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Porto Alegre, Brazil

Velasco R.,Hospital Universitari Of Bellvitge | Bruna J.,Hospital Universitari Of Bellvitge | Briani C.,University of Padua | Argyriou A.A.,University of Patras | And 9 more authors.
Journal of Neurology, Neurosurgery and Psychiatry | Year: 2014

Objectives: Peripheral neuropathy ranks among the most common dose-limiting and disabling side-effect of oxaliplatin (OXA)-based chemotherapy. The aim of this prospective, multicentre study was to define early clinical and neurophysiological markers that may help to identify patients at risk of developing severe, treatment emergent, cumulative OXA-induced peripheral neuropathy (OXAIPN). Methods: 200 colorectal cancer patients, scheduled to receive OXA-based chemotherapy, were prospectively followed. Detailed neurological assessment employing the clinical Total Neuropathy Score (TNSc), oncological rating scales (National Common Institute-Common Toxicity Criteria V.3) and nerve conduction studies (NCS) were performed at baseline, mid-treatment and at the end of chemotherapy. Symptoms of OXA-induced acute neurotoxicity were systematically recorded. Results: According to TNSc, 36 (18%) patients developed grade 3 OXAIPN. These patients were predominantly men ( p=0.005), presented a significant decrease in all NCS (p<0.001), reported more acute neuropathic symptoms (p<0.001) and received higher OXA cumulative dose ( p=0.003). Multivariate analysis showed that three variables obtained at intermediate follow-up, namely, the number of acute symptoms (OR 1.9; CI 95% 1.2 to 3.2; p=0.012) and the >30% decrease in sensory nerve action potential amplitude from the baseline value in radial (OR 41.4; CI 95% 4.98 to 343.1; p=0.001) and dorsal sural nerves (OR 24.96; CI 95% 2.6 to 239.4; p=0.005) were independently associated with the risk of developing severe OXAIPN. Conclusions: High-grade OXA neurotoxicity can be predicted by clinical and neurophysiological information obtained at mid-treatment. Neurological assessment of acute neuropathy symptoms and radial and dorsal sural nerves NCS should be carefully monitored to predict and hopefully prevent the induction of severe OXAIPN. Source

Valls-Sole J.,University of Barcelona | Castellote J.M.,Complutense University of Madrid | Kofler M.,University of Barcelona | Casanova-Molla J.,University of Barcelona | And 2 more authors.
Journal of Pain | Year: 2012

Evoked potentials (EPs) to radiant or contact heat pain stimuli reflect the synchronization of brain activity to noxious inputs. However, we do not know how they relate to conscious awareness (AW) of a sensation. In healthy volunteers, we determined the time of AW for thermal noxious and non-noxious sensory inputs and examined its correlation to parametric measures of vertex EPs. Subjects had to report the position of the hand of a Libet's clock at the moment they perceived either a laser or a thermode stimulus. AW was determined after subtracting the position of the clock hand at the moment of stimulus delivery from the one reported by the subject, in ms. Subjects estimated AW in all single trials, including those in which no EPs could be identified. Mean AW was estimated earlier than the corresponding EP latency for both types and intensities of stimuli. There was a weak but significant negative correlation of AW to EPs amplitude, which was higher than the correlation of AW to EPs latency. Our results indicate that the timing of AW is influenced by the subjective relevance of sensory inputs. This feature could be used for the analysis of cognitive aspects of pain processing. Perspective: This article presents a way to measure the subjective awareness of the sensation induced by a noxious heat stimulus, either radiant or contact, in healthy human subjects. This method could be used for the analysis of cognitive aspects of pain processing. © 2012 by the American Pain Society. Published by Elsevier Inc. All rights reserved. Source

Costa J.,University of Lisbon | Costa J.,CIBER ISCIII | Gonzalez H.A.,Polytechnic University of Catalonia | Valldeoriola F.,University of Barcelona | And 6 more authors.
Movement Disorders | Year: 2010

