Long-term follow up of intractable chronic short lasting unilateral neuralgiform headache disorders treated with occipital nerve stimulation

BACKGROUND: Occipital nerve stimulation is a potential treatment option for medically intractable short-lasting unilateral neuralgiform headache attacks. We present long-term outcomes in 31 patients with short-lasting unilateral neuralgiform headache attacks treated with occipital nerve stimulation in an uncontrolled open-label prospective study. METHODS: Thirty-one patients with intractable short-lasting unilateral neuralgiform headache attacks were treated with bilateral occipital nerve stimulation from 2007 to 2015. Data on attack characteristics, quality of life, disability and adverse events were collected. Primary endpoint was change in mean daily attack frequency at final follow-up. RESULTS: At a mean follow-up of 44.9 months (range 13-89) there was a 69% improvement in attack frequency with a response rate (defined as at least a 50% improvement in daily attack frequency) of 77%. Attack severity reduced by 4.7 points on the verbal rating scale and attack duration by a mean of 64%. Improvements were seen in headache-related disability and depression. Adverse event rates were favorable, with no electrode migration or erosion reported. CONCLUSION: Occipital nerve stimulation appears to offer a safe and efficacious treatment for refractory short-lasting unilateral neuralgiform headache attacks with significant improvements sustained in the long term. The procedure has a low adverse event rate when conducted in highly specialised units

OnabotulinumtoxinA for hemicrania continua: open label experience in 9 patients

BACKGROUND: Hemicrania continua is a strictly unilateral, continuous headache, typically mild to moderate in severity, with severe exacerbations commonly accompanied by cranial autonomic features and migrainous symptoms. It is exquisitely responsive to Indomethacin. However, some patients cannot tolerate treatment, often due to gastrointestinal side effects. Therapeutic alternatives are limited and controlled evidence lacking. METHODS: We present our experience of nine patients treated with OnabotulinumtoxinA for hemicrania continua. All patients were injected using the PREEMPT (Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy) protocol for migraine. RESULTS: Five of nine patients demonstrated a 50% or more reduction in moderate to severe headache days with OnabotulinumtoxinA with a median reduction in moderate to severe headache days of 80%. Patient estimate of response was 80% or more in five subjects. The median and mean duration of response in the five responders was 11 and 12 weeks (range 6-20 weeks). Improvements were also seen in headache-associated disability CONCLUSIONS: OnabotulinumtoxinA adds a potential option to the limited therapeutic alternatives available in hemicrania continua

The effect of graphene-poly(methyl methacrylate) fibres on microbial growth

A novel class of ultra-thin fibres, which affect microbial growth, were explored. The microbial properties of poly(methyl methacrylate) fibres containing 2, 4 and 8 wt% of graphene nanoplatelets (GNPs) were studied. GNPs were dispersed in a polymeric solution and processed using pressurized gyration. Electron microscopy was used to characterize GNP and fibre morphology. Scanning electron microscopy revealed the formation of beaded porous fibres. GNP concentration was found to dictate fibre morphology. As the GNP concentration increased, the average fibre diameter increased from 0.75 to 2.71 mm, while fibre porosity decreased. Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa were used to investigate the properties of 2, 4 and 8 wt% GNP-loaded fibres. GNP-loaded fibres (0 wt%) were used as the negative control. The fibres were incubated for 24 h with the bacteria; bacterial colony-forming units were enumerated by adopting the colony-counting method. The presence of 2 and 4 wt% GNP-loaded fibres promoted microbial growth, while 8 wt% GNP-loaded fibres showed antimicrobial activity. These results indicate that the minimum inhibitory concentration of GNPs required within a fibre is 8 wt%

The Hy-MASS concept : Hydrothermal microwave assisted selective scissoring of cellulose for: In situ production of (meso)porous nanocellulose fibrils and crystals

