'Essential tremor' or 'the essential tremors': Is this one disease or a family of diseases?

Neuroepidemiology

Volumn 42, Issue 2, 2014, Pages 81-89

  Louis, Elan D ^a,b,c  

^a Taub Institute for Research on Alzheimer's Disease and the Aging Brain and the Gertrude H Sergievsky Center   (United States)

^b NONE   (United States)

^c NONE   (United States)

Author keywords

Classification; Clinical features; Disease; Essential tremor; Genetics; Heterogeneity; Neurodegeneration; Pathology

Indexed keywords

ALZHEIMER DISEASE; AUTOPSY; CLINICAL FEATURE; COGNITIVE DEFECT; DISEASE ASSOCIATION; DISEASE COURSE; DISEASE MARKER; DISEASE PREDISPOSITION; DYSTONIA; ESSENTIAL TREMOR; GENETIC HETEROGENEITY; HUMAN; INVOLUNTARY MOVEMENT; MENTAL DISEASE; ONSET AGE; PARKINSON DISEASE; PATHOGENESIS; PHENOMENOLOGY; PROGRESSIVE SUPRANUCLEAR PALSY; REVIEW; TREATMENT RESPONSE; PATHOLOGY; CEREBELLUM DEGENERATION; ENVIRONMENTAL FACTOR; GENETIC ASSOCIATION; GENETIC SUSCEPTIBILITY; GENOTYPE ENVIRONMENT INTERACTION; HEREDITY; LEWY BODY; PHENOTYPE;

AGE OF ONSET; ESSENTIAL TREMOR; HUMANS;

EID: 84896707640     PISSN: 02515350     EISSN: 14230208     Source Type: Journal    
DOI: 10.1159/000356351     Document Type: Review

References (118)

