Improvement of head and neck range of motion induced by chronic pallidal deep brain stimulation for cervical dystonia.

BACKGROUND: Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has become an accepted treatment for severe cervical dystonia (CD). Assessment of therapeutic efficacy of DBS mostly focused on head position at rest but hardly on limitations of head and neck mobility, which represent a functionally important impairment in CD. OBJECTIVE: We aimed to determine prospectively head and neck range of motion (ROM) preoperatively and during chronic bilateral GPi DBS in a series of 11 patients with idiopathic CD or segmental dystonia with prominent CD using a computerized motion analysis. METHODS: Maximum horizontal rotation of the head in the transverse plane and lateral inclination in the frontal plane were measured preoperatively and at a median of 7 months of chronic GPi DBS, using an ultrasound-based three-dimensional measuring system combined with surface electromyography of cervical muscles. RESULTS: Horizontal rotation of the head increased from 78.8° ± 31.5° (mean ± SD) preoperatively to 100.7° ± 24.7° with GPi DBS (p < 0.01), thereby improvement of head rotation to the anti-dystonic side (+ 14,2° ± 12,2°) was greater than to the pro-dystonic side (+ 7,8° ± 9,2°; p < 0.05). Movement-related agonistic-antagonistic EMG modulation during head rotation was enhanced with GPi DBS in both sternocleidomastoid (modulation index (MI) 35.8% ± 26.7% preoperatively vs. 67.3% ± 16.9% with GPi DBS, p < 0.01), and splenius capitis muscles (MI 1.9% ± 24.5% preoperatively vs. 44.8% ± 11.6% with GPi DBS, p < 0.01). CONCLUSION: Chronic bilateral GPi DBS significantly improves head ROM in CD, likely due to enhanced agonist-antagonist EMG activity with reduced co-contraction. Computerized motion analysis provides an objective measurement to assess the improvement of head and neck mobility in CD.

Physical activity level in people with age related white matter changes correlates to better motor performance, lower comorbidity and higher cognitive level.

BACKGROUND: Physical activity plays a pivotal role in the development of disability and may modify the negative effect of vascular risk factors on progression of both cardio and cerebrovascular disorders. The aim of this study was to evaluate the activity level in people with age-related white matter changes as identified on magnetic resonance imaging (MRI) in relation to motor performance, cognition and perceived health. METHODS: Data came from the first year follow up of one participating centers of the LADIS study. Fifty one subjects were first enrolled in the study. Complete first year follow up data was available for 41 subjects. Information on comorbidity, physical activity level, physical function, cognition, level of white matter changes and perceived health was collected. Physical activity level was classified with a yes or no question and with the Frenchay Activities Index (FAI). RESULTS: Only 36% of the subjects in this study were physically active according to the yes/no question. 27.5% of the subjects were active according to the FAI score which evaluates the everyday activities. Being active discriminated subjects with better physical function. Subjects active according to the FAI score had a higher cognitive level (p ≤ 0.01), lower comorbidity (p = 0.02) and performed better on all motor function tasks as assessed by walking speed (p ≤ 0.01) and the Short Physical Performance battery (SPPB) (p ≤ 0.01). CONCLUSIONS: Being physically active seems to be a long term protective factor. In our study, the majority of subjects with Age Related White Mattter Changes (ARWMC) with no or mild Instrumental Activity of Daily Living (IADL) disability did not attain recommended level of activity at first year follow up. Whether or not increasing physical activity may slow down cognitive decline and lessen development of disability in physically inactive subjects with manifest ARWC remains to be studied. TRIAL REGISTRATION: not applicable.

Micrographia induced by pallidal DBS for segmental dystonia: a subtle sign of hypokinesia?

Recently parkinsonism has been reported as a rare side effect of globus pallidus internus (GPi) deep brain stimulation (DBS) for dystonia. In the present systematic prospective study in 11 patients with segmental dystonia not affecting distal arm function, we could demonstrate significant changes in handwriting characterized by mild micrographia following GPi-DBS. We propose that this finding reflects GPi-DBS-induced disturbances of basal ganglia function in terms of a mild hypokinetic syndrome, as a result of outflow alterations in pallido-thalamo-cortical pathways.

Chronic deep brain stimulation for segmental dystonia.

Fourteen consecutive patients with segmental dystonia underwent chronic deep brain stimulation (DBS) surgery in the frame of a prospective study protocol. Twelve patients received chronic pallidal stimulation, while 2 patients with prominent dystonic tremor received chronic thalamic ventrointermediate nucleus stimulation. Twelve patients had primary dystonia, and 2 patients secondary dystonia. The Burke-Fahn-Marsden dystonia rating scale (BFM motor) showed a mean relative improvement of 57.3% at the first follow-up (FU1, mean 7 months) and 57.8% at the second follow-up (FU2, mean 16 months). The mean BFM scores were 34.9 +/- 17.7 preoperatively, 14.9 +/- 11.7 at FU1, and 14.8 +/- 10.3 at FU2. Scores of the disability subscale improved by 43% at FU1 and 36% at FU2. Improvement was comparatively less in those patients with secondary dystonia. Dysarthria was a limitation of DBS in 4 patients when using high voltage. Overall, chronic DBS is a very effective treatment option for medically refractory segmental dystonia.

Sparse decomposition and modeling of anatomical shape variation.

