Headache and Other Pain Syndromes in Multiple Sclerosis: A Narrative Review.

Multiple sclerosis is a chronic and progressive neurological disease, with an important socio-economic burden. Over time, an increased incidence of headaches like migraines and tension headaches has been observed among these patients. Headaches have not been considered as multiple sclerosis-related symptoms, even representing a red flag for multiple sclerosis diagnosis. It is uncertain whether the headache-multiple sclerosis association could be explained by the presence of common triggers or a common physiopathological mechanism (involvement of tertiary B-cell follicles). An important differential diagnosis is between multiple sclerosis attacks and migraines with aura, which can also be associated with neurological deficits. Another important aspect is the occurrence or exacerbation of the cephalalgic syndrome after the initiation of therapy for multiple sclerosis (DMTs), or the improvement of headache after the initiation of certain DMT drugs. In addition to headaches, individuals diagnosed with multiple sclerosis often report experiencing diverse pain syndromes, contributing to an additional decline in their overall quality of life. These syndromes are frequently neglected, the focus being on slowing down the progression of neurological deficits. This review aims to evaluate the characteristics of multiple-sclerosis-related headaches (frequency, possible correlation with attacks, and disease-modifying therapies) and the key distinctions in imaging characteristics between demyelinating lesions in multiple sclerosis and those observed in cases of primary headaches.

Migraine Comorbidities.

Novel knowledge about the interrelationships and reciprocal effects of migraine and epilepsy, migraine and mood disorders, or migraine and irritable bowel syndrome has emerged in recent decades. Over time, comorbid pathologies associated with migraine that share common physiopathological mechanisms were studied. Among these studied pathologies is epilepsy, a disorder with common ion channel dysfunctions as well as dysfunctions in glutamatergic transmission. A high degree of neuronal excitement and ion channel abnormalities are associated with epilepsy and migraine and antiepileptic drugs are useful in treating both disorders. The coexistence of epilepsy and migraine may occur independently in the same individual or the two may be causally connected. The relationship between cortical spreading depression (CSD) and epileptic foci has been suggested by basic and clinical neuroscience research. The most relevant psychiatric comorbidities associated with migraine are anxiety and mood disorders, which influence its clinical course, treatment response, and clinical outcome. The association between migraine and major depressive disorder can be explained by a robust molecular genetic background. In addition to its role as a potent vasodilator, CGRP is also involved in the transmission of nociception, a phenomenon inevitably linked with the stress and anxiety caused by frequent migraine attacks. Another aspect is the role of gut microbiome in migraine's pathology and the gut-brain axis involvement. Irritable bowel syndrome patients are more likely to suffer migraines, according to other studies. There is no precise explanation for how the gut microbiota contributes to neurological disorders in general and migraines in particular. This study aims to show that migraines and comorbid conditions, such as epilepsy, microbiota, or mood disorders, can be connected from the bench to the bedside. It is likely that these comorbid migraine conditions with common pathophysiological mechanisms will have a significant impact on best treatment choices and may provide clues for future treatment options.

Towards an electroencephalographic measure of awareness based on the reactivity of oscillatory macrostates to hearing a subject's own name.

We proposed that the brain's electrical activity is composed of a sequence of alternating states with repeating topographic spectral distributions on scalp electroencephalogram (EEG), referred to as oscillatory macrostates. The macrostate showing the largest decrease in the probability of occurrence, measured as a percentage (reactivity), during sensory stimulation was labelled as the default EEG macrostate (DEM). This study aimed to assess the influence of awareness on DEM reactivity (DER). We included 11 middle cerebral artery ischaemic stroke patients with impaired awareness having a median Glasgow Coma Scale (GCS) of 6/15 and a group of 11 matched healthy controls. EEG recordings were carried out during auditory 1 min stimulation epochs repeating either the subject's own name (SON) or the SON in reverse (rSON). The DEM was identified across three SON epochs alternating with three rSON epochs. Compared with the patients, the DEM of controls contained more posterior theta activity reflecting source dipoles that could be mapped in the posterior cingulate cortex. The DER was measured from the 1 min quiet baseline preceding each stimulation epoch. The difference in mean DER between the SON and rSON epochs was measured by the salient EEG reactivity (SER) theoretically ranging from -100% to 100%. The SER was 12.4 ± 2.7% (Mean ± standard error of the mean) in controls and only 1.3 ± 1.9% in the patient group (P < 0.01). The patient SER decreased with the Glasgow Coma Scale. Our data suggest that awareness increases DER to SON as measured by SER.

