Paratonia in Dementia: A Systematic Review

Abstract

Background: Paratonia is a dementia-induced motor abnormality. Although paratonia affects virtually all people with dementia, it is not well known among clinicians and researchers.

Objective: The aim of this study was to perform a systematic review of the literature on the definition, pathogenesis, diagnosis, and intervention of paratonia as well as to propose a research agenda for paratonia.

Methods: In this systematic review, the Embase, PubMed, CINAHL, and Cochrane CENTRAL databases were searched for articles published prior to December 2019. Two independent reviewers performed data extraction and assessed the risk of bias of the studies. The following data were extracted: first author, year of publication, study design, study population, diagnosis, assessment, pathogenesis, therapy and interventions.

Results: Thirty-five studies met the inclusion criteria and were included. Most studies included in the review mention clinical criteria for paratonia. Additionally, pathogenesis, method of assessment, diagnosis, and paratonia severity as are interventions to address paratonia are also discussed.

Conclusion: This systematic review outlines what is currently known about paratonia, as well as discusses the preliminary research on the underlying mechanisms of paratonia. Although paratonia has obvious devastating impacts on health and quality of life, the amount of research to date has been limited. In the last decade, there appears to have been increased research on paratonia, which hopefully will increase the momentum to further advance the field.

Keywords: Dementia; motor disorders; motor skills disorders; paratonia; systematic review.

Fig. 1

Typical (fetal) posture of patient with advanced paratonia with flexion and adduction of the extremities.

Fig. 2

Flowchart of selection process.

Fig. 3

The PAI procedure: The examiner starts with a slow movement of the limb, after which the movement is accelerated. A construct of five criteria allows a categorical diagnosis of paratonia, i.e., paratonia can only be diagnosed when all five criteria are present; 1) an involuntary variable resistance; 2) a degree of resistance that varies depending on the speed of the movement (e.g., a low resistance to slow movements and a high resistance to fast movement; 3) resistance to passive movement can be felt in any direction (no distinct pattern); 4) no clasp-knife phenomenon; and 5) resistance is present in 2 movement directions in 1 limb or in 2 different limbs. With permission from Cambridge University Press reprinted from; Diagnosing paratonia in the demented elderly: reliability and validity of the Paratonia Assessment Instrument (PAI) [42].