DEAR DR. ROACH: Have you ever heard of a “low blood pressure stroke”? That was my husband’s (incorrect) diagnosis several years back when he suddenly could not move his arms and legs. He was told that not enough oxygen was getting to his spine. (His blood pressure is historically low, usually around 90/60.)
That lasted about seven months, and he was bedridden the entire time. He then went to a neurosurgeon and was (correctly) diagnosed with a spinal cord injury. He had C1-C2 surgery and had use of his limbs the next day. After months of physical therapy, he regained a lot of function.
We’ve never heard of that diagnosis before or after his experience. Does it really exist? — E.S.K.
ANSWER: The brain has tremendous ability to regulate its own blood flow under a very wide range of blood pressures, but there are some limits. When a person is used to very high blood pressure levels, such as 200/110 for months or years, a sudden drop to 90/60 (or even 120/80, sometimes) can cause a stroke. That’s the main reason we don’t lower blood pressure very quickly in people who have had very high blood pressure levels for a long time. It takes weeks or months for the brain to recover its ability to regulate blood flow.