Hemihypomimia: an atypical and interesting feature of Parkinson's disease

Bradykinesia is a key feature of Parkinson's disease (PD)[1]. In contrast to facial bradykinesia, limb bradykinesia is a well described phenomenon. Hypomimia develops in almost all PD patients[2] as a symmetrical feature. Hemihypomimia is a rare manifestation seen mostly, but not exclusively, on right-sided PD[2]. We present images of two patients with hemihypomimia ([Figure 1]).

Figure 1 (A) A 52-year old man, diagnosed to have PD presents marked right-side hypomimia; (B): A 46-year old man diagnosed with PD displaying evident right-sided hypomimia.

Understanding the underlying mechanisms of how hemihypomimia develops, and why it predominantly affects the right side of the face deserves further assessment. Larger case series are needed to elucidate the pathophysiology and clinical implications of this interesting feature of PD.

• References

• 1 Bologna M, Fabbrini G, Marsili L, Defazio G, Thompson PD, Berardelli A.Facial bradykinesia. J Neurol Neurosurg Psychiatry. 2013 Jun;84(6):681-5. https://doi.org/10.1136/jnnp-2012-303993
• 2 Ozekmekçi S, Benbir G, Ozdogan FY, Ertan S, Kiziltan ME.Hemihypomimia, a rare persistent sign in Parkinson's disease: follow up of 11 patients. J Neurol. 2007 Mar;254(3):347-50.