Headache onset after vaccination against SARS-CoV-2: a systematic literature review and meta-analysis.

BACKGROUND: Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are used to reduce the risk of developing Coronavirus Disease 2019 (COVID-19). Despite the significant benefits in terms of reduced risk of hospitalization and death, different adverse events may present after vaccination: among them, headache is one of the most common, but nowadays there is no summary presentation of its incidence and no description of its main features. METHODS: We searched PubMed and EMBASE covering the period between January 1st 2020 and August 6th, 2021, looking for record in English and with an abstract and using three main search terms (with specific variations): COVID-19/SARS-CoV-2; Vaccination; headache/adverse events. We selected manuscript including information on subjects developing headache after injection, and such information had to be derived from a structured form (i.e. no free reporting). Pooled estimates and 95% confidence intervals were calculated. Analyses were carried out by vaccine vs. placebo, by first vs. second dose, and by mRNA-based vs. "traditional" vaccines; finally, we addressed the impact of age and gender on post-vaccine headache onset. RESULTS: Out of 9338 records, 84 papers were included in the review, accounting for 1.57 million participants, 94% of whom received BNT162b2 or ChAdOx1. Headache was generally the third most common AE: it was detected in 22% (95% CI 18-27%) of subjects after the first dose of vaccine and in 29% (95% CI 23-35%) after the second, with an extreme heterogeneity. Those receiving placebo reported headache in 10-12% of cases. No differences were detected across different vaccines or by mRNA-based vs. "traditional" ones. None of the studies reported information on headache features. A lower prevalence of headache after the first injection of BNT162b2 among older participants was shown. CONCLUSIONS: Our results show that vaccines are associated to a two-fold risk of developing headache within 7 days from injection, and the lack of difference between vaccine types enable to hypothesize that headache is secondary to systemic immunological reaction than to a vaccine-type specific reaction. Some descriptions report onset within the first 24 h and that in around one-third of the cases, headache has migraine-like features with pulsating quality, phono and photophobia; in 40-60% of the cases aggravation with activity is observed. The majority of patients used some medication to treat headache, the one perceived as the most effective being acetylsalicylic acid.

A method to assess the default EEG macrostate and its reactivity to stimulation.

OBJECTIVE: The default mode network (DMN) is deactivated by stimulation. We aimed to assess the DMN reactivity impairment by routine EEG recordings in stroke patients with impaired consciousness. METHODS: Binocular light flashes were delivered at 1 Hz in 1-minute epochs, following a 1-minute baseline (PRE). The EEG was decomposed in a series of binary oscillatory macrostates by topographic spectral clustering. The most deactivated macrostate was labeled the default EEG macrostate (DEM). Its reactivity (DER) was quantified as the decrease in DEM occurrence probability during stimulation. A normalized DER index (DERI) was calculated as DER/PRE. The measures were compared between 14 healthy controls and 32 comatose patients under EEG monitoring following an acute stroke. RESULTS: The DEM was mapped to the posterior DMN hubs. In the patients, these DEM source dipoles were 3-4 times less frequent and were associated with an increased theta activity. Even in a reduced 6-channel montage, a DER below 6.26% corresponding to a DERI below 0.25 could discriminate the patients with sensitivity and specificity well above 80%. CONCLUSION: The method detected the DMN impairment in post-stroke coma patients. SIGNIFICANCE: The DEM and its reactivity to stimulation could be useful to monitor the DMN function at bedside.

Imaging the effective networks associated with cortical function through intracranial high-frequency stimulation.

