Pallidal Deep Brain Stimulation in Patients with Prior Bilateral Pallidotomy and Selective Peripheral Denervation for Treatment of Dystonia.

INTRODUCTION: Deep brain stimulation (DBS) of the globus pallidus internus has become an accepted treatment for severe isolated idiopathic and inherited dystonia. Patients who had other forms of surgery earlier, such as radiofrequency lesioning or selective peripheral denervation, however, usually are not considered candidates for DBS. OBJECTIVE: The aim of this study was to evaluate the long-term outcome of pallidal DBS in a rare subgroup of patients who had undergone both pallidotomy and selective peripheral denervation previously with a waning effect over the years. METHODS: Pallidal DBS was performed according to a prospective study protocol in 2 patients with isolated idiopathic dystonia, and patients were followed for a period of at least 6 years. RESULTS: Both patients benefitted from long-lasting amelioration of dystonia after pallidal DBS, which was comparable to that of patients who did not have previous surgeries. In a 62-year-old female with cervical dystonia both the Burke-Fahn-Marsden (BFM) and the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) motor scores were improved at follow-up 8 years after surgery (50 and 39%). In a 32-year-old male with generalized dystonia, the BFM motor and disability scores showed marked improvement at 6.5 years of follow-up (82 and 66%). CONCLUSIONS: Pallidal DBS can yield marked and long-lasting improvement in patients who underwent both pallidotomy and selective peripheral denervation earlier. Therefore, such patients, in general, should not be excluded from DBS.

The dimensions of "failed back surgery syndrome": what is behind a label?

BACKGROUND: The term failed back surgery syndrome (FBSS) has been criticized for being too unspecific and several studies have shown that a variety of conditions may underlie this label. The aims of the present study were to describe the specific symptoms and to investigate the primary and secondary underlying causes of FBSS in a contemporary series of patients who had lumbar spinal surgery before. METHODS: We used a multilevel approach along three different axes defining symptomatic, morphological, and functional pathology dimensions. RESULTS: Within the study period of 3 years, a total of 145 patients (74 f, 71 m, mean age 51a, range 32-82a) with the external diagnosis of FBSS were included. Disk surgery up to 4 times and surgery for spinal stenosis up to 3 times were the commonest index operations. Most often, the patients complained of low back pain (n = 126), pseudoradicular pain (n = 54), and neuropathic pain (n = 44). Imaging revealed osteochondrosis (n = 61), spondylarthrosis (n = 48), and spinal misalignment (n = 32) as the most frequent morphological changes. The majority of patients were assigned at least to two different symptomatic subcategories and morphological subcategories, respectively. According to these findings, one or more functional pathologies were assigned in 131/145 patients that subsequently enabled a specific treatment strategy. CONCLUSIONS: FBSS has become rather a vague and imprecisely used generic term. We suggest that it should be avoided in the future both with regard to its partially stigmatizing connotation and its inherent hindering to provide individualized medicine.

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.

Subdural Hematoma and Oral Anticoagulation: A Therapeutic Dilemma from the Neurosurgical Point of View.

BACKGROUND: Oral anticoagulation is a common prophylactic therapy for several diseases with a high thromboembolic risk. Such medication harbors a possible hemorrhage risk, with a special risk for subdural hematoma (SDH). The safety and efficacy of resumption of oral anticoagulation versus long-term discontinuation has not been fully clarified in patients who experienced SDH while under treatment with oral anticoagulation. MATERIAL AND METHODS: We investigated the outcome of 49 patients who were identified retrospectively to have a SDH while receiving oral anticoagulation. RESULTS: Most bleeding occurred while patients were within the recommended therapeutic window for oral anticoagulation. Mortality was 15%. The event-free survival probability was higher in the group of patients with reinstitution of phenprocoumon therapy than in the group without. Over a median follow-up of 32 months, thromboembolic events occurred in 4 of 23 patients without oral anticoagulation versus in none of 15 patients with phenprocoumon; hemorrhagic complications occurred in 1 in 23 versus 3 in 15 patients. CONCLUSIONS: Reinstitution of oral anticoagulation with phenprocoumon after previous SDH appears to have an acceptable risk for hemorrhagic complications. Decision making might consider case-by-case differences. To establish specific guidelines, prospective large cohort studies are needed.

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.

