Diffusion tensor imaging of the trigeminal nerve in patients with trigeminal neuralgia due to multiple sclerosis.

INTRODUCTION: Neurovascular compression (NVC) is the most common cause of trigeminal neuralgia (TN), leading to microstructural changes in the affected nerve detectable using diffusion tensor imaging (DTI). But TN may also emerge as a symptom of multiple sclerosis (MS). The aim of this study was to evaluate if patients with MS-related TN feature the same DTI characteristics as patients with TN caused by NVC. METHODS: Twelve patients with MS-related TN, 12 age-matched patients with NVC-related TN, and 12 healthy controls were included. Using 3T-DTI, mean fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were calculated for each affected and contralateral trigeminal nerve in patients with MS and NVC-related TN as well as healthy controls. Furthermore, presence of NVC was evaluated for patients with TN. RESULTS: There was no significant difference concerning FA or ADC when comparing the affected and the non-affected sides in patients with MS. FA was significantly lower and ADC higher in patients with MS on the TN affected as well as on the non-affected side compared to the non-affected side of patients with idiopathic TN or healthy controls. Likewise, FA was significantly lower on the affected side compared to the non-affected side in patients with idiopathic TN or healthy controls. NVC was evident in 41.7/0% on the affected/contralateral side in MS patients and 100/8% in the patients with NVC-related TN. CONCLUSION: In patients with MS-related TN, DTI reveals microstructural changes within the trigeminal nerve not only on the affected side but also on the clinically non-affected side.

Long-term efficacy and safety of chronic globus pallidus internus stimulation in different types of primary dystonia.

BACKGROUND: Deep brain stimulation (DBS) of the globus pallidus internus (GPi) offers a very promising therapy for medically intractable dystonia. However, little is known about the long-term benefit and safety of this procedure. We therefore performed a retrospective long-term analysis of 18 patients (age 12-78 years) suffering from primary generalized (9), segmental (6) or focal (3) dystonia (minimum follow-up: 36 months). METHODS: Outcome was assessed using the Burke-Fahn-Marsden (BFM) scores (generalized dystonia) and the Tsui score (focal/segmental dystonia). Follow-up ranged between 37 and 90 months (mean 60 months). RESULTS: Patients with generalized dystonia showed a mean improvement in the BFM movement score of 39.4% (range 0-68.8%), 42.5% (range -16.0 to 81.3%) and 46.8% (range -2.7 to 83.1%) at the 3- and 12-month, and long-term follow-up, respectively. In focal/segmental dystonia, the mean reduction in the Tsui score was 36.8% (range 0-100%), 65.1% (range 16.7-100%) and 59.8% (range 16.7-100%) at the 3- and 12-month, and long-term follow-up, respectively. Local infections were noted in 2 patients and hardware problems (electrode dislocation and breakage of the extension cable) in 1 patient. CONCLUSION: Our data showed Gpi-DBS to offer a very effective and safe therapy for different kinds of primary dystonia, with a significant long-term benefit in the majority of cases.

Adverse events associated with deep brain stimulation in patients with childhood-onset dystonia.

BACKGROUND: Data on pediatric DBS is still limited because of small numbers in single center series and lack of systematic multi-center trials. OBJECTIVES: We evaluate short- and long-term adverse events (AEs) of patients undergoing deep brain stimulation (DBS) during childhood and adolescence. METHODS: Data collected by the German registry on pediatric DBS (GEPESTIM) were analyzed according to reversible and irreversible AEs and time of occurrence with relation to DBS-surgery: Intraoperative, perioperative (<4 weeks), postoperative (4 weeks < 6 months) and long term AEs (>6 months). RESULTS: 72 patients with childhood-onset dystonia from 10 DBS-centers, who received 173 DBS electrodes and 141 implantable pulse generators (IPG), were included in the registry. Mean time of postoperative follow-up was 4.6 ±â€¯4 years. In total, 184 AEs were documented in 53 patients (73.6%). 52 DBS-related AEs in 26 patients (36.1%) required 45 subsequent surgical interventions 4.7 ±â€¯4.1 years (range 3 months-15 years) after initial implantation. The total risk of an AE requiring surgical intervention was 7.9% per electrode-year. Hardware-related AEs were the most common reason for surgery. There was a tendency of a higher rate of AEs in patients aged 7-9 years beyond 6 months after implantation. DISCUSSION: The intraoperative risk of AEs in pediatric patients with dystonia undergoing DBS is very low, whereas the rate of postoperative hardware-related AEs is a prominent feature with a higher occurrence compared to adults, especially on long-term follow-up. CONCLUSION: Factors leading to such AEs must be identified and patient management has to be focused on risk minimization strategies in order to improve DBS therapy and maximize outcome in pediatric patients.