1. Louis ED, Broussolle E, Goetz CG, Krack P, Kaufmann P, Mazzoni P: Historical underpinnings of the term essential tremor in the late 19th century. Neurology 2008; 71: 856-859.
2. Koehler PJ, Keyser A: Tremor in Latin texts of Dutch physicians: 16th-18th centuries. Mov Disord 1997; 12: 798-806.
3. Louis ED: Essential tremor. Arch Neurol 2000; 57: 1522-1524.
4. Benito-Leon J: Essential tremor: from a monosymptomatic disorder to a more complex entity. Neuroepidemiology 2008; 31: 191-192.
5. Ottman R: Gene-environment interaction: definitions and study designs. Prev Med 1996; 25: 764-770.
6. Louis ED, Ferreira JJ: How common is the most common adult movement disorder? Update on the worldwide prevalence of essential tremor. Mov Disord 2010; 25: 534-541.
7. Bergareche A, De La Puente E, López De Munain A, Sarasqueta C, De Arce A, Poza JJ, Martí-Massó JF: Prevalence of essential tremor: a door-to-door survey in Bidasoa, Spain. Neuroepidemiology 2001; 20: 125-128.
8. Liu HC, Wang SJ, Fuh JL, Liu CY, Lin KP, Lin CH, Wang PN, Lin KN, Wang HC, Chen HM, Chang R, Larson EB, Wu GS, Chou P, Teng EL: The Kinmen Neurological Disorders Survey (KINDS): a study of a Chinese population. Neuroepidemiology 1997; 16: 60-68.
9. Louis ED, Thawani SP, Andrews HF: Prevalence of essential tremor in a multiethnic, community-based study in northern Manhattan, New York, NY, USA. Neuroepidemiology 2009; 32: 208-214.
10. Benito-León J: How common is essential tremor? Neuroepidemiology 2009; 32: 215-216.
11. Louis ED, Hafeman D, Parvez F, Alcalay RN, Islam T, Siddique AB, Patwary TI, Melkonian S, Argos M, Levy D, Ahsan H: Prevalence of essential tremor in Araihazar, Bangladesh: a population-based study. Neuroepidemiology 2011; 36: 71-76.
12. Benito-León J: Essential tremor: one of the most common neurodegenerative diseases? Neuroepidemiology 2011; 36: 77-78.
13. Higgins JJ, Jankovic J, Lombardi RQ, Pucilowska J, Ashizawa T, Ruszczyk MU: Haplotype analysis of the ETM2 locus in familial essential tremor. Neurogenetics 2003; 4: 185-189.
14. Gulcher JR, Jónsson P, Kong A, Kristjánsson K, Frigge ML, Kárason A, Einarsdóttir IE, Stefánsson H, Einarsdóttir AS, Sigurthoardóttir S, Baldursson S, Björnsdóttir S, Hrafnkelsdóttir SM, Jakobsson F, Benedickz J, Stefánsson K: Mapping of a familial essential tremor gene, FET1, to chromosome 3q13. Nat Genet 1997; 17: 84-87.
15. Shatunov A, Sambuughin N, Jankovic J, Elble R, Lee HS, Singleton AB, Dagvadorj A, Ji J, Zhang Y, Kimonis VE, Hardy J, Hallett M, Goldfarb LG: Genomewide scans in North American families reveal genetic linkage of essential tremor to a region on chromosome 6p23. Brain 2006; 129: 2318-2331.
16. Thier S, Lorenz D, Nothnagel M, Poremba C, Papenqut F, Appenzeller S, Paschen S, Hofschulte F, Hussl AC, Hering S, Poewe W, Asmus F, Gasser T, Schöls L, Christensen K, Nebel A, Schreiber S, Klebe S, Deuschl G, Kuhlenbäumer G: Polymorphisms in the glial glutamate transporter SLC1A2 are associated with essential tremor. Neurology 2012; 79: 243-248.
17. Stefansson H, Steinberg S, Petursson H, Gustafsson O, Gudjonsdottir IH, Jonsdottir GA, Palsson ST, Jonsson T, Saemundsdottir J, Bjornsdottir G, Böttcher Y, Thorlacius T, Haubenberger D, Zimprich A, Auff E, Hotzy C, Testa CM, Miyatake LA, Rosen AR, Kristleifsson K, Rye D, Asmus F, Schöls L, Dichgans M, Jakobsson F, Benedikz J, Thorsteinsdottir U, Gulcher J, Kong A, Stefansson K: Variant in the sequence of the LINGO1 gene confers risk of essential tremor. Nat Genet 2009; 41: 277-279.
18. Aridon P, Ragonese P, De Fusco M, Salemi G, Casari G, Savettieri G: Further evidence of genetic heterogeneity in familial essential tremor. Parkinsonism Relat Disord 2008; 14: 15-18.
