Exercise-associated hippocampal plasticity and hippocampal microvascular plasticity in chronic refractory schizophrenia patients

RANDALL - WIN_20150331_130356Donna Jane-Mai Lang, Alexander Rauscher, Allen E Thornton, Kristina Gicas Geoff Smith, Vina Goghari, Olga Leonova, Randall F White, Fidel Vila-Rodriguez, Wayne Su, Barbara Humphries, Aaron Phillips, William Honer, Alexandra Talia Vertinsky, Darren E Warburton. Poster presented at 15th International Congress on Schizophrenia Research, Colorado Springs, Colorado. March 29-April 1, 2015.

Abstract

Background: Hippocampal deficits are a commonly reported finding in chronic schizophrenia patients, and may contribute to severity of illness. Regular exercise is thought to remediate both hippocampal volume reductions and neurovascular flow to this region.

Methods: Seventeen chronic refractory schizophrenia patients were enrolled in a 12-week exercise intervention trial. Clinical assessments (PANSS, SOFAS, Hamilton Anxiety Scale (HAMAS), Calgary Depression Scale, Extrapyramidal Symptom Severity Scale), physical assessments (BMI, resting heart rate (RHR), blood pressure (BP), VO2 Max) and 3T MRI data (3D structural MRI, susceptibility weighted imaging) were ascertained at baseline and 12 weeks. Repeated measures ANOVAs with total (L+R) hippocampal and total hippocampal venule volumes expressed as ratios to total brain volume and total hippocampal volume respectively. Additional correlational models were applied.

Results: Patients had a significant increase in total hippocampal volume after 12 weeks of exercise (F(1, 33) = 6.8, p. = 0.019. Total hippocampal venule volume was not significantly increased after exercise (F(1, 33) = 0.17), although the overall increase in venule volume was 7-7.5%. A significant positive relationship between absolute change in total hippocampal volume and absolute change in hippocampal venule volume was observed (r = .52, p. = 0.04). Patients exhibited reduced symptom severity (p. = 0.0005), improved social and occupational functioning (p. = 0.0004), and a strong trend for reduced depression severity (p. = 0.06) at the end of the 12-week exercise intervention. Measures of BMI, RHR, BP and VO2 Max were not statistically different at 12 weeks, however exploratory investigations revealed a potential, but statistically nonsignificant relationship between improved VO2 Max capacity and reduced HAMAS score (r = -.44, p. = .067).

Conclusion: We observed exercise-associated hippocampal volume increases after 12 weeks of regular exercise in chronic refractory schizophrenia patients, as was previously reported by Pajonk et al, 2010. Moreover, these changes in hippocampal volume were correlated to changes in hippocampal venule volumes. These data support the hypothesis that regular exercise offers remediation in both hippocampal tissue volume and hippocampal microvascular volume in chronically treated refractory patients. Relationships to other clinical measures still remain to be clearly established.