title: Midbrain sonography in patients with essential tremor.
abstract: Several studies have reported an increased risk to develop Parkinson's disease (PD) in essential tremor (ET) populations. Hyperechogenicity of the substantia nigra (SN) is a common transcranial sonography (TCS) finding in PD and has been suggested as a PD risk-marker in nonparkinsonian subjects. This study compared SN areas of 44 ET patients with 100 controls and 100 PD patients. Sixteen percent of ET patients had SN hyperechogenicity as compared with 3% of controls and 75% of PD patients. These findings might correspond to an increased risk of ET patients to develop PD. Long-term follow-up will show if those with hyperechogenic SN develop PD, while these without will not.
authors.affiliation: Department of Neurology, Medical University Innsbruck, Austria.
authors.forename: Heike
authors.initials: H
authors.lastname: Stockner
authors.forename: Martin
authors.initials: M
authors.lastname: Sojer
authors.forename: Klaus Seppi
authors.initials: KS
authors.lastname: K
authors.forename: Joerg
authors.initials: J
authors.lastname: Mueller
authors.forename: Gregor K
authors.initials: GK
authors.lastname: Wenning
authors.forename: Christoph
authors.initials: C
authors.lastname: Schmidauer
authors.forename: Werner
authors.initials: W
authors.lastname: Poewe
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D020329:Essential Tremor / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications; D013378:Substantia Nigra / Q000000981:diagnostic imaging*; D017585:Ultrasonography, Doppler, Transcranial