Electromagnetic-guided neuronavigation for safe placement of intraventricular catheters in pediatric neurosurgery.

OBJECT: Ventricular catheter shunt malfunction is the most common reason for shunt revision. Optimal ventricular catheter placement can be exceedingly difficult in patients with small ventricles or abnormal ventricular anatomy. Particularly in children and in premature infants with small head size, satisfactory positioning of the ventricular catheter can be a challenge. Navigation with electromagnetic tracking technology is an attractive and innovative therapeutic option. In this study, the authors demonstrate the advantages of using this technology for shunt placement in children. METHODS: Twenty-six children ranging in age from 4 days to 14 years (mean 3.8 years) with hydrocephalus and difficult ventricular anatomy or slit ventricles underwent electromagnetic-guided neuronavigated intraventricular catheter placement in a total of 29 procedures. RESULTS: The single-coil technology allows one to use flexible instruments, in this case the ventricular catheter stylet, to be tracked at the tip. Head movement during the operative procedure is possible without loss of navigation precision. The intraoperative catheter placement documented by screenshots correlated exactly with the position on the postoperative CT scan. There was no need for repeated ventricular punctures. There were no operative complications. Postoperatively, all children had accurate shunt placement. The overall shunt failure rate in our group was 15%, including 3 shunt infections (after 1 month, 5 months, and 10 months) requiring operative revision and 1 distal shunt failure. There were no proximal shunt malfunctions during follow-up (mean 23.5 months). CONCLUSIONS: The electromagnetic-guided neuronavigation system enables safe and optimal catheter placement, especially in children and premature infants, alleviating the need for repeated cannulation attempts for ventricular puncture. In contrast to stereotactic techniques and conventional neuronavigation, there is no need for sharp head fixation using a Mayfield clamp. This technique may present the possibility of reducing proximal shunt failure rates and costs for hydrocephalus treatment in this age cohort.

Stereotactic drainage of empyema of the cavum septi pellucidi et vergae.

BACKGROUND: Persistent midline ventricular cavae may only rarely cause clinical symptoms. Exceptionally, empyemas may develop in these cavae. Optimal treatment has been defined only poorly so far. METHODS: Here, we report successful treatment of a bacterial empyema in the cavum septi pellucidi et vergae due to sphenoid sinus sinusitis in a 36-year-old woman by stereotactic puncture and drainage of the empyema and long-term administration of antibiotics. RESULTS AND CONCLUSIONS: Stereotactic puncture and drainage accompanied by antibiotic therapy result in beneficial outcome in the long term. Transcallosal interhemispheric approaches and free-hand techniques should be discouraged since, according to previously published reports, they may result in severe morbidity or mortality in this condition.

Combined pallidal and subthalamic nucleus stimulation in sporadic dystonia-parkinsonism.

Multifocal deep brain stimulation (DBS) is a new technique that has been introduced recently. A 39-year-old man with dystonia-parkinsonism underwent the simultaneous implantation of subthalamic nucleus (STN) and globus pallidus internus (GPi) DBS electrodes. While bilateral STN DBS controlled the parkinsonian symptoms well and allowed for a reduction in levodopa, the improvement of dystonia was only temporary. Additional GPi DBS also alleviated dystonic symptoms. Formal assessment at the 1-year follow-up showed that both the parkinsonian symptoms and the dystonia were markedly improved via continuous bilateral combined STN and GPi stimulation. Sustained benefit was achieved at 3 years postoperatively.

Bilateral deep brain stimulation for cervical dystonia in patients with previous peripheral surgery.

