A Brain Stimulation to Remember

What's the science?

Brain abnormalities in Alzheimer’s disease are often found in a region of the brain known as the precuneus. This week in NeuroimageKoch and colleagues report that stimulating the precuneus in early Alzheimer’s patients improved memory and changed the way this region was connected to other brain regions.

How did they do it?

They stimulated neurons in Alzheimer’s patients by inducing an electrical field using pulses from a magnetic coil (called repetitive transcranial magnetic stimulation or rTMS). Before and after rTMS, they administered a memory test and measured how patients’ brains responded to magnetic pulses using electroencephalography (EEG).

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What did they find?

Patients who received stimulation showed improvement on a memory test. The patients’ brains also changed. When a magnetic pulse was applied, EEG recordings showed increased power of brain waves in the precuneus. They also found increased brain activity in the precuneus as well as in a frontal region of the brain: the medial prefrontal cortex. Brain circuity is known to be damaged in Alzheimer's, so changes in how these two brain regions function together may be helping to improve memory.

What's the impact?

Brain stimulation has been used to successfully improve symptoms in some disorders such as depression, obsessive compulsive disorders, and schizophrenia, but its potential to improve brain function in Alzheimer’s has only been recognized recently. Brain stimulation could be used in the future as a non-pharmacological intervention for Alzheimer’s patients with memory impairment.

Read the original journal article here.

G. Koch et al., Transcranial magnetic stimulation of the precuneus enhances memory and neural activity in prodromal Alzheimer’s disease. Neuroimage. 169, 302–311 (2018).