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Background: Pisa syndrome (PS) or lateral axial dystonia is often seen in patients with Parkinson's disease (PD). It is characterized by a marked and reversible lateral flexion of the trunk (LFT) more than 10°., Objective: To assess the effectiveness of a program of postural exercises and assess the effectiveness in term of pattern of muscular hyperactivity., Methods: A total of 6 patients with PD and PS enrolled in the program of 10 sessions of postural exercise (90 min/session). EMG of thoraco-lumbar paraspinal muscles was performed to detect the pattern of muscular hyperactivity. Outcomes were examined using the Unified Parkinson's Disease Rating Scale part II and part III, degree of LFT and Visual Analogues Scale for back pain., Results: EMG showed two patterns of muscular hyperactivity; ipsilateral to the bending side and contralateral to the bending side. The exercise improved the outcomes in both groups. Patients with muscular hyperactivity ipsilateral to the bending side gained more improvements., Conclusion: Our results show that the exercise may be considered as a possible treatment for patients with PD and PS irrespective of the pattern of muscular activation. The effectiveness of exercise differed according to the pattern of muscular activation.

Introduction: Recent studies have suggested that the cerebellum may be involved in the pathophysiology of resting tremor in patients with Parkinson's disease (PD). The aim of the study was to investigate the effects of cerebellar continuous theta burst stimulation (cTBS) on cerebello-thalamo-cortical connectivity and resting tremor in PD patients., Methods: Thirteen PD patients and ten healthy subjects underwent two experimental sessions: (i) 'real' cTBS, delivered over the cerebellar hemisphere and (ii) 'sham' cerebellar cTBS, delivered over the neck muscles. The two sessions were performed at least one week apart. The effects of 'real' and 'sham' cerebellar cTBS were quantified as excitability changes in the contralateral primary motor cortex or as possible changes in resting tremor in the ipsilateral hand. Primary motor cortex excitability was assessed by recording the input/output curve of the motor-evoked potentials from the contralateral first dorsal interosseous muscle., Results: Resting tremor was rated clinically and objectively assessed by means of kinematic techniques. 'Real' cerebellar cTBS, though not 'sham' cerebellar cTBS, reduced the excitability in the contralateral primary motor cortex both in healthy subjects and in patients with PD. There was no significant change in rest tremor severity, as assessed by a clinical examination or kinematic techniques, after either 'real' or 'sham' cerebellar cTBS in patients. Lastly, there was no correlation between individual changes in M1 excitability and clinical or kinematic measures of resting tremor in patients., Conclusion: The cerebello-thalamo-cortical connectivity, as tested by cTBS, is not predominantly involved in the generation of resting tremor in PD., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Introduction: somatosensory temporal discrimination threshold (STDT) measures the ability to perceive two stimuli as being sequential. Altered STDT has been reported in Parkinson's disease (PD). The cerebellum seems to play a role in the pathophysiology of PD, and may consequently be involved in the pathophysiology of STDT abnormalities., Methods: STDT was investigated in fifteen PD patients who underwent real and sham cerebellar continuous theta burst stimulation (cTBS) in the OFF condition. Eight patients underwent a further real cTBS session in ON condition. STDT was measured on both hands before, 5 and 25 min after real and sham cTBS delivered over the cerebellar hemisphere ipsilateral to the more affected side. We controlled the efficacy of our protocol by monitoring primary motor cortex (M1) excitability. Ten healthy subjects acted as control group., Results: STDT values were increased in PD patients in the OFF condition compared with healthy subjects and PD patients in the ON condition. In PD patients OFF condition, real but not sham cerebellar cTBS, significantly reduced STDT values only in the hand ipsilateral to the stimulated cerebellar hemisphere. Cerebellar cTBS also decreased motor evoked potentials (MEP) size in the contralateral M1. When PD patients were tested in the ON condition, cerebellar cTBS failed to modify STDT values., Conclusion: cerebellar cTBS improved STDT values in PD patients exclusively in OFF condition. We hypothesize that cerebellar stimulation partially compensates for increased STDT values only when patients are OFF dopaminergic therapy. This suggests that the cerebellum may act as compensatory system in PD., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

