Cognitive deficits in essential tremor consistent with frontosubcortical dysfunction

Higginson, Christopher I.; Wheelock, Vicki; Levine, Dawn; King, David S.; Pappas, Conrad T. E.; Sigvardt, Karen A.

doi:10.1080/13803390701754738

Cited by 65 publications

(89 citation statements)

References 20 publications

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“…While numbers of cases and controls were limited in most individual studies (the exception being the study by Benito-Leon and colleagues, with 232 cases and 696 controls [Benito-Leon et al 2006a]), when taken as a whole, overall participant numbers are robust. In addition, while most studies either excluded potential participants with psychiatric comorbidities or medications that could impact cognition [Higginson et al 2008;Gasparini et al 2001;Passamonti et al 2011], or controlled for these conditions [Benito-Leon et al 2006a], other studies did not [Duane and Vermilion, 2002].…”

Section: Current Literature On the Relationships Between Et And Cognimentioning

confidence: 99%

“…All studies used either self-established [Lombardi et al 2001;Duane and Vermilion, 2002] or previously published standardized criteria for diagnosis of ET [Fahn et al 1993;Louis et al 1998;Salemi et al 1994;Bain et al 2000]. In addition, other neurological conditions that could mimic ET, such as PD, were specifically evaluated and potential participants with these symptoms were excluded [Kim et al 2009;Frisina et al 2009;Lombardi et al 2001;Higginson et al 2008;Gasparini et al 2001;Lacritz et al 2002;Benito-Leon et al 2006a;Sahin et al 2006;Schwartz et al 1999;Passamonti et al 2011;Duane and Vermilion, 2002]. There were certain limitations to some studies.…”

Section: Current Literature On the Relationships Between Et And Cognimentioning

confidence: 99%

“…Association of ET with cognitive dysfunction Studies on cognition in ET have predominantly assessed two areas: the integrity of various neuropsychological abilities, particularly executive functioning [Kim et al 2009;Frisina et al 2009;Lombardi et al 2001;Higginson et al 2008;Gasparini et al 2001;Sahin et al 2006;Schwartz et al 1999;Passamonti et al 2011] and the extent to which patients with ET are at increased risk for mild cognitive impairment (MCI) or dementia [Benito-Leon et al 2006b;Bermejo-Pareja et al 2007;Thawani et al 2009]. …”

Section: Current Literature On the Relationships Between Et And Cognimentioning

confidence: 99%

“…However, cross-sectional and longitudinal studies have increasingly demonstrated that ET may be associated with cognitive impairment or dementia in a subsection of patients [Kim et al 2009;Frisina et al 2009;Lombardi et al 2001;Higginson et al 2008;Gasparini et al 2001;Troster et al 2002;Lacritz et al 2002;Benito-Leon et al 2006a, 2006bLouis et al 2010a;BermejoPareja et al 2007;Thawani et al 2009]. This association does not appear to be accounted for by medication side effects [Lombardi et al 2001;Higginson et al 2008] or psychiatric symptoms [Li et al 2011], and may be related to cognitive changes associated with ET itself; alternately, it may be associated with concomitant neurodegenerative diseases that themselves have been reported to be associated with ET, including Alzheimer's disease (AD), Parkinson's disease (PD), Lewy body dementia (DLB) or progressive supranuclear palsy (PSP). This review summarizes the current literature on the potential relationships between ET and cognitive change, and suggests areas of further evaluation and treatment of ET patients with cognitive impairment.…”

Section: Introductionmentioning

confidence: 99%

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The cognitive side of essential tremor: what are the therapeutic implications?

