Does Temporary Externalization of Electrodes After Deep Brain Stimulation Surgery Result in a Higher Risk of Infection?

OBJECTIVES: Deep brain stimulation (DBS) is a well-established surgical therapy for movement disorders that comprises implantation of stimulation electrodes and a pacemaker. These procedures can be performed separately, leaving the possibility of externalizing the electrodes for local field potential recording or testing multiple targets for therapeutic efficacy. It is still debated whether the temporary externalization of DBS electrodes leads to an increased risk of infection. We therefore aimed to assess the risk of infection during and after lead externalization in DBS surgery. MATERIALS AND METHODS: In this retrospective study, we analyzed a consecutive series of 624 DBS surgeries, including 266 instances with temporary externalization of DBS electrodes for a mean of 6.1 days. Patients were available for follow-up of at least one year, except in 15 instances. In 14 patients with negative test stimulation, electrodes were removed. All kinds of infections related to implantation of the neurostimulation system were accounted for. RESULTS: Overall, infections occurred in 22 of 624 surgeries (3.5%). Without externalization of electrodes, infections were noted after 7 of 358 surgeries (2.0%), whereas with externalization, 15 of 252 infections were found (6.0%). This difference was significant (p = 0.01), but it did not reach statistical significance when comparing groups within different diagnoses. The rate of infection with externalized electrodes was highest in psychiatric disorders (9.1%), followed by Parkinson's disease (7.3%), pain (5.7%), and dystonia (5.5%). The duration of the externalization of the DBS electrodes was comparable in patients who developed an infection (6.1 ± 3.1 days) with duration in those who did not (6.0 ± 3.5 days). CONCLUSIONS: Although infection rates were relatively low in our study, there was a slightly higher infection rate when DBS electrodes were externalized. On the basis of our results, the indication for electrode externalization should be carefully considered, and patients should be informed about the possibility of a higher infection risk when externalization of DBS electrodes is planned.

Microelectrode recording and hemorrhage in functional neurosurgery: a comparative analysis in a consecutive series of 645 procedures.

OBJECTIVE: Functional stereotactic neurosurgery including deep brain stimulation (DBS) and radiofrequency lesioning is well established and widely used for treatment of movement disorders and various other neurological and psychiatric diseases. Although functional stereotactic neurosurgery procedures are considered relatively safe, intracranial hemorrhage resulting in permanent neurological deficits may occur in 1%-3% of patients. Microelectrode recording (MER) has been recognized as a valuable tool for refining the final target in functional stereotactic neurosurgery. Moreover, MER provides insight into the underlying neurophysiological pathomechanisms of movement disorders and other diseases. Nevertheless, there is an ongoing controversy on whether MER increases the risk for hemorrhage. The authors aimed to compare the risk of hemorrhage in functional stereotactic neurosurgical procedures with regard to the use of MER. METHODS: The authors performed a comparative analysis on a consecutive series of 645 functional neurosurgery procedures, including 624 DBS surgeries and 21 radiofrequency lesionings, to evaluate whether the use of MER would increase the risk for hemorrhage. MER was performed in 396 procedures, while no MER was used in 249 cases. The MER technique involved the use of a guiding cannula and a single trajectory when feasible. Postoperative CT scans were obtained within 24 hours after surgery in all patients and screened for the presence of hemorrhage. RESULTS: Twenty-one intracranial hemorrhages were detected on the postoperative CT scans (3.2%). Of the 21 intracranial hemorrhages, 14 were asymptomatic and 7 were symptomatic. Symptoms were transient except in 1 case. There was no statistically significant correlation between hemorrhage and the use of MER at any site (subdural, ventricle, trajectory, target, whether asymptomatic or symptomatic). There were 4 cases of symptomatic hemorrhage in the MER group (1%) and 3 cases in those without MER (1.2%). CONCLUSIONS: Intraoperative MER did not increase the overall risk of hemorrhage in the authors' experience using primarily a single MER trajectory and a guiding cannula.

