The added value of spinal cord lesions to disability accrual in multiple sclerosis.

Spinal cord MRI is not routinely performed for multiple sclerosis (MS) monitoring. Here, we explored whether spinal cord MRI activity offers any added value over brain MRI activity for clinical outcomes prediction in MS. This is a retrospective, monocentric study including 830 MS patients who underwent longitudinal brain and spinal cord MRI [median follow-up 7 years (range: < 1-26)]. According to the presence (or absence) of MRI activity defined as at least one new T2 lesion and/or gadolinium (Gd) enhancing lesion, each scan was classified as: (i) brain MRI negative/spinal cord MRI negative; (ii) brain MRI positive/spinal cord MRI negative; (iii) brain MRI negative/spinal cord MRI positive; (iv) brain MRI positive/spinal cord MRI positive. The relationship between such patterns and clinical outcomes was explored by multivariable regression models. When compared with the presence of brain MRI activity alone: (i) Gd + lesions in the spine alone and both in the brain and in the spinal cord were associated with an increased risk of concomitant relapses (OR = 4.1, 95% CI 2.4-7.1, p < 0.001 and OR = 4.9, 95% CI 4.6-9.1, p < 0.001, respectively); (ii) new T2 lesions at both locations were associated with an increased risk of disability worsening (HR = 1.4, 95% CI = 1.0-2.1, p = 0.05). Beyond the presence of brain MRI activity, new spinal cord lesions are associated with increased risk of both relapses and disability worsening. In addition, 16.1% of patients presented asymptomatic, isolated spinal cord activity (Gd + lesions). Monitoring MS with spinal cord MRI may allow a more accurate risk stratification and treatment optimization.

Whole brain surface-based morphometry and tract-based spatial statistics in migraine with aura patients: difference between pure visual and complex auras.

Background: The migrainous aura has different clinical phenotypes. While the various clinical differences are well-described, little is known about their neurophysiological underpinnings. To elucidate the latter, we compared white matter fiber bundles and gray matter cortical thickness between healthy controls (HC), patients with pure visual auras (MA) and patients with complex neurological auras (MA+). Methods: 3T MRI data were collected between attacks from 20 patients with MA and 15 with MA+, and compared with those from 19 HCs. We analyzed white matter fiber bundles using tract-based spatial statistics (TBSS) of diffusion tensor imaging (DTI) and cortical thickness with surface-based morphometry of structural MRI data. Results: Tract-based spatial statistics showed no significant difference in diffusivity maps between the three subject groups. As compared to HCs, both MA and MA+ patients had significant cortical thinning in temporal, frontal, insular, postcentral, primary and associative visual areas. In the MA group, the right high-level visual-information-processing areas, including lingual gyrus, and the Rolandic operculum were thicker than in HCs, while in the MA+ group they were thinner. Discussion: These findings show that migraine with aura is associated with cortical thinning in multiple cortical areas and that the clinical heterogeneity of the aura is reflected by opposite thickness changes in high-level visual-information-processing, sensorimotor and language areas.

A Hypothalamic Mechanism Regulates the Duration of a Migraine Attack: Insights from Microstructural and Temporal Complexity of Cortical Functional Networks Analysis.

The role of the hypothalamus and the limbic system at the onset of a migraine attack has recently received significant interest. We analyzed diffusion tensor imaging (DTI) parameters of the entire hypothalamus and its subregions in 15 patients during a spontaneous migraine attack and in 20 control subjects. We also estimated the non-linear measure resting-state functional MRI BOLD signal's complexity using Higuchi fractal dimension (FD) and correlated DTI/fMRI findings with patients' clinical characteristics. In comparison with healthy controls, patients had significantly altered diffusivity metrics within the hypothalamus, mainly in posterior ROIs, and higher FD values in the salience network (SN). We observed a positive correlation of the hypothalamic axial diffusivity with migraine severity and FD of SN. DTI metrics of bilateral anterior hypothalamus positively correlated with the mean attack duration. Our results show plastic structural changes in the hypothalamus related to the attacks severity and the functional connectivity of the SN involved in the multidimensional neurocognitive processing of pain. Plastic changes to the hypothalamus may play a role in modulating the duration of the attack.

Late-onset seizures and epilepsy: Electroclinical features suggestive of autoimmune etiology.

Introduction: Late-onset epilepsy (LOE) has recently become a topic of intense research. Besides stroke, tumors, and dementia, autoimmune encephalitis (AE) has emerged as another possible cause of recurrent seizures in the elderly, and may account for a proportion of cases of LOE of unknown origin (LOEUO). This 24-h ambulatory electroencephalography (AEEG)-based study compared patients with LOEUO and AE to identify features suggestive of immune-mediated seizures in the elderly. Materials and methods: We retrospectively reviewed 232 AEEG examinations performed in patients over 55 years with ≥6-month follow-up, and selected 21 subjects with AE and 25 subjects with LOEUO. Clinical charts and AEEG recordings were carefully analyzed. Results: Twenty-five patients with LOEUO (12 women, mean age at onset 67.9 years) and 21 AE subjects (8 women, mean age at onset 65.7 years) were enrolled. High-frequency seizures were reported in 20/21 AE and 7/25 LOEUO cases (p < 0.00001). Focal aware seizures were more common in AE (14/21 vs. 6/25, p = 0.00058), whereas "isolated" focal-to-bilateral tonic-clonic seizures occurred in 5/25 patients with LOEUO only (p = 0.053). AE subjects reported ictal autonomic manifestations more frequently (p = 0.0033). Three-hundred-seventy and 24 seizures were recorded in 13/21 patients with AE and 3/25 patients with LOEUO, respectively (p = 0.0006). Interictal epileptiform discharges were observed in 70% of both groups, but their sleep activation was more common in AE (p = 0.06). Conclusion: Our study shows that high-frequency focal seizures with autonomic manifestations should raise the suspicion of AE in the elderly with new-onset seizures. It also highlights the relevant contribution of AEEG, which might reduce the diagnostic delay and provide useful clues to recognize AE.

