European Section

European Literature Review

Functional Movement Disorders Are Not Uncommon in the Elderly

Amit Batla, MD, DM
 

Authors: Amit Batla, MD, DM, Maria Stamelou MD, PhD, Mark J. Edwards MD, Isabel Pareés MD, Tabish A. Saifee MRCP,
Zoe Fox PhD, and Kailash P. Bhatia MD FRCP; Article first published online: 15 FEB 2013; DOI: 10.1002/mds.25350; Movement Disorders, Vol. 28, No. 4, 2013; ©The Movement Disorder Society

Abstract

Background: Functional movement disorders (FMDs) are thought to be rare in the elderly. Clinical characteristics of the elderly people who develop FMDs are rarely reported. The objective of this study was to highlight the clinical characteristics of FMD in the elderly and compared these with a cohort of patients with a younger age of onset. Methods: The authors performed a retrospective review of the clinical records of patients with FMD who were seen at their center in the last 5 years and had consented to be included in research studies. Patients fulfilling currently accepted diagnostic criteria for FMD as documented, clinically established, or probable were included.

Results: Of 151 patients with FMD who were identified and had sufficient information, 21.0% (n=33) had an onset after age 60 years (elderly group). The mean age of onset of FMD was 63.5 years (standard deviation, 5.2 years) in the elderly group and 35.5 years (standard deviation, 12.6 years) in the younger group. Tremor was the most common movement disorder in both groups (elderly group, 33.3%; younger group: 38.9%). Fixed dystonia was not observed in any patient who had an FMD onset after age 60 years. Gait abnormalities were significantly more common in the elderly group (69.7%) than in younger patients (23.5%; P<0.001). Associated psychogenic nonepileptic seizures tended to be more common in elderly patients (18.2%) compared with younger patients (13%; P=0.06).

Conclusions: Contrary to common perceptions, FMDs are not uncommon in the elderly, and 1 in 5 patients in the current cohort, onset of FMD occurred after age 60 years. Gait abnormalities and psychogenic nonepileptic seizures may be more common in older patients.

Commentary

MDS-ES Web Editor's commentary by Carlo Colosimo, MD, PhD
Sapienza University of Rome, Italy

Functional movement disorders (FMD) are often suspected in young adults but not in the elderly. In this retrospective review on a large series (N=151) of FMD, Batla and colleagues from the National Hospital for Neurology in London, report the prevalence and clinical characteristics of the elderly people who developed FMD.

They were able to show that FMD are not uncommon in the elderly and their clinical characteristics are similar but not equal to those observed in a cohort of patients with a younger age of onset. Tremor was the most common movement disorder in both groups (elderly group, 33.3%; younger group: 38.9%), whereas gait abnormalities were significantly more common in the elderly group (69.7%) than in younger patients (23.5%). Conversely, the characteristic syndrome of fixed dystonia, frequently seen in adult-onset FMD, was not observed in any of the elderly patients who had FMD. Interestingly, one-third of these elderly patients did not have a prior history of psychiatric disorder. Some of them were mistaken as stroke because of their sudden onset and the lack of psychiatric background.

Practical conclusions from this paper are that: (1) We should never exclude the possibility of FMD in the elderly, since in 20% of the cases included in this cohort onset of FMD occurred after age 60 years. Some of these FMD are not easily suspected, because they present without a pre-existing psychiatric disorder or previous history of functional disorders. (2) FMD should be considered in the differential diagnosis with acute stroke in the emergency setting.