Long-Term Efficacy of Occipital Nerve Stimulation for Medically Intractable Cluster Headache.

BACKGROUND: Occipital nerve stimulation (ONS) has been proposed to treat refractory chronic cluster headache (rCCH) but its efficacy has only been showed in small short-term series. OBJECTIVE: To evaluate ONS long-term efficacy in rCCH. METHODS: We studied 105 patients with rCCH, treated by ONS within a multicenter ONS prospective registry. Efficacy was evaluated by frequency, intensity of pain attacks, quality of life (QoL) EuroQol 5 dimensions (EQ5D), functional (Headache Impact Test-6, Migraine Disability Assessment) and emotional (Hospital Anxiety Depression Scale [HAD]) impacts, and medication consumption. RESULTS: At last follow-up (mean 43.8 mo), attack frequency was reduced >50% in 69% of the patients. Mean weekly attack frequency decreased from 22.5 at baseline to 9.9 (P < .001) after ONS. Preventive and abortive medications were significantly decreased. Functional impact, anxiety, and QoL significantly improved after ONS. In excellent responders (59% of the patients), attack frequency decreased by 80% and QoL (EQ5D visual analog scale) dramatically improved from 37.8/100 to 73.2/100. When comparing baseline and 1-yr and last follow-up outcomes, efficacy was sustained over time. In multivariable analysis, low preoperative HAD-depression score was correlated to a higher risk of ONS failure. During the follow-up, 67 patients experienced at least one complication, 29 requiring an additional surgery: infection (6%), lead migration (12%) or fracture (4.5%), hardware dysfunction (8.2%), and local pain (20%). CONCLUSION: Our results showed that long-term efficacy of ONS in CCH was maintained over time. In responders, ONS induced a major reduction of functional and emotional headache-related impacts and a dramatic improvement of QoL. These results obtained in real-life conditions support its use and dissemination in rCCH patients.

CHI3L1, NTRK2, 1p/19q and IDH Status Predicts Prognosis in Glioma.

The aim of this study was to identify relevant biomarkers for the prognosis of glioma considering current molecular changes such as IDH mutation and 1p19q deletion. Gene expression profiling was performed using the TaqMan Low Density Array and hierarchical clustering using 96 selected genes in 64 patients with newly diagnosed glioma. The expression dataset was validated on a large independent cohort from The Cancer Genome Atlas (TCGA) database. A differential expression panel of 26 genes discriminated two prognostic groups regardless of grade and molecular groups of tumors: Patients having a poor prognosis with a median overall survival (OS) of 23.0 ± 9.6 months (group A) and patients having a good prognosis with a median OS of 115.0 ± 6.6 months (group B) (p = 0.007). Hierarchical clustering of the glioma TCGA cohort supported the prognostic value of these 26 genes (p < 0.0001). Among these genes, CHI3L1 and NTRK2 were identified as factors that can be associated with IDH status and 1p/19q co-deletion to distinguish between prognostic groups of glioma from the TCGA cohort. Therefore, CHI3L1 associated with NTRK2 seemed to be able to provide new information on glioma prognosis.

OnabotulinumtoxinA injections in chronic migraine, targeted to sites of pericranial myofascial pain: an observational, open label, real-life cohort study.

BACKGROUND: OnabotulinumtoxinA has proven its efficacy in reducing the number of headache days in chronic migraine (CM) patients. The usual paradigm includes 31 pericranial injection sites with low dose (5 U) per site. The aim of this study is to present the results obtained using a simpler injection protocol of onabotulinumtoxinA, with injection sites targeted to pericranial myofascial sites of pain. METHODS: Observational, open label, real-life, cohort study. We enrolled 63 consecutive patients fulfilling the diagnostic criteria of CM, and refractory to conventional treatments. The patients were injected using a "follow-the-pain" pattern into the corrugator and/or temporalis and/or trapezius muscles. The doses per muscle were fixed. According to the number of muscles injected, the total dose could vary from 70 to 150 U per session. Patients were considered responders if they had a ≥ 50% decrease in number of headache days in at least two consecutive injection cycles. RESULTS: Forty one patients (65.1% in intention to treat analysis) responded to treatment. In 70.7% of responders, the effect size was even higher, with a reduction ≥70% in the number of headache days. The associated cervical pain and muscle tenderness, present in 33 patients, was reduced by ≥50% in 31 patients (94%). Triptan consumption dramatically decreased (81%) in responders. The trapezius was the most frequently injected muscle. We observed no serious adverse event. The mean patient satisfaction rate was 8.5/10. CONCLUSIONS: This study provides additional robust evidence supporting the efficacy of onabotulinumtoxinA injections in CM. Furthermore, the paradigm we used, with reduced number of injection sites targeted to pericranial myofascial sites of pain, may provide evidence in favor of the implication of myofascial trigger points in migraine chronicization. TRIAL REGISTRATION: ClinicalTrials.gov Protocol Record I17022 ClinicalTrials.gov Identifier: NCT03175263 . Date of registration: June 7, 2017. Retrospectively registered.

Occipital nerve stimulation improves the quality of life in medically-intractable chronic cluster headache: Results of an observational prospective study.

