Browsing by Subject "MOTOR"

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  • Rusanen, Anna-Mari; Lappi, Otto; Kuokkanen, Jesse; Pekkanen, Jami (2021)
    The fundamental cognitive problem for active organisms is to decide what to do next in a changing environment. In this article, we analyze motor and action control in computational models that utilize reinforcement learning (RL) algorithms. In reinforcement learning, action control is governed by an action selection policy that maximizes the expected future reward in light of a predictive world model. In this paper we argue that RL provides a way to explicate the so-called action-oriented views of cognitive systems in representational terms.
  • Arnulfo, Gabriele; Narizzano, Massimo; Cardinale, Francesco; Fato, Marco Massimo; Palva, Jaakko Matias (2015)
    Background: Invasive monitoring of brain activity by means of intracerebral electrodes is widely practiced to improve pre-surgical seizure onset zone localization in patients with medically refractory seizures. Stereo-Electroencephalography (SEEG) is mainly used to localize the epileptogenic zone and a precise knowledge of the location of the electrodes is expected to facilitate the recordings interpretation and the planning of resective surgery. However, the localization of intracerebral electrodes on post-implant acquisitions is usually time-consuming (i.e., manual segmentation), it requires advanced 3D visualization tools, and it needs the supervision of trained medical doctors in order to minimize the errors. In this paper we propose an automated segmentation algorithm specifically designed to segment SEEG contacts from a thresholded post-implant Cone-Beam CT volume (0.4 mm, 0.4 mm, 0.8 mm). The algorithm relies on the planned position of target and entry points for each electrode as a first estimation of electrode axis. We implemented the proposed algorithm into DEETO, an open source C++ prototype based on ITK library. Results: We tested our implementation on a cohort of 28 subjects in total. The experimental analysis, carried out over a subset of 12 subjects (35 multilead electrodes; 200 contacts) manually segmented by experts, show that the algorithm: (i) is faster than manual segmentation (i.e., less than 1s/subject versus a few hours) (ii) is reliable, with an error of 0.5 mm +/- 0.06 mm, and (iii) it accurately maps SEEG implants to their anatomical regions improving the interpretability of electrophysiological traces for both clinical and research studies. Moreover, using the 28-subject cohort we show here that the algorithm is also robust (error <0.005 mm) against deep-brain displacements (<12 mm) of the implanted electrode shaft from those planned before surgery. Conclusions: Our method represents, to the best of our knowledge, the first automatic algorithm for the segmentation of SEEG electrodes. The method can be used to accurately identify the neuroanatomical loci of SEEG electrode contacts by a non-expert in a fast and reliable manner.
  • Kilpeläinen, Tommi; Julku, Ulrika; Svarcbahs, Reinis; Myöhänen, Timo (2019)
    Alpha-synuclein (aSyn) is the main component of Lewy bodies, the histopathological marker in Parkinson's disease (PD), and point mutations and multiplications of the aSyn coding SNCA gene correlate with early onset PD. Therefore, various transgenic mouse models overexpressing native or point-mutated aSyn have been developed. Although these models show highly increased aSyn expression they rarely capture dopaminergic cell loss and show a behavioural phenotype only at old age, whereas SNCA mutations are risk factors for PD with earlier onset. The aim of our study was to re-characterize a transgenic mouse strain carrying both A30P and A53T mutated human aSyn. Our study revealed decreased locomotor activity for homozygous transgenic mice starting from 3 months of age which was different from previous studies with this mouse strain that had behavioural deficits starting only after 7-9 months. Additionally, we found a decreased amphetamine response in locomotor activity and decreased extracellular dopaminergic markers in the striatum and substantia nigra with significantly elevated levels of aSyn oligomers. In conclusion, homozygous transgenic A30P*A53T aSyn mice capture several phenotypes of PD with early onset and could be a useful tool for aSyn studies.
