Pearls and pitfalls: Electrophysiology for primary headaches

in Cephalalgia : An International Journal of Headache (2013)

Lateral inhibition in visual cortex of migraine patients between attacks

in Journal of Headache & Pain (2013), 14

Stimulation of the sphenopalatine ganglion (SPG) for cluster headache treatment. Pathway CH-1: A randomized, sham-controlled study.

in Cephalalgia : An International Journal of Headache (2013)

BackgroundThe pain and autonomic symptoms of cluster headache (CH) result from activation of the trigeminal parasympathetic reflex, mediated through the sphenopalatine ganglion (SPG). We investigated the ... [more ▼]

BackgroundThe pain and autonomic symptoms of cluster headache (CH) result from activation of the trigeminal parasympathetic reflex, mediated through the sphenopalatine ganglion (SPG). We investigated the safety and efficacy of on-demand SPG stimulation for chronic CH (CCH).MethodsA multicenter, multiple CH attack study of an implantable on-demand SPG neurostimulator was conducted in patients suffering from refractory CCH. Each CH attack was randomly treated with full, sub-perception, or sham stimulation. Pain relief at 15 minutes following SPG stimulation and device- or procedure-related serious adverse events (SAEs) were evaluated.FindingsThirty-two patients were enrolled and 28 completed the randomized experimental period. Pain relief was achieved in 67.1% of full stimulation-treated attacks compared to 7.4% of sham-treated and 7.3% of sub-perception-treated attacks (p < 0.0001). Nineteen of 28 (68%) patients experienced a clinically significant improvement: seven (25%) achieved pain relief in >/=50% of treated attacks, 10 (36%), a >/=50% reduction in attack frequency, and two (7%), both. Five SAEs occurred and most patients (81%) experienced transient, mild/moderate loss of sensation within distinct maxillary nerve regions; 65% of events resolved within three months.InterpretationOn-demand SPG stimulation using the ATI Neurostimulation System is an effective novel therapy for CCH sufferers, with dual beneficial effects, acute pain relief and observed attack prevention, and has an acceptable safety profile compared to similar surgical procedures. [less ▲]

Cluster headache Award 2012: Central modulation in cluster headache patients treated with occipital nerve stimulation

in Journal of Headache & Pain (2012, September 16)

Theta burst and quadripulse repetitive Transcranial Magnetic Stimulation (rTMS) may have therapeutic potentials in migraine prevention: a proof-of-concept study in healthy volunteers and a pilot-trial in migraine patients.

in Frontiers in Human Neuroscience (2012, September)

A novel CACNA1A mutation results in episodic ataxia with migrainous features without headache

in Cephalalgia : An International Journal of Headache (2012)

Neurostimulation therapies for primary headache disorders: present and future

in Current Opinion in Neurology (2012), 25(3), 269-276

Purpose of review Most pharmacological treatments of primary headache disorders are partially effective and have cumbersome side effects. Therapies with better efficacy and tolerance are needed ... [more ▼]

Purpose of review Most pharmacological treatments of primary headache disorders are partially effective and have cumbersome side effects. Therapies with better efficacy and tolerance are needed. Neurostimulation techniques may have this potential. This is an attempt to summarize the latest clinical trial results published in the field. Recent findings Hypothalamic deep brain stimulation is effective in drug-resistant chronic cluster headache (drCCH) but not riskless. Recent anatomical MRI studies indicate that the effective stimulation sites are rather widespread. Occipital nerve stimulation (ONS) seems to be effective in up to 76% of drCCH patients and its benefit long-lasting. A minority of patients are able to abandon preventive drugs. Its mechanism of action appears nonspecific. In chronic migraine, randomized controlled trials of ONS showed recently encouraging results, but long-term studies are missing. An ongoing sham-controlled trial suggests sphenopalatine ganglion neurostimulation (SPGS) efficacy in drCCH acute treatment, but possibly also in preventive therapy. Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) modulate cortical excitability and connectivity. TMS could prevent headache when applied over the occipital cortex during the migraine aura. Repetitive TMS and tDCS have provided mixed results in a few small studies and warrant further trials. Summary Neurostimulation therapies inaugurate a new era in headache management and offer a promising alternative to medications. Future studies are necessary to provide evidence-based efficacy data, knowledge on their mode of action and information about their pharmaco-economic advantages. [less ▲]

