AUTHOR=Louis Elan D. , Rohl Brittany , Collins Kathleen , Cosentino Stephane 

TITLE=Poorer Cognitive Performance in Patients with Essential Tremor-Parkinson’s Disease vs. Patients with Parkinson’s Disease

JOURNAL=Frontiers in Neurology

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2015.00106

DOI=10.3389/fneur.2015.00106

ISSN=1664-2295

ABSTRACT=<sec id="ST1"><title>Background</title><p>Patients with essential tremor (ET) seem to be at increased risk of developing Parkinson’s disease (PD). Surprisingly, little has been written about this clinical entity, ET-PD. Cognitive dysfunction is a well-known feature of PD, and can also be an issue in patients with ET. Whether the presence of the combined diagnosis, ET-PD, is associated with additive cognitive effects as compared with PD has not been studied.</p></sec><sec id="ST2"><title>Methods</title><p>Thirty ET-PD patients and 53 age-matched PD patients were enrolled in a clinical-epidemiological study. Two cognitive screens, the Telephone Interview for Cognitive Status (TICS, score = 0–41) and Folstein Mini-Mental State Examination (MMSE; range 0–30), were administered.</p></sec><sec id="ST3"><title>Results</title><p>The MMSE score was lower in ET-PD than PD [26.5 ± 3.1 (median 28.0) vs. 28.4 ± 2.2 (median 29.0), <italic>p</italic> = 0.001]. The TICS score was lower in ET-PD than PD [31.7 ± 3.9 (32.0) vs. 35.0 ± 2.0 (35.0), <italic>p</italic> &lt; 0.001]. Subscores of these tests that related to orientation (<italic>p</italic> &lt; 0.001), language (<italic>p</italic> &lt; 0.001), and working memory (<italic>p</italic> = 0.001) were lower in ET-PD than PD, whereas the delayed memory subscore was only marginally lower in ET-PD than PD (<italic>p</italic> = 0.06), and the two groups did not differ with respect to the motor/construction subscore (<italic>p</italic> = 0.22). Both global cognitive scores were inversely correlated with disease duration (for MMSE score, Spearman’s <italic>r</italic> = −0.46, <italic>p</italic> &lt; 0.001; for TICS score, Spearman’s <italic>r</italic> = −0.53, <italic>p</italic> &lt; 0.001).</p></sec><sec id="ST4"><title>Conclusion</title><p>The combined diagnosis, ET-PD, seemed to be associated with additive cognitive effects as compared with PD alone.</p></sec>