title: Using the Accelerometers Integrated in Smartphones to Evaluate Essential Tremor.
abstract: Background/Aims: Evaluation of tremor constitutes a crucial step from the diagnosis to the initial treatment and follow-up of patients with essential tremor. The severity of tremor can be evaluated using clinical rating scales, accelerometry, or electrophysiology. Clinical scores are subjectively given, may be affected by intra- and interevaluator variations due to different experience, delays between consultations, and subtle changes in tremor severity. Existing medical devices are not routinely used: they are expensive, time-consuming, not easily accessible. We aimed at showing that a smartphone application using the accelerometers embedded in smartphones is effective for quantifying the tremor of patients presenting with essential tremor. Methods: We developed a free iPhone/iPod application, Itremor, and evaluated different parameters on 8 patients receiving deep brain stimulation of the ventral intermediate nucleus of the thalamus: average and maximum accelerations, time above 1 g of acceleration, peak frequency, typical magnitude of tremor, for postural and action tremors, on and off stimulation. Results: We demonstrated good correlations between the parameters measured with Itremor and clinical score in all conditions. Itremor evaluation enabled higher discriminatory power and degree of reproducibility than clinical scores. Conclusion: Itremor can be used for routine objective evaluation of essential tremor, and may facilitate adjustment of the treatment. © 2015 S. Karger AG, Basel.
authors.affiliation: Neurosurgery Department, Assistance Publique-Hôpitaux de Paris (APHP), Groupe Henri-Mondor Albert-Chenevier, Université Paris 12 UPEC, Faculté de Médecine, Créteil, France.
authors.forename: Suhan
authors.initials: S
authors.lastname: Senova
authors.forename: Damien
authors.initials: D
authors.lastname: Querlioz
authors.forename: Claire
authors.initials: C
authors.lastname: Thiriez
authors.forename: Pierre
authors.initials: P
authors.lastname: Jedynak
authors.forename: Béchir
authors.initials: B
authors.lastname: Jarraya
authors.forename: Stéphane
authors.initials: S
authors.lastname: Palfi