Direct electrical stimulation (DES) is considered to be the gold standard for mapping cortical function. A careful mapping of the eloquent cortex is key to successful resective or ablative surgeries, with a minimal postoperative deficit, for treatment of drug-resistant epilepsy. There is accumulating evidence suggesting that not only local, but also remote activations play an equally important role in evoking clinical effects. By introducing a new intracranial stimulation paradigm and signal analysis methodology allowing to disambiguate EEG responses from stimulation artifacts we highlight the spatial extent of the networks associated with clinical effects. Our study includes 26 patients that underwent stereoelectroencephalographic investigations for drug-resistant epilepsy, having 337 depth electrodes with 4,351 contacts sampling most brain structures. The routine high-frequency electrical stimulation protocol for eloquent cortex mapping was altered in a subtle way, by alternating the polarity of the biphasic pulses in a train, causing the splitting the spectral lines of the artifactual components, exposing the underlying tissue response. By performing a frequency-domain analysis of the EEG responses during DES we were able to capture remote activations and highlight the effect's network. By using standard intersubject averaging and a fine granularity HCP-MMP parcellation, we were able to create local and distant connectivity maps for 614 stimulations evoking specific clinical effects. The clinical value of such maps is not only for a better understanding of the extent of the effects' networks guiding the invasive exploration, but also for understanding the spatial patterns of seizure propagation given the timeline of the seizure semiology.

Correction: Exploring the reproducibility of functional connectivity alterations in Parkinson's disease.

[This corrects the article DOI: 10.1371/journal.pone.0188196.].

Exploring the reproducibility of functional connectivity alterations in Parkinson's disease.

Since anatomic MRI is presently not able to directly discern neuronal loss in Parkinson's Disease (PD), studying the associated functional connectivity (FC) changes seems a promising approach toward developing non-invasive and non-radioactive neuroimaging markers for this disease. While several groups have reported such FC changes in PD, there are also significant discrepancies between studies. Investigating the reproducibility of PD-related FC changes on independent datasets is therefore of crucial importance. We acquired resting-state fMRI scans for 43 subjects (27 patients and 16 normal controls, with 2 replicate scans per subject) and compared the observed FC changes with those obtained in two independent datasets, one made available by the PPMI consortium (91 patients, 18 controls) and a second one by the group of Tao Wu (20 patients, 20 controls). Unfortunately, PD-related functional connectivity changes turned out to be non-reproducible across datasets. This could be due to disease heterogeneity, but also to technical differences. To distinguish between the two, we devised a method to directly check for disease heterogeneity using random splits of a single dataset. Since we still observe non-reproducibility in a large fraction of random splits of the same dataset, we conclude that functional heterogeneity may be a dominating factor behind the lack of reproducibility of FC alterations in different rs-fMRI studies of PD. While global PD-related functional connectivity changes were non-reproducible across datasets, we identified a few individual brain region pairs with marginally consistent FC changes across all three datasets. However, training classifiers on each one of the three datasets to discriminate PD scans from controls produced only low accuracies on the remaining two test datasets. Moreover, classifiers trained and tested on random splits of the same dataset (which are technically homogeneous) also had low test accuracies, directly substantiating disease heterogeneity.

Increased connectivity between sensorimotor and attentional areas in Parkinson's disease.

INTRODUCTION: Our study is using Independent Component Analysis (ICA) to evaluate functional connectivity changes in Parkinson's disease (PD) in an unbiased manner. METHODS: Resting-state functional magnetic resonance imaging (rs-fMRI) data was collected for 27 PD patients and 16 healthy subjects. Differences for intra- and inter-network connectivity between healthy subjects and patients were investigated using FMRIB Software Library (FSL) tools (Melodic ICA, dual regression, FSLNets). RESULTS: Twenty-three ICA maps were identified as components of neuronal origin. For intra-network connectivity changes, eight components showed a significant connectivity increase in patients (p < 0.05); these were correlated with clinical scores and were largest for (sensori)motor networks. For inter-network connectivity changes, we found higher connectivity between the sensorimotor network and the spatial attention network (p = 0.0098) and lower connectivity between anterior and posterior default mode networks (DMN) (p = 0.024), anterior DMN and visual recognition networks (p = 0.026), as well as between visual attention and main dorsal attention networks (p = 0.03), for patients as compared to healthy subjects. The area under the Receiver Operating Characteristics (ROC) curve for the best predictor (partial correlation between sensorimotor and spatial attention networks) was 0.772. These functional alterations were not associated with any gray or white matter structural changes. CONCLUSION: Our results show higher connectivity between sensorimotor and spatial attention areas in patients that may be related to the reduced movement automaticity in PD.

