Electrical stimulation of the brain against Alzheimer's disease
Exposure to certain areas of the brain of patients with Alzheimer's disease with weak electrical impulses in some cases allows to suspend the degeneration of nervous tissue and improve cognitive function.
According to the head of the study, Andreas Lozano (Andres Lozano) from the West Toronto Clinic, Canada, in Alzheimer's disease, there is a decrease in the volume of brain tissue, especially the hippocampus. Moreover, the results of positron emission tomography indicate that with this neurodegenerative disease, glucose consumption by nerve cells decreases in the temporal lobe of the brain (temporal lobe), which includes the hippocampus, and in the posterior part of the cingulate gyrus (posterior cingulate). This indicates a deterioration of these regions of the brain, which play an important role in memory processes.
As part of the phase I clinical study, scientists attempted to restore these disorders by exposing subcortical structures to electrical impulses. To do this, they inserted electrodes into the brains of 6 patients who had been diagnosed with Alzheimer's disease at least a year ago.
Electrodes placed in the immediate vicinity of the fornix of the brain– a cluster of neurons transmitting signals to and from the hippocampus–constantly emitted weak electrical discharges at a frequency of 130 times per second.
A survey conducted a year after the start of therapy showed that deep stimulation increased the activity of nerve cells in the affected regions of the brain. Moreover, all six patients had an increase in glucose metabolism both in the temporal lobe and in the posterior part of the cingulate gyrus. At the same time, two patients had an increase in the volume of hippocampal tissue – by 5 and 8%.
Checking the level of cognitive abilities using generally accepted psychological tests (Alzheimer's Disease Assessment Scale cognitive subscale and Mini Mental State Examination) revealed an improvement and /or a slowdown in the deterioration of indicators, at least in some patients. This effect was most pronounced in patients with enlarged hippocampus. The graph from the article in the Annals of Neurology shows the MMSE results of the patient with the most impressive improvement in cognitive functions.
Researchers do not fully understand the mechanisms of action of deep brain stimulation. However, the results of recent studies in mice indicate that electrical impulses can trigger the formation of new neurons in brain tissue. Moreover, deep brain stimulation of mice promoted the synthesis of proteins that stimulate the formation of new contacts between neurons.
The authors admit that the number of patients who took part in the study is too small to obtain reliable results, so they are already starting phase II of the study, within which therapy is planned for about 50 patients.
Article by Adrian W. Laxton et al. A phase I trial of deep brain stimulation of memory circuits in Alzheimer's disease is published in the journal Annals of Neurology.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of New Scientist:
Alzheimer's damage reversed with a jolt.
24.11.2011