title: Alzheimer's-related changes in non-demented essential tremor patients vs. controls: links between tau and tremor?
abstract: BACKGROUND
  In addition to tremor, patients with essential tremor (ET) may exhibit non-motor features, including a range of cognitive deficits. Several prospective, population-based epidemiological studies have reported an association between ET and incident dementia, especially Alzheimer's disease (AD). Moreover, in a brain repository-based study, a larger than expected proportion of ET patients also developed pathological changes characteristic of progressive supranuclear palsy, further suggesting a link between ET and tau pathology.
  
  
  METHODS
  We selected a group of ET patients that were free of dementia clinically and without AD on postmortem examination. Our hypothesis was that neuronal tauopathic burden would be higher in the brains of these ET patients compared to controls. We compared Braak stage for neuronal tangles and Consortium to Establish a Registry for Alzheimer's Disease (CERAD) scores for neuritic plaques in the two groups.
  
  
  RESULTS
  The two groups were similar in age (82.6 ± 6.0 vs. 80.4 ± 8.1, p = 0.22). The 40 ET patients had a higher Braak neurofibrillary stage than 32 controls (means: 2.2 ± 1.2 vs. 1.2 ± 1.1; medians: 2.0 vs. 1.0, p < 0.001). Meanwhile, CERAD scores for neuritic plaques were similar in patients and controls (means: 0.6 ± 0.9 vs. 0.5 ± 0.6; medians: 0.0 vs. 0.0, p = 0.83).
  
  
  CONCLUSIONS
  While ET itself is not a tauopathy (i.e., a neurodegenerative disorder among whose main features are accumulation of hyperphosphorylated tau protein), ET may predispose individuals to accumulate more widespread cellular tau aggregates, and thus tau could play a central role in the cognitive impairment that can accompany ET.
authors.affiliation: Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA.
authors.forename: Jie J
authors.initials: JJ
authors.lastname: Pan
authors.affiliation: G.H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Lee
authors.affiliation: G.H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
authors.forename: Lawrence S
authors.initials: LS
authors.lastname: Honig
authors.affiliation: Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA.
authors.forename: Jean-Paul G
authors.initials: JP
authors.lastname: Vonsattel
authors.affiliation: Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA.
authors.forename: Phyllis L
authors.initials: PL
authors.lastname: Faust
authors.affiliation: Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA; G.H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA. Electronic address: EDL2@columbia.edu.
authors.forename: Elan D
authors.initials: ED
authors.lastname: Louis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D020329:Essential Tremor / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D016874:Neurofibrillary Tangles / Q000473:pathology*; D058225:Plaque, Amyloid / Q000150:complications / Q000473:pathology; D011569:Psychiatric Status Rating Scales; D018709:Statistics, Nonparametric; D016875:tau Proteins / Q000378:metabolism*
chemical_list: D016875:tau Proteins
keywords: Alzheimer's disease; Braak; Dementia; Essential tremor; Neurofibrillary tangle; Tau