Preventive Antimigraine Drugs

in Fernandez-de-las-Penas, C; Chaitow, L; Schoenen, Jean (Eds.) Multidisciplinary Management of Migraine (2012)

Mesenchymal Stem Cell Graft Improves Recovery after Spinal Cord Injury in Adult Rats through Neurotrophic and Pro-Angiogenic Actions.

in PLoS ONE (2012), 7(6), 39500

Numerous strategies have been managed to improve functional recovery after spinal cord injury (SCI) but an optimal strategy doesn't exist yet. Actually, it is the complexity of the injured spinal cord ... [more ▼]

Numerous strategies have been managed to improve functional recovery after spinal cord injury (SCI) but an optimal strategy doesn't exist yet. Actually, it is the complexity of the injured spinal cord pathophysiology that begets the multifactorial approaches assessed to favour tissue protection, axonal regrowth and functional recovery. In this context, it appears that mesenchymal stem cells (MSCs) could take an interesting part. The aim of this study is to graft MSCs after a spinal cord compression injury in adult rat to assess their effect on functional recovery and to highlight their mechanisms of action. We found that in intravenously grafted animals, MSCs induce, as early as 1 week after the graft, an improvement of their open field and grid navigation scores compared to control animals. At the histological analysis of their dissected spinal cord, no MSCs were found within the host despite their BrdU labelling performed before the graft, whatever the delay observed: 7, 14 or 21 days. However, a cytokine array performed on spinal cord extracts 3 days after MSC graft reveals a significant increase of NGF expression in the injured tissue. Also, a significant tissue sparing effect of MSC graft was observed. Finally, we also show that MSCs promote vascularisation, as the density of blood vessels within the lesioned area was higher in grafted rats. In conclusion, we bring here some new evidences that MSCs most likely act throughout their secretions and not via their own integration/differentiation within the host tissue. [less ▲]

Effect of systemic kynurenine on cortical spreading depression and its modulation by sex hormones in rat.

in Experimental Neurology (2012), 236(2), 207-14

BACKGROUND: The aura symptoms in migraine are most likely due to cortical spreading depression (CSD). CSD is favored by NMDA receptor activation and increased cortical excitability. The latter probably ... [more ▼]

BACKGROUND: The aura symptoms in migraine are most likely due to cortical spreading depression (CSD). CSD is favored by NMDA receptor activation and increased cortical excitability. The latter probably explains why migraine with aura may appear when estrogen levels are high, like during pregnancy. Kynurenic acid, a derivative of tryptophan metabolism, is an endogenous NMDA receptor antagonist whose cerebral concentrations can be augmented by systemic administration of its precursor l-kynurenine. OBJECTIVE: To determine if exogenous administration of l-kynurenine is able to influence KCl-induced CSD in rat, if the effect is sex-dependent and if it differs in females between the phases of the estrous cycle. METHODS: Adult Sprague-Dawley rats (n=8/group) received intraperitoneal (i.p.) injections of l-kynurenine (L-KYN, 300mg/kg), L-KYN combined with probenecid (L-KYN+PROB) that increases cortical concentration of KYNA by blocking its excretion from the central nervous system, probenecid alone (PROB, 200mg/kg) or NaCl. Cortical kynurenic acid concentrations were determined by HPLC (n=7). Thirty minutes after the injections, CSDs were elicited by application of 1M KCl over the occipital cortex and recorded by DC electrocorticogram. In NaCl and L-KYN groups, supplementary females were added and CSD frequency was analyzed respective to the phases of the estrous cycle determined by vaginal smears. RESULTS: In both sexes, PROB, L-KYN and L-KYN+PROB increased cortical kynurenic acid level. PROB, L-KYN and L-KYN+PROB with increasing potency decreased CSD frequency in female rats, while in males such an effect was significant only for L-KYN+PROB. The inhibitory effect of L-KYN on CSD frequency in females was most potent in diestrus. CONCLUSION: l-Kynurenine administration suppresses CSD, most likely by increasing kynurenic acid levels in the cortex. Females are more sensitive to this suppressive effect of l-kynurenine than males. These results emphasize the role of sex hormones in migraine and open interesting novel perspectives for its preventive treatment. [less ▲]