Why Are Some Parkinson Disease Patients Unaware of Their Dyskinesias?

Abstract

Objective: To test the hypothesis that anosognosia-for-dyskinesias in Parkinson's disease (PD) results from a failure to detect discrepancies between intended and actual movement.Background: PD patients often complain of drug-induced dyskinesias (involuntary

Postural adaptation to a slow sensorimotor set-changing task in Parkinson's disease1

“…In a study by Jenkinson and colleagues, participants moved their hands inside a mirror box in which the refl ected and moving hands moved in opposite directions while the obscured and visible hands moved in the same direction. PD participants with no anosognosia of dyskinesia described the incongruent movements as feeling stranger than the congruent movements, whereas those with anosognosia reported that all movements felt equally strange (Jenkinson, Edelstyn, Stephens, & Ellis, 2009 ). In another study, PD participants were unable to distinguish between one vs two fl exions of the index fi nger or wrist as accurately as age-matched controls when the time interval between pairs of muscle stimulations was very short ( Fiorio, Stanzani, Rothwell, Bhatia, Moretto, Fiaschi, et al ., 2007 ).…”

Behavioural and neuroimaging correlates of impaired self-awareness of hypo- and hyperkinesia in Parkinson's disease

“…Although various motor deficits exist, such as resting tremor or reduced speed and amplitude of movements, that are not adequately perceived by PD patients (Maier et al, 2012), so far, research has mainly focused on Levodopa-induced dyskinesia (LID) (Amanzio et al, 2010;Jenkinson, Edelstyn, Stephens, & Ellis, 2009;Sitek, Soltan, Wieczorek, Robowski, & Slawek, 2011;Vitale et al, 2001). While LID are typically induced by dopamine replacement therapy (DRT) and therefore appear in the medication ON-state, the characteristic parkinsonian motor deficits, i.e., hypo-/bradykinesia and resting tremor, are most pronounced during the medication OFF-state.…”

“…Especially a dysfunction in action monitoring, related to the medial prefrontal -ventral striatal circuit including the anterior cingulate cortex, has been suggested to be associated with ISAm-LID (Amanzio et al, 2010;Amanzio et al, 2014). Similarly, differences in the evaluation of intended versus actual movements have been suspected to underlie ISAm-LID (Jenkinson et al, 2009). One explanation for the discrepant findings in ISAm-LID may stem from the fact that thus far psychometrically validated methods to examine ISAm-LID in PD are lacking (Maier et al, 2015;Pietracupa, Latorre, Berardelli, & Fabbrini, 2014).…”

Parkinsonian Patients and Poor Awareness of Dyskinesias

“…PD patients with poor self-awareness of LID did not detect any differences between congruent and incongruent movement, whereas non-anosognosic PD patients and healthy volunteers reported incongruent movement as being stranger than congruent movement. The findings of Jenkinson et al’s (8) work thus support the hypothesis that normal motor awareness entails a comparison of intended and actual movement. Indeed, the intactness of the comparator in non-anosognosic PD patients and healthy volunteers is demonstrated by the finding that incongruent movement was reported to be stranger than congruent movement by both these groups, as well as by the fact that there were no significant differences between non-anosognosic PD patients and healthy volunteers.…”

“…Other authors have proposed alternative or complementary hypotheses. For example, one noteworthy finding comes from the work by Jenkinson et al (8), who highlighted the fact that normal motor awareness entails a correct comparison of intended vs. actual movement, and predicted in their work that anosognosia of LID in PD arises from a failure to detect discrepancies between intended movement and visual feedback. To test their hypothesis, they used a mirror to reverse the expected visual consequence of an executed movement.…”