Headache Frontiers: Using Magnetoencephalography to Investigate Pathophysiology of Chronic Migraine

Headache in Sturge-Weber syndrome: A systematic review

BACKGROUND

Sturge-Weber syndrome (SWS) is a neurocutaneous disorder for which the neurological aspects, particularly headaches, remain poorly understood, despite significantly affecting morbidity. The present study aimed to elucidate the prevalence, characteristics and treatment strategies, as well as explore the pathogenesis of headaches, in SWS.

METHODS

Using Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, we systematically reviewed observational studies, case reports and series from eight databases (Cochrane Library, EBSCO, Embase, Medline, PubMed, Science Direct, Scopus and Web of Science), published from 1978 to 2023, to investigate the prevalence, characteristics, medication response and pathogenic theories of headaches in SWS.

RESULTS

The review analyzed 48 studies, uncovering headache prevalence between 37% and 71%. Migraine-like headache affected up to 52% of individuals. Prophylactic and acute treatments included non-steroidal anti-inflammatory drugs, triptans and antiepileptic drugs, despite the lack of established guidelines. Life-threatening headaches in SWS are uncommon, typically accompanied by other neurological symptoms. The pathogenesis of headaches in SWS is considered to involve venous congestion and neuronal hyperexcitability linked to leptomeningeal angiomas.

CONCLUSIONS

Headaches occur more frequently in individuals with SWS than in the general population. Despite symptoms meeting migraine criteria, these headaches should be considered secondary to vascular conditions. Implementing acute and prophylactic treatment is advised to reduce the impact on patients' lives.

Auditory attention alterations in migraine: A behavioral and MEG/EEG study

OBJECTIVES

To evaluate alterations of top-down and/or bottom-up attention in migraine and their cortical underpinnings.

METHODS

19 migraineurs between attacks and 19 matched control participants performed a task evaluating jointly top-down and bottom-up attention, using visually-cued target sounds and unexpected task-irrelevant distracting sounds. Behavioral responses and magneto- and electro-encephalography signals were recorded. Event-related potentials and fields were processed and source reconstruction was applied to event-related fields.

RESULTS

At the behavioral level, neither top-down nor bottom-up attentional processes appeared to be altered in migraine. However, migraineurs presented heightened evoked responses following distracting sounds (orienting component of the N1 and Re-Orienting Negativity, RON) and following target sounds (orienting component of the N1), concomitant to an increased recruitment of the right temporo-parietal junction. They also displayed an increased effect of the cue informational value on target processing resulting in the elicitation of a negative difference (Nd).

CONCLUSIONS

Migraineurs appear to display increased bottom-up orienting response to all incoming sounds, and an enhanced recruitment of top-down attention.

SIGNIFICANCE

The interictal state in migraine is characterized by an exacerbation of the orienting response to attended and unattended sounds. These attentional alterations might participate to the peculiar vulnerability of the migraine brain to all incoming stimuli.

The visual system as target of non-invasive brain stimulation for migraine treatment: Current insights and future challenges

The visual network is crucially implicated in the pathophysiology of migraine. Several lines of evidence indicate that migraine is characterized by an altered visual cortex excitability both during and between attacks. Visual symptoms, the most common clinical manifestation of migraine aura, are likely the result of cortical spreading depression originating from the extrastriate area V3A. Photophobia, a clinical hallmark of migraine, is linked to an abnormal sensory processing of the thalamus which is converged with the non-image forming visual pathway. Finally, visual snow is an increasingly recognized persistent visual phenomenon in migraine, possibly caused by increased perception of subthreshold visual stimuli. Emerging research in non-invasive brain stimulation (NIBS) has vastly developed into a diversity of areas with promising potential. One of its clinical applications is the single-pulse transcranial magnetic stimulation (sTMS) applied over the occipital cortex which has been approved for treating migraine with aura, albeit limited evidence. Studies have also investigated other NIBS techniques, such as repetitive TMS (rTMS) and transcranial direct current stimulation (tDCS), for migraine prophylaxis but with conflicting results. As a dynamic brain disorder with widespread pathophysiology, targeting migraine with NIBS is challenging. Furthermore, unlike the motor cortex, evidence suggests that the visual cortex may be less plastic. Controversy exists as to whether the same fundamental principles of NIBS, based mainly on findings in the motor cortex, can be applied to the visual cortex. This review aims to explore existing literature surrounding NIBS studies on the visual system of migraine. We will first provide an overview highlighting the direct implication of the visual network in migraine. Next, we will focus on the rationale behind using NIBS for migraine treatment, including its effects on the visual cortex, and the shortcomings of currently available evidence. Finally, we propose a broader perspective of how novel approaches, the concept of brain networks and the integration of multimodal imaging with computational modeling, can help refine current NIBS methods, with the ultimate goal of optimizing a more individualized treatment for migraine.

An Apparently Classical Case Report of Sturge-Weber Syndrome

Sturge-Weber syndrome is a rare, sporadic, congenital neurocutaneous syndrome, likely due to abnormal development of the cephalic microvasculature. Symptoms and signs depend on the extent and location of the venous dysplasia. We describe a case of a 33-year-old woman presenting with drug-resistant epilepsy, chronic headache, and recurring nonepileptic seizures. Computed tomography and magnetic resonance imaging scans showed severe frontoparietal right hemisphere atrophy, prevalent right frontoparietal leptomeningeal enhancement, circumscribed angioma of the left rolandic sulcus, and prominent deep venous system. We report an apparently classical Sturge-Weber syndrome and hypothesize a shared pathophysiologic mechanism for clinical symptoms. We speculate that all the main symptoms observed in our patient could be the expression of a functional imbalance between the atrophic right hemisphere and the hyperexcitable left cortex.

Biomarker Development for Brain-Based Disorders: Recent Progress in Psychiatry

Biomarkers are biological measures that are indicative of a specific disorder, its severity or response to treatment. They are widely used in many areas of medicine, but biomarker development for brain-based disorders lags behind. Using examples from the field of psychiatry, this article reviews the concepts of biomarkers, challenges to their development and the recent progress along those lines. In addition to discussing historical biomarker candidates such as cortisol or catecholamine levels, we include progress from recent genetic, epigenetic, proteomic, neuroimaging and EEG studies. Successful identification of biomarkers will advance the field of psychiatry towards the goal of biological tests for diagnosis, symptom management and treatment response.