You are rotating on the medical service and are asked to name and interpret
the bedside test your attending is performing on an 86 year-old-man.
What is your diagnosis, what test or tests would you order to confirm your suspicions,
and what treatment, if any, do you recommend?
DIAGNOSIS: Palmar-mental (Radovici) sign, one of several frontal release signs
that occur with loss of frontal lobe inhibition of primative reflexes. Other frontal
release signs include the grasp reflex, the glabellar reflex, the snout reflex, and
the startle reflex. All of these reflexes may be seen in normal infants, but become
suppressed by the frontal lobes with aging.
An appropriate diagnostic approach in this patient would be as follows: 1. Check
the other frontal release signs - the more that are positive, the more likely one
is dealing with a form of dementia such as Alzheimer's disease; and 2. Perform a minimental
test. The need for more invasive and expensive testing depends on the results of the
remainder of the neurological exam.
Note the contraction of the episilateral mentalis (chin) muscle when the patient's palm is stroked by the thumb nail. This reflex may be unilateral or bilateral.
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