Long-term outcome of patients with vaccine-induced immune thrombotic thrombocytopenia and cerebral venous sinus thrombosis.

We present the long-term outcomes of 44 patients who developed cerebral venous sinus thrombosis after vaccination with the adenoviral vector ChAdOx1 nCoV-19 COVID-19 vaccine. Assessment of the Extended Glasgow Outcome Scale was performed within 3-6 months after the initial hospital admissions. Patient outcomes ranged from good recovery (13 patients, 29.6%) to moderate disability (11 patients, 25.0%) and severe disability or vegetative state (6 patients, 13.6%). Fatal outcomes were reported in 14 patients (31.8%).

Are Transventricular Approaches Associated With Increased Hemorrhage? A Comparative Study in a Series of 624 Deep Brain Stimulation Surgeries.

BACKGROUND: Deep brain stimulation (DBS) surgery has advanced tremendously, for both clinical applications and technology. Although DBS surgery is an overall safe procedure, rare side effects, in particular, hemorrhage, may result in devastating consequences. Although there are certain advantages with transventricular trajectories, it has been reasoned that avoidance of such trajectories would likely reduce hemorrhage. OBJECTIVE: To investigate the possible impact of a transventricular trajectory as compared with a transcerebral approach on the occurrence of symptomatic and asymptomatic hemorrhage after DBS electrode placement. METHODS: Retrospective evaluation of 624 DBS surgeries in 582 patients, who underwent DBS surgery for movement disorders, chronic pain, or psychiatric disorders. A stereotactic guiding cannula was routinely used for DBS electrode insertion. All patients had postoperative computed tomography scans within 24 hours after surgery. RESULTS: Transventricular transgression was identified in 404/624 DBS surgeries. The frequency of hemorrhage was slightly higher in transventricular than in transcerebral DBS surgeries (15/404, 3.7% vs 6/220, 2.7%). While 7/15 patients in the transventricular DBS surgery group had a hemorrhage located in the ventricle, 6 had an intracerebral hemorrhage along the electrode trajectory unrelated to transgression of the ventricle and 2 had a subdural hematoma. Among the 7 patients with a hemorrhage located in the ventricle, only one became symptomatic. Overall, a total of 7/404 patients in the transventricular DBS surgery group had a symptomatic hemorrhage, whereas the hemorrhage remained asymptomatic in all 6/220 patients in the transcerebral DBS surgery group. CONCLUSION: Transventricular approaches in DBS surgery can be performed safely, in general, when special precautions such as using a guiding cannula are routinely applied.

Case report: Pallidal deep brain stimulation for treatment of tardive dystonia/dyskinesia secondary to chronic metoclopramide medication.

Objectives: Tardive dystonia/dyskinesia (TDD) occurs as a side effect of anti-dopaminergic drugs, including metoclopramide, and is often refractory to medication. While pallidal deep brain stimulation (DBS) has become an accepted treatment for TDD secondary to neuroleptic medication, there is much less knowledge about its effects on metoclopramide-induced TDD. Methods: We present the case of a woman with metoclopramide-induced TDD, whose symptoms were initially misjudged as "functional." After 8 years of ineffective medical treatments, she received bilateral implantation of quadripolar electrodes into the posteroventral lateral globus pallidus internus (GPi). Results: GPi DBS led to significant symptom reduction [Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) motor score 24/44 at admission and 7/44 at discharge]. Chronic stimulation led to full recovery from TDD symptoms 9 years after surgery. The BFMDRS motor score decreased to 0.5 (98% improvement). Discussion: Pallidal DBS may result in sustained improvement of TDD secondary to chronic metoclopramide intake in the long term.

Deep brain stimulation in patients on chronic antiplatelet or anticoagulation treatment.

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.

