Nociception-specific blink reflex: pharmacology in healthy volunteers.

BACKGROUND: The physiology and pharmacology of activation or perception of activation of pain-coding trigeminovascular afferents in humans is fundamental to understanding the biology of headache and developing new treatments. METHODS: The blink reflex was elicited using a concentric electrode and recorded in four separate sessions, at baseline and two minutes after administration of ramped doses of diazepam (final dose 0.07 mg/kg), fentanyl (final dose 1.11 µg/kg), ketamine (final dose 0.084 mg/kg) and 0.9 % saline solution. The AUC (area under the curve, µV*ms) and the latency (ms) of the ipsi- and contralateral R2 component of the blink reflex were calculated by PC-based offline analysis. Immediately after each block of blink reflex recordings certain psychometric parameters were assessed. RESULTS: There was an effect due to DRUG on the ipsilateral (F 3,60 = 7.3, P < 0.001) AUC as well as on the contralateral (F 3,60 = 6.02, P < 0.001) AUC across the study. A significant decrement in comparison to placebo was observed only for diazepam, affecting the ipsilateral AUC. The scores of alertness, calmness, contentedness, reaction time and precision were not affected by the DRUG across the sessions. CONCLUSION: Previous studies suggest central, rather than peripheral changes in nociceptive trigeminal transmission in migraine. This study demonstrates a robust effect of benzodiazepine receptor modulation of the nociception specific blink reflex (nBR) without any µ-opiate or glutamate NMDA receptor component. The nociception specific blink reflex offers a reproducible, quantifiable method of assessment of trigeminal nociceptive system in humans that can be used to dissect pharmacology relevant to primary headache disorders.

[Therapy and care of patients with chronic migraine: expert recommendations of the German Migraine and Headache Society/German Society for Neurology as well as the Austrian Headache Society/Swiss Headache Society]. / Therapie und Versorgung bei chronischer Migräne : Expertenempfehlung der Deutschen Migräne- und Kopfschmerzgesellschaft/Deutsche Gesellschaft für Neurologie sowie der Österreichischen Kopfschmerzgesellschaft/Schweizerischen Kopfwehgesellschaft.

Chronic migraine (CM) was first defined in the second edition of the International Headache Society (IHS) classification in 2004. The definition currently used (IHS 2006) requires the patient to have headache on more than 15 days/month for longer than 3 months and a migraine headache on at least 8 of these monthly headache days and that there is no medication overuse. In daily practice the majority of the patients with CM also report medication overuse but it is difficult to determine whether the use is the cause or the consequence of CM. Most the patients also have other comorbidities, such as depression, anxiety and chronic pain at other locations. Therapy has to take this complexity into consideration and is generally multimodal with behavioral therapy, aerobic training and pharmacotherapy. The use of analgesics should be limited to fewer than 15 days per month and use of triptans to fewer than 10 days per month. Drug treatment should be started with topiramate, the drug with the best scientific evidence. If there is no benefit, onabotulinum toxin A (155-195 Units) should be used. There is also some limited evidence that valproic acid and amitriptyline might be beneficial. Neuromodulation by stimulation of the greater occipital nerve or vagal nerve is being tested in studies and is so far an experimental procedure only.

Transdermal rotigotine causes impulse control disorders in patients with restless legs syndrome.

INTRODUCTION: Dopaminergic drugs are the mainstay of treatment for restless legs syndrome (RLS). We analyzed the frequency and clinical characteristics of impulse control disorders (ICD) in patients with RLS on transdermal rotigotine treatment. METHODS: Retrospective case series at a university movement disorder clinic (n = 28, 17 women). Symptoms of ICD were assessed via detailed history taking and scoring with the Zurich Screening Questionnaire for ICD (ZICD) prior to and after initiation of treatment. RESULTS: None of the patients had a history of ICD prior to treatment. Baseline mean scores for patients who did (8.0 ± 2.5) and did not (6.2 ± 2.7) develop ICD under treatment did not differ. Six male patients (21%) developed various symptoms of ICD (mean ZICD scores 20.7 ± 10.2) on rotigotine treatment (mean dose: 3.8 mg/d), including binge eating, hypersexuality, compulsive shopping, pathological gambling, and punding, equaling a prevalence rate of 21%. Also in the non-ICD group, ZICD scores increased (7.5 ± 2.8). CONCLUSION: This is the first report of ICD in patients treated with transdermal rotigotine for RLS. In contrast to literature, even low doses of rotigotine (mean 3.8 mg/d) can cause ICD. Therefore every prescribing physician should be aware that ICD may emerge in both RLS and PD patients on any dopaminergic treatment, and should actively ask for such symptoms. The ZICD questionnaire not only replicated the findings of detailed history taking but also showed an increased tendency towards impulsive behaviour in subjects that did not develop ICD.

Focal neuromyotonia: do I love you?

We present a rare case of focal neuromyotonia in a 73-year-old woman with a follow up of 5 years. The clinical picture showed a fixed contraction of the 3rd and 4th finger of the left hand. Similar to other published cases, our patient suffered from COPD and was treated with beta-2-sympathomimetics. This clinical picture shows a rare but rather salient differential diagnosis of Dupuytren's contracture. EMG of the affected muscles may yield a diagnosis and prevent the patient from a long and ineffective treatment "odyssey".

Headache patients in primary care and a tertiary care unit in Zürich, Switzerland.

The Headache and Pain Clinic (HPC) is a unit of the Zürich Neurology Department, established in 1966. In the present study demographic features, clinical characteristics and medical management of primary and tertiary care patients were compared in two groups of 181 patients each, seen by general practitioners (GPs) or the HPC, respectively, for primary headaches in 1998. There was a preponderance of women and the socially underprivileged in both samples. Chronic headache was overrepresented in the HPC (44.7%). Loss of work for >2 months was found exclusively in the HPC (9.9%). Of the GP patients, 40% were using triptans and 26.5% in the HPC. One-third of both groups had had complementary and alternative medical treatment. Differences in management strategies reflected differences in headache severity and chronicity. Results indicated that remaining shortcomings of diagnosis and treatment of headache in primary care could be minimized by involving GPs in similar non-commercial studies.

Abnormal blink reflex studies in a patient with supraorbital neuralgia.

A 44-year-old female with gabapentin-responsive supraorbital neuralgia is presented. She had pre- and post-treatment nociceptive-specific blink reflexes carried out which tracked the good clinical outcome from treatment. The results of the electrophysiological testing imply some central component to the pathophysiology of supra-orbital neuralgia.

Familial SUNCT.

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) is a rare type of primary headache. In this report we describe the occurrence of SUNCT in a family. Unfortunately, one of the siblings was already dead. However, clear and detailed information from close relatives and her general practitioner confirmed the diagnosis of SUNCT. It is likely that genetic factors contribute to all types of trigeminal autonomic cephalalgias.