Deep Brain Stimulation (DBS) of the Nucleus Basalis Meynert (NBM) to Treat Cognitive Deficits in Light to Moderate Alzheimer's Disease

In the study at hand, six patients with light to moderate Alzheimer's disease will be enrolled and implanted with bilateral electrodes in the nucleus basalis Meynert. The stereotactic implantation of the electrodes will be guided by computerized tomography (CT) and magnetic resonance tomography (MRT).

Basically, even though deep brain stimulation is an invasive method, there are only few side effects. Surgical risks correspond with the risk of DBS in morbus Parkinson or other movement disorders (0,4-6%).

After the baseline examination, the patients will be implanted with the electrodes; accordingly all follow-ups are accomplished postoperative. From the second week after the operation, the conventional stimulation takes place as a doubleblind, randomized change between ON and OFF periods. Modifications of the stimulation parameter to obtain the best possible result are possible.

Throughout the one-year observation-period, the patients will be followed closely to monitor the effects of DBS on their cognitive abilities, psychopathological well being, the quality of life, praxie and nutritional condition using standardized neurological and psychiatric rating scales.

Inclusion criteria

• German speaking male/female subjects
• age:60-80
• AD assessed by DSM-IV, ICD-10 and NINCDS-ADRDA-Scale
• no Lewy-Body-dementia or other form of dementia
• MMST >18 and <26
• stable psychopharmacological medication
• no psychotic symptoms, no suicidal tendency
• education for at least 8 years
• written informed consent of the patient
• consent of at least two family members
• no contraindication regarding PET-examination
• no contraindication regarding anesthesia or stereotactic operation

Exclusion criteria

• legal accommodation
• clinical co-morbidity
• contraindication of MRT examination
• psychotic symptoms last six months
• aggressive behavior or suicidal tendency
• verbal IQ <85
• stereotactic operation in previous history
• neoplastic neurological diseases
• serious organic disease