FACILITORY PARATONIA AND FRONTAL-LOBE FUNCTIONING

Objective: To learn if paratonia predicts frontal cognitive impairment s. Background: Paratonia, an alteration of tone to passive movement, c an be divided into oppositional paratonia (''gegenhalten,'' ''paratoni c rigidity'') and facilitory paratonia. Although paratonia has been th ought to be induced by frontal lobe dysfunction, previous studies sugg est that paratonia does not correlate with cognitive impairment. Howev er, only oppositional paratonia has been studied in this manner, and i n these studies only the presence or absence of paratonia was assessed instead of a quantitative scale. Facilitory paratonia has not been st udied for its relation to cognitive function. Methods: Twenty-five pat ients evaluated for degenerative dementia were assessed on semiquantit ative 5-point scales for paratonia by two independent raters. A quanti fiable test-the modified Kral procedure-which assesses continued movem ent by the patient after cessation of passive movement was also admini stered for comparison with facilitory paratonia. To assess frontal lob e function, subjects were tested for echopraxia, distractibility, and word fluency. To screen for other cognitive defects, subjects were giv en the Mini-Mental State Examination (MMSE). Results The modified Kral . procedure strongly correlated with subjective rating of facilitory p aratonia. This correlation was significantly stronger than the correla tion with oppositional paratonia. The modified Kral procedure was also highly predictive of echopraxia, but was less predictive of other fro ntal lobe tests. Facilitory paratonia, oppositional paratonia, and the modified Kral procedure each strongly predicted scores on the MMSE. C onclusions: Both facilitory and oppositional paratonia strongly predic t general cognitive performance. The modified Kral procedure is a reli able indicator of facilitory paratonia and a predictor of impaired per formance on frontal lobe tests.