19. Kovach MJ, Ruiz J, Kimonis K, Mueed S, Sinha S, Higgins C, Elble S, Elble R, Kimonis VE: Genetic heterogeneity in autosomal dominant essential tremor. Genet Med 2001; 3: 197-199.
20. Merner ND, Girard SL, Catoire H, Bourassa CV, Belzil VV, Riviere JB, Hince P, Levert A, Dionne-Laporte A, Spiegelman D, Noreau A, Diab S, Szuto A, Fournier H, Raelson J, Belouchi M, Panisset M, Cossette P, Dupré N, Bernard G, Chouinard S, Dion PA, Rouleau GA: Exome sequencing identifies FUS mutations as a cause of essential tremor. Am J Hum Genet 2012; 91: 313-319.
21. Parmalee N, Mirzozoda K, Kisselev S, Merner N, Dion P, Rouleau G, Clark L, Louis ED: Genetic analysis of the FUS/TLS gene in essential tremor. Eur J Neurol 2013; 20: 534-539.
22. Labbe C, Soto-Ortolaza AI, Rayaprolu S, Harriott AM, Strongosky AJ, Uitti RJ, Van Gerpen JA, Wszolek ZK, Ross OA: Investigating the role of FUS exonic variants in essential tremor. Parkinsonism Relat Disord 2013; 19: 755-777.
23. Weiner WJ: There is no Parkinson disease. Arch Neurol 2008; 65: 705-708.
24. Louis ED, Ford B, Frucht S, Barnes LF, Tang M-X, Ottman R: Risk of tremor and impairment from tremor in relatives of patients with essential tremor: a communitybased family study. Ann Neurol 2001; 49: 761-769.
25. Louis ED: Environmental epidemiology of essential tremor. Neuroepidemiology 2008; 31: 139-149.
26. Louis ED, Benito-Leon J, Moreno-Garcia S, Vega S, Romero JP, Bermejo-Pareja F, Gerbin M, Viner AS, Factor-Litvak P, Jiang WD, Zheng W: Blood harmane (1-methyl-9H-pyrido[ 3, 4-b]indole) concentration in essential tremor cases in Spain. Neurotoxicology 2013; 34: 264-268.
27. Whitwell JL, Dickson DW, Murray ME, Weigand SD, Tosakulwong N, Senjem ML, Knopman DS, Boeve BF, Parisi JE, Petersen RC, Jack CR Jr, Josephs KA: Neuroimaging correlates of pathologically defined subtypes of Alzheimer's disease: a case-control study. Lancet Neurol 2012; 11: 868-877.
28. Gorelick PB: Role of inflammation in cognitive impairment: results of observational epidemiological studies and clinical trials. Ann NY Acad Sci 2010; 1207: 155-162.
29. Louis ED: Essential tremor: evolving clinicopathological concepts in an era of intensive post-mortem enquiry. Lancet Neurol 2010; 9: 613-622.
30. Axelrad JE, Louis ED, Honig LS, Flores I, Ross GW, Pahwa R, Lyons FE, Faust PL, Vonsattel JPG: Reduced Purkinje cell number in essential tremor: a postmortem study. Arch Neurol 2008; 65: 101-107.
31. Kuo SH, Erickson-Davis C, Gillman A, Faust PL, Vonsattel JPG, Louis ED: Increased number of heterotopic Purkinje cells in essential tremor. J Neurol Neurosurg Psychiatry 2011; 82: 1038-1040.
32. Erickson-Davis CR, Faust PL, Vonsattel JPG, Gupta S, Honig LS, Louis ED: 'Hairy baskets' associated with degenerative Purkinje cell changes in essential tremor. J Neuropathol Exp Neurol 2010; 69: 262-271.
33. Kuo SH, Tang G, Louis ED, Ma K, Babji R, Balatbat M, Cortes E, Vonsattel JP, Yamamoto A, Sulzer D, Faust PL: Lingo-1 expression is increased in essential tremor cerebellum and is present in the basket cell pinceau. Acta Neuropathol 2013; 125: 879-889.
34. Louis ED, Faust PL, Vonsattel JPG: Purkinje cell loss is a characteristic of essential tremor: towards a more mature understanding of pathogenesis. Parkinsonism Relat Disord 2012; 18: 1003-1004.
35. Bebin EM, Bebin J, Currier RD, Smith EE, Perry TL: Morphometric studies in dominant olivopontocerebellar atrophy. Comparison of cell losses with amino acid decreases. Arch Neurol 1990; 47: 188-192.
