Brain Memory Structures Shrink in Sleep Apnea

The mammillary bodies are two small structures lying deep in the brain, near the hippocampus, that are involved with the transfer of memories from one brain center to another. Very-high-resolution MRI (magnetic resolution imaging) can be used to calculate their volume, and studies have shown that their volume is reduced in patients suffering from memory loss due to alcoholism, Alzheimer’s, or other conditions.

Now a publication in the Neuroscience Letters has described shrinkage of the mammillary bodies in subjects with obstructive sleep apnea. The exact underlying mechanism is uncertain, but it may be due to lack of oxygen or inflammatory changes in these bodies, possibly assisted by nutritional deficits.

The loss of memory in alcoholism, part of what’s called Korsakoff’s Syndrome, is best treated by massive doses of vitamin B1 (thiamine). In a future study, these UCLA researchers plan to explore whether supplemental vitamin B1 can help restore memory in patients with sleep apnea, and, presumably, they will repeat the special MRI exam to see if there’s some recovery of mammillary body size.