“Twiddler syndrome” in two patients with deep brain stimulation

Twiddler syndrome occurs when a patient intentionally or unintentionally manipulates an implantable generator (usually a pacemaker) and dislodges the pacing leads, causing malfunction of the device. Though the syndrome has been described in patients with pacemakers, to our knowledge only one spontaneous case has been described in patients undergoing deep brain stimulation for movement disorders. We report the clinical cases of two patients with Parkinson’s disease who had subthalamic bilateral electrodes implanted and presented the twiddler syndrome 2 and 3 years after surgery. We analysed the possible mechanisms of this syndrome and note that twiddler syndrome should be suspected in patients undergoing deep brain stimulation and showing hardware dysfunction.     

Double electrodes simultaneous stimulation and implantation technique in deep brain stimulation

Posttraumatictremorisoftenoneofthecausesofdisabilityinheadinjurypatients.Usually,pharmacotherapyforthistypeoftremorisnoteffective.Sinceearly1970s,surgicalablationoftheventralthalamushasbeenusedtotreatvarioustypesof tremor.1Nowadays,deepbrainstimulation(DBS)confirmsitsefficacyinalleviatingdifferentformsof tremor,includingposttraumatictremor.2,3Such therapyhasbeenreportedachievingaround80%successrateinthetreatmentofposttraumatictremor.4Thesesuccessfulresultssuggestthattheapplicationof DBSther…     

Stereotactic neurosurgery for disabling tremor in multiple sclerosis: thalamotomy or deep brain stimulation?

Disabling tremor is common in multiple sclerosis and up to 75% of patients experience tremor at some point during their disease. The treatment of this tremor, however, remains challenging. Pharmacotherapy in general has been disappointing and stereotactic neurosurgery is becoming increasingly popular. However, the results of stereotactic treatments reported are variable and no systematic review has been performed. The aim of this study was to assess the role of thalamotomy and deep brain stimulation in the treatment of tremor in multiple sclerosis, and to compare the differences in efficacy and safety between the two techniques. We identified the relevant published studies and cases by searching the MEDLINE, EMBASS and the references lists of related articles, and performed a systematic review and assessment of the full texts of all articles selected. Initial tremor suppression was seen in 93.8% of patients who had thalamotomy and 96% in those who had deep brain stimulation. A total of 63.5% of patients had persistent tremor suppression at 12 months or more after thalamotomy. Twelve results for deep brain stimulation were not available in the reviewed literature. Functional improvement was seen only in 47.8% of those who underwent thalamotomy as opposed to 85.2% of those who had deep brain stimulation. While three of the four reported deaths were in patients who underwent thalamotomy, three of the four procedure-related haemorrhages followed DBS. Other common adverse effects like hemiparesis, dysarthria, swallowing difficulties, balance disorder, etc., was reported in both procedures. Numerous studies have attempted to assess the efficacy and safety of thalamotomy and DBS in the treatment of MS tremor, but no standardized outcome measures were used. Nonetheless, the data suggest that both thalamotomy and thalamic DBS are comparable procedures for tremor suppression and that adverse effects can occur with both procedures.     

Are complications less common in deep brain stimulation than in ablative procedures for movement disorders?

The side effects and complications of deep brain stimulation (DBS) and ablative lesions for tremor and Parkinson's disease were recorded in 256 procedures (129 DBS and 127 lesions). Perioperative complications (seizures, haemorrhage, confusion) were rare and did not differ between the two groups. The rate of hardware-related complications was 17.8%. In ventral intermediate (Vim) thalamotomies, the rate of side effects was 74.5%, in unilateral Vim-DBS 47.3%, while in 7 bilateral Vim-DBS 13 side effects occurred. Most of the side effects of Vim-DBS were reversible upon switching off, or altering, stimulation parameters. In unilateral pallidotomy, the frequency of side effects was 21.9%, while in bilateral staged pallidotomies it was 33.3%. Eight side effects occurred in 11 procedures with pallidal DBS. In 22 subthalamic nucleus DBS procedures, 23 side effects occurred, of which 8 were psychiatric or cognitive. Unilateral ablative surgery may not harbour more postoperative complications or side effects than DBS. Some of the side effects following lesioning are transient and most but not all DBS side effects are reversible. In the Vim DBS is safer than lesioning, while in the pallidum, unilateral lesions are well tolerated.     

Does deep brain stimulation improve lower urinary tract symptoms in Parkinson's disease?

Aims

To investigate whether deep brain stimulation (DBS) of the globus pallidus pars interna (GPi) or the subthalamic nucleus (STN) improve lower urinary tract symptoms (LUTS) in advanced Parkinson's disease (PD).

