RT Journal Article
SR Electronic
T1 Temporal discrimination in patients with dystonia and tremor and patients with essential tremor
JF Neurology
JO Neurology
FD Lippincott Williams & Wilkins
SP 76
OP 84
DO 10.1212/WNL.0b013e31827b1a54
VO 80
IS 1
A1 Michele Tinazzi
A1 Alfonso Fasano
A1 Alessandro Di Matteo
A1 Antonella Conte
A1 Francesco Bove
A1 Tommaso Bovi
A1 Alessia Peretti
A1 Giovanni Defazio
A1 Mirta Fiorio
A1 Alfredo Berardelli
YR 2013
UL http://n.neurology.org/content/80/1/76.abstract
AB Objective: To investigate whether psychophysical techniques assessing temporal discrimination could help in differentiating patients who have tremor associated with dystonia or essential tremor.Methods: We tested somatosensory temporal discrimination thresholds (TDT) and temporal discrimination movement thresholds (TDMT) in 39 patients who had tremor associated with dystonia or essential tremor presenting with upper-limb tremor of comparable severity and compared their findings with those from a group of 25 sex- and age-matched healthy control subjects.Results: TDT was higher in patients who had tremor associated with dystonia than in those with essential tremor and healthy controls (110.6 ± 31.3 vs 63.1 ± 15.2 vs 62.4 ± 9.2; p < 0.001). Conversely, TDMT was higher in patients with essential tremor than in those with tremor associated with dystonia and healthy controls (113.7 ± 14.7 vs 103.4 ± 11.3 vs 100.4 ± 4.2; p < 0.001). Combining the 2 tests in a pattern for essential tremor (abnormal TDMT/normal TDT) and tremor associated with dystonia (normal TDMT/abnormal TDT) yielded a positive predictive value (PPV) of 86.7% and a negative predictive value (NPV) of 70.8% for diagnosing essential tremor and a PPV of 100.0% and NPV of 74.1% for diagnosing tremor associated with dystonia.Conclusions: TDT and TDMT testing should prove a useful tool for differentiating tremor associated with dystonia and essential tremor. Our findings imply that the pathophysiologic mechanisms underlying tremor associated with dystonia differ from those for essential tremor.123I-FP-CIT SPECT=123I-labeled N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4-iodophenyl)nortropane SPECT; ANOVA=analysis of variance; CI=confidence interval; cTBS=continuous theta-burst stimulation; ET=essential tremor; FCR=flexor carpi radialis; FDI=first dorsal interosseous; HC=healthy control; ISI=interstimulus interval; NPV=negative predictive value; PPV=positive predictive value; TAD=tremor associated with dystonia; TDMT=temporal discrimination movement threshold; TDT=temporal discrimination threshold; TRS=Tremor Rating Scale