Forniceal deep brain stimulation in severe Alzheimer's disease: A case report.

BACKGROUND Forniceal deep brain stimulation (DBS) has been proposed as an alternative treatment for Alzheimer's disease (AD). Previous studies on mild to moderate AD patients demonstrated improvements in cognitive functions brought about by forniceal DBS. Here, we report our longitudinal findings in one severe AD patient for whom the activities of daily living (ADL) rather than cognitive function significantly improved after 3 mo of continuous stimulation. CASE SUMMARY In 2011, a 62-year-old Chinese male with no previous history of brain injury or other neuropsychological diseases and no family history of dementia developed early symptoms of memory decline and cognitive impairment. Five years later, the symptoms had increased to the extent that they affected his daily living. He lost the ability to work as a businessman and to take care of himself. The patient was given a clinical diagnosis of probable AD and was prescribed donepezil and subsequently memantine, but no improvement in symptoms was observed. The patient then received DBS surgery. After 3 mo of continuous stimulation, the patient's ADL score decreased from 65 points to 47 points, indicating the quality of the patient's daily living improved distinctly. Other scores remained unchanged, suggesting no significant improvement in cognitive function. A follow-up positron emission tomography scan demonstrated perceivable increased glucose metabolism in the classical AD-related brain regions. CONCLUSION Based on this case we hypothesize that forniceal DBS may improve ADL through elevating regional glucose metabolism in the brain.