TY - JOUR
T1 - Similar association between objective and subjective symptoms in functional and organic tremor
AU - Kramer, Gerrit
AU - Dominguez-Vega, Zeus T.
AU - Laarhoven, Heleen S. A.
AU - Brandsma, Rick
AU - Smit, Marenka
AU - van der Stouwe, A. M. Madelein
AU - Elting, Jan Willem J.
AU - Maurits, Natasha M.
AU - Rosmalen, Judith G. M.
AU - Tijssen, Marina A. J.
PY - 2019/7
Y1 - 2019/7
N2 - Background: A previous study reported a dramatic mismatch in objectively detected and self-reported tremor duration in patients with functional tremor. As these findings have an important and widespread impact in both clinical care and research, we conducted a validation study with a longer study duration and a larger sample of patients.Methods: Fourteen patients with functional tremor and 19 with organic tremor completed a 30 day study period. Objective tremor duration was recorded using a wrist-worn accelerometer. Simultaneously, participants completed a web-based diary five times a day, each time rating their symptom burden since the previous diary entry.Results: Patients with functional tremor had shorter objective tremor duration compared to patients with organic tremor (21.6% vs 30.7%, P = 0.034). A post-hoc analysis revealed the difference in objective duration was mainly due to patients with essential tremor (37.2%). Subjective symptom burden was not significantly different between functional and organic tremors (38.7 vs 28.7 on a 0-100 VAS scale, P = 0.138). Finally, a mixed model analysis did not reveal significant differences in the association between subjective and objective tremor symptoms (P = 0.168).Conclusions: patients with functional tremor do have an objectively detectable, persistent tremor during daily life activities. Furthermore, they have a similar symptom burden and a similar association between subjective and objective tremor symptoms as patients with organic tremor.
AB - Background: A previous study reported a dramatic mismatch in objectively detected and self-reported tremor duration in patients with functional tremor. As these findings have an important and widespread impact in both clinical care and research, we conducted a validation study with a longer study duration and a larger sample of patients.Methods: Fourteen patients with functional tremor and 19 with organic tremor completed a 30 day study period. Objective tremor duration was recorded using a wrist-worn accelerometer. Simultaneously, participants completed a web-based diary five times a day, each time rating their symptom burden since the previous diary entry.Results: Patients with functional tremor had shorter objective tremor duration compared to patients with organic tremor (21.6% vs 30.7%, P = 0.034). A post-hoc analysis revealed the difference in objective duration was mainly due to patients with essential tremor (37.2%). Subjective symptom burden was not significantly different between functional and organic tremors (38.7 vs 28.7 on a 0-100 VAS scale, P = 0.138). Finally, a mixed model analysis did not reveal significant differences in the association between subjective and objective tremor symptoms (P = 0.168).Conclusions: patients with functional tremor do have an objectively detectable, persistent tremor during daily life activities. Furthermore, they have a similar symptom burden and a similar association between subjective and objective tremor symptoms as patients with organic tremor.
KW - Functional movement disorder
KW - Tremor
KW - Actigraphy
KW - Self-report
KW - Ambulatory assessment
KW - PSYCHOGENIC MOVEMENT-DISORDERS
KW - RATING-SCALE
KW - PARKINSONS
KW - TIME
U2 - 10.1016/j.parkreldis.2019.05.026
DO - 10.1016/j.parkreldis.2019.05.026
M3 - Article
VL - 64
SP - 2
EP - 7
JO - Parkinsonism & Related Disorders
JF - Parkinsonism & Related Disorders
SN - 1353-8020
ER -