were less likely than others to comply with hospital policy (p < 0.0001). We conclude that an interventional program including specific hospital policy mandates, physician education, and provision of trained counselors was not adequate to ensure optimal HIV antibody testing practices. If this gap between policy and practice is to be closed, additional interventions, or alternatively modification of policy guidelines, will be needed.