title: Purkinje cell loss is a characteristic of essential tremor.
abstract: This paper began as a letter to the editor, commenting on several methodological and conceptual problems with the paper by Rajput et al. [1]. We were asked by the editors to expand the paper to include a more general discussion of the role of the cerebellum in essential tremor (ET). The study of the neuropathological underpinnings of essential tremor (ET) is a relatively new undertaking. The purpose of this paper is three-fold. The first is to comment on methodological problems in a recently-published paper by Rajput et al., the major one being the small sample size of that study, which resulted in a Type II statistical error. Hence, one cannot conclude based on their data that there is no Purkinje cell (PC) loss in ET. Secondly, we comment on conceptual problems with that study, which suggested that PC loss might not be a featured characteristic of ET because it is also found in other disease states. We discuss why this is an erroneous conclusion. Our third purpose is to more broadly discuss the role of the cerebellum in ET, giving consideration to the wealth of clinical and postmortem data that have accumulated over recent years. In this discussion, we make the following points: (1) it is now generally recognized that ET is a disease of cerebellar systems dysfunction, (2) given the nature of the postmortem work, revealing the presence of several types of structural-anatomical changes within the cerebellum and absence of detectable changes in other brain regions, the most empirically-based explanation is that the primary problem in ET is in the cerebellum itself, (3) that the collection of cellular changes in the cerebellum in ET are also present in other cerebellar degenerations should add to rather than detract from the notion that ET is a disease of cerebellar degeneration.
authors: Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA. EDL2@columbia.edu
authors: Elan D
authors: ED
authors: Louis
authors: Phyllis L
authors: PL
authors: Faust
authors: John-Paul G
authors: JP
authors: Vonsattel
references: Brain. 2007 Dec;130(Pt 12):3297-307
references: 18025031
references: Curr Opin Neurol. 2007 Aug;20(4):447-52
references: 17620881
references: Mov Disord. 1997 Nov;12(6):1068-72
references: 9399240
references: Mov Disord. 2009 Oct 30;24(14):2033-41
references: 19750493
references: Arch Neurol. 1994 Aug;51(8):772-8
references: 8042925
references: Arch Neurol. 2009 Oct;66(10):1202-8
references: 19822775
references: Lancet Neurol. 2010 Jun;9(6):613-22
references: 20451458
references: Parkinsonism Relat Disord. 2011 Jan;17(1):16-21
references: 20817536
references: Arch Neurol. 2008 Jan;65(1):101-7
references: 18195146
references: J Neuropathol Exp Neurol. 2010 Mar;69(3):262-71
references: 20142764
references: Ann Neurol. 2008 Nov;64(5):485-91
references: 19067353
references: Neurology. 2004 Mar 23;62(6):932-6
references: 15037695