Objective: Paratonia is an external stimulus dependent increase in muscle tone that is absent at rest. It is thought to occur commonly in Alzheimer disease (AD) but is understudied. This study examines paratonia in a multiracial sample.
Methods: The sample consisted of 80 patients who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for AD. They received a battery of neuropsychiatric assessments. The authors examined the relationship between paratonia and multiple variables.
Results: Bivariate and logistic regression analyses revealed that paratonia correlated significantly with disease stage (based on the Geriatric Depression Scale) and number of frontal release symptoms. There were no significant correlations of paratonia with age, race, sex, depression, physical health, neuroimaging findings, functioning, or neuropsychiatric symptoms. The authors found significant association with frontal symptoms.
Conclusions: The potential utility of paratonia as an independent marker of disease stage in AD and its role in signifying frontal lobe dysfunction suggests that closer attention should be paid to its assessment.