Background
In the aging society, many patients with movement disorders, pain syndromes, or psychiatric disorders who are candidates for deep brain stimulation (DBS) surgery suffer also from ...cardiovascular co-morbidities that require chronic antiplatelet or anticoagulation treatment. Because of a presumed increased risk of intracranial hemorrhage during or after surgery and limited knowledge about perioperative management, chronic antiplatelet or anticoagulation treatment often has been considered a relative contraindication for DBS. Here, we evaluate whether or not there is an increased risk for intracranial hemorrhage or thromboembolic complications in patients on chronic treatment (paused for surgery or bridged with subcutaneous heparin) as compared to those without.
Methods
Out of a series of 465 patients undergoing functional stereotactic neurosurgery, 34 patients were identified who were on chronic treatment before and after receiving DBS. In patients with antiplatelet treatment, medication was stopped in the perioperative period. In patients with vitamin K antagonists or novel oral anticoagulants (NOACs), heparin was used for bridging. All patients had postoperative stereotactic CT scans, and were followed up for 1 year after surgery.
Results
In patients on chronic antiplatelet or anticoagulation treatment, intracranial hemorrhage occurred in 2/34 (5.9%) DBS surgeries, whereas the rate of intracranial hemorrhage was 15/431 (3.5%) in those without, which was statistically not significant. Implantable pulse generator pocket hematomas were seen in 2/34 (5.9%) surgeries in patients on chronic treatment and in 4/426 (0.9%) without. There were only 2 instances of thromboembolic complications which both occurred in patients without chronic treatment. There were no hemorrhagic complications during follow-up for 1 year.
Conclusions
DBS surgery in patients on chronic antiplatelet or anticoagulation treatment is feasible. Also, there was no increased risk of hemorrhage in the first year of follow-up after DBS surgery. Appropriate patient selection and standardized perioperative management are necessary to reduce the risk of intracranial hemorrhage and thromboembolic complications.
Cross-sectional studies have shown an association between the severity of age-related white matter change (ARWMC) and lower body motor function. However, the association between prevalent ARWMC and ...incident deterioration of balance and gait remains insufficiently investigated. This study investigates if the degree of prevalent ARWMC has a differential effect on lower body motor function as it changes over time, hypothesizing that individuals with more severe baseline white matter pathology experience greater clinical deterioration independent of potential confounders. This is of clinical relevance: given the increasing use of neuroimaging, incidental white matter pathology is common; being able to delineate natural trajectories of balance and gait function given ARWMC may improve patient advice and help optimize allocation of care.
639 non-disabled elderly individuals with prevalent ARWMC (grading of severity of ARWMC using the Fazekas scale) were followed up yearly for 3 years, as part of the Leukoaraiosis and Disability Study. The primary outcome variable, reflecting the temporal course of gait and balance function, was the change of scores on the Short Physical Performance Battery (SPPB) over time versus the severity of ARWMC. We used linear mixed modelling to analyse change over time. Explorative analysis was carried out investigating the effect of age on potential deterioration of gait and balance function. We used propensity scores to adjust for multiple confounders that affect both the exposure (i.e. ARWMC) and outcome.
Subjects' lower body motor function deteriorated by 2.6% per year. However, after adjustment for baseline motor impairment and potential confounders, only subjects with moderate -0.22 points per year on the SPPB (equals -2.3%); 95% CI -0.35 to -0.09, p < 0.001 or severe -0.46 points per year (equals -4.7%); 95% CI -0.63 to -0.28, p < 0.0001 ARWMC show a loss of function. Age shows differential effects: relatively younger elderly subjects have similar temporal dynamics in SPPB change independent of their individual degree of ARWMC severity; however, subjects with severe ARWMC and who are older than 75.9 years deteriorate significantly more rapidly than their counterparts with only mild or moderate white matter pathology.