The hydrothermal microwave-assisted selective scissoring (Hy-MASS) of depectinated orange peel residues (OPR), produced via conventional acid hydrolysis and acid-free microwave processing, to yield (meso)porous nanocellulose fibrils and crystals simultaneously in the absence of additional auxiliary reagents and/or mechanical treatment is reported. In the stepwise microwave hydrothermal treatment (MHT) of OPR from 120 °C-200 °C at 20 °C intervals, release of residual pectins and hemicelluloses is observed up to 180 °C producing nanocellulose fibrils (3-15 × 500-2000 nm). Beyond 180 °C, selective leaching/hydrolysis of amorphous regions occur to yield nanocellulose crystals (200-400 × 40-50 nm) and crystallites (5-15 × 40-50 nm). This selective, step-wise scissoring process is termed Hy-MASS Concept. Structure, morphology and properties of (meso)porous nanocellulose are strongly influenced by pectin extraction methodology employed. With acid depectinated OPR, deconstruction of the lignocellulosic matrix via microwave is hastened by approx. 20 °C with respect to acid-free microwave depectinated OPR. Td of acid depectinated nanocelluloses (CMC) is ca. 350 °C compared to microwave depectinated nanocelluloses (MMC, Td, varies 342-361 °C). Nanocellulose produced via microwave pre-treatment is (meso)porous: BJH pore size 5-35 nm; BET surface area, 1.5-107 m2 g-1, and; BJH pore volume, 0.01-0.27 cm3 g-1, when compared to acid pre-treated counterparts. The crystallinity index of CMC and MMC increases in two stages, 120-140 °C (ca. 8%) and at 180-200 °C (5-9%). XRD revealed presence of calciuim salts, most likely calcium oxalate. The hydration capacities of nanocelluloses (12-23 g water per g sample) are much higher than their precursors or literature citrus nanocellulose

Microvascular decompression or neuromodulation in patients with SUNCT and trigeminal neurovascular conflict?

Objectives To assess the effectiveness of neuromodulation and trigeminal microvascular decompression (MVD) in patients with medically-intractable short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT). Methods Two patients with medically refractory SUNCT underwent MVD following beneficial but incomplete response to neuromodulation (occipital nerve stimulation and deep brain stimulation). MRI confirmed neurovascular conflict with the ipsilateral trigeminal nerve in both patients. Results Although neuromodulation provided significant benefit, it did not deliver complete relief from pain and management required numerous postoperative visits with adjustment of medication and stimulation parameters. Conversely, MVD was successful in eliminating symptoms of SUNCT in both patients with no need for further medical treatment or neuromodulation. Conclusion Neuromodulation requires expensive hardware and lifelong follow-up and maintenance. These case reports highlight that microvascular decompression may be preferable to neuromodulation in the subset of SUNCT patients with ipsilateral neurovascular conflict

Ventral tegmental area deep brain stimulation in refractory short-lasting unilateral neuralgiform headache attacks

Short-lasting unilateral neuralgiform headache attacks are primary headache disorders characterized by short-lasting attacks of unilateral pain accompanied by autonomic features. A small minority are refractory to medical treatment. Neuroimaging studies have suggested a role of the posterior hypothalamic region in their pathogenesis. Previous case reports on deep brain stimulation of this region, now understood to be the ventral tegmental area, for this disorder are limited to a total of three patients. We present a case series of 11 new patients treated with ventral tegmental area deep brain stimulation in an uncontrolled, open-label prospective observational study. Eleven patients with refractory short-lasting unilateral neuralgiform headache attacks underwent ipsilateral ventral tegmental area deep brain stimulation in a specialist unit. All patients had failed, or been denied access to, occipital nerve stimulation within the UK’s National Health Service. Primary endpoint was change in mean daily attack frequency at final follow-up. Secondary outcomes included attack severity, attack duration, headache load (a composite score of attack frequency, severity and duration), quality of life measures, disability and affective scores. Information was also collected on adverse events. Eleven patients (six male) with a median age of 50 years (range 26–67) were implanted between 2009 and 2014. Median follow-up was 29 months (range 7–63). At final follow-up the median improvement in daily attack frequency was 78% (interquartile range 33%). Response rate (defined as at least a 50% improvement in daily attack frequency) was 82% and four patients were rendered pain-free for prolonged periods of time. Headache load improved by 99% (interquartile range 52%). Improvements were observed in a number of quality of life, disability and affect measures. Adverse events included mild incision site pain, subcutaneous displacement of the implantable pulse generator, transient oscillopsia and minor wound infection. One patient required removal of the system due to wound infection. Ventral tegmental area deep brain stimulation may be an effective treatment option for refractory short-lasting unilateral neuralgiform headache attack patients who have failed other therapies

