Glabellar reflex

The glabellar reflex is a primitive reflex. It is elicited by tapping the forehead between the eyebrows and nose and observing that the eyes blink. Successive tapping of the glabella eventually leads to habituation with blinking being suppressed. While suppression of the glabellar reflex may not occur and/or may take longer to occur during childhood development, lack of habituation in adults is categorized as a pathologic sign (often called Myerson’s sign). Myerson’s sign is present in many older individuals. It is associated with many brain conditions, including, but not limited to, dementia and parkinsonism. While research on the utility of an abnormal habituation of the glabellar reflex have been limited, most studies point to the physical exam finding being better correlated with an advanced stage of a neurodegenerative condition rather than as a diagnostic tool.