According
to a recent study in Neurology, those with amyloid plaques, an early symptom of
Alzheimer's disease, and severe sleep apnea have smaller medial temporal lobe
brain volumes, which includes the hippocampus. In individuals without plaques,
this correlation—which would indicate a loss of brain cells—was not present.
The study does not prove a connection between sleep apnea and reduced brain
volume, though.
In
those with early indications of Alzheimer's disease, severe sleep apnea has
been linked to decreased brain volume in areas important for memory, according
to a recent research. The study stresses the necessity for more investigation
into therapies for sleep-disordered breathing in order to perhaps enhance cognition
and postpone neurodegeneration.
In
the research, those with amyloid plaques in the brain—an early indicator of
Alzheimer's disease—but no memory issues were compared to those without amyloid
plaques.
Geraldine
Rauchs, PhD, of Inserm in Caen, France, is the study's lead author. "We
found that people with amyloid plaques who had more severe sleep apneas also
were more likely to have lower volumes in the medial temporal lobe area of the
brain, including the hippocampus, which plays a role in memory and Alzheimer's
disease," she said. Even though they had severe sleep apneas, those
without amyloid plaques did not have this smaller brain volume.
The
study simply demonstrates a connection; it does not establish that sleep apnea
causes decreased brain volume.
There
were 122 participants in the trial, with an average age of 69 and no memory
issues. There were amyloid plaques in the brains of 26 individuals. Brain
scans, memory assessments, and a home overnight sleep study were all done on
the participants. After an average of 21 months, the memory tests were
administered once more.
More
severe sleep apneas were linked to reduced brain volume in the medial temporal
lobe region of the brain in individuals with amyloid plaques, which may
indicate the death of brain cells. People without amyloid plaques did not show
this association.
Sleep
apneas at the beginning of the trial did not correlate with memory performance
at the conclusion of the study.
The
fact that the identical verbal learning test was administered at both the
beginning and conclusion of the research constituted a study restriction, and
it's likely that familiarity with the exam may have prevented some memory
degradation.
Reference:
"Association of Sleep-Disordered Breathing and Medial Temporal Lobe
Atrophy in Cognitively Unimpaired Amyloid-Positive Older Adults" by Claire
André, Elizabeth Kuhn, Stéphane Rehel, Valentin Ourry, Solène
Demeilliez-Servouin, Cassandre Palix, Francesca Felisatti, Pierre Champetier,
Sophie Dautricourt, Paul Yushkevich, Denis Viv