Janicki

Cosentino

Louis

2013

Ther Adv Neurol Disord

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While essential tremor (ET) has traditionally been categorized as a pure motor disease, cross-sectional and longitudinal studies of cognition in ET have demonstrated that these patients may have cognitive dysfunction. Recent epidemiological studies demonstrate an association between ET (particularly with onset after age 65) and increased risk for cognitive impairment and dementia. Although existing studies have generally conceptualized cognitive changes in ET as consistent with a 'frontosubcortical' or 'corticocerebellar' profile, results from these same studies suggest that cognitive impairment in ET may in fact be heterogeneous. Furthermore, the underlying mechanisms remain uncertain. Cognitive changes could be a byproduct of the cerebellar dysfunction of ET itself; alternately, they may be a feature of concomitant neurodegenerative diseases that have been associated in several studies with ET, including Alzheimer's disease, Parkinson's disease or progressive supranuclear palsy. While the study of cognitive dysfunction in ET has received research attention in recent years, the results of these studies have not been translated into the clinical domain and clinical practice. This review first summarizes the current literature on the potential relationships between ET and cognitive change. We then suggest areas of further clinical evaluation and treatment; these suggestions are directed at physicians caring for ET patients who may demonstrate or complain of cognitive impairment. As we discuss, clinicians should ideally screen ET patients for possible signs or symptoms of cognitive impairment in addition to assessing for psychiatric comorbidity and quality of life. These recommendations are in contrast to most current clinical practice, which does not routinely include such assessment among ET patients. To our knowledge, there have been no pharmacotherapeutic trials to date of any agent for cognitive change associated with ET. We believe that studies for this indication are now called for. Future efforts in this direction will also need to take into account the pathobiology of cognitive changes in ET, which itself is an area that is ripe for future investigations.

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Section: Current Literature On the Relationships Between Et And Cognimentioning

confidence: 99%

Section: Current Literature On the Relationships Between Et And Cognimentioning

confidence: 99%

Section: Current Literature On the Relationships Between Et And Cognimentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The cognitive side of essential tremor: what are the therapeutic implications?

Janicki

Cosentino

Louis

2013

Ther Adv Neurol Disord

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“…Mild cognitive deficits have been reported to occur in patients with essential tremor (ET) in many independent studies, [1][2][3][4][5][6][7][8] including a population-based study of largely treatment-naive ET patients (Neurological Disorders in Central Spain [NEDICES] study). 8 These studies suggest that a frontosubcortical-type dysfunction occurs in some patients with ET.…”

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confidence: 99%

Rate of cognitive decline during the premotor phase of essential tremor

et al. 2013

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Objective: To characterize the rate of cognitive decline during the premotor phase of essential tremor (ET) in comparison to prevalent ET cases and controls.Methods: In this population-based, prospective study of people aged 65 years and older (Neurological Disorders in Central Spain), a 37-item version of the Mini-Mental State Examination was administered at 2 visits (baseline and follow-up, approximately 3 years later). We compared the rate of cognitive decline in 3 groups: prevalent ET cases (i.e., participants diagnosed with ET at baseline and at follow-up), "premotor" ET cases (i.e., participants diagnosed with incident ET at follow-up, but not at baseline), and controls (i.e., participants not diagnosed with ET at baseline or follow-up).Results: The 2,375 participants included 135 prevalent ET cases, 56 premotor ET cases, and 2,184 controls. During the follow-up period of 3.4 6 0.5 years (mean 6 SD), the 37-item version of the Mini-Mental State Examination declined by 0.7 6 3.3 points (0.2 6 1.0 points/year) in prevalent ET cases, 1.1 6 3.5 points (0.3 6 1.0 points/year) in premotor ET cases, and 0.1 6 3.9 points (0.0 6 1.2 points/year) in controls (p 5 0.014). The difference between premotor ET cases and controls was significant (p 5 0.046), as was the difference between prevalent ET cases and controls (p 5 0.027). Conclusions:In this prospective cohort, cognitive test scores in premotor and prevalent ET cases declined at a faster rate than in elders without this disease. A decline in global cognitive function may occur in a premotor phase of ET. Mild cognitive deficits have been reported to occur in patients with essential tremor (ET) in many independent studies, 1-8 including a population-based study of largely treatment-naive ET patients (Neurological Disorders in Central Spain [NEDICES] study).8 These studies suggest that a frontosubcortical-type dysfunction occurs in some patients with ET. [9][10][11][12][13][14] In the NEDICES study, lower cognitive test scores were associated with more reported functional difficulty, indicating a clinical-functional correlate. 15 The NEDICES study provided evidence that cognitive deficits in ET are not static, and appear to be progressing at a faster rate than in elders without this disease. 16 There could be a "premotor" stage of ET, as there is in other adultonset and late-life motor disorders. However, population-based studies that prospectively assess whether cognitive dysfunction appears in premotor ET (i.e., those subjects who were free of ET at baseline but who developed ET during the follow-up) have not been conducted.We hypothesized that the cognitive deficits in premotor and prevalent ET would not be static, but would deteriorate, and that this deterioration would occur at a rate above that observed in similarly aged controls. Using data from the NEDICES study, we evaluated ET

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