Neurologists working at the NYU School of Medicine have developed a test that can identify some rare degenerative brain diseases, reports NYU Langone Health. Published in the Annals of Neurology journal, the test involves comparing blood pressure and heart rate in a patient between lying down and just after standing up. Since it doesn’t require expensive medical equipment, this test could be easily carried out at a patient’s bedside and may lead to faster diagnoses for patients.
The group of degenerative brain diseases that the test identifies are known as synucleinopathies, and includes diseases such as dementia with Lewy bodies, Parkinson’s disease, and multiple system atrophy amongst others. The diseases in this group often share some symptoms, including tremors, rigidity, postural instability, cognitive impairment, and sleep disorders, although the presentation of these symptoms varies. Synucleinopathies are associated with an excessive build-up of the protein alpha-synuclein in the brain. This injures the nerves linked to blood pressure and heart rate, allowing these two factors to be used as a way to diagnose synucleinopathies.
The new test involves measuring whether blood pressure falls without heart rate increasing, after standing up from a lying down position. If blood pressure does fall, it is a sign that a patient may have a synucleinopathy. Researchers evaluated patients using this test and identified 402 individuals that showed a fall in blood pressure after standing, also called orthostatic hypotension. Of these patients, 378 were diagnosed with a synucleinopathy. The remaining minority of 24 patients were evaluated and found to have orthostatic hypotension for other reasons, such as dehydration, medications, and anaemia. The 378 patients identified with neurogenic orthostatic hypotension showed double the fall in blood pressure but only one-third the rise in heart rate compared to other patients.
This new test may therefore provide a relatively fast method of diagnosing some degenerative neurological disorders, which may lead to earlier diagnoses for some people.
Dr Lucy Norcliffe-Kaufmann, the lead researcher, says the test “should have widespread applicability.”