BACKGROUND: There are no data available concerning whether patients with cervical dystonia who have recurrent or new symptoms after peripheral denervation surgery benefit similarly from pallidal deep brain stimulation compared with patients who receive primarily pallidal stimulation. METHODS: Data on 7 cervical dystonia patients with recurrent or progressive dystonia after peripheral denervation who underwent pallidal stimulation were prospectively collected. Deep brain stimulation was performed in Mannheim/Hannover, Germany, or in Umea, Sweden. To the subgroup from Mannheim/Hannover, a second group of patients without previous peripheral surgery was matched. Assessments included the Toronto Western Spasmodic Torticollis Rating Scale and the Burke-Fahn-Marsden dystonia rating scale, as well as the Tsui scale in the Swedish patients. RESULTS: The 4 patients from Mannheim/Hannover experienced sustained improvement from pallidal stimulation by a mean of 57.5% according to the Toronto Western Spasmodic Torticollis Rating Scale (P < .05) and by a mean of 69.5% according to the Burke-Fahn-Marsden dystonia rating scale (P < .05) at long-term follow-up of 40.5 months. The patients from Umea had a mean Tsui score of 7 prior to surgery and a mean score of 3 at the mean follow-up of 8 months (62.5%). In the matched group the Toronto Western Spasmodic Torticollis Rating Scale improved by 58.8% and the Burke-Fahn-Marsden dystonia rating scale by 67% (P < .05) at long-term follow-up (mean, 41.5 months). CONCLUSIONS: Patients who had prior peripheral surgery for cervical dystonia experience improvement from subsequent pallidal stimulation that is comparable to that of de novo patients.

Deep brain stimulation for treatment of hemichorea-hemiballism after craniopharyngioma resection: long-term follow-up.

Hemichorea-hemiballism is a rare movement disorder that has various causes. In treatment-resistant cases, both thalamic and pallidal functional procedures have been shown to yield beneficial results. Until now it has not been clarified whether the thalamus or the pallidum would yield a superior outcome. After resection of a craniopharyngioma in this patient at the age of 49 years, hemichorea-hemiballism developed, with a latency of several weeks. Because the patient was greatly impaired by the movement disorder, she underwent implantation of deep brain stimulation (DBS) electrodes in the thalamic ventralis intermedius nucleus and the posteroventral lateral globus pallidus internus. Although both pallidal and thalamic stimulation could suppress the movement disorder, the voltage needed was clearly less with thalamic than with pallidal stimulation. At the last available follow-up 25 months postoperatively, complete subsidence of hemichorea-hemiballism was achieved with long-term thalamic stimulation. Long-term DBS therapy is an efficient treatment modality for refractory hemichorea-hemiballism in the long run (> 2 years). A bifocal (thalamic and pallidal) target paradigm allowed selection of the optimal stimulation site. Thalamic DBS was more favorable with regard to energy consumption.

Subcutaneous peripheral neurostimulation for the treatment of severe chronic poststernotomy neuralgia.

OBJECTIVE: Poststernotomy pain frequently develops after sternotomy in thoracic and cardiovascular surgery, and may affect patients' quality of life. In some cases of severe poststernotomy neuralgia, pharmacologic therapy does not provide adequate relief. CASE REPORT: We report on a 42- year-old woman who underwent sternotomy for aortic and mitral valve replacement. She developed severe chronic poststernotomy neuralgia that was refractory to medical treatment. After local anesthesia markedly but only transiently alleviated pain, we considered the option of subcutaneous peripheral neurostimulation (SPNS). Plate electrodes were implanted bilaterally in the parasternal region at the site of maximal pain. After a period of test stimulation, the electrodes were connected to a dual-channel implantable pulse generator. SPNS induced paresthesias in the painful area. Revision surgery was necessary twice because of electrode migration. Chronic SPNS markedly alleviated pain (visual-analog scale, VAS, 9/10 preoperatively, 2/10 postoperatively) and allodynia (VAS 9/10 preoperatively, 2/10 postoperatively) at the last available follow-up, 15 months postoperatively. CONCLUSIONS: SPNS may be a viable treatment option in patients with severe chronic poststernotomy neuralgia.

Stereotactic versus endoscopic surgery in periventricular lesions.