36. Kume A, Takahashi A, Hashizume Y, Asai J: A histometrical and comparative study on Purkinje cell loss and olivary nucleus cell loss in multiple system atrophy. J Neurol Sci 1991; 101: 178-186.
37. Seidel K, Siswanto S, Brunt ER, den Dunnen W, Korf HW, Rub U: Brain pathology of spinocerebellar ataxias. Acta Neuropathol 2012; 124: 1-21.
38. Louis ED, Faust PL, Vonsattel JPG, Honig LS, Rajput A, Robinson CA, Rajput A, Pahwa R, Lyons KE, Ross GW, Borden S, Moskowitz CB, Lawton A, Hernandez N: Neuropathological changes in essential tremor: 33 cases compared with 21 controls. Brain 2007; 130: 3297-3307.
39. Rajput A, Robinson CA, Rajput AH: Essential tremor course and disability: a clinicopathologic study of 20 cases. Neurology 2004; 62: 932-936.
40. Shill H, Adler CH, Sabbagh MN, Conoor DJ, Caviness JN, Hentz JG, Beach TG: Pathological changes in prospectively-ascertained essential tremor subjects. Neurology 2008; 70: 1452-1455.
41. Ross GW, Dickson D, Cerosimo M: Pathological investigation of essential tremor. Neurology 2004; 62:A537-A538.
42. Louis ED, Honig LS, Vonsattel JPG, Maraganore DM, Borden S, Moskowitz CB: Essential tremor associated with focal nonnigral Lewy bodies: a clinicopathologic study. Arch Neurol 2005; 62: 1004-1007.
43. Louis ED, Erickson-Davis C, Pahwa R, Lyons KE, Garber A, Moskowitz CB, Lawton A, Faust PL, Vonsattel JPG: Essential tremor with ubiquitinated Purkinje cell intranuclear inclusions. Acta Neuropathol 2010; 119: 375-377.
44. Louis ED, Mazzoni P, Ma KJ, Moskowitz CB, Lawton A, Garber A, Vonsattel JPG: Essential tremor with ubiquitinated intranuclear inclusions and cerebellar degeneration. Clin Neuropathol 2012; 31: 119-126.
45. Rajput AH, Robinson CA, Rajput ML, Robinson SL, Rajput A: Essential tremor is not dependent upon cerebellar Purkinje cell loss. Parkinsonism Relat Disord 2012; 18: 626-628.
46. Shill HA, Adler CH, Beach TG: Pathology in essential tremor. Parkinsonism Relat Disord 2012; 18(suppl 1):S135-S137.
47. Louis ED: Age of onset: can we rely on essential tremor patients to report this? Data from a prospective, longitudinal study. Neuroepidemiology 2013; 40: 93-98.
48. Louis ED, Hernandez N, Rabinowitz D, Ottman R, Clark LN: Predicting age of onset in familial essential tremor: how much does age of onset run in families? Neuroepidemiology 2013; 40: 269-273.
49. Benito-Leon J, Bermejo-Pareja F, Louis ED: Incidence of essential tremor in three elderly populations of central Spain. Neurology 2005; 64: 1721-1725.
50. Rajput AH, Offord KP, Beard CM, Kurland LT: Essential tremor in Rochester, Minnesota: a 45-year study. J Neurol Neurosurg Psychiatry 1984; 47: 466-470.
51. Deuschl G, Elble R: Essential tremor - neurodegenerative or nondegenerative disease towards a working definition of ET. Mov Disord 2009; 24: 2033-2041.
52. Louis ED, Ford B, Frucht S, Ottman R: Mild tremor in relatives of patients with essential tremor: what does this tell us about the penetrance of the disease? Arch Neurol 2001; 58: 1584-1589.
53. Louis ED, Dogu O: Does age of onset in essential tremor have a bimodal distribution? Data from a tertiary referral setting and a population-based study. Neuroepidemiology 2007; 29: 208-212.
54. Louis ED, Ford B, Pullman S, Baron K: How normal is 'normal'? Mild tremor in a multiethnic cohort of normal subjects. Arch Neurol 1998; 55: 222-227.
55. Louis ED: Essential tremor. Clin Geriatr Med 2006; 22: 843-857.
56. Jain S, Lo SE, Louis ED: Common misdiagnosis of a common neurological disorder: how are we misdiagnosing essential tremor? Arch Neurol 2006; 63: 1100-1104.
57. Louis ED, Applegate LM, Rios E: ICD-9 CM code 333.1 as an identifier of patients with essential tremor: a study of the positive predictive value of this code. Neuroepidemiology 2007; 28: 181-185.
