Data on the prevalence and clinical value of primitive reflexes (PRs) in dementia are controversial, mainly due to a lack of standardization of the methods by which these signs are elicited and scored. A standardized protocol was used to investigate eight PRs in 20 patients with Alzheimer's disease (AD), 20 patients with vascular dementia (VD), and 20 control subjects for each group. Both patient groups showed considerably more PRs than the control groups. The prevalence of PRs was related to the severity of dementia. No single reflex or combination of PR pathognomonic for dementia could be distinguished. The PR profile of AD and VD patients were similar.
Vreeling, F. W., Houx, P. J., Jolles, J., & Verhey, F. R. J. (1995). Primitive reflexes in alzheimer's disease and vascular dementia. Journal of Geriatric Psychiatry and Neurology, 8(2), 111-117. https://doi.org/10.1177/089198879500800207