OBJECT: Endoscopic and stereotactic surgery have gained widespread acceptance as minimally invasive tools for the diagnosis of intracerebral pathologies. We investigated the specific advantages and disadvantages of each technique in the assessment of periventricular lesions. METHOD: This study included a retrospective series of 70 patients with periventricular lesions. Endoscopic surgery was performed in 17 patients (mean age, 37 years; range, 4 months-78 years) and stereotactic biopsy in 55 patients (mean age, 63 years; range, 23-80 years), including two patients who underwent both procedures. RESULTS: Hydrocephalus was present in 13/17 patients in the endoscopic group (77%) and in 11/55 patients in the stereotactic group (20%). Diagnosis was achieved in all patients in the endoscopic group and in all but one patient in the stereotactic group, in whom histological diagnosis was obtained by endoscopic biopsy during a second operation. In the endoscopic group, additional procedures performed included ventriculostomy (2/17), cyst fenestration (3/17), endoscopic shunt revision (3/17) and placement of Rickham reservoirs or external cerebrospinal fluid drains (6/17). Adverse events occurred in one patient after endoscopy (chronic subdural hematoma) and in two patients after stereotactic surgery (one mild hemiparesis and one transitory paresis of the contralateral leg). CONCLUSIONS: Endoscopic and stereotactic surgery have distinct advantages and disadvantages in approaching periventricular lesions. The advantages of endoscopy encompass the possibility to perform additional surgical procedures during the same session (e.g. tumour reduction, third ventriculostomy, fenestration of a cyst). The visual control reduces the hazard of injury to anatomical structures and allows for a better control of bleeding although there is a considerable blind-out in such situations. The advantages of stereotactic surgery include a smaller approach and precise planning of the trajectory. It is usually performed under local anaesthesia. Both methods provide a safe and efficient therapeutic option in periventricular lesions with low surgical-related morbidity.

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.

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.

Less is more: adaptation of voltage after battery replacement in deep brain stimulation for dystonia.

BACKGROUND: To maintain the efficacy of deep brain stimulation (DBS) on dystonic symptoms, slight incremental increase in voltage may be necessary over years after a steady state has been reached following the initial programming of optimal settings. So far however, no data are available regarding the adjustment of voltage after implantable pulse generator (IPG) replacement to achieve sustained optimal control of dystonia with the least side effects. METHODS: We analyzed stimulation settings before and after IPG replacement for battery depletion (n = 61) in 18 patients with chronic DBS of the globus pallidus internus or the ventral intermediate nucleus of the thalamus for dystonia. RESULTS: The stimulation intensity could be significantly reduced by 24.8% after IPG replacement. The amount of voltage reduction was equal between bipolar and monopolar stimulation modes (24.9 vs. 24.3%, p = 0.89) and significantly correlated with the magnitude of stimulation intensity before IPG replacement (ρ = 0.429, p = 0.001). CONCLUSIONS: After IPG replacement, in patients with DBS for segmental dystonia the voltage can be reduced by approximately 25%. This phenomenon might be explained by a gradual decrease in the electrical energy effectively delivered by the IPG in the course of the lifetime of the battery or neuroplastic processes in particular in the period around battery replacement.

Chronic deep brain stimulation in patients with tardive dystonia without a history of major psychosis.

Tardive dystonia usually occurs with a delay after neuroleptic exposure in patients with major psychosis. A subgroup of patients, however, is given such medication for "mild depression" or "neurasthenia." Tardive dystonia, in general, may respond favorably to pallidal deep brain stimulation (DBS). Nevertheless, it remains unclear thus far whether or not similar beneficial outcome is achieved with pallidal DBS in different subgroups of patients with tardive dystonia. Four women (mean age 59 years at surgery) underwent stereotactic pallidal DBS in the frame of an observational study. Tardive dystonia occurred secondary to medication with fluspirilene and haloperidol, and injection of long-acting depot neuroleptics prescribed for mild depression or "nervousness." Assessment included the Burke-Fahn-Marsden (BFM) scale preoperatively and at 12 months follow-up. Extended follow-up was available at a mean of 27.3 months postoperatively (range 16-36 months). There were no surgically related complications. All 4 patients experienced sustained statistically significant benefit from pallidal DBS. Mean improvement at 12 months was 77% for the BFM motor score (range, 45-91%; P = 0.043), and 84% at the last available follow-up (range, 70-91%; P = 0.03). This was paralleled by improvement of the BFM disability score. Chronic pallidal DBS in patients with tardive dystonia without a history of major psychosis provides sustained improvement which is similar to that in other subgroups of patients with tardive dystonia. This effect is stable on extended follow-up for up to 3 years.

Microvascular decompression of the anterior inferior cerebellar artery for intermediate nerve neuralgia.

The authors present the case of a 63-year-old woman with a 5-year history of intractable paroxysmal 'atypical' otofacial pain. The patient's pain attacks were not typical for either trigeminal or vagoglossopharyngeal neuralgia. Surgical exploration via a suboccipital retromastoid craniotomy showed vascular compression of the nervus intermedius by the anterior inferior cerebellar artery and the patient's pain was successfully managed with microvascular decompression.