Symptomatic "Migraine with Aura" Due to Occipital Arteriovenous Malformation or "Headache Attributed to Arteriovenous Malformation (AVM)" Associated with Simple Partial Seizures in an Adolescent Patient - Case Presentation.

Arteriovenous malformations (AVMs) of the brain consist in a network of dilated vessels that form an abnormal communication between the arterial and venous system. The clinical presentation of AVM could be with acute haemorrhagic stroke, due to their rupture or with seizures or recurrent headache. We present the case of 12 year old male child who was admitted in our clinic for "migraine with visual aura"-like episodes with visual positive phenomena. On cerebral MRI (T1, contrast enhancement) we found a right occipital arterio-venous malformation of 2-3 cm in diameter. The patient was referred to gamma knife stereotactic radiosurgery treatment.

Effects and tolerability of betahistine in patients with vestibular vertigo: results from the Romanian contingent of the OSVaLD study.

BACKGROUND AND METHODS: An efficacy population of 245 patients with vertigo of peripheral vestibular origin was recruited in Romania as part of a 3-month multinational, post-marketing surveillance study of open-label betahistine 48 mg/day (OSVaLD). Endpoints were changes in the Dizziness Handicap Index (primary endpoint), Medical Outcome Study Short-Form 36 (SF-36v2(®)), and the Hospital Anxiety and Depression Scale. RESULTS: During treatment, the total Dizziness Handicap Index score improved by 41 points (on a 100-point scale). Statistically significant improvements of 12-14 points were recorded in all three domains of the Dizziness Handicap Index scale (P<0.0001). Betahistine therapy was also accompanied by progressive improvements in mean Hospital Anxiety and Depression anxiety and depression scores (P<0.0001) and significant improvements in both the physical and mental component summary of the SF-36v2 (P<0.0001). Betahistine was well tolerated, with only one suspected adverse drug reaction recorded in the Romanian safety population (n=259). CONCLUSION: Betahistine 48 mg/day was associated with improvements in multiple measures of health-related quality of life and had a good tolerability profile in these Romanian patients with recurrent peripheral vestibular vertigo.

Chronic migraine - new treatment options.

Chronic migraine (CM) is defined as headache occurring more than fifteen days/month for at least three consecutive months, with headache having the clinical features of migraine without aura for at least eight days per month. Recently, new treatment options became available in chronic migraine patients. Topiramate is effective in chronic migraine, in the presence or absence of medication overuse, and/or other migraine prophylaxis. Efficacy of onabotulinumtoxin A as a preventive treatment of chronic migraine has been shown in the PREEMPT studies. Occipital nerve stimulation (ONS) is an invasive treatment for refractory chronic headaches. ONS has encouraging results in refractory chronic migraine patients in commercially funded, multi-centre randomized trials.

Microemboli detection in patients with carotid artery stenting--a potential marker for future cognitive impairment?