Evolution of Surface Nanopores in Pressurised Gyrospun Polymeric Microfibers

The selection of a solvent or solvent system and the ensuing polymer–solvent interactions are crucial factors affecting the preparation of fibers with multiple morphologies. A range of poly(methylmethacrylate) fibers were prepared by pressurised gyration using acetone, chloroform, N,N-dimethylformamide (DMF), ethyl acetate and dichloromethane as solvents. It was found that microscale fibers with surface nanopores were formed when using chloroform, ethyl acetate and dichloromethane and poreless fibers were formed when using acetone and DMF as the solvent. These observations are explained on the basis of the physical properties of the solvents and mechanisms of pore formation. The formation of porous fibers is caused by many solvent properties such as volatility, solubility parameters, vapour pressure and surface tension. Cross-sectional images show that the nanopores are only on the surface of the fibers and they were not inter-connected. Further, the results show that fibers with desired nanopores (40–400 nm) can be prepared by carefully selecting the solvent and applied pressure in the gyration process

Prognostic factors for chronic headache: A systematic review

OBJECTIVE: To identify predictors of prognosis and trial outcomes in prospective studies of people with chronic headache. METHODS: This was a systematic review of published literature in peer-reviewed journals. We included (1) randomized controlled trials (RCTs) of interventions for chronic headache that reported subgroup analyses and (2) prospective cohort studies, published in English, since 1980. Participants included adults with chronic headache (including chronic headache, chronic migraine, and chronic tension-type headache with or without medication overuse headache). We searched key databases using free text and MeSH terms. Two reviewers independently extracted data and assessed the methodologic quality of studies and overall quality of evidence identified using appropriate published checklists. RESULTS: We identified 16,556 titles, removed 663 duplicates, and reviewed 199 articles, of which 27 were included in the review-17 prospective cohorts and 10 RCTs with subgroup analyses reported. There was moderate-quality evidence indicating that depression, anxiety, poor sleep and stress, medication overuse, and poor self-efficacy for managing headaches are potential prognostic factors for poor prognosis and unfavorable outcomes from preventive treatment in chronic headache. There was inconclusive evidence about treatment expectations, age, age at onset, body mass index, employment, and several headache features. CONCLUSIONS: This review identified several potential predictors of poor prognosis and worse outcome postinterventions in people with chronic headache. The majority of these are modifiable. The findings also highlight the need for more longitudinal high-quality research of prognostic factors in chronic headache

Optimal deep brain stimulation site and target connectivity for chronic cluster headache

OBJECTIVE: To investigate the mechanism of action of deep brain stimulation for refractory chronic cluster headache and the optimal target within the ventral tegmental area. METHODS: Seven patients with refractory chronic cluster headache underwent high spatial and angular resolution diffusion MRI preoperatively. MRI-guided and MRI-verified electrode implantation was performed unilaterally in 5 patients and bilaterally in 2. Volumes of tissue activation were generated around active lead contacts with a finite-element model. Twelve months after surgery, voxel-based morphometry was used to identify voxels associated with higher reduction in headache load. Probabilistic tractography was used to identify the brain connectivity of the activation volumes in responders, defined as patients with a reduction of ≥30% in headache load. RESULTS: There was no surgical morbidity. Average follow-up was 34 ± 14 months. Patients showed reductions of 76 ± 33% in headache load, 46 ± 41% in attack severity, 58 ± 41% in headache frequency, and 51 ± 46% in attack duration at the last follow-up. Six patients responded to treatment. Greatest reduction in headache load was associated with activation in an area cantered at 6 mm lateral, 2 mm posterior, and 1 mm inferior to the midcommissural point of the third ventricle. Average responders' activation volume lay on the trigeminohypothalamic tract, connecting the trigeminal system and other brainstem nuclei associated with nociception and pain modulation with the hypothalamus, and the prefrontal and mesial temporal areas. CONCLUSIONS: We identify the optimal stimulation site and structural connectivity of the deep brain stimulation target for cluster headache, explicating possible mechanisms of action and disease pathophysiology