Centromedian-Parafascicular and Somatosensory Thalamic Deep Brain Stimulation for Treatment of Chronic Neuropathic Pain: A Contemporary Series of 40 Patients.

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.

Body weight gain in patients with bilateral deep brain stimulation for dystonia.

In patients with Parkinson's disease, significant weight gain following chronic deep brain stimulation (DBS) has been reported. Recently, relevant weight gain could be demonstrated also following subthalamic nucleus DBS in patients with primary cervical dystonia. Prospective analyses of body weight changes following DBS in patients with dystonia, however, have not been published so far. We aimed to analyse the changes of body weight following DBS in patients with dystonia. The body mass index (BMI) of 17 consecutive patients with segmental or generalised dystonia (mean age 54.6 ± 16.1 years) treated with bilateral DBS of the globus pallidus internus (GPi) (n = 14) or the thalamic ventral intermediate nucleus (n = 3) was measured preoperatively (pre-OP) and at three follow-up (FU) time points post-DBS surgery (FU1 = 7 months, FU2 = 17 months, FU3 = 72 months). All patients benefited from marked improvement in their dystonia. The mean BMI pre-OP (SD) was 22.5 (±3.7) kg/m(2) and increased stepwise to 24.0 (±3.3) kg/m(2) at FU1, 24.4 (±3.7) kg/m(2) at FU2 and 24.9 (±3.7) kg/m(2) at FU3 (p < 0.05 at all three FUs compared to pre-OP). Relative BMI increase and improvement of dystonia were correlated (p = 0.025). Chronic bilateral GPi DBS in patients with dystonia is associated with significant body weight gain, in particular during the first 6 months post-OP. This probably is a result of improvement of dystonic motor symptoms and recovery of eating dysfunction rather than a target-specific phenomenon.

Phenotypic ASCO Characterisation of Young Patients with Ischemic Stroke in the Prospective Multicentre Observational sifap1 Study.

BACKGROUND: The prospective, multinational European 'Stroke in Young Fabry Patients' (sifap1) study collected 4,467 patients with acute ischemic cerebrovascular events aged 18-55 years. Initially, aetiologic subtyping was performed using the TOAST classification; however, recently the phenotypic ASCO classification was presented and might be more useful to identify stroke aetiologies in young patients with a wide set of different causes. ASCO is a classification system divided in four etiologic categories (Atherosclerosis, Small vessel disease (SVD), Cardiac embolism, Other cause) with different grades of severity (1-3) and aims to characterise patients in a more comprehensive way. METHODS: We determined the ASCO score for each patient, according to prospectively collected data using the study protocol. The distribution of aetiologies was analysed with regard to concomitant causes, cryptogenic stroke and different age groups. RESULTS: A potentially causal aetiology (grade 1) was detected in 29.3% of 4,467 patients. Merging grades 1 and 2, a suspected aetiology was found in 54.1%. In 8.6% of patients concomitant aetiologies were identified. Most common causes were cervical arterial dissection and persistent foramen ovale, but there was also a high prevalence of large artery atherosclerosis and SVD especially in older patients of this collective. About 50% of patients had more than one finding with a lower grade of evidence (grade 3). In 14% final classification of strictly cryptogenic stroke was made. CONCLUSIONS: This is the largest study to date, using the ASCO characterisation of ischemic stroke aetiologies. ASCO classification provides first evidence that many young patients presenting with acute stroke have concomitant stroke aetiologies associated with a substantial atherosclerosis risk profile. ASCO could be integrated in clinical routine and registry data banks, as well as large clinical trials to improve stroke documentation.

Asymptomatic and symptomatic carotid stenosis: an obsolete classification?

