The Center for Cognitive Disorders, Department of Psychiatry and Psychotherapy at Klinikum rechts der Isar has enrolled the first patient in Europe in a new study investigating the safety and efficacy of deep brain stimulation (THS) in patients with mild dementia associated with Alzheimer's disease. The patient was implanted with two directional THS electrodes as well as a neurostimulator at the Neurosurgery Clinic of LMU Hospital in Munich, Germany. The "ADvance II" study is investigating the effectiveness of electrical stimulation of the fornix (THS-f) – an important nerve pathway in the brain's memory circuitry – in patients with Alzheimer's disease. Scientific research to date suggests that this could be affected even in the early stages of Alzheimer's disease.
Study examines effect of THS in mild dementia
Alzheimer's disease is a progressive neurodegenerative disease and by far the most common cause of dementia, and leads to an inexorably increasing impairment of memory and other mental abilities. Today, an estimated 1.7 million Germans suffer from dementia, with the resulting costs to society amounting to over 73 billion euros in 2016 alone 1 ). Alzheimer's dementia is one of the leading causes of death in the elderly 2,3 ). So far, no way has been found to prevent, cure or at least slow down this disease. The new study will now show whether THS can lead to an improvement in patients with mild dementia in Alzheimer's disease.
For THS, electrodes are first implanted in the brain during a neurosurgical procedure, which are then connected to a pacemaker via cables – similar to a heart pacemaker. This medical device continuously delivers mild electrical pulses to precisely defined areas of the brain after surgery. The therapy is already approved in the European Union, USA, and Canada for the treatment of Parkinson's disease, dystonia, and essential tremor.
Promising approach for neurological diseases
"Alzheimer's disease, as the most common cause of dementia development, will continue to gain societal importance due to demographic changes. There is an urgent need for better treatment options. In a preliminary study, deep brain stimulation of the fornix increased the activity of the neural network for memory. Also increase the neuronal activity of associated other brain regions. With the results of the ADvance II study, we hope to gain insights into how this procedure affects patients' clinical symptoms and how well affected individuals tolerate the brain surgery it requires. At present, it is too early to assess a potential benefit for patients," says Professor Timo Grimmer of the Center for Cognitive Disorders, Klinikum rechts der Isar.
"Deep brain stimulation is a promising therapeutic approach and has been used very successfully for more than two decades in other neurological diseases such as Parkinson's disease, essential tremor, dystonia and, more recently, epilepsy. We are pleased that we can now contribute to Alzheimer's research with this neurosurgical procedure in close collaboration with dementia specialists", explains Priv.-Doz. Dr. Jan-Hinnerk Mehrkens, Head of Functional Neurosurgery at the Department of Neurosurgery and Polyclinic at LMU Hospital.
1) Federal Health Gazette Health Research Health Protection. 2019 Aug; 62(8):981-992.
2) Heron, M. Deaths: Leading causes for 2014. National vital statistics reports 2016; 65(5).
3) Alzheimer's Association 2016 Alzheimer's disease facts and figures. Alzheimer's Dement 2016; 12(4):459-509.
About the ADvance II study
The ADvance II trial is a randomized, controlled, double-blind study designed to enroll up to 210 subjects. The study will enroll patients with mild Alzheimer's dementia who are over 65 years of age. The study is conducted by the research company Functional Neuromodulation in Germany, the U.S. and Canada. The study is led by Professor Jurgen Voges, Department of Stereotactic Neurosurgery, University of Magdeburg, Germany; Professor Constantine Lyketsos, Chair of Psychiatry, Johns Hopkins Bayview Medical Center, Baltimore, Maryland, USA; and Professor Andres Lozano, Department of Neurosurgery, University of Toronto, Ontario, Canada.