AIMS: To monitor the long-term cognitive function evolution of patients undergoing carotid artery stenting (CAS), using detection of embolic signals (ES) as a potential marker of cognitive decline. METHODS: This is an ongoing prospective nonrandomized single-center study of patients undergoing carotid artery angioplasty and stenting using standard techniques. Neurologic status is evaluated by history, physical examination and the National Institutes of Health Stroke Scale. A complete Doppler-ultrasound investigation of the brain-supplying arteries has been performed in every patient. A 45minute cognitive battery designed to assess motor speed/coordination and executive function, psychomotor speed, language (naming), working memory/concentration, verbal fluency, and learning/memory is performed by a certified neuropsychologist in the first week after CAS and repeated a year after the procedure. Each patient undergoes bilateral ultrasonographic-Doppler monitoring of the middle cerebral artery (MCA) for microemboli detection. The patients are monitored during the first week after CAS and again a year after stenting. RESULTS: 32 patients were included. The mean baseline Mini-Mental State Examination (MMSE) score was 28.7 points. During the first ultrasonographic monitoring 28 patients (87.5%) had at least three times more ES detected on the stented side (a mean of 24ES/30minutes was detected in the stented side compared to a mean of 4ES/30min in the non-stented side). At the one-year follow-up 68% of the patients who have undergone CAS maintain a high number of ES detected in the territory of the stented carotid artery, finding that is well correlated with the cognitive decline in those patients, as assessed by the MMSE score. CONCLUSIONS: ES detection is a useful tool for predicting cognitive decline that can be used to monitor CAS patients and adjust preventive measures in order to avoid progression of vascular cognitive impairment. It is important that further studies comparing carotid endarterectomy and CAS monitor long-term cognitive function outcome.

Neurocognitive disorders in DSM 5 project - personal comments.

The actual criteria for diagnosis of dementia have many shortages, due to the fact that both DSM 4 and ICD 10 criteria are essentially based on the typical evolution of Alzheimer's disease, which is the most frequent, but not the only one cause of dementia in the general population. In the new project of DSM-5, proposed for public debate by the American Psychiatric Association (APA), new criteria for neurocognitive disorders are defined which seem more suitable to cover in a much more appropriate way all the entities potentially leading to dementia. In our view, these new criteria are also in line with the updated knowledge about these diseases as they are reflected in the recent publications and recommendations of international experts and medical associations.

Diffusion abnormality maps in demyelinating disease: correlations with clinical scores.

BACKGROUND AND PURPOSE: Magnetic resonance imaging (MRI) has been explored as a noninvasive tool to assess pathology in multiple sclerosis (MS) patients. However, the correlation between classical MRI measures and physical disability is modest in MS. The diffusion tensor imaging (DTI) MRI technique holds particular promise in this regard. The present study shows brain regions where FA and individual diffusivities abnormalities are present and check their correlations with physical disability clinical scores. METHODS: Eight patients and 12 matched healthy controls were recruited. The Multiple Sclerosis Functional Composite was administered. For MR-DTI acquisitions, a Genesis Signa 1.5 T MR system, an EP/SE scanning sequence, 25 gradient directions were used. RESULTS: Tract Based Spatial Statistics (TBSS) group comparisons showed reduced FA and increased individual diffusivities in several brain regions in patients. Significant correlations were found between FA and: EDSS, 9-HPT(NON)DOM and 25 FW score; between λ2 and: P100 (r&l), 9-HPT(NON)DOM and 25 FW; between λ3 and: 9-HPT(NON)DOM and 25 FW score. CONCLUSIONS: Fractional anisotropy and individual radial diffusivities proved to be important markers of motor disabilities in MS patients when the disease duration mean and the disability scores values range are relatively high.

Diffusion Tensor Imaging (DTI) - A New Imaging Technique Applyed in Multiple Sclerosis.

Some patients with ischemic stroke are subject to hemorrhagic transformation, a complication leading to increased patient morbidity and mortality. The discovery of biomarkers that can be used to identify ischemic strokes prone to this complication are very important for the clinical practice because therapy could be altered to mitigate the risk. We discuss here the results of a trial that evaluated for the first time tight junction proteins as biomarkers of blood-brain barrier disruption and hemorrhagic transformation in ischemic stroke.

[Assessment of a patient with optic neuropathy]. / Evaluarea pacientului cu neuropatie optica.

Optic neuropathy (ON) is defined as the reduction of vision due to inflammatory lesion of the optic nerve. The patient with ON has to be evaluated clinically but also with complex techniques (magnetic resonance imaging, visual evoked potentials, cerebrospinal fluid examination) because ON could be the presenting symptom in multiple sclerosis patients. Corticosteroids should be administrated intravenous and the patient should be followed by the neurologist in order to signal the appearance of new neurological signs.