Behavioural studies indicate that a newly acquired motor skill is rapidly consolidated from an initially unstable state to a more stable state, whereas neuroimaging studies demonstrate that the brain engages new regions for performance of the task as a result of this consolidation. However, it is not known where a new skill is retained and processed before it is firmly consolidated. Some early aspects of motor skill acquisition involve the primary motor cortex (M1), but the nature of that involvement is unclear. We tested the possibility that the human M1 is essential to early motor consolidation. We monitored changes in elementary motor behaviour while subjects practised fast finger movements that rapidly improved in movement acceleration and muscle force generation. Here we show that low-frequency, repetitive transcranial magnetic stimulation of M1 but not other brain areas specifically disrupted the retention of the behavioural improvement, but did not affect basal motor behaviour, task performance, motor learning by subsequent practice, or recall of the newly acquired motor skill. These findings indicate that the human M1 is specifically engaged during the early stage of motor consolidation.

The aim of the study was to evaluate and compare health-related quality of life (HR-QoL) and depression in essential blepharospasm (BSP) and idiopathic cervical dystonia (CD), to identify the clinical and demographic factors associated with poor HR-QoL in both disorders and to analyse the effect of Botulinum Toxin A (BtxA) therapy. Two hundred-twenty consecutive patients with BSP (N = 89, 62 % women, mean age 64 years, mean disease duration 7 years) and CD (N = 131, 64 % women, mean age 53 years, mean disease duration 8 years) recruited from routine referrals to eight Austrian dystonia clinics were included. HR-QoL was measured by the Short Form 36 (SF-36) and depression by the Beck Depression Inventory (BDI). At baseline, patients with CD and BSP scored significantly worse in all eight SF-36 domains compared with an age-matched community sample. In addition, 47 % of patients with CD and 37 % of those with BSP were depressed. Women with BSP scored significantly lower in all SF-36 domains and were more depressed than male patients. In contrast, there was no significant effect of gender on HR-QoL and depression in CD. Neck pain had a significant impact on all SF-36 domains and represented the main determinant of depression in CD. Although BtxA therapy resulted in a significant improvement of clinical symptoms in BSP and CD, HR-QoL did not improve in BSP and only two of the eight SF-36 domains improved significantly in patients with CD. The present study for the first time demonstrated that BSP has a substantial impact on health status emphasizing the need for psychological support with interventions aimed at treating depression in these patients. Our results provide further evidence for the profound impact of CD on HR-QoL and indicate the importance of an adequate management of neck pain in addition to reducing the severity of dystonia in CD. The mismatch between objective BtxA derived improvement of dystonia and lack of change of HR-QoL as determined by the SF-36 illustrates the need for optimized disease specific quality of life rating scales in patients with craniocervical dystonia.

No abstract

The geste antagoniste (moving an arm to the face or head) is a well-known clinical feature in cervical dystonia (CD) to alleviate the abnormal posture. The clinical phenomenology of these manoeuvres has not so far been assessed systematically. Fifty patients with idiopathic CD aware of at least one geste antagoniste (60% women, mean age at onset 44.1 years, mean disease duration 7.5 years) were subjected to a standardized investigation including a semiquantitative clinical rating scale and polymyographic recordings of six cervical muscles. Twenty-seven patients (54%) demonstrated more than one geste antagoniste (range 2-5). A clinically significant (> or = 30%) reduction of head deviation was observed in 41 patients (82 %). Dystonic head posture improved by a mean of 60 % along all planes by the geste manoeuvre with a complete cessation of head oscillations in nine of 33 patients (27 %) with phasic CD. No significant laterality of the "geste-arm" or the facial target area was found. The duration of geste-effects depended significantly on disease duration and determined the patient's self-rating of the benefit of the manoeuvre. EMG-polygraphy revealed two types of geste-induced polymyographic changes: a decrease in recruitment density and amplitude in at least one dystonic muscle (66%), and an increased tonic muscle activation in the remaining patients. The remarkable efficacy of the geste antagoniste and the considerable variety in performance, duration, and EMG-pattern of these manoeuvres warrant further investigation of the therapeutic use of sensorimotor stimulation, in particular for those CD patients who experience limited or no effect from botulinum toxin therapy.

The present study was performed to assess dose-response relationships of local botulinum toxin A (BtxA) treatment in children and teenagers with spastic gait due to cerebral palsy (CP) in a randomized, double-blind study employing a "high-dose" (200 units Botox per leg) and a "low-dose" (100 units Botox per leg) treatment arm in 33 patients with CP. Response parameters included changes in muscle tone assessed by the Ashworth scale at knee joint, range-of-motion (ROM) measurements at knee and ankle joint, objective analysis of longitudinal gait parameters as well as subjective assessments of improvement. Patients in the "high-dose" arm received 40-80 units Botox/muscle versus 20-40 units Botox/muscle in the "low-dose" group. Patients in both treatment arms showed significant improvement of Ashworth score (p<0.001) and ROM (p<0.01), while gait analysis revealed significant increase in gait velocity (p<0.01) and stride-length (p<0.001) over baseline. Subjects in the "high-dose" group showed significantly greater improvement on objective response measurements compared to "low-dose" patients. Also, children aged 7 years or less had greater functional benefit compared to the subgroup of patients older than 7 years. Incidence and severity of side-effects were similar in both treatment groups. The present study demonstrated dose-dependent functional improvement of dynamic deformities and spastic gait pattern in children and young adults with CP treated with local injections of botulinum toxin. A dose of 200 units Botox per leg distributed to 4 or 5 muscle bellies per leg is superior compared to 100 units Botox per leg without significantly affecting the risk of side-effects.