Results of direct and indirect revascularisation for adult European patients with Moyamoya angiopathy.

There is little information concerning clinical data and revascularization procedures in adult European patients with Moyamoya disease. More data are available on juvenile European Moyamoya angiopathy and its microsurgical therapies. This analysis summarizes our clinical experience in European adult patients with Moyamoya angiopathy. Nine adult European patients underwent surgical revascularization for Moyamoya angiopathy between 1997 and 2005. Direct intracranial-extracranial (EC-IC) bypass was considered the primary surgical modality. In case of unsuitable donor or recipient arteries, encephalo-myo-synangiosis (EMS) was chosen as an indirect modality. The current analysis confirms that direct EC-IC-bypass is a feasible option for most cases of adult European Moyamoya disease. Exact definition of long-term benefits would require a multicentric study. EMS appears to be of questionable value in the adult European population.

Chronic electrostimulation of the trigeminal ganglion in trigeminal neuropathy: current state and future prospects.

Over two decades ago, the electrostimulation of the trigeminal ganglion (TGES) was established as a treatment option for patients with trigeminopathic pain due to a (iatrogenic) lesion of the trigeminal nerve, on whom the other therapeutic methods, either neurosurgical or conservative have very limited efficacy and usually are associated with a poor outcome. The technique of TGES which uses the setup also used for the thermocoagulation lesion for trigeminal neuralgia was first published by Steude in 1984 and has not been altered substantially. After a percutaneous puncture with a 16 gage needle of the oval foramen, a monopolar electrode (diameter 0.9mm, custom-made) is placed in the postganglionic trigeminal nerve. After a successful test-stimulation phase, a permanent electrode pulse generator system is implanted. Our experience includes more than 300 patients with a minimum follow-up of one year. Of these patients, 52% showed a good to excellent analgesic effect. The TGES-induced analgesia was persistent in long term-follow-up in all patients. The impact of TGES on cerebral pain modulation was proven by electrophysiology and PET. TGES is an effective, minimally invasive and reversible treatment option in selected patients with trigeminopathic pain; it should, therefore, always be considered as the primary treatment-option. Electrodes with two leads and a diameter not exceeding the 0.9 mm, allowing bipolar stimulation might enhance the neuromodulatory efficacy and options of TGES.

[Surgical treatment of lumbar spinal canal stenosis in elderly patients]. / Rückenschmerzen, Sensibilitätsstörungen, Schmerzen beim Gehen. Denken Sie an die Claudicatio spinalis?

Lumbar spinal stenosis is one of the most frequent causes of spinal surgical interventions in over 60-year olds. The exact relationship between degenerative changes and the resulting symptoms is unclear since imaging shows stenotic changes in the spines of many symptom-free patients. The concurrence of imaging findings, the symptoms described and manifestations is crucial for the indication of surgical decompression. Nevertheless, spinal claudication that is refractory to conservative therapy is the most frequent indication for surgery. The success rate two years after OP is approximately 80% in over 75-year olds. Five years after surgical intervention, an improvement in the symptoms is still recognizable in 50% of these patients.

Return to participation - significant improvement after bilateral pallidal stimulation in rapidly progressive DYT-1 dystonia.

We report the case of an 8-year-old girl who developed progressive generalized dystonia, rendering her unable to walk and sit within months despite medical therapy with dopamine and anti-cholinergic agents. She was found to have a 9q34.1 GAG-deletion, which is known to cause DYT1-dystonia. DYT-1 dystonia is an autosomal dominant condition with incomplete penetrance that usually starts in childhood. It is known to be refractory to pharmacotherapy. Reports on deep brain stimulation in this condition reveal marked benefits of the treatment in the pediatric and adult populations. The patient underwent bilateral stimulation of the internal globus pallidus 18 months after symptom onset. Postoperatively, her clinical status improved significantly as measured by the Burke-Fahn-Marsden dystonia rating scale and the resolution of a unilateral hip dislocation. Normal participation was regained.

The positive predictive value of O-(2-[18F]fluoroethyl)-L-tyrosine (FET) PET in the diagnosis of a glioma recurrence after multimodal treatment.

