Giacomo Koch

Publications (121) View all

• Source

  Available from: Carmelo Mario Vicario

  Article: Temporal accuracy and variability in the left and right posterior parietal cortex.

  Carmelo M Vicario, Davide Martino, Giacomo Koch
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  ABSTRACT: Several brain imaging and lesion studies have suggested a role for the posterior parietal cortex (PPC) in computing interval-timing tasks. PPC seems also to have a key role in modulating visuospatial mechanisms, which are known to affect temporal performance. By applying Transcranial Direct Current Stimulation (tDCS) over the left and right PPC, we aimed to modulate timing ability performance in healthy humans performing a cognitively controlled timing task. In two separate experiments we compared time-processing abilities of two groups of healthy adults submitted to anodal, cathodal or sham tDCS over right or left PPC, by employing a supra-second time reproduction task. Cathodal stimulation over the right PPC affected temporal accuracy by leading participants to overestimate time intervals. Moreover, when applied to the left PPC, it reduced variability in reproducing temporal intervals. No effect was reported for anodal stimulation. These results expand current knowledge on the role of parietal cortex on temporal processing. We provide evidence that parietal cortex of both hemispheres is involved in temporal processing by acting on distinct components of timing performance such as accuracy and variability.
  Neuroscience 04/2013; · 3.38 Impact Factor
• Article: Theta burst stimulation improves visuo-spatial attention in a patient with traumatic brain injury.

  Sonia Bonnì, Chiara Mastropasqua, Marco Bozzali, Carlo Caltagirone, Giacomo Koch
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  ABSTRACT: Recent studies showed that non-invasive brain stimulation methods, such as repetitive transcranial magnetic stimulation (rTMS) can improve the symptoms of neglect in stroke patients. Here, we adopted this approach to improve visuo-spatial deficit in a patient with traumatic brain injury (TBI) that showed important symptoms of visuo-spatial neglect. We found that continuous theta burst stimulation (cTBS) applied over the left posterior parietal cortex (PPC) induced a clinical improvement of cognitive disorder associated to a functional changes of fronto-parietal network as assessed by means of TMS and resting state fMRI.
  Neurological Sciences 03/2013; · 1.32 Impact Factor
• Article: Intra-arterial Thrombectomy versus Standard Intravenous Thrombolysis in Patients with Anterior Circulation Stroke Caused by Intracranial Arterial Occlusions: A Single-center Experience.

  Fabrizio Sallustio, Giacomo Koch, Silvia Di Legge, Costanza Rossi, Barbara Rizzato, Simone Napolitano, Domenico Samà, Natale Arnò, Angela Giordano, Domenicantonio Tropepi, [......], Costantino Del Giudice, Alessio Spinelli, Sebastiano Fabiano, Matteo Stefanini, Daniel Konda, Carlo Andrea Reale, Enrico Pampana, Giovanni Simonetti, Paolo Stanzione, Roberto Gandini
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  ABSTRACT: BACKGROUND: Severely impaired patients with persisting intracranial occlusion despite standard treatment with intravenous (IV) administration of recombinant tissue plasminogen activator (rtPA) or presenting beyond the therapeutic window for IV rtPA may be candidates for interventional neurothrombectomy (NT). The safety and efficacy of NT by the Penumbra System (PS) were compared with standard IV rtPA treatment in patients with severe acute ischemic stroke (AIS) caused by large intracranial vessel occlusion in the anterior circulation. METHODS: Consecutive AIS patients underwent a predefined treatment algorithm based on arrival time, stroke severity as measured by the National Institutes of Health Stroke Scale (NIHSS) score, and site of arterial occlusion on computed tomographic angiography (CTA). NT was performed either after a standard dose of IV rtPA (bridging therapy [BT]) or as single treatment (stand-alone NT [SAT]). Rates of recanalization, symptomatic intracranial bleeding (SIB), mortality, and functional outcome in NT patients were compared with a historical cohort of IV rtPA treated patients (i.e., controls). Three-month favourable outcome was defined as a modified Rankin Scale (mRS) score ≤2. RESULTS: Forty-six AIS patients were treated with NT and 51 with IV rtPA. The 2 groups did not differ with regard to demographics, onset NIHSS score (18.5 ± 4 v 17 ± 5; P = .06), or site of intracranial occlusion. Onset-to-treatment time in the NT and IV rtPA groups was 230 minutes (±78) and 176.5 (±44) minutes, respectively (P = .001). NT patients had significantly higher percentages of major improvement (≥8 points NIHSS score change at 24 hours; 26% v 10%; P = .03) and partial/complete recanalization (93.5% v 45%; P < .0001) compared to controls. Treatment by either SAT or BT similarly improved the chance of early recanalization and early clinical improvement. No significant differences were observed in the rate of SIB (11% v 6%), 3-month mortality (24% v 25%), or favorable outcome (40% v 35%) between NT and IV rtPA patients. CONCLUSIONS: Despite significantly delayed time of intervention, NT patients had higher rates of recanalization and early major improvement, with no differences in symptomatic intracranial hemorrhages. Early NIHSS score improvement did not translate into better 3-month mortality or outcome. NT seems a safe and effective adjuvant treatment strategy for selected patients with severe AIS secondary to large intracranial vessel occlusion in the anterior circulation.
  Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 02/2013;
• Article: Study of cerebello-thalamocortical pathway by transcranial magnetic stimulation in Parkinson's disease.

