Post-Stroke Dementia Biomarkers
Stroke is the fifth leading cause of death in the United States and is a major cause of serious disability for adults. Post-stroke dementia (PSD) is the major form of dementia in the elderly. Of the 800,000 people in the US that have strokes every year, about 10% of first-time stroke victims will suffer from PSD, while 30% of recurrent stroke patients suffer from this type of dementia. Also, vascular dementia is more prevalent in men, as well as populations more affected by cerebral small-vessel disease including Asians, Hispanics, and Africans.
Cholinergic activity is shown throughout the central nervous system and it has effects on inflammation, oxidative stress, and apoptosis. Acetylcholine (ACh) binds to macrophage muscarinic receptors to regulate inflammatory processes after stroke, and ACh levels are significantly lower in cerebrospinal fluid in patients with small-vessel vascular dementia. This suggests that cholinergic agents or cholinesterase inhibitors, both of which increase ACh levels, could be used as a treatment option.
A recent paper by Yu-Li Liu and colleagues from Taiwan has suggested that butyrylcholinesterase (BChE) activity may be a useful biomarker for PSD. In blood, BChE accounts for up to 90% of all cholinesterase activity and the combination of AChE and BChE regulates the levels of ACh. In this study, it was shown that the concentration and activity of BChE, as well as the total cholinesterase activity, was decreased in PSD patients. In addition, there may be a genetic change that reduces BChE activity. The authors did note that the use of BChE as a marker for PSD would have to be evaluated cautiously as the number of participants in the study was low. Additionally, they did not measure concentrations of ACh and the determination of PSD in the participants was by clinical presentation.