Background Occipital nerve stimulation (ONS) has been proposed to treat chronic medically-intractable cluster headache (iCCH) in small series of cases without evaluation of its functional and emotional impacts. Methods We report the multidimensional outcome of a large observational study of iCCH patients, treated by ONS within a nationwide multidisciplinary network ( https://clinicaltrials.gov NCT01842763), with a one-year follow-up. Prospective evaluation was performed before surgery, then three and 12 months after. Results One year after ONS, the attack frequency per week was decreased >30% in 64% and >50% in 59% of the 44 patients. Mean (Standard Deviation) weekly attack frequency decreased from 21.5 (16.3) to 10.7 (13.8) ( p = 0.0002). About 70% of the patients responded to ONS, 47.8% being excellent responders. Prophylactic treatments could be decreased in 40% of patients. Functional (HIT-6 and MIDAS scales) and emotional (HAD scale) impacts were significantly improved, as well as the health-related quality of life (EQ-5D). The mean (SD) EQ-5D visual analogic scale score increased from 35.2 (23.6) to 51.9 (25.7) ( p = 0.0037). Surgical minor complications were observed in 33% of the patients. Conclusion ONS significantly reduced the attack frequency per week, as well as the functional and emotional headache impacts in iCCH patients, and dramatically improved the health-related quality of life of responders.

Endovascular Management of Deep Arteriovenous Malformations: Single Institution Experience in 22 Consecutive Patients.

BACKGROUND: The management of arteriovenous malformations (AVMs) in the basal ganglia, insula, and thalamus is demanding for all treatment modalities. OBJECTIVE: To define safety and outcomes of embolization used as a stand-alone therapy for deep-seated AVMs. METHODS: A cohort of 22 patients with AVMs located in the basal ganglia, thalamus, and insula who underwent embolization between January 2008 and December 2013. RESULTS: Eighteen of 22 (82%) patients had anatomic exclusion. The mean size was 2.98 ± 1.28 cm, and the mean number of sessions was 2.1 per patient. Most patients presented with hemorrhage (82%, n = 18), and 3 (14%) patients were in a deteriorated neurological status (modified Rankin Scale >2) at presentation. Sixty-eight percent of ruptured AVMs had size ≤3 cm. A single transarterial approach was performed in 9 (41%) cases, double catheterization was used in 4 (18%), and the transvenous approach was required in 8 (36%) cases. Procedure-related complications were registered in 3 (14%) cases. One death was associated with treatment, and complementary radiosurgery was required in 2 (9%) patients. CONCLUSION: Embolization therapy appears to be safe and potentially curative for certain deep AVMs. Our results demonstrate a high percentage of anatomic obliteration with rates of complications that may approach radiosurgery profile. In particular, embolization as stand-alone therapy is most suitable to deep AVMs with small nidus size (≤3 cm) and/or associated with single venous drainage in which microsurgery might not be indicated.

The mamillothalamic tract is a good landmark for the anterior border of the subthalamic nucleus on axial MR images.

BACKGROUND: Identification of the subthalamic nucleus (STN) on MR images is difficult, and the use of external landmarks could be of interest for STN targeting in deep brain stimulation (DBS). OBJECTIVES: Our aim was to explore the relationship between the anteroposterior coordinates of (1) the center of the mamillothalamic tract and (2) the anterior border of the STN on axial MR images. PATIENTS AND METHODS: The brains of 16 healthy volunteers were imaged on a 3T MR system. Four millimeters under the anterior-posterior commissure plane, we noted the y coordinates of (1) the center of the mamillothalamic tract and (2) the anterior border of the STN. RESULTS: The coordinates were y(STN) = 14.7 ± 1.23 mm and y(Tmth) = 14.3 ± 1.13 mm from the posterior commissure for the STN and the mamillothalamic tract, respectively. The mean difference was 0.4 mm (range 0-1 mm). Pearson's coefficient was 0.97 (p < 0.01). CONCLUSION: We observed a strong correlation between the anteroposterior coordinates of the mamillothalamic tract and the anterior border of the STN (which is located between 0 and 1 mm in front of the mamillothalamic tract). The mamillothalamic tract could be a good anterior landmark for STN targeting. It could also be tested for target determination in DBS for severe obsessive-compulsive disorder.

Anatomy of the human thalamus based on spontaneous contrast and microscopic voxels in high-field magnetic resonance imaging.

BACKGROUND: Since the pioneering studies of human thalamic anatomy based on histology and binding techniques, little new work has been done to bring this knowledge into clinical practice. OBJECTIVE: With the advent of magnetic resonance imaging (MRI) we hypothesized that it was possible, in vitro, to make use of high spontaneous MRI contrasts between white and grey matter to directly identify the subcompartmentalisation of the thalamus. METHODS: An anatomic specimen was imaged at high field (4.7 T) (basal ganglia plus thalamus block; 3-dimensional (3D) T1-weighted spin echo sequence; matrix, 256 x 256 x 256; isotropic voxel, 0.250 mm/edge; total acquisition time, 14 hours 30 minutes). Nuclei were manually contoured on the basis of spontaneous contrasted structures; labeling relied on 3D identification from classic knowledge; stereotactic location of centers of nuclei was computed. RESULTS: Almost all intrathalamic substructures, nuclei, and white matter laminae were identified. Using 3D analysis, a simplified classification of intrathalamic nuclei into 9 groups was proposed, based on topographic MRI anatomy, designed for clinical practice: anterior (oral), posterior, dorsal, intermediate, ventral, medial, laminar, superficial, and related (epi and metathalamus). The overall 4.7-T anatomy matches that presented in the atlases of Schaltenbrand and Bailey (1959), Talairach et al (1957), and Morel et al (1997). CONCLUSION: It seems possible to identify the subcompartments of the thalamus by spontaneous MRI contrast, allowing a tissue architectural approach. In addition, the MRI tissue architecture matches the earlier subcompartmentalization based on cyto- and chemoarchitecture. This true 3D anatomic study of the thalamus may be useful in clinical neuroscience and neurosurgical applications.