Uncertainty exists on whether Parkinson's disease (PD) and essential tremor (ET) patients have similar degree of impairment during motor tasks. We investigated this problem by analyzing nonlinear dynamics of repetitive movements in 21 control subjects, 33 mild-moderate PD patients, and 18 ET patients. Accelerometer signals were recorded during finger tapping and unbounded forearm movements between two points, and processed with moving average filtering to generate a new signal consisting of the temporal distance between consecutive cycles. We calculated: mean interpeak interval (slowness), interpeak interval variability (irregularity), and beat decay (BD) of the auto mutual information (AMI) value, which estimates signal predictability by measuring the loss of signal information over a timescale. Both PD and ET had longer interpeak interval (except for finger tapping), higher interpeak interval variability, and higher BD-AMI values than controls (P ≤ 0.007, all comparisons). ET patients had higher BD-AMI values than PD (P = 0.003). BD-AMI was the parameter that discriminated better between subjects (diagnosis accuracies about 80%). No differences existed between PD patients with and without tremor or between PD or ET patients with different disease stages, for any parameter. Evaluation of nonlinear dynamics of oscillatory repetitive movements is a feasible and promising tool for studying movement physiology. Movement performance is more predictable in PD and ET than in controls, even in early disease stages. Slowness and irregularity of movement in PD and ET cannot be fully explained by tremor. Some common pathogenic mechanisms leading to bradykinesia may contribute to this impairment. © 2010 Movement Disorder Society. Source

Llado A.,Other Cognitive Disorders Unit | Fortea J.,Other Cognitive Disorders Unit | Ojea T.,Universitario Carlos Haya | Bosch B.,Other Cognitive Disorders Unit | And 5 more authors.
European Journal of Neurology | Year: 2010

Objective: To describe a novel mutation (K239N) in the PSEN1 associated with familial Alzheimer's disease (AD). Methods and results: The proband was a man who developed cognitive decline with marked behavioural abnormalities at age 57. At age 70, he was admitted into a psychiatric facility because of aggressiveness and a suicide attempt. Family history was consistent with autosomal dominant AD. One of the two other family members studied presented also with prominent behavioural symptoms at age 42 and has also been forced into a psychiatric facility because of aggressiveness at age 56. The remainder patient has presented a prototypical AD, but starting at age 71. Direct sequencing of PSEN1 in the three living affected members disclosed a heterozygous G to C transition in exon 7 of PSEN1 leading to the K239N mutation. Conclusion: The K239N mutation is associated with autosomal dominant AD with a wide range of age of onset and incomplete penetrance at the age of 65, prominent behavioural features and slow progression. © 2010 EFNS and PNS. Source

Brunoni A.R.,University of Sao Paulo | Schestatsky P.,Federal University of Rio Grande do Sul | Schestatsky P.,EMG Unit | Lotufo P.A.,University of Sao Paulo | And 2 more authors.
Clinical Neurophysiology | Year: 2014

Objective: To compare blinding integrity and associated factors for transcranial direct current stimulation (tDCS) vs. placebo-pill, the gold standard blinding method. Methods: Parallel trial. Depressed participants were randomized to verum/placebo sertraline and active/sham tDCS (2. mA, 30-min 10-daily sessions and two additional, fortnight sessions) over 6. weeks. Blinding was assessed in completers (n=102) and in a random subgroup (n=35) of raters and participants, in which we also inquired to qualitatively describe their strongest guessing reason. Results: Participants and raters presented similar performance for predicting treatment assignment at endpoint, correctly guessing tDCS and sertraline beyond chance. Nevertheless, clinical response was associated with correct prediction and tDCS non-responders failed to predict the allocation group. For tDCS, ". trouble concentrating" was inversely associated with correct prediction. ". Skin redness" was more reported for active-tDCS, but did not predict the allocation group. The qualitative reasons for raters' guessing were not associated with correct prediction, whereas for participants clinical response and adverse effects were directly and inversely associated with correct prediction, respectively. Conclusion: Blinding integrity of tDCS and sertraline were comparable and mainly associated with efficacy rather than blinding failure. Significance: TDCS blinding can be improved by adopting parallel designs and avoiding subjects' awareness of skin redness. © 2013 International Federation of Clinical Neurophysiology. Source

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