  • Leino, Sakari; Kohtala, Samuel; Rantamäki, Tomi; Koski, Sini K.; Rannanpää, Saara; Salminen, Outi (2018)
    BackgroundThe treatment of Parkinson's disease is often complicated by levodopa-induced dyskinesia (LID). Nicotinic acetylcholine receptor agonists can alleviate LID in animal models but may be less effective in conditions of severe dopaminergic denervation. While the mechanisms of LID remain incompletely understood, elevated corticostriatal levels of the brain-derived neurotrophic factor (BDNF) have been suggested to play a role. Here, female mice with near-total unilateral 6-hydroxydopamine-induced nigrostriatal lesions were chronically treated with levodopa, and the effects of the 7 nicotinic receptor partial agonist AZD0328 and nicotine on LID were assessed. At the end of the experiment, BDNF protein levels in the prefrontal cortex and striatum were measured.ResultsFive-day treatments with three escalating doses of AZD0328 and a 10-week treatment with nicotine failed to alleviate LID. BDNF levels in the lesioned striatum correlated positively with LID severity, but no evidence was found for a levodopa-induced elevation of corticostriatal BDNF in the lesioned hemisphere. The nicotine treatment decreased BDNF levels in the prefrontal cortex but had no effect on striatal BDNF.ConclusionsThe findings suggest that treatment of LID with nicotinic agonists may lose its effectiveness as the disease progresses, represent further evidence for a role for BDNF in LID, and expand previous knowledge on the effects of long-term nicotine treatment on BDNF.
  • Hernandez-Pavon, Julio C.; Makela, Niko; Lehtinen, Henri; Lioumis, Pantelis; Makela, Jyrki P. (2014)
  • Grau-Sanchez, Jennifer; Ramos-Escobar, Neus; Sierpowska, Joanna; Rueda, Nohora; Susana, Redón; Rifà, Xavi; Veciana de las Heras, Misericordia; Pedro, Jordi; Särkämö, Teppo Tapio; Duarte, Esther; Rodríguez-Fornells, Antoni (2018)
    The effect of music-supported therapy (MST) as a tool to restore hemiparesis of the upper extremity after a stroke has not been appropriately contrasted with conventional therapy. The aim of this trial was to test the effectiveness of adding MST to a standard rehabilitation program in subacute stroke patients. A randomized controlled trial was conducted in which patients were randomized to MST or conventional therapy in addition to the rehabilitation program. The intensity and duration of the interventions were equated in both groups. Before and after 4 weeks of treatment, motor and cognitive functions, mood, and quality of life (QoL) of participants were evaluated. A follow-up at 3 months was conducted to examine the retention of motor gains. Both groups significantly improved their motor function, and no differences between groups were found. The only difference between groups was observed in the language domain for QoL. Importantly, an association was encountered between the capacity to experience pleasure from music activities and the motor improvement in the MST group. MST as an add-on treatment showed no superiority to conventional therapies for motor recovery. Importantly, patient's intrinsic motivation to engage in musical activities was associated with better motor improvement.
  • Fekonja, Lucius S.; Wang, Ziqian; Cacciola, Alberto; Roine, Timo; Aydogan, D. Baran; Mewes, Darius; Vellmer, Sebastian; Vajkoczy, Peter; Picht, Thomas (2022)
    Tumors and their location distinctly alter both local and global brain connectivity within the ipsilesional hemisphere of glioma patients. Gliomas that infiltrate networks and systems, such as the motor system, often lead to substantial functional impairment in multiple systems. Network-based statistics (NBS) allow to assess local network differences and graph theoretical analyses enable investigation of global and local network properties. Here, we used network measures to characterize glioma-related decreases in structural connectivity by comparing the ipsi- with the contralesional hemispheres of patients and correlated findings with neurological assessment. We found that lesion location resulted in differential impairment of both short and long connectivity patterns. Network analysis showed reduced global and local efficiency in the ipsilesional hemisphere compared to the contralesional hemispheric networks, which reflect the impairment of information transfer across different regions of a network.
  • Leta, Valentina; Dafsari, Haidar S.; Sauerbier, Anna; Metta, Vinod; Titova, Nataliya; Timmermann, Lars; Ashkan, Keyoumars; Samuel, Michael; Pekkonen, Eero; Odin, Per; Antonini, Angelo; Martinez-Martin, Pablo; Parry, Miriam; van Wamelen, Daniel J.; Ray Chaudhuri, K. (2021)
    Device-aided therapies, including levodopa-carbidopa intestinal gel infusion, apomorphine subcutaneous infusion, and deep brain stimulation, are available in many countries for the management of the advanced stage of Parkinson's disease (PD). Currently, selection of device-aided therapies is mainly focused on patients' motor profile while non-motor symptoms play a role limited to being regarded as possible exclusion criteria in the decision-making process for the delivery and sustenance of a successful treatment. Differential beneficial effects on specific non-motor symptoms of the currently available device-aided therapies for PD are emerging and these could hold relevant clinical implications. In this viewpoint, we suggest that specific non-motor symptoms could be used as an additional anchor to motor symptoms and not merely as exclusion criteria to deliver bespoke and patient-specific personalised therapy for advanced PD.