Methods

An exploratory post‐hoc analysis was performed of specific LUTS items of questionnaires used in a randomized clinical trial with 128 patients (NSTAPS study). First, we compared scores on LUTS items at baseline and 12 months for the GPi DBS and STN DBS group separately. Second, we divided the group by sex, instead of DBS location; to assess a possible gender associated influence of anatomical and pathophysiological differences, again comparing scores at baseline and 12 months. Third, we reported on Foley‐catheter use at baseline and after 12 months.

Results

Urinary incontinence and frequency improved after both GPi DBS and STN DBS at 12 months, postoperatively, but this was only statistically significant for the STN DBS group (P = 0.004). The improvements after DBS were present in both men (P = 0.01) and women (P = 0.05). Nocturia and urinary incontinence did not improve significantly after any type of DBS, irrespective of sex. At 12 months, none of the patients had a Foley‐catheter.

Conclusions

Urinary incontinence and frequency significantly improved after STN DBS treatment in male and female patients with PD. Nocturia and nighttime incontinence due to parkinsonism did not improve after DBS, irrespective of gender.     

Tremor reduction and quality of life after deep brain stimulation for multiple sclerosis–associated tremor

Background

Tremor is an important cause of disability and poor quality of life amongst multiple sclerosis (MS) patients. We assessed the outcomes of ventral intermediate (VIM) nucleus deep brain stimulation for the treatment of multiple sclerosis (MS)–associated tremor at a single centre in a prospective fashion.

Methods

Sixteen patients (9 female, 7 male) with a mean age of 41.7 years (range 24–59) underwent surgery. The median duration of MS prior to surgery was 6.5 years and median duration of tremor prior to surgery was 4 years. Case selection was by multidisciplinary assessment with carers, therapists, neurosurgeons and movement disorder neurologists. Tremor was scored pre-operatively and at 6 to 12 months post operatively using Bain and/or Fahn–Tolosa–Marin systems. The Euro-Qol 5D tool was used to assess quality of life before and after surgery.

Results

The mean tremor reduction was 39 % with a range between 0 and 87 %. Five of 16 patients achieved at least 50 % tremor reduction and 11 of 16 achieved at least 30 % tremor reduction at last follow up, mean 11.6 months (range 3–80). Tremor was significantly reduced as rated by Bain scores (Wilcoxon matched pairs, Z?=?3.07, p?=?.002) and tended to significance as rated by Fahn scores (Wilcoxon matched pairs, Z?=?1.85, p?=?0.06). Sub-analysis of activities of daily living measures from the Fahn system showed post operative improvement in feeding (statistically significant), hygiene, dressing, writing and working. Mean visual analogue scores (0–100) of patient reported well-being increased from 54.6 to 57.4 post operatively with a trend to significance (Student’s t-test, t?=?1.26, p?=?0.2). Euro-Qol 5D utility values increased following surgery with a trend to significance which was greater in the group with at least 50 % tremor reduction than in those with none or at least 30 % tremor reduction.

Conclusions

VIM DBS may reduce severe, disabling tremor in patients with MS. This tremor reduction tends to be associated with improved quality of life and function in those who respond. Patient reported outcome measures may not correlate with physician rated clinical outcome such as tremor scoring systems and more subtle assessment of these patients is required.     

Two-step tunneling technique of deep brain stimulation extension wires—a description

Introduction

While a significant body of literature exists on the intracranial part of deep brain stimulation surgery, the equally important second part of the intervention related to the subcutaneous tunneling of deep brain stimulation extension wires is rarely described. The tunneling strategy can consist of a single passage of the extension wires from the frontal incision site to the subclavicular area, or of a two-step approach that adds a retro-auricular counter-incision. Each technique harbors the risk of intraoperative and postoperative complications.

Method

At our center, we perform a two-step tunneling procedure that we developed based on a cadaveric study.

Results

In 125 consecutive patients operated since 2002, we did not encounter any complication related to our tunneling method.

Conclusion

Insufficient data exist to fully evaluate the advantages and disadvantages of each tunneling technique. It is of critical importance that authors detail their tunneling modus operandi and report the presence or absence of complications. This gathered data pool may help to formulate a definitive conclusions on the safest method for subcutaneous tunneling of extension wires in deep brain stimulation.     

Perfusion brain SPECT in assessing motor improvement after deep brain stimulation in Parkinson’s disease

Background

High-frequency deep brain stimulation (DBS) of the subthalamic nucleus (STN) has become an established therapeutic approach for the management of patients with late-stage idiopathic Parkinson’s disease (PD). The aim of the present study was to assess regional cerebral blood flow (rCBF) changes related to motor improvement.