Only moderate and severe ARWMC is independently associated - on average - with a deterioration of gait and balance. Albeit the possibility of unmeasured confounding and other methodological constraints, there is nonetheless evidence of large interindividual variability: some subjects with moderate or severe ARWMC stay stable over time or even show improvement. Furthermore, there is explorative analysis showing that younger elderly subjects may be able to better compensate even severe ARWMC. These individuals' gait and balance function stays relatively stable over time, whereas their older counterparts deteriorate significantly. This may point towards a threshold effect given ARWMC.
Introduction: The treatment of neuropathic and central pain still remains a major challenge. Thalamic deep brain stimulation (DBS) involving various target structures is a therapeutic option which ...has received increased re-interest. Beneficial results have been reported in several more recent smaller studies, however, there is a lack of prospective studies on larger series providing long term outcomes. Methods: Forty patients with refractory neuropathic and central pain syndromes underwent stereotactic bifocal implantation of DBS electrodes in the centromedian–parafascicular (CM–Pf) and the ventroposterolateral (VPL) or ventroposteromedial (VPM) nucleus contralateral to the side of pain. Electrodes were externalized for test stimulation for several days. Outcome was assessed with five specific VAS pain scores (maximum, minimum, average pain, pain at presentation, allodynia). Results: The mean age at surgery was 53.5 years, and the mean duration of pain was 8.2 years. During test stimulation significant reductions of all five pain scores was achieved with either CM–Pf or VPL/VPM stimulation. Pacemakers were implanted in 33/40 patients for chronic stimulation for whom a mean follow-up of 62.8 months (range 3–180 months) was available. Of these, 18 patients had a follow-up beyond four years. Hardware related complications requiring secondary surgeries occurred in 11/33 patients. The VAS maximum pain score was improved by ≥50% in 8/18, and by ≥30% in 11/18 on long term follow-up beyond four years, and the VAS average pain score by ≥50% in 10/18, and by ≥30% in 16/18. On a group level, changes in pain scores remained statistically significant over time, however, there was no difference when comparing the efficacy of CM–Pf versus VPL/VPM stimulation. The best results were achieved in patients with facial pain, poststroke/central pain (except thalamic pain), or brachial plexus injury, while patients with thalamic lesions had the least benefit. Conclusion: Thalamic DBS is a useful treatment option in selected patients with severe and medically refractory pain.
Highlights • First prospective quantitative evaluation of gait changes after GPi DBS. • Finding and detailed description of hypokinetic gait with GPi DBS. • New aspect of altered gait variability.
Abnormalities in the somatosensory system are increasingly being recognized in patients with dystonia. The aim of this study was to investigate whether sensory abnormalities are confined to the ...dystonic body segments or whether there is a wider involvement in patients with idiopathic dystonia. For this purpose, we recruited 20 patients, 8 had generalized, 5 had segmental dystonia with upper extremity involvement, and 7 had cervical dystonia. In total, there were 13 patients with upper extremity involvement. We used Quantitative Sensory Testing (QST) at the back of the hand in all patients and at the shoulder in patients with cervical dystonia. The main finding on the hand QST was impaired cold detection threshold (CDT), dynamic mechanical allodynia (DMA), and thermal sensory limen (TSL). The alterations were present on both hands, but more pronounced on the side more affected with dystonia. Patients with cervical dystonia showed a reduced CDT and hot detection threshold (HDT), enhanced TSL and DMA at the back of the hand, whereas the shoulder QST only revealed increased cold pain threshold and DMA. In summary, QST clearly shows distinct sensory abnormalities in patients with idiopathic dystonia, which may also manifest in body regions without evident dystonia. Further studies with larger groups of dystonia patients are needed to prove the consistency of these findings.
