Hippocampal gray matter reduction associates with memory deficits in adolescents with history of prematurity

Mónica Giméneza, Carme Junquéa, , , Ana Narberhausa, Xavier Caldúa, Pilar Salgado-Pinedaa, Núria Bargallób, Dolors Segarraa and Francesc Botetc
Department of Psychiatry and Clinical Psychobiology, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, 08036, Barcelona, Spain
bNeuroradiology Section, Radiology Department, Centre de Diagnòstic per la Imatge (CDI), Hospital Clínic, Faculty of Medicine, University of Barcelona, 08036, Barcelona, Spain
cPediatrics Section, Department of Obstetrics and Gynecology, Pediatrics, Radiology and Physics Medicine, Hospital Clínic, Casa Maternitat, 08028, Barcelona, Spain

Received 15 December 2003; revised 30 June 2004; accepted 7 July 2004. Available online 2 November 2004.

Using optimized voxel-based morphometry (VBM), we compared the relationship between hippocampal and thalamic gray matter loss and memory impairment in 22 adolescents with history of prematurity (HP) and 22 normal controls.

We observed significant differences between groups in verbal learning and verbal recognition, but not in visual memory. VBM analysis showed significant left hippocampal and bilateral thalamic reductions in HP subjects.

Using stereological methods, we also observed a reduction in hippocampal volume, with left posterior predominance. We found correlations between left hippocampal gray matter reductions (assessed by VBM) and verbal memory (learning and percentage of memory loss) in the premature group.

The stereological analysis showed a correlation between verbal learning and the left posterior hippocampus. Our results suggest that left hippocampal tissue loss may be responsible for memory impairment and is probably related to the learning disabilities that HP subjects present during schooling.