Recent advances in statistics have spawned powerful methods for regression and data decomposition that promote sparsity, a property that facilitates interpretation of the results. Sparse models use a small subset of the available variables and may perform as well or better than their full counterparts if constructed carefully. In most medical applications, models are required to have both good statistical performance and a relevant clinical interpretation to be of value. Morphometry of the corpus callosum is one illustrative example. This paper presents a method for relating spatial features to clinical outcome data. A set of parsimonious variables is extracted using sparse principal component analysis, producing simple yet characteristic features. The relation of these variables with clinical data is then established using a regression model. The result may be visualized as patterns of anatomical variation related to clinical outcome. In the present application, landmark-based shape data of the corpus callosum is analyzed in relation to age, gender, and clinical tests of walking speed and verbal fluency. To put the data-driven sparse principal component method into perspective, we consider two alternative techniques, one where features are derived using a model-based wavelet approach, and one where the original variables are regressed directly on the outcome.

Long-term follow-up of chronic spinal cord stimulation for medically intractable orthostatic tremor.

Orthostatic tremor (OT) is a rare form of tremor occurring in the legs when standing upright. Medical treatment frequently is unsatisfactory, thus in selected cases, surgical treatment, such as spinal cord stimulation (SCS) or thalamic deep brain stimulation has been proposed. We report the long-term results (follow-up (FU) 34-133 months) of SCS in four patients with medically intractable OT. Outcome was assessed by recording the time tolerated to stand still pre- and post-operatively and by a patient self-rating (PSR) scale (0 = poor to 6 = excellent). Furthermore, surface electromyography (EMG) recordings of different leg muscles were performed to estimate tremor activity with and without SCS post-operatively. With chronic SCS, all four patients showed an improvement of unsteadiness occurring in the presence of stimulation-induced paraesthesia of the legs. The mean standing time improved from 51 s (SD 47 s, range 4-120 s) pre-operatively to 220 s (SD 184 s, range 10-480 s) with SCS at last available FU. Tremor activity in the EMG of the anterior tibial muscle was reduced by 30-60 % with SCS compared with off SCS. PSR score was 4 or 5 in three patients and 3 in the other. In conclusion, SCS is an effective long-term treatment option in patients with otherwise intractable OT.

From trepidant abasia to motor network failure--gait disorders as a consequence of subcortical vascular encephalopathy (SVE): review of historical and contemporary concepts.

Gait disorders in progressive subcortical vascular encephalopathy (SVE) and their impact on the burden of disability in the growing elderly population are underrepresented in medical scientific literature. The absence of a clear framework for the diagnosis and classification for gait disorders on the basis of SVE has multiple reasons: (1) neither movement disorder specialists nor stroke specialists are truly familiar with this topic and feel responsible for its treatment, (2) the existing terminology lacks a clear concept and a consistent classification, and (3) only in recent years have large prospective trials started to address the natural course of SVE. This article reviews the classical descriptions of gait disturbances with preferential view to our present concept of SVE, and comments on historical and current nosology of gait disorders aiming to propose for a new classification.

Deep brain stimulation for camptocormia in dystonia and Parkinson's disease.

Camptocormia, or "bent spine syndrome", may occur in various movement disorders such as primary dystonia or idiopathic Parkinson's disease (PD). Although deep brain stimulation (DBS) is an established treatment in refractory primary dystonia and advanced PD, few data are available on the effect of DBS on camptocormia comparing these two conditions. Seven patients (4 with dystonia, 3 with PD; mean age 60.3 years at surgery, range 39-73 years) with camptocormia were included in the study. Five patients underwent bilateral GPi DBS and two patients underwent bilateral STN DBS guided by CT-stereotactic surgery and microelectrode recording. Pre- and postoperative motor assessment included the BFM in the dystonia patients and the UPDRS in the PD patients. Severity of camptocormia was assessed by the BFM subscore for the trunk at the last available follow-up at a mean of 17.3 months (range 9-36 months). There were no surgical complications. In the four patients with dystonia there was a mean improvement of 53% in the BFM motor score (range 41-79%) and of 63% (range 50-67%) in the BFM subscore for the trunk at the last available follow-up (mean 14.3 months, range 9-18 months). In the three patients with camptocormia in PD who underwent bilateral STN DBS (2 patients) or pallidal DBS (1 patient), the PD symptoms improved markedly (mean improvement in the UPDRS motor subscore stimulation on/medication off 55%, range 49-61%), but there was no or only mild improvement of camptocormia in the two patients who underwent STN DBS, and only moderate improvement in the patient with GPi DBS at the last available follow-up (mean 21 months, range 12-36 months). GPi DBS is an effective treatment for camptocormia in dystonia. The response of camptocormia to chronic STN or GPi DBS in PD is more heterogenous. The latter may be due to a variety of causes and needs further clarification.

Ultrasound and arterial wall disease.

Rapid progress in non-invasive ultrasound techniques has resulted in a wide variety of clinical applications for the assessment of cerebrovascular diseases. Recent highlights in ultrasound research include the evaluation of vascular ageing as a degenerative process, the demonstration of plaque development, motion and vulnerability in atherosclerosis and multi-dimensional as well as innovative imaging techniques (e.g., compound imaging) to depict early and small vascular lesions. In addition, echo-contrast agents have been used to compensate for difficulties in visualising late, severe or subtotal obstructive plaques, but failed to be really superior to conventional techniques as evidenced in a prospective, multi-centre trial (Contrast Enhanced Duplex sonography versus Arteriography Studies - CEDAS). With increasing sophistication of ultrasound methodology, it becomes essential to establish standards for data acquisition and interpretation: three consensus meetings have provided detailed recommendations on quantification of carotid atherosclerosis, characterisation of carotid artery plaques and detection of microembolism by transcranial Doppler as a potential indicator of stroke risk.