Since many years, clinical decisions about the management of patients with carotid stenosis have been based on the distinction between "asymptomatic" and "symptomatic" presentations. This was also reflected by the design of previous studies on the surgical versus conservative treatment and of current studies on interventional treatment versus surgery. Both terms, however, only address different phases of activity of the one and the same condition and blur the significant message that carotid stenosis is a most important marker of systemic atherosclerosis, which is accompanied by a much higher risk of cardiovascular events rather than stroke. As a consequence, early diagnosis and followup during best medical treatment, life-style management, regular cardiovascular assessment, and good control of all vascular risk factors should be recommended in all patients with carotid stenosis-whether identified in the long-lasting "silent" or short-lasting "vulnerable" period lasting only a few weeks after cerebral ischemia. Patients in this short time window benefit from additional carotid intervention, under the condition of an individually favorable benefit-risk ratio ("individual vulnerability").

Ischemic stroke in young adults: classification and risk factors.

Our aim was to analyze an important subgroup represented by young adult patients (19-45 years) with acute ischemic stroke according to stroke classification (including the novel ASCO score), infarct types and risk factors. All patients up to 45 years of age with an acute ischemic stroke confirmed by MRI and treated in our stroke unit from 2006 to 2009 were recruited for this study. Patients were neurologically examined and underwent thorough stroke work-up. One hundred four patients (58 women, 46 men) with a mean age of 38 ± 6.9 years were evaluated. The mean NIHSS score (±SD) was 3 ± 5 on admission and 1 ± 4 on discharge. The classification using TOAST/ASCO (grade 1) was as follows: Macroangiopathic 10.6%/8.7%, cardiac origin 21.2%/10.6%, microangiopathic 9.6%/9.6%, other causes 19.2%/13.5% and undetermined 39.4%/19.2% (for A0S0C0O0). The most common risk factors were smoking (55.2%), hypertension (31.4%) and hyperlipidemia (27.6%). Twenty nine of 74 patients with TEE (39.2%) had a patent foramen ovale (PFO). Hypoplastic posterior circulation (21.9%) and migraine (21.0%) were also quite common. Young adult ischemic stroke patients share many of the characteristic risk factors with the general elderly ischemic stroke population. If regular work-up includes TEE, a high percentage of young patients reveal comorbidities with PFO, hypoplasia of the posterior circulation and migraine. The ASCO classification should be favored for a better classification of coexisting stroke subtypes and lower number of undetermined etiologies in this patient group.

Gender differences in acute ischemic stroke: etiology, stroke patterns and response to thrombolysis.

BACKGROUND AND PURPOSE: Differences between women and men in relation to stroke are increasingly being recognized. METHODS: From July 2004 until June 2007, 237 acute ischemic stroke (AIS) patients were treated with recombinant tissue plasminogen activator (rtPA) within 3 hours after onset of symptoms in our stroke unit. Baseline characteristics, etiology, CT/MRI stroke patterns, clinical outcome, and complications of women were compared to those of men. RESULTS: Of 237 AIS patients (mean age 70.7 years), 111 (46.8%) were women and 126 (53.2%) were men. Women were older (P=0.001), but history of hyperlipidemia (P=0.03), smoking (P=0.03), and coronary heart disease (P<0.001) was less frequent than in men. Internal carotid artery disease occurred more often in men (P=0.02), whereas atrial fibrillation was observed more often in women (P=0.002). In men borderzone/small embolic and lacunar stroke was found more frequently (39.7 versus 27.2%), whereas women showed a higher percentage of large territorial stroke (72.8 versus 60.3%, P=0.09). Baseline National Institute of Health Stroke Scale scores (12.5 versus 11.3), NIHSS score at discharge (11.0 versus 9.5), 3-month-outcome modified Rankin Scale score, thrombolysis-related (17.1% versus 13.5%) or independent complications (32.4% versus 30.2%), and mortality after 3 months (13.5% versus 9.5%) were similar. CONCLUSIONS: Differences of stroke lesion patterns in genders are paralleled by differences in etiology and risk factor profiles (women, cardioembolism; men, large and small vessel disease). Baseline characteristics, rates of rtPA-related and independent complications, as well as clinical outcomes were not different between women and men with AIS.