Thursday, August 30, 2007

Postural hypotension

Assuming the upright position is a recurrent battle against gravity. Our cardiovascular needs to adjust in order to assure an uninterrupted supply of oxygenated blood to the brain. Old people lose some of that vascular tone that allows for seamless postural transitions.

I've mentioned before that my Mom is having postural TIAs. Within 10-15 minutes of getting out of bed, parts of her brain start to shut down due to lack of blood flow. She abruptly loses the ability to find the right word, a condition known as expressive aphasia. A brief but deep sleep often restores her language function.

Susan Moon's mother blacks out from postural hypotension. Here's an excerpt from her poem in the latest issue of JAMA:

Before my mother folds inward from her knees,
I fight gravity's tug by pushing her forward--
just a few more steps to the chair--
but she is already leaving me,
hip and knee closing like books
all the way to the floor.
A few heartbeats later
she opens her eyes, gazes around as if
she's never seen this world before.

3 comments:

Mauigirl said...

Very interesting - my aunt has been having events like this and she was diagnosed with TIA's. But if it is just due to postural hypotension, would that have less of an ominous prognosis? I've read that TIA's may predict a real stroke at some point, but if they're caused by postural hypotension rather than blockage, perhaps not? In her case, it almost always happens after she's been leaning over and straightens up.

Femail doc said...

Well I've never actually seen anything quite like this until my Mom started in with it. My best guess is that it would be the same prognosis because there must certainly be markedly narrowed cerebral blood vessels to certain regions of the brain in order for specific functions (such as speech) to blink out.

Over the course of the four months during which this has been happening, Mom is certainly losing ground with respect to movement and memory, so she is clearly having permanent damage along with the reversible episodes.

There's an interesting chapter on little strokes in Dr. Sherwin Nuland's book How We Die. Here's a a description of one lady's downhill course:

She saw that with each attack of dizziness or fainting or confusion she became a little older, a little weaker, and a little more tired; her step became more hesitant, her memory less trustworthy, her handwriting less legible, and her interest in life less keen. She knew that for 10 years or more, she had been moving step by step towards the grave.

Mauigirl said...

Yes, you're probably right, if speech is affected then it probably doesn't matter which way it was caused, it's not a good thing.

My aunt has indeed gotten less steady on her feet during the last couple of years since this started happening. Her thinking processes seem pretty good but she does tire easily. That is a sad but eloquent quotation from the book.