58. Brennan KC, Jurewicz EC, Ford B, Pullman SL, Louis ED: Is essential tremor predominantly a kinetic or a postural tremor? A clinical and electrophysiological study. Mov Disord 2002; 17: 313-316.
59. Louis ED: The primary type of tremor in essential tremor is kinetic rather than postural: cross-sectional observation of tremor phenomenology in 369 cases. Eur J Neurol 2013; 20: 725-727.
60. Thenganatt MA, Louis ED: Distinguishing essential tremor from Parkinson's disease: bedside tests and laboratory evaluations. Expert Rev Neurother 2012; 12: 687-696.
61. Deuschl G, Wenzelburger R, Loffler K, Raethjen J, Stolze H: Essential tremor and cerebellar dysfunction clinical and kinematic analysis of intention tremor. Brain 2000; 123(Pt 8): 1568-1580.
62. Louis ED, Frucht SJ, Rios E: Intention tremor in essential tremor: prevalence and association with disease duration. Mov Disord 2009; 24: 626-627.
63. Cohen O, Pullman S, Jurewicz E, Watner D, Louis ED: Rest tremor in patients with essential tremor: prevalence, clinical correlates, and electrophysiologic characteristics. Arch Neurol 2003; 60: 405-410.
64. Hubble JP, Busenbark KL, Pahwa R, Lyons K, Koller WC: Clinical expression of essential tremor: effects of gender and age. Mov Disord 1997; 12: 969-972.
65. Hardesty DE, Maraganore DM, Matsumoto JY, Louis ED: Increased risk of head tremor in women with essential tremor: longitudinal data from the Rochester Epidemiology Project. Mov Disord 2004; 19: 529-533.
66. Louis ED, Rios E, Applegate LM, Hernandez NC, Andrews HF: Jaw tremor: prevalence and clinical correlates in three essential tremor case samples. Mov Disord 2006; 21: 1872-1878.
67. Putzke JD, Whaley NR, Baba Y, Wszolek ZK, Uitti RJ: Essential tremor: predictors of disease progression in a clinical cohort. J Neurol Neurosurg Psychiatry 2006; 77: 1235-1237.
68. Louis ED, Agnew A, Gillman A, Gerbin M, Viner AS: Estimating annual rate of decline: prospective, longitudinal data on arm tremor severity in two groups of essential tremor cases. J Neurol Neurosurg Psychiatry 2011; 82: 761-765.
69. Bares M, Lungu OV, Husarova I, Gescheidt T: Predictive motor timing performance dissociates between early diseases of the cerebellum and Parkinson's disease. Cerebellum 2010; 9: 124-135.
70. Louis ED, Rios E, Rao AK: Tandem gait performance in essential tremor: clinical correlates and association with midline tremors. Mov Disord 2010; 25: 1633-1638.
71. Louis ED: Factor analysis of motor and nonmotor signs in essential tremor: are these signs all part of the same underlying pathogenic process? Neuroepidemiology 2009; 33: 41-46.
72. Rao AK, Uddin J, Gillman A, Louis ED: Cognitive motor interference during dual-task gait in essential tremor. Gait Posture 2013; 38: 403-409.
73. Hoskovcová M, Ulmanová O, Sprdlík O, Sieger T, Nováková J, Jech R, Růžička E: Disorders of balance and gait in essential tremor are associated with midline tremor and age. Cerebellum 2013; 12: 27-34.
74. Klebe S, Stolze H, Grensing K, Volkmann J, Wenzelburger R, Deuschl G: Influence of alcohol on gait in patients with essential tremor. Neurology 2005; 65: 96-101.
75. Stolze H, Petersen G, Raethjen J, Wenzelburger R, Deuschl G: The gait disorder of advanced essential tremor. Brain 2001; 124: 2278-2286.
76. Trillenberg P, Fuhrer J, Sprenger A, Hagenow A, Kömpf D, Wenzelburger R, Deuschl G, Heide W, Helmchen C: Eye-hand coordination in essential tremor. Mov Disord 2006; 21: 373-379.
77. Helmchen C, Hagenow A, Miesner J, Sprenger A, Rambold H, Wenzelburger R, Heide W, Deuschl G: Eye movement abnormalities in essential tremor may indicate cerebellar dysfunction. Brain 2003; 126: 1319-1332.
