Using the Accelerometers Integrated in Smartphones to Evaluate Essential Tremor.

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.

Unilateral thalamic deep brain stimulation for disabling kinetic tremor in multiple sclerosis.

BACKGROUND: Surgical options of multiple sclerosis (MS) tremor treatment are limited and narrowed to thalamotomy or deep brain stimulation of the thalamic nucleus ventralis intermedius. Lack of qualification protocol frequently results in poor outcome. OBJECTIVE: To determine prospectively the efficacy and safety of unilateral ventralis intermedius deep brain stimulation as a tool to control disabling kinetic arm tremor related to MS. METHODS: Neurological and neuropsychological evaluations were performed 1 month and 1 day before surgery and 1, 3, and 6 months after surgery. The evaluation included measurement of tremor and dexterity, Extended Disability Status Scale, Mini Mental State Examination, and quality-of-life assessment. Nine consecutive patients were enrolled in the group. Mean age at the time of surgery was 38.9 ± 9 years; median Extended Disability Status Scale at baseline was 7.1. Mean MS duration was 11.7 years, and mean tremor duration was 6.11 years. Mean postural and kinetic scores and hand capacity were measured. RESULTS: One month after surgery, median scores off and on stimulation were 12 and 6 for postural tremor, 12 and 10.5 for kinetic tremor score, 12 and 7.5 for manual capacity, and 22 and 20 for functional handicap, respectively. Similar results were 10 and 4, respectively, at the 3-month follow-up. Six months after surgery, median scores off and on stimulation were 10.4 and 4 for postural tremor and 12 and 7.8 for kinetic tremor, respectively. CONCLUSION: This prospective study confirms the value and safety of ventralis intermedius deep brain stimulation for treatment of kinetic tremor related to MS. Accurate and precise presurgical qualification plays a key role in successful treatment.

Repetitive behaviours in patients with Gilles de la Tourette syndrome: tics, compulsions, or both?

BACKGROUND: Repetitive behaviours (RB) in patients with Gilles de la Tourette syndrome (GTS) are frequent. However, a controversy persists whether they are manifestations of obsessive-compulsive disorder (OCD) or correspond to complex tics. METHODS: 166 consecutive patients with GTS aged 15-68 years were recruited and submitted to extensive neurological, psychiatric and psychological evaluations. RB were evaluated by the YBOCS symptom checklist and Mini International Neuropsychiatric Interview (M.I.N.I), and classified on the basis of a semi-directive psychiatric interview as compulsions or tics. RESULTS: RB were present in 64.4% of patients with GTS (107/166) and categorised into 3 major groups: a 'tic-like' group (24.3%-40/166) characterised by RB such as touching, counting, 'just right' and symmetry searching; an 'OCD-like' group (20.5%-34/166) with washing and checking rituals; and a 'mixed' group (13.2%-22/166) with both 'tics-like' and 'OCD-like' types of RB present in the same patient. In 6.3% of patients, RB could not be classified into any of these groups and were thus considered 'undetermined'. CONCLUSIONS: The results confirm the phenomenological heterogeneity of RB in GTS patients and allows to distinguish two types: tic-like behaviours which are very likely an integral part of GTS; and OCD-like behaviours, which can be considered as a comorbid condition of GTS and were correlated with higher score of complex tics, neuroleptic and SSRIs treatment frequency and less successful socio-professional adaptation. We suggest that a meticulous semiological analysis of RB in GTS patients will help to tailor treatment and allow to better classify patients for future pathophysiologic studies. TRIAL REGISTRATION: ClinicalTrials.gov NCT00169351.

New mutations in protein kinase Cgamma associated with spinocerebellar ataxia type 14.

Autosomal dominant cerebellar ataxias (ADCA) are a heterogeneous group of neurological disorders. Point mutations in the gene encoding protein kinase Cgamma (PRKCG) are responsible for spinocerebellar ataxia 14 (SCA14). We screened for mutations in the PRKCG gene, in a large series of 284 ADCA index cases, mostly French (n=204) and German (n=48), in whom CAG repeat expansions in the known SCA genes were previously excluded. Six mutations were found that segregated with the disease and were not detected on 560 control chromosomes, including F643L (exon 18), already reported in another French kindred. Five new missense mutations were identified in exons 4 (C114Y/G123R/G123E), 10 (G360S) and 18 (V692G). All but one (V692G) were located in highly conserved regions of the regulatory or catalytic domains of the protein. All six SCA14 families were French and there was no evidence of reduced penetrance. The phenotype consisted in a very slowly progressive cerebellar ataxia with a mean age at onset of 33.5+/-14.2 years (range 15 to 60 years), occasionally associated with executive dysfunction, myoclonus, myorythmia, tremor or decreased vibration sense. SCA14 represented only 1.5% (7/454) of French ADCA families but none of the German families. It should, however, be considered in patients with slowly progressive ADCA, particularly when myoclonus and cognitive impairment are present.