  Fátima Carrillo, Francisco J Palomar, Virginia Conde, Francisco J Diaz-Corrales, Paolo Porcacchia, Miguel Fernández-Del-Olmo, Giacomo Koch, Pablo Mir
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  ABSTRACT: BACKGROUND: Although functional changes in the activation of the cerebellum in Parkinson's disease (PD) patients have been consistently described, it is still debated whether such altered cerebellar activation is a natural consequence of PD pathophysiology or rather it involves compensatory mechanisms. OBJECTIVE/HYPOTHESIS: We used different forms of cerebellar transcranial magnetic stimulation to evaluate the hypothesis that altered cerebello-cortical interactions can be observed in PD patients and to evaluate the role of dopaminergic treatment. METHODS: We studied the effects of a single cerebellar magnetic pulse over the excitability of the contralateral primary motor cortex tested with motor-evoked potentials (MEPs) (cerebellar-brain inhibition-CBI) in a group of 16 PD patients with (ON) and without dopaminergic treatment (OFF), and in 16 age-matched healthy controls. Moreover, we also tested the effects of cerebellar continuous theta-burst stimulation (cTBS) on MEP amplitude, short intracortical inhibition (SICI) and short intracortical facilitation (SICF) tested in the contralateral M1 in 13 PD patients in ON and OFF and in 16 age-matched healthy controls. RESULTS: CBI was evident in controls but not in PD patients, even when tested in both ON and OFF conditions. Similarly, cerebellar cTBS reduced MEP amplitude and SICI in controls but not in PD patients under any condition. CONCLUSION(S): These results demonstrate that PD patients have deficient short-latency and long-lasting cerebellar-thalamocortical inhibitory interactions that cannot be promptly restored by standard dopaminergic medication.
  Brain Stimulation 01/2013; · 3.76 Impact Factor
• Article: The right frontopolar cortex is involved in visual-spatial prospective memory.

  Alberto Costa, Massimiliano Oliveri, Francesco Barban, Sonia Bonnì, Giacomo Koch, Carlo Caltagirone, Giovanni A Carlesimo
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  ABSTRACT: The involvement of frontopolar cortex in mediating prospective memory processes has been evidenced by various studies, mainly by means of neuroimaging techniques. Recently, one transcranial magnetic stimulation study documented that transient inhibition of left Brodmann Area (BA) 10 impaired verbal prospective memory. This result raises the issue of whether the BA 10 involvement in prospective memory functioning may be modulated by the physical characteristics of the stimuli used. The present study aimed to investigate the role of the frontopolar cortex in visual-spatial PM by means of the application of inhibitory theta-burst stimulation. Twelve volunteers were evaluated after inhibitory theta-burst stimulation over left BA 10, right BA10 and CZ (control condition). In the prospective memory procedure, sequences of four spatial positions (black squares) each were presented. During the inter-sequence delay, subjects had to reproduce the sequence in the observed order (ongoing task forward) or the reverse order (backward). At the occurrence of a target position, subjects had to press a key on the keyboard (prospective memory score). Recall and recognition of the target positions were also tested. We found that prospective memory accuracy was lower after theta-burst stimulation over right BA10 than CZ (p<0.01), whereas it was comparable in left BA10 and CZ conditions. No significant difference was found among the three conditions on recall and recognition of target positions and on ongoing task performance. Our findings provide a novel strong evidence for a specific involvement of right frontopolar cortex in visual-spatial prospective memory. In the context of previous data providing evidence for left BA 10 involvement in verbal prospective memory, our results also suggest material-specific lateralization of prospective memory processes in BA 10.
  PLoS ONE 01/2013; 8(2):e56039. · 4.09 Impact Factor