A long-term follow-up study of cerebrospinal fluid somatostatin in delirium

Cerebrospinal fluid somatostatin-like immunoreactivity (CSF SLI) was determined for elderly delirious patients during the acute stage and after 1- and 4-year follow-up periods, and the SLI levels were compared with age-equivalent controls. As a whole group, and also when the group was subdivided according to the severity of cognitive decline at the acute stage, type of delirium or the central nervous system disease, delirious patients showed significant reduction of SLI as compared with the controls. In the follow-up, we observed a further reduction of CSF SLI together with significant correlations in the second, third and fourth samples between SLI levels and Mini-Mental State Examination scores. Our results suggest a role for somatostatinergic dysfunction in the genesis of some symptoms of delirium, and this dysfunction may be linked to the long-term prognosis of delirious patients.