Methods

Twenty-one PD patients underwent two rCBF SPECT studies at rest, once preoperatively in the off-meds state and the other postoperatively (at 6?±?2 months) in the off medication/on stimulation state. Patients were classified according to the UPDRS and H&Y scale. NeuroGam software was used to register, quantify, and compare two sequential brain SPECT studies of the same patient in order to investigate rCBF changes during STN stimulation in comparison with preoperative rCBF. The relationship between rCBF and UPDRS scores was used as a covariate of interest.

Results

Twenty patients showed clinical improvement during the first months after surgery, resulting in a 44 % reduction of the UPDRS motor score. The administered mean daily levodopa dose significantly decreased from 850?±?108 mg before surgery to 446?±?188 mg during the off-meds state (p?<?0.001, paired t test). At the 6-month postoperative assessment, we noticed rCBF increases in the pre-supplementary motor area (pre-SMA) and the premotor cortex (PMC) (mean rCBF increase = 10.2 %, p?<?0.05), the dorsolateral prefrontal cortex and in associative and limbic territories of the frontal cortex (mean rCBF increase = 8.2 %, p?>?0.05). A correlation was detected between the improvement in motor scores and the rCBF increase in the pre-SMA and PMC (r?=?0.89, p?<?0.001).

Conclusions

Our study suggests that STN stimulation leads to improvement in neural activity and rCBF increase in higher-order motor cortical areas.     

Staged bilateral deep brain stimulation of the subthalamic nucleus for the treatment of Parkinson’s disease

Background  Several investigators have described the efficacy and safety of unilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) for the treatment of Parkinson’s disease (PD). Some patients who underwent unilateral STN DBS required additional surgery on the contralateral side because the unilateral treatment was insufficient. The goal of this study was to assess the efficacy and safety of staged bilateral STN DBS compared to the simultaneous bilateral procedure. Methods  Ten patients with medically intractable PD underwent staged bilateral STN DBS, and 12 patients underwent a simultaneous bilateral procedure. Clinical assessments were performed preoperatively and 6 months after the last surgery using the Unified Parkinson’s Disease Rating Scale (UPDRS), motor and activity of daily living (ADL) subscores, and Hoehn and Yahr stages. Findings  Both the staged and simultaneous groups experienced significant improvement in the UPDRS motor and ADL scores, and the Hoehn and Yahr stages. There were no statistical differences between the two groups in the percent improvement in UPDRS scores. The rate of adverse events in the staged group (20%) was less than that of the simultaneous group (42%), although the difference was not statistically significant. Conclusions  Both the staged bilateral STN DBS and the simultaneous bilateral procedure are effective and safe treatment options, but the staged bilateral procedure may be regarded as the preferred choice for the treatment of some patients. No financial support was received for this research. The findings presented herein have not been previously published.     

Thalamic deep brain stimulation for post-traumatic neuropathic limb pain: Efficacy at five years’ follow-up and effective volume of activated brain tissue

Chronic neuropathic pain affects 7%–10% of the population. Deep brain stimulation (DBS) has shown variable but promising results in its treatment. This study prospectively assessed the long-term effectiveness of DBS in a series of patients with chronic neuropathic pain, correlating clinical results with neuroimaging. Sixteen patients received 5 years’ post-surgical follow-up in a single center. Six had phantom limb pain after amputation and 10 had deafferentation pain after traumatic brachial plexus injury. Patient-reported outcome measures were completed before and after surgery, using VAS, UWNPS, BPI and SF-36 scores. Neuroimaging evaluated electrode location and effective volumes of activated tissue (VAT). Two subgroups were created based on the percentage of VAT superimposed upon the ventroposterolateral thalamic nucleus (eVAT), and clinical outcomes were compared. Analgesic effect was assessed at 5 years and compared to preoperative pain, with an improvement on VAS of 76.4% (p = 0.0001), on UW-NPS of 35.2% (p = 0.3582), on BPI of 65.1% (p = 0.0505) and on SF-36 of 5% (p = 0.7406). Eight patients with higher eVAT showed improvement on VAS of 67.5% (p = 0.0017) while the remaining patients, with lower eVAT, improved by 50.6% (p = 0.03607). DBS remained effective in improving chronic neuropathic pain after 5 years. While VPL-targeting contributes to success, analgesia is also obtained by stimulating surrounding posterior ventrobasal thalamic structures and related spinothalamocortical tracts.