Genetik der Migräne

Genetics of migraine: an update

An important genetic component of migraine was systematically established by epidemiological studies in the 1990s. Over the past 15 years, significant progress has been made in unraveling the genetic basis and pathophysiological mechanisms of familial hemiplegic migraine, a rare and severe autosomal-dominant subtype of migraine with aura. Three different causative genes (CACNA1A, ATP1A2 and SCN1A), all of which are involved in cerebral ion translocation, have been identified. Functional studies and mouse models have shown that mutations in these genes, by different mechanisms, cause a disturbed cerebral glutamate homeostasis and, thus, increase susceptibility to cortical spreading depression, the likely correlate of migraine aura. More recently, genome-wide association studies have, for the first time, detected robust risk variants associated with the more common, genetically complex types of migraine, which has generated new perspectives for genetic research in migraine. This review summarizes the current knowledge about migraine genetics, with a focus on both familial hemiplegic migraine and recent results of genome-wide association studies.

[Facial and eye pain - Neurological differential diagnosis]

Head and facial pain are common in neurological practice and the pain often arises in the orbit or is referred into the eye. This is due to the autonomic innervation of the eye and orbit. There are acute and chronic pain syndromes. This review gives an overview of the differential diagnosis and treatment. Idiopathic headache syndromes, such as migraine and cluster headache are the most frequent and are often debilitating conditions. Trigemino-autonomic cephalalgias (SUNCT and SUNA) have to be taken into account, as well as trigeminal neuralgia. Trigemino-autonomic headache after eye operations can be puzzling and often responds well to triptans. Every new facial pain not fitting these categories must be considered symptomatic and a thorough investigation is mandatory including magnetic resonance imaging. Infiltrative and neoplastic conditions frequently lead to orbital pain. As a differential diagnosis Tolosa-Hunt syndrome and Raeder syndrome are inflammatory conditions sometimes mimicking neoplasms. Infections, such as herpes zoster ophthalmicus are extremely painful and require rapid therapy. It is important to consider carotid artery dissection as a cause for acute eye and neck pain in conjunction with Horner's syndrome and bear in mind that vascular oculomotor palsy is often painful. All of the above named conditions should be diagnosed by a neurologist with special experience in pain syndromes and many require an interdisciplinary approach.

[What is migraine?]

Migraine is a multifactorial and heterogeneous disorder. Diagnostic criteria have been established by the International Headache Society, however these are only supportive in terms of definition. The pathophysiology involves neuronal and vascular phenomena. The former is supported by the cortical spreading depression being the aura correlate and by brainstem and hypothalamic activation during the pain phase; the latter is suggested by the association between migraine and cardiovascular disease and findings of pathological vasoreactivity and endothelial dysfunction. Triptans and calcitonin gene-related peptide receptor antagonists show only a relative migraine-specific action; up to 30% of patients are nonresponders. Despite a clear genetic component, the discovery of specific genes for common forms of migraine remains elusive. Electrophysiological studies consistently indicate a characteristic "dyshabituation" concurring with clinical features of altered sensory perception. The age- and sex-specific pattern along with the effect of external factors on the course of migraine argue in favor of the involvement of epigenetic mechanisms. Knowledge about migraine is still limited, which hampers a definition.

A case of Sturge-Weber syndrome with symptomatic hemiplegic migraine: clinical and multimodality imaging data during a prolonged attack

Hemiplegic migraine (HM) in the setting of Sturge-Weber syndrome (SWS) has been previously described. Here, we report clinical and multimodal imaging data on a 21-year-old man with SWS and HM, who presented during an acute HM attack with a dense left-hemispheric syndrome (expressive aphasia and right sensorimotor hemiplegia), lasting for more than 10 days. Repeated EEGs were without evidence of status epilepticus. Consistent with previous findings in prolonged migraine aura, perfusion computed tomography demonstrated left-hemispheric hyperperfusion on day 7. 18F-FDG positron emission tomography (day 7) revealed left-hemispheric hypermetabolism. After 14 days, the patient was symptom-free and discharged home. Follow-up after 30 days showed normal neurological status. Our observation confirms and reinforces the comorbidity of SWS and HM and shows that prolonged HM attacks are associated with complex changes of both cerebral perfusion and glucose metabolism. A pathophysiological model explaining both the association between SWS/HM and the observed imaging changes is presented.