Primitive reflexes and cognitive function.
BACKGROUND
Data on the prevalence of primitive reflexes (PR) in adulthood, their pathological significance and relationship to age and cognition are controversial.


OBJECTIVE
To study the relationship between PR and cognition in 30 patients with probable Alzheimer's disease (AD) and 154 control subjects.


METHODS
Diagnosis of probable AD was based on DSM-IV, NINCDS-ADRDA, and CAMDEX criteria. Primitive reflexes were quantified from zero (absent) to 1 (mild) or 2 (markedly present). The Cognitive Abilities Screening Instrument-Short Form (CASI-S) was used to evaluate registration, temporal orientation, verbal fluency and recall. A drawing test was added.


RESULTS
Most frequent PR among demented and controls were suck (77% and 62%, respectively) and snout (60% and 27%), followed by glabellar (30% and 19%), paratonia (37% and 5%), and palmomental (23% and 5%). None of controls had more than three PR. Frequency of PR tended to increase with age and cognitive deterioration. Grasp and Babinski responses were found only in dementia patients. Primitive reflexes were not correlated with each other, except snout with suck, and snout with glabellar reflex.


CONCLUSIONS
The finding of grasp and Babinski sign, or the presence of more than three primitive signs, particularly the combination of paratonia, snout, suck, and palmomental reflexes strongly suggests brain dysfunction, especially when these signs are marked and accompanied by deficits in orientation, recall, verbal fluency, and constructional praxis.
Damasceno
Alfredo
A
Department of Neurology, Medical School, State University of Campinas, Campinas, SP, Brazil.
Delicio
Adriane M
AM
Mazo
Daniel F C
DF
Zullo
João F D
JF
Scherer
Patricia
P
Ng
Ronny T Y
RT
Damasceno
Benito P
BP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications* / Q000503:physiopathology; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D012021:Reflex, Abnormal / Q000502:physiology*; D012720:Severity of Illness Index