78. Leegwater-Kim J, Louis ED, Pullman SL, Floyd AG, Borden S, Moskowitz CB, Honig LS: Intention tremor of the head in patients with essential tremor. Mov Disord 2006; 21: 2001-2005.
79. Louis ED, Hernandez N, Alcalay RN, Tirri DJ, Ottman R, Clark LN: Prevalence and features of unreported dystonia in a family study of 'pure' essential tremor. Parkinsonism Relat Disord 2013; 19: 359-362.
80. Hedera P, Phibbs FT, Fang JY, Cooper MK, Charles PD, Davis TL: Clustering of dystonia in some pedigrees with autosomal dominant essential tremor suggests the existence of a distinct subtype of essential tremor. BMC Neurol 2010; 10: 66.
81. Lombardi WJ, Woolston DJ, Roberts JW, Gross RE: Cognitive deficits in patients with essential tremor. Neurology 2001; 57: 785-790.
82. Duane DD, Vermilion KJ: Cognitive deficits in patients with essential tremor. Neurology 2002; 58: 1706.
83. Bermejo-Pareja F: Essential tremor - a neurodegenerative disorder associated with cognitive defects? Nat Rev Neurol 2011; 7: 273-282.
84. Frisina PG, Tse W, Halbig TD, Libow LS: The pattern of cognitive-functional decline in elderly essential tremor patients: an exploratory- comparative study with Parkinson's and Alzheimer's disease patients. J Am Med Dir Assoc 2009; 10: 238-242.
85. Gasparini M, Bonifati V, Fabrizio E, Fabbrini G, Brusa L, Lenzi GL, Meco G: Frontal lobe dysfunction in essential tremor: a preliminary study. J Neurol 2001; 248: 399-402.
86. Kim JS, Song IU, Shim YS, Park JW, Yoo JY, Kim YI, Lee KS: Impact of tremor severity on cognition in elderly patients with essential tremor. Neurocase 2010; 16: 50-58.
87. Lacritz LH, Dewey R Jr, Giller C, Cullum CM: Cognitive functioning in individuals with 'benign' essential tremor. J Int Neuropsychol Soc 2002; 8: 125-129.
88. Louis ED, Huey ED, Gerbin M, Viner AS: Apathy in essential tremor, dystonia, and Parkinson's disease: a comparison with normal controls. Mov Disord 2012; 27: 432-434.
89. Woods SP, Scott JC, Fields JA, Poquette A, Troster AI: Executive dysfunction and neuropsychiatric symptoms predict lower health status in essential tremor. Cogn Behav Neurol 2008; 21: 28-33.
90. Louis ED, Huey ED, Gerbin M, Viner AS: Depressive traits in essential tremor: impact on disability, quality of life, and medication adherence. Eur J Neurol 2012; 19: 1349-1354.
91. Louis ED, Benito-Leon J, Bermejo-Pareja F: Self-reported depression and anti-depressant medication use in essential tremor: cross-sectional and prospective analyses in a population- based study. Eur J Neurol 2007; 14: 1138-1146.
92. Miller KM, Okun MS, Fernandez HF, Jacobson CE 4th, Rodriguez RL, Bowers D: Depression symptoms in movement disorders: comparing Parkinson's disease, dystonia, and essential tremor. Mov Disord 2007; 22: 666-672.
93. Louis ED: Essential tremor as a neuropsychiatric disorder. J Neurol Sci 2010; 289: 144-148.
94. Louis ED, Okun MS: It is time to remove the 'benign' from the essential tremor label. Parkinsonism Relat Disord 2011; 17: 516-520.
95. Benito-Leon J, Louis ED, Bermejo-Pareja F: Elderly-onset essential tremor is associated with dementia. Neurology 2006; 66: 1500-1505.
96. Louis ED, Ford B, Barnes LF: Clinical subtypes of essential tremor. Arch Neurol 2000; 57: 1194-1198.
97. Louis ED, Faust PL, Vonsattel JPG, Honig LS, Henchcliffe C, Pahwa R, Lyons KE, Rios E, Erickson-Davis C, Moskowitz CB, Lawton A: Older onset essential tremor: more rapid progression and more degenerative pathology. Mov Disord 2009; 24: 1606-1612.
