Hippocampal sulcal cavities: prevalence, risk factors and relationship to memory impairment

While hippocampal volumes have been extensively examined in neuropsychiatric disorders and ageing, small areas of signal variation within the hippocampus commonly observed on MRI, described as hippocampal sulcal cavities (HSCs), have received less attention. We review the published literature on HSCs to examine their prevalence, putative aetiological factors such as hypertension, and possible cognitive correlates. HSCs were reported in 77 (66 weighted mean) of patients with memory disorders and 48 (47 weighted mean) of controls, and the prevalence increased with age in healthy subjects (r = 0.64, p = 0.047). A number of studies reported hypertension as a risk factor, and related their presence to poorer memory function. Further work is needed to fully understand the clinical significance of these lesions.