Causal experimental evidence that physical activity prevents disability in older people is sparse. Being physically active has nonetheless been shown to be associated with disability-free survival in ...observational studies. Observational studies are, however, prone to bias introduced by time-dependent confounding. Time-dependent confounding occurs when an exposure (e.g. being physically active at some time-point) potentially affects the future status of a confounder (such as depression sometime later), and both variables have an effect on latter outcome (i.e. disability). "Conventional" analysis with e.g. Cox-regression is the mainstay when analyzing longitudinal observational studies. Unfortunately, it does not provide unbiased estimates in the presence of time-dependent confounding. Marginal structural models (MSM) - a relatively new class of causal models - have the potential to adequately account for time-dependent confounding. Here we analyze the effect of older people being physically active on disability, in a large long-term observational study. We address time-dependent confounding by using marginal structural models and provide a non-technical practical demonstration of how to implement this type of modeling.
Data is from 639 elderly individuals ascertained in the European multi-center Leukoaraiosis and Disability study (LADIS), followed-up yearly over a period of three years. We estimated the effect of self-reported physical activity on the probability to transit to instrumental disability in the presence of a large set of potential confounders. We compare the results of "conventional" modeling approaches to those estimated using marginal structural models, highlighting discrepancies.
A "conventional" Cox-regression-like adjustment for salient baseline confounders signals a significant risk reduction under physical activity for later instrumental disability (OR 0.62, 95% CI 0.44-0.90). However, given MSM estimation, the effect is attenuated towards null (OR 1.00, 95% CI 0.57-1.76).
Contrary to most reports, we did not find that physical activity in older people prevents future instrumental disability, when taking time-dependent confounding into account. This result may be due to the characteristics our particular study population. It is, however, also conceivable that previous evidence neglected the effect of this type of bias. We suggest that analysts of longitudinal observational studies consider marginal structural models as a further modeling approach.
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.
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.
Background: Detection of defective deep brain stimulation (DBS) contacts/electrodes is sometimes challenging. Case Report: We report a patient with Tourette syndrome (TS), who presented with abrupt ...tic increase and mild generalized headache 9 years after DBS implantation. On the suspicion of a hardware defect, a fracture of the DBS electrode and extension lead was ruled out by radiography and standard implantable pulse generator readouts. Further investigation revealed position-dependent modifiable therapeutic impedances, suggesting an impaired contact of the extension lead/adaptor. After replacement normal impedances were recorded, and the patient fully recovered. Discussion: In DBS dysfunction with inconspicuous hardware check, position-dependent defects might be suspected.
Objective Our purpose was to classify the rare entity of spontaneous spinal ischemia with clinical, magnetic resonance-tomographic, and electrophysiological parameters to determine criteria for ...outcome prediction. Methods We analyzed the stroke registry database of the University Hospital Mannheim, Germany, from 2004 to 2010 for patients with a diagnosis of vascular spinal cord ischemia. Results Ten patients were identified (mean age 65 years range 50-83, 5 women). In 5 patients an etiology was found. Spinal diffusion-weighted magnetic resonance imaging revealed acute ischemia in 7 patients at initial imaging and this diagnosis was confirmed during the first week in the remaining 3 patients. Electrophysiological studies showed abnormal motor evoked potentials (MEPs) in 8 patients and abnormal somatosensory evoked potentials (SSEPs) in 7 patients. After rehabilitation, 5 patients had regained walking ability, whereas 5 patients stayed wheelchair bound. All patients with unfavorable outcome (American Spinal Injury Association (ASIA) Impairment score AIS score of ≤C) showed severe pyramidal tract lesions in MEPs during the first week. All patients with normal MEPs had an excellent outcome (AIS of E, P < .05). Conclusions Diffusion-weighted imaging (DWI) is a useful tool to confirm acute spinal ischemia suspected in patients within the first days after symptom onset. Poor outcome was associated with severe electrophysiological abnormalities in MEPs and SSEPs. Normal MEPs were significantly predictive of an excellent prognosis. A multimodal diagnostic approach combining DWI and electrophysiological evaluation facilitates the prediction of the individual clinical outcome.
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