Prevalence, incidence and risk factors of paratonia in patients with dementia: a one-year follow-up study

BACKGROUND: Paratonia is a progressive motor problem that is observed in individuals with dementia and is not a well-known phenomenon. This study explores the development and risk factors of paratonia in moderate stage dementia patients.

METHODS: A multi-center, longitudinal, one-year follow-up cohort study was performed. Patients with an established diagnosis of dementia, with a score of 6 or lower on the Global Deterioration Scale (GDS) were included. The participants were assessed using the Paratonia Assessment Instrument (PAI), the Timed Up and GO test, the Qualidem, the Global Deterioration Scale (Reisberg et al., 1982) and the Mini-mental State Examination. Information about each patient's diagnosis of dementia, comorbidities and use of medication were obtained from the participant's medical file. The PAI was assessed every three months, the other variables at baseline and after 12 months. Cross-tabulation χ2 and logistic regression tests were used for the statistical analyses.

RESULTS: Baseline measures were assessed in the 204 participants - 111 (54%) female and 93 (46%) male, with a mean age of 79.8 years (56-97). Seventy-one patients (34.8%) were diagnosed with paratonia at baseline, and 51 patients developed paratonia over one year. The highest hazard ratio (3.1) for developing paratonia within one year was observed in the vascular dementia group. The logistic regression analysis revealed that the presence of diabetes mellitus (OR = 10.7) was significantly related to the development of paratonia (Wald χ2 p-value < 0.01).

CONCLUSIONS: Diabetes mellitus and likely vascular damage are risk factors for the development of paratonia.