OBJECTIVE: To explore prospectively the positive predictive value of O-(2-[(18)F]fluoroethyl)-L-tyrosine (FET)-PET in selected patients with a magnetic resonance imaging (MRI)-based suspicion of a glioma recurrence or progression. Methods Patients with a supratentorial glioma (initial World Health Organization (WHO) grade II, III or IV) were considered eligible if they had both an MRI-(new/progressive contrast-enhancing lesion) and FET-PET-based diagnosis of a recurrence/progression after various forms and combinations of irradiation and chemotherapy. Criterion for tumour recurrence/progression in FET-PET was a standardized uptake value (SUVmax)/Background (BG) ratio of >2.0 in the late uptake phase. All patients underwent multimodal (MRI, FET-PET) imaging-guided stereotactic biopsy. The positive predictive value was defined as the proportion of MRI and FET-PET findings indicating glioma recurrence/progression that also tested positive for tumour recurrence/progression after stereotactic biopsy. RESULTS: Thirty-one patients with initially WHO grade II (17), WHO grade III (6), and grade IV glioma (8) were included. In 26 patients FET-PET results indicating tumour recurrence/progression were concordant with the biopsy results. In five patients histopathologic evaluation failed to reveal a "vital" tumour. FET-PET findings were also discordant with the radiographic and clinical follow-up in these five patients. The positive predictive value of FET-PET was 84%. CONCLUSION: The positive predictive value of FET-PET using the standard ratio method is high, but not high enough to replace stereotactic biopsy in this highly selected study cohort. Whether the calculation of FET uptake in the early phase and/or the evaluation of uptake kinetics will improve the positive predictive value of FET-PET deserves prospective evaluation.

Perfusion MRI before and after acetazolamide administration for assessment of cerebrovascular reserve capacity in patients with symptomatic internal carotid artery (ICA) occlusion: comparison with 99mTc-ECD SPECT.

INTRODUCTION: Impaired cerebral vascular reserve (CVR) in patients with symptomatic internal carotid artery (ICA) occlusion is regarded as a possible indication for performing extra-/intracranial (EC/IC) bypass surgery. As perfusion MR imaging (MRI) can demonstrate cerebral haemodynamics at capillary level, our hypothesis was that perfusion MRI could be used in these patients for the evaluation of CVR following acetazolamide challenge in a similar way to single photon emission CT (SPECT) and might provide additional information. METHODS: Enrolled in the study were 12 patients (mean age 61.3 years; 11 male, 1 female) with symptomatic unilateral ICA occlusion proven by angiography. Both perfusion MRI and 99m-technetium-ethyl-cysteinate dimer ((99m)Tc-ECD) SPECT were performed before and after injection of acetazolamide (Diamox ,1000 mg i.v.). CVR parameters including regional cerebral blood flow (rCBF) and volume (rCBV), and mean transit times (MTT) were measured by perfusion MRI. RESULTS: The patients with impaired CVR proven by SPECT (n = 9) had a negative mean rCBF increment (-46.52%), negative rCBV increment (-13.5%) and delayed MTT (mean +2.98 s), respectively, on the occluded side (Student's t-test all P < 0.05). The patients with sufficient CVR (n = 3) had a mean rCBF increment of 1.2%, a decrement of rCBV of 10.46%, and a mean MTT shortening of 0.27 s following the acetazolamide injection. CONCLUSIONS: Perfusion MRI before and after acetazolamide administration compares favourably with (99m)Tc-ECD SPECT for the detection of impaired CVR. The impact that perfusion MRI studies (before and after acetazolamide administration) might have on the treatment decision in patients with ICA occlusion has yet to be determined by a prospective study.

Management of haemorrhagic type moyamoya disease with intraventricular haemorrhage during pregnancy.

Moyamoya ("hazy puff-of-smoke") disease represents a rare condition with progressive narrowing and occlusion of basal cranial vessels with secondary specific neoangiogenesis; we report on a 25-year-old primigravida with known moyamoya disease who suffered from acute bilateral intraventricular haemorrhage at 24 weeks gestation. She underwent bilateral external ventricular drainage and intraventricular recombinant tissue plasminogen activator (r-TPA) lysis was performed. At 34 weeks' gestation, a healthy girl was delivered via Caesarean section. Encephalomyosynangiosis (EMS) and extra-intracranial (EC/IC) bypass surgery were performed six and eight months after delivery, respectively. The patient recovered almost completely and showed only mild residual deficits. Prompt diagnosis and immediate interdisciplinary treatment might have been the key for optimal maternal and neonatal outcome in our patient.