In this study in patients with Parkinson's disease (PD), off and on dopaminergic therapy, with and without L-dopa-induced dyskinesias (LIDs), we tested intermittent theta-burst stimulation (iTBS), a technique currently used for non-invasively inducing long-term potentiation (LTP)-like plasticity in primary motor cortex (M1). The study group comprised 20 PD patients on and off dopaminergic therapy (11 patients without and 9 patients with LIDs), and 14 age-matched healthy subjects. Patients had mild-to-moderate PD, and no additional neuropsychiatric disorders. We clinically evaluated patients using the Unified Parkinson's Disease Rating Scale (UPDRS) and the Unified Dyskinesia Rating Scale (UDysRS). The left M1 was conditioned with iTBS at 80% active motor threshold intensity. Twenty motor evoked potentials (MEPs) were recorded from right first interosseous muscle before and at 5, 15 and 30 min after iTBS. Between-group analysis of variance (ANOVA) testing healthy subjects versus patients with and without LIDs, on and off therapy showed a significant interaction between factors "Group" and "Time". After iTBS, MEP amplitudes in healthy subjects increased significantly at 5, 15 and 30 min (p<0.01 at all time-points) but in PD patients with and without LIDs, on and off therapy, remained unchanged. In PD patients with and without LIDs, on and off therapy iTBS fails to increase MEP responses. This finding suggests lack of iTBS-induced LTP-like plasticity in M1 in PD regardless of patients' clinical features., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Whereas numerous studies document the effects of dopamine medication and deep brain stimulation on motor function in patients with Parkinson's disease, few have investigated deep brain stimulation-induced changes in sensory functions. In this study of 13 patients with Parkinson's disease, we tested the effects of deep brain stimulation on the somatosensory temporal discrimination threshold. To investigate whether deep brain stimulation and dopaminergic medication induce similar changes in somatosensory discrimination, somatosensory temporal discrimination threshold values were acquired under four experimental conditions: (i) medication ON/deep brain stimulation on; (ii) medication ON/deep brain stimulation off; (iii) medication OFF/deep brain stimulation on; and (iv) medication OFF/deep brain stimulation off. Patients also underwent clinical and neuropsychological evaluations during each experimental session. Somatosensory temporal discrimination threshold values obtained in patients were compared with 13 age-matched healthy subjects. Somatosensory temporal discrimination threshold values were significantly higher in patients than in healthy subjects. In patients, somatosensory temporal discrimination threshold values were significantly lower when patients were studied in medication ON than in medication OFF conditions. Somatosensory temporal discrimination threshold values differed significantly between deep brain stimulation on and deep brain stimulation off conditions only when the patients were studied in the medication ON condition and were higher in the deep brain stimulation on/medication ON than in the deep brain stimulation off/medication ON condition. Dopamine but not subthalamic nucleus deep brain stimulation restores the altered somatosensory temporal discrimination in patients with Parkinson's disease. Deep brain stimulation degrades somatosensory temporal discrimination by modifying central somatosensory processing whereas dopamine restores the interplay between cortical and subcortical structures.

We investigated abnormal premotor to motor (PMd-to-M1) connectivity in Parkinson's disease (PD) with repetitive transcranial magnetic stimulation (rTMS). We studied 28 patients off and on dopaminergic therapy and 28 healthy subjects. We delivered 5 Hz rTMS over M1 before and after conditioning PMd with 5 Hz rTMS. In healthy subjects, motor-evoked potentials (MEPs) elicited by M1-rTMS were facilitated and PMd-rTMS left MEPs unchanged. In patients, before PMd-rTMS, M1-rTMS induced no MEP facilitation, whereas after PMd-rTMS, it significantly facilitated MEPs only when patients were on therapy. In the second experiment, we delivered M1-rTMS under 3 different attention-demanding tasks: eyes closed, attention directed to the stimulated hand, and attention directed to the nonstimulated hand. In healthy subjects, a more pronounced MEP facilitation was present when subjects directed attention to the stimulated hand. In patients, the MEP facilitation was present when attention was directed to the stimulated hand only when patients were on therapy. Finally, we delivered M1-rTMS in patients on therapy while they were looking at the stimulated hand, before and after 1 Hz PMd-rTMS. PMd-rTMS reduced the attention-induced MEP facilitation. We conclude that in addition to abnormal M1 plasticity, the reduced MEP facilitation in PD also reflects altered PMd-to-M1 connectivity.

Unilateral STN-DBS significantly improves the performance of contralateral sequential arm movements. Whether unilateral STN-DBS also improves ipsilateral sequential movement is unclear. In this study in unmedicated parkinsonian patients, we tested the effect of unilateral STN-DBS on the performance of ipsilateral sequential movements and compared it with the performance of contralateral sequential movements. Three-dimensional movements were recorded with the ELITE system and three kinematic variables were considered: total movement time (TMT), total inter-onset latency (IOL), and spatial accuracy. Unilateral STN-DBS significantly decreased TMT in the contralateral arm and only tended to do so also in the ipsilateral arm, whereas it significantly decreased IOL and worsened spatial accuracy only on the contralateral side. Before unilateral STN-DBS a positive correlation was present between the clinical impairment and the TMTs in the contralateral and ipsilateral sides. After unilateral STN-DBS the UPDRS scores improved in the contralateral and to a lesser extent also in the ipsilateral side. Correlation analysis between clinical and kinematic data showed no differences between the contralateral and ipsilateral sides. Our kinematic findings show that after STN-DBS parkinsonian patients' performance of a sequential motor task improves significantly on the contralateral but only tended to do so on the ipsilateral side. Ipsilateral changes can be explained by the observation that the output structures of the basal ganglia send large ipsilateral and less dense contralateral projections to the thalamus., ((c) 2007 Movement Disorder Society.)

In Parkinson's disease, unilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN), unlike bilateral stimulation, excludes ipsilateral confounding effects so that the contralateral effects of DBS on motor performance can be investigated alone. Because no kinematic study has yet investigated how unilateral STN-DBS affects the performance of a contralateral fast sequential motor act, we performed a kinematic analysis of the movement duration, switching time and spatial accuracy of a motor arm sequence in 10 parkinsonian patients. Patients were studied without dopaminergic therapy and when they were OFF and ON unilateral STN-DBS. We found that unilateral STN-DBS significantly improved movement time of a motor sequence and the switching time from one sequential step to the next, whereas accuracy deteriorated. We conclude that unilateral STN-DBS improves the performance of contralateral sequential arm movements in patients with Parkinson's disease.