Facial bradykinesia

Abstract

The aim of this paper is to summarise the main clinical and pathophysiological features of facial bradykinesia in Parkinson's disease (PD) and in atypical parkinsonism. Clinical observation suggests that reduced spontaneous and emotional facial expressions are features of facial bradykinesia in PD and atypical parkinsonism. In atypical parkinsonism, facial bradykinesia is complicated by additional dystonic features. Experimental studies evaluating spontaneous and emotional facial movements demonstrate that PD is characterised by a reduction in spontaneous blinking and emotional facial expression. In PD, neurophysiological studies show that voluntary orofacial movements are smaller in amplitude and slower in velocity. In contrast, movements of the upper face (eg, voluntary blinking) are normal in terms of velocity and amplitude but impaired in terms of switching between the closing and opening phases. In progressive supranuclear palsy (PSP), voluntary blinking is not only characterised by a severely impaired switching between the closing and opening phases of voluntary blinking, but is also slow in comparison with PD. In conclusion, in PD, facial bradykinesia reflects abnormalities of spontaneous, emotional and voluntary facial movements. In PSP, spontaneous and voluntary facial movements are abnormal but experimental studies on emotional facial movements are lacking. Data on facial bradykinesia in other atypical parkinsonism diseases, including multiple system atrophy and corticobasal degeneration, are limited. In PD, facial bradykinesia is primarily mediated by basal ganglia dysfunction whereas in PSP, facial bradykinesia is a consequence of a widespread degeneration involving the basal ganglia, cortical and brainstem structures.

Facial emotion recognition in Parkinson's disease: A review and new hypotheses

“…Hypomimia has considerable repercussions on patients' (often perceived as bored, anxious or cranky135, 136, 137) and relatives' quality of life, damaging interpersonal relationships and gradually increasing social isolation 1, 138. Patients, caregivers, and clinicians can break this vicious cycle.…”

“…Hence, in HCs, facial electromyography (EMG) could highlight congruent facial muscle responses to facial expressions, which could foster emotion recognition 130, 131, 132. However, one of the most frequent and distinctive Parkinsonian motor symptoms is hypomimia 1. Thus, in addition to central disorders, emotional symptoms in PD may be induced by peripheral dysfunction associated with impaired facial mimicry.…”

“…The original description characterizing Parkinson's disease (PD) by motor symptoms1, 2 has been updated because patients also experience cognitive and psychiatric symptoms,3, 4, 5, 6, 7 including emotional impairments. These lead to difficulties in describing bodily sensations, physiological arousal and feelings, expressing emotions, and identifying others' emotions from prosody and facial expression 8, 9, 10.…”

Reduced facial expressiveness in Parkinson's disease: A pure motor disorder?

“…At facial level, bradykinesia may account for abnormalities of spontaneous, emotional and voluntary facial movements [2]. Voluntary orofacial movements are smaller in amplitude and slower in velocity in PD, possibly influencing the release of facial emotions [2]. Expressiveness of spontaneous facial emotions, rated by subjective rating scales or objective computerized methods, has been consistently reported to be impaired in PD [3][4][5], while expressiveness of posed facial emotions has been reported either normal [4] or impaired [5].…”

“…At facial level, bradykinesia may account for abnormalities of spontaneous, emotional and voluntary facial movements [2]. Voluntary orofacial movements are smaller in amplitude and slower in velocity in PD, possibly influencing the release of facial emotions [2].…”