98. Louis ED, Hernandez N, Ionita-Laza I, Ottman R, Clark LN: Does rate of progression run in essential tremor families? Slower versus faster progressors. Parkinsonism Relat Disord 2013; 19: 363-366.
99. Rincon F, Louis ED: Benefits and risks of pharmacological and surgical treatments for essential tremor: disease mechanisms and current management. Expert Opin Drug Saf 2005; 4: 899-913.
100. Zesiewicz TA, Ward CL, Hauser RA, Sanchez-Ramos J, Staffetti JF, Sullivan KL: A double-blind placebo-controlled trial of zonisamide (zonegran) in the treatment of essential tremor. Mov Disord 2007; 22: 279-282.
101. Sasso E, Perucca E, Calzetti S: Double-blind comparison of primidone and phenobarbital in essential tremor. Neurology 1988; 38: 808-810.
102. Findley LJ, Calzetti S: Double-blind controlled study of primidone in essential tremor: preliminary results. Br Med J (Clin Res Ed) 1982; 285: 608.
103. Gironell A, Kulisevsky J, Barbanoj M, Lopez-Villegas D, Hernandez G, Pascual-Sedano B: A randomized placebo-controlled comparative trial of gabapentin and propranolol in essential tremor. Arch Neurol 1999; 56: 475-480.
104. Louis ED: Treatment of essential tremor: are there issues we are overlooking? Front Neurol 2011; 2: 91.
105. Seibyl J, Russell D, Jennings D, Marek K: Neuroimaging over the course of Parkinson's disease: from early detection of the atrisk patient to improving pharmacotherapy of later-stage disease. Semin Nucl Med 2012; 42: 406-414.
106. Holland D, McEvoy LK, Desikan RS, Dale AM: Enrichment and stratification for predementia Alzheimer disease clinical trials. PLoS One 2012; 7:e47739.
107. Sperling RA, Karlawish J, Johnson KA: Preclinical Alzheimer disease - the challenges ahead. Nat Rev Neurol 2013; 9: 54-58.
108. Schuurman PR, Bosch DA, Bossuyt PM, Bonsel GJ, van Someren EJ, de Bie RM, Merkus MP, Speelman JD: A comparison of continuous thalamic stimulation and thalamotomy for suppression of severe tremor. N Engl J Med 2000; 342: 461-468.
109. Bermejo-Pareja F: An old problem not yet resolved: the association of several neurodegenerative disorders. Neuroepidemiology 2011; 37: 11-12.
110. Adler CH, Shill HA, Beach TG: Essential tremor and Parkinson's disease: lack of a link. Mov Disord 2011; 26: 372-377.
111. LaRoia H, Louis ED: Association between essential tremor and other neurodegenerative diseases: what is the epidemiological evidence? Neuroepidemiology 2011; 37: 1-10.
112. Benito-Leon J, Louis ED, Bermejo-Pareja F: Risk of incident Parkinson's disease and parkinsonism in essential tremor: a population based study. J Neurol Neurosurg Psychiatry 2009; 80: 423-425.
113. Benito-Leon J, Louis ED, Bermejo-Pareja F: Risk of incident Parkinson's disease and Parkinsonism in essential tremor: a populationbased study. Neurology 2008; 70:A191.
114. Tan EK, Lee SS, Fook-Chong S, Lum SY: Evidence of increased odds of essential tremor in Parkinson's disease. Mov Disord 2008; 23: 993-997.
115. Rocca WA, Bower JH, Ahlskog JE, Elbaz A, Grossardt BR, McDonnell SK, Schaid DJ, Maraganore DM: Increased risk of essential tremor in first-degree relatives of patients with Parkinson's disease. Mov Disord 2007; 22: 1607-1614.
116. Louis ED, Benito-Leon J: Alzheimer's disease, Parkinson's disease and essential tremor: three common degenerative diseases with shared mechanisms? Eur J Neurol 2010; 17: 765-766.
117. Bermejo-Pareja F, Louis ED, Benito-Leon J: Risk of incident dementia in essential tremor: a population-based study. Mov Disord 2007; 22: 573-580.
118. Louis ED, Babij R, Ma K, Cortes E, Vonsattel JPG: Essential tremor followed by progressive supranuclear palsy: postmortem reports of 11 patients. J Neuropathol Exp Neurol 2013; 72: 8-17.