Positive initial results for DBS in Alzheimer’s


Recent research showed that after implantation of a DBS in six patients with Alzheimer’s, half of them had either improved memory, or a slower rate of decline.

“We showed that not only is this a safe procedure, but that the evidence is there to warrant a bigger trial,” said Andres Lozano and colleagues, who conducted the research. “Any amount of time that extends quality of life and quality years to someone with Alzheimer’s may be a benefit.”


“Alzheimer’s disease (AD) is characterised by functional impairment in the neural elements and circuits underlying cognitive and memory functions,” according to Lozano. Initially, affected individuals have mild memory problems, which progress over time, to the point of needing total care. Other, later symptoms can include anxiety, wandering, and aggression. No treatment can stop the disease. However, some drugs, may delay its progression, and others, including antipsychotics, may help treat certain symptoms for a limited time.


Lozano and his team investigated the theory that electrical stimulation of structures deep in the brain, including the hypothalamus, might improve symptoms by enrolling six willing participants with early signs of Alzheimer’s in their study.


Each patient left the hospital within three days after the study and continued their standard medical therapy for Alzheimer’s disease, as well as continuous stimulation from the implanted device for one year. During that time, the subjects were assessed with cognitive testing, brain mapping, and imaging. Their cognitive function was evaluated by several different types of measurement scales. Positive emission tomography (PET) scans were used to assess the way the DBS device changed glucose metabolism in the brain. In half of the patients, by six or 12 months, their cognitive function had either improved or had declined at a slower rate than expected.


“Evaluation of the Alzheimer’s Disease Assessment Scale cognitive subscale and the Mini Mental State Examination suggested possible improvements and/or slowing in the rate of cognitive decline at six and 12 months in some patients,” according to the researchers. In addition, the PET scans showed that the abnormal glucose metabolism typically seen in patients with AD improved after insertion of the DBS device, and the improvement continued throughout the year of follow-up. None of the patients had serious side effects during the year after the device was implanted. Experts say that although the study is small, the results are encouraging. Future, larger studies may provide more information on a potentially effective therapy for treating AD, or slowing the decline, which could complement additional therapies. “There is an urgent need for novel therapeutic approaches for AD. Modulating pathological brain activity in this illness with DBS merits further investigation,” the authors said.