  • Udd, Marianne; Lyytinen, Jukka; Eerola-Rautio, Johanna; Kenttämies, Anu; Lindström, Outi; Kylänpää, Leena; Pekkonen, Eero (2017)
    Background: Continuous levodopa-carbidopa intestinal gel (LCIG) diminishes daily off time and dyskinesia in patients with advanced Parkinsons disease (PD). Complications are common with percutaneous endoscopic gastrostomy with a jejunal extension tube (PEG-J). Aim of the Study: To report the clinical outcome of LCIG in patients with advanced PD in the years 2006-2014 at Helsinki University Hospital. Patients and Methods: Levodopa-carbidopa intestinal gel treatment started following PEG-J placement in patients with advanced PD after successful in-hospital LCIG trial with a nasojejunal tube. Demographics, PEG-J procedures, discontinuation of LCIG, complications and mortality were retrospectively analyzed. Results [mean (SD)]: Sixty patients with advanced PD [age 68(7) years; duration of PD: 11(4) years] had LCIG treatment for 26(23) months. The majority of patients with advanced PD were satisfied with the LCIG treatment. For 51 patients (85%), the pump was on for 16hr a day, and for nine patients (15%) it was on for 24hr a day. After 6months, the levodopa-equivalent daily dose (LEDD) had increased by 30% compared to pre-LCIG LEDD. Sixty patients underwent a total of 156 PEG-J procedures, and 48 patients (80%) had a total of 143 complications. Forty-six patients (77%) had 119 PEG-J or peristomal complications, and 22 patients (37%) had a total of 25 other complications. The most common complications were accidental removal of the J-tube in 23 patients (38%) and 5% weight loss in 18 patients (30%). Fifteen patients discontinued the LCIG after 21 (21) months. At the end of the follow-up period of 33(27) months, 38 patients were still on LCIG and nine (15%) had died. Conclusion: Most patients were satisfied with LCIG treatment. A few patients lost weight whereas the majority had complications with PEG-J. When LCIG treatment is carried out, neurological and endoscopic units must be prepared for multiple endoscopic procedures.
  • Määttänen, Laura; Ripatti, Liisa; Rautava, Päivi; Koivisto, Mari; Haataja, Leena (2020)
    Aim To study whether cerebral palsy (CP) increases the risk of hospital-treated injuries in children up to 13 years of age. Methods A Finnish population-based cohort (n=328 903) of children born during 2001 to 2006 was followed up for hospital-treated injuries until the end of 2014 via linkage of nation-wide registers. The rate of first injury was compared in children with and without CP. The effect of CP type, gender, severe comorbidities (intellectual disability, epilepsy, hearing or visual impairment), and the type of injury was evaluated. Results Children with CP had an increased risk of injury compared with children without CP (unadjusted HR: 1.2, 95% CI: 1.0 - 1.4, p=0.40). Girls with CP (n=191) had a higher risk of injury compared with girls without CP (29% vs 22%, HR: 1.4, 95% CI: 1.1 to 1.8, p = 0.01). Any comorbidity increased the risk of injury (HR: 1.5, 95% CI: 1.1 to 2.2, p = 0.015) among children with CP. Children with CP had a higher risk of traumatic brain injury (HR: 1.7, 95% CI 1.2 to 2.4, p = 0.002) than children without CP. Conclusion Girls with CP had the highest risk of hospital-treated injury. Children with CP are particularly prone to traumatic brain injuries.
  • Vainio, Lari; Vainio, Martti (2021)
    Recent evidence has shown linkages between actions and segmental elements of speech. For instance, close-front vowels are sound symbolically associated with the precision grip, and front vowels are associated with forward-directed limb movements. The current review article presents a variety of such sound-action effects and proposes that they compose a category of sound symbolism that is based on grounding a conceptual knowledge of a referent in articulatory and manual action representations. In addition, the article proposes that even some widely known sound symbolism phenomena such as the sound-magnitude symbolism can be partially based on similar sensorimotor grounding. It is also discussed that meaning of suprasegmental speech elements in many instances is similarly grounded in body actions. Sound symbolism, prosody, and body gestures might originate from the same embodied mechanisms that enable a vivid and iconic expression of a meaning of a referent to the recipient.