<unk> s are primitive reflexes traditionally held to be a sign of disorders that affect the<unk>  lobes. The appearance of such signs reflects the area of brain dysfunction rather than a specific disorder which may be diffuse, such as a dementia, or localised, such as a tumor. One reflex thought to have good localizing value is the palmar grasp reflex which usually signifies damage to the<unk>  lobe of the opposite side. The glabellar reflex or "glabellar tap" is present in individuals with extrapyramidal disorders such as Parkinson's disease. These reflexes are believed to be "hard-wired" before birth, and are therefore able to be elicited in the newborn. As the brain matures, certain areas (usually within the<unk>  lobes) exert an inhibitory effect, thus causing the reflex to disappear. When disease processes disrupt these inhibitory pathways, the reflex is<unk> d" from inhibition and can be elicited once again, hence the term<unk> ". Some<unk> s and their role in infancy: * Palmar grasp: Baby naturally grabs objects placed in palm. * Palmomental reflex: stroking on the thenar eminence of the hand causes contraction of mentalis muscles of the chin. * Rooting reflex: Baby finds breast to suckle. * Sucking reflex: Baby sucks breast / bottle / teat to get milk. * Snout reflex: Involved in suckling. * Glabellar reflex: May protect eyes in certain situations.
Frontal release sign
Deep sulcus sign
Blue field entoptic phenomenon
Entoptic phenomenon
Galant reflex
Empty delta sign
White cerebellum sign
Moniz sign