title: Re-emergent tremor in Parkinson's disease.
abstract: Re-emergent tremor (RET) is a postural tremor that appears after a variable delay in patients with Parkinson's disease (PD). The aim of the present study was to evaluate the occurrence and the clinical characteristics of RET in a population of patients with PD.
  
  
  
  We consecutively assessed 210 patients with PD. We collected the patients' demographic and clinical data. RET was clinically characterized in terms of latency, severity and body side affected. We also investigated a possible relationship with motor and non-motor symptoms and differences in the clinical features in patients with and without RET.
  
  
  
  RET was present in 42/210 patients. The mean latency of RET was 9.20 ± 6.8 seconds. Mean severity was 2.4 ± 1.9. RET was unilateral in 21 patients. Patients with RET had less severe speech, posture and gait disorders and upper limb and global bradykinesia than patients without RET. Similar findings were observed when we compared patients with RET with patients with tremor at rest associated with action tremor, patients with isolated action tremor and patients with no tremor. By contrast, patients with RET tremor did not clinically differ from those with isolated tremor at rest.
  
  
  
  Our results suggest that patients with RET and patients with isolated tremor at rest represent the same clinical subtype, whereas patients with action tremor (whether isolated or associated with tremor at rest) might belong to a distinct subtype that is clinically worse. Patients with RET represents a benign subtype of PD, even within the tremor-dominant phenotype.
authors.affiliation: Neuromed Institute IRCCS, Via Atinense 18, 86077, Pozzilli (IS), Italy. Electronic address: daniele.belvisi@uniroma1.it.
authors.forename: Daniele
authors.initials: D
authors.lastname: Belvisi
authors.affiliation: Neuromed Institute IRCCS, Via Atinense 18, 86077, Pozzilli (IS), Italy; Department of Neurology and Psychiatry, "Sapienza" University of Rome, Viale dell'Università 30, 00185 Rome, Italy. Electronic address: antonella.conte@uniroma1.it.
authors.forename: Antonella
authors.initials: A
authors.lastname: Conte
authors.affiliation: Neuromed Institute IRCCS, Via Atinense 18, 86077, Pozzilli (IS), Italy; Department of Neurology and Psychiatry, "Sapienza" University of Rome, Viale dell'Università 30, 00185 Rome, Italy. Electronic address: matteo.bologna@uniroma1.it.
authors.forename: Matteo
authors.initials: M
authors.lastname: Bologna
authors.affiliation: Department of Neurology and Psychiatry, "Sapienza" University of Rome, Viale dell'Università 30, 00185 Rome, Italy. Electronic address: bloise.mc@gmail.com.
authors.forename: Maria Carmela
authors.initials: MC
authors.lastname: Bloise
authors.affiliation: Neuromed Institute IRCCS, Via Atinense 18, 86077, Pozzilli (IS), Italy; Department of Neurology and Psychiatry, "Sapienza" University of Rome, Viale dell'Università 30, 00185 Rome, Italy. Electronic address: antonio.suppa@uniroma1.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Suppa
authors.affiliation: Neuromed Institute IRCCS, Via Atinense 18, 86077, Pozzilli (IS), Italy. Electronic address: alessandraformica@yahoo.it.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Formica
authors.affiliation: Department of Neurology and Psychiatry, "Sapienza" University of Rome, Viale dell'Università 30, 00185 Rome, Italy. Electronic address: matteo_cos90@hotmail.it.
authors.forename: Matteo
authors.initials: M
authors.lastname: Costanzo
authors.affiliation: Department of Neurology and Psychiatry, "Sapienza" University of Rome, Viale dell'Università 30, 00185 Rome, Italy. Electronic address: pierluigicardone91@gmail.com.
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Cardone
authors.affiliation: Neuromed Institute IRCCS, Via Atinense 18, 86077, Pozzilli (IS), Italy; Department of Neurology and Psychiatry, "Sapienza" University of Rome, Viale dell'Università 30, 00185 Rome, Italy. Electronic address: giovanni.fabbrini@uniroma1.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Fabbrini
authors.affiliation: Neuromed Institute IRCCS, Via Atinense 18, 86077, Pozzilli (IS), Italy; Department of Neurology and Psychiatry, "Sapienza" University of Rome, Viale dell'Università 30, 00185 Rome, Italy. Electronic address: alfredo.berardelli@uniroma1.it.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Berardelli
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D014202:Tremor / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*
keywords: Action tremor; Parkinson's disease; Re-emergent tremor; Rest tremor; Subtype