Olfactory impairment in autoimmune encephalitis: another piece of the puzzle.

BACKGROUND: Despite being long neglected, olfaction has recently become a focus of intense research in neuroscience, as smell impairment has been consistently documented in both neurodegenerative and neuroinflammatory diseases. Considering the close anatomo-functional correlations between the limbic system and the central olfactory structures, we investigated olfaction in a population of patients with autoimmune encephalitis (AE). METHODS: Nineteen adult subjects (14 males, median age 64 years) diagnosed with definite (14/19) or possible (5/19) AE and followed for ≥ 6 months were enrolled. The Brief Smell Identification Test (B-SIT), a 12-item, forced-choice, scratch-and-sniff measure, was used to assess the patients' olfactory function in comparison with a group of sex- and age-matched healthy controls (HC). According to the B-SIT score, subjects were classified as anosmic (< 6), hyposmic (6-8) and normal (≥ 9). Electro-clinical, laboratory and neuroimaging findings were reviewed. RESULTS: Smell impairment was revealed in 15/19 patients (9 hyposmic, 6 anosmic), compared with 5/19 HC (p = 0.0029). Age, gender and smoking habits did not affect the participants' performance at B-SIT. Olfactory dysfunction appeared more common among patients with definite AE (p = 0.0374), regardless of autoantibody status. Subjects with higher modified Rankin Scale (mRS) scores at AE onset more likely presented hyposmia/anosmia (p = 0.033), and so did those with bilateral ictal/interictal EEG abnormalities (p = 0.006). CONCLUSIONS: We found olfaction to be impaired in a significantly large proportion of AE cases. Smell deficits appeared more common in subjects with severe AE (as indicated by both definite diagnosis and higher mRS score), and might represent an additional feature of immune-mediated encephalitis.

Hypothalamic structural integrity and temporal complexity of cortical information processing at rest in migraine without aura patients between attacks.

The hypothalamus has been attributed an important role during the premonitory phase of a migraine attack. Less is known about the role played by the hypothalamus in the interictal period and its relationship with the putative neurocognitive networks previously identified in the pathophysiology of migraine. Our aim was to test whether the hypothalamic microstructure would be altered during the interictal period and whether this co-existed with aberrant connectivity at cortical level. We collected multimodal MRI data from 20 untreated patients with migraine without aura between attacks (MO) and 20 healthy controls (HC) and studied fractional anisotropy, mean (MD), radial (RD), and axial diffusivity of the hypothalamus ROI as a whole from diffusion tensor imaging (DTI). Moreover, we performed an exploratory analysis of the same DTI metrics separately for the anterior and posterior hypothalamic ROIs bilaterally. From resting-state functional MRI, we estimated the Higuchi's fractal dimension (FD), an index of temporal complexity sensible to describe non-periodic patterns characterizing BOLD signature. Finally, we correlated neuroimaging findings with migraine clinical features. In comparison to HC, MO had significantly higher MD, AD, and RD values within the hypothalamus. These findings were confirmed also in the exploratory analysis on the sub-regions of the hypothalamus bilaterally, with the addition of lower FA values on the posterior ROIs. Patients showed higher FD values within the salience network (SN) and the cerebellum, and lower FD values within the primary visual (PV) network compared to HC. We found a positive correlation between cerebellar and SN FD values and severity of migraine. Our findings of hypothalamic abnormalities between migraine attacks may form part of the neuroanatomical substrate that predisposes the onset of the prodromal phase and, therefore, the initiation of an attack. The peculiar fractal dimensionality we found in PV, SN, and cerebellum may be interpreted as an expression of abnormal efficiency demand of brain networks devoted to the integration of sensory, emotional, and cognitive information related to the severity of migraine.

Thalamo-cortical networks in subtypes of migraine with aura patients.

BACKGROUND: We searched for differences in resting-state functional connectivity (FC) between brain networks and its relationship with the microstructure of the thalamus between migraine with pure visual auras (MA), and migraine with complex neurological auras (MA+), i.e. with the addition of at least one of sensory or language symptom. METHODS: 3T MRI data were obtained from 20 patients with MA and 15 with MA + and compared with those from 19 healthy controls (HCs). We collected resting state data among independent component networks. Diffusivity metrics of bilateral thalami were calculated and correlated with resting state ICs-Z-scores. RESULTS: As compared to HCs, both patients with MA and MA + disclosed disrupted FC between the default mode network (DMN) and the right dorsal attention system (DAS). The MA + subgroup had lower microstructural metrics than both HCs and the MA subgroup, which correlated negatively with the strength of DMN connectivity. Although the microstructural metrics of MA patients did not differ from those of HCs, these patients lacked the correlation with the strength of DAS connectivity found in HCs. CONCLUSIONS: The present findings suggest that, as far as MRI profiles are concerned, the two clinical phenotypes of migraine with aura have both common and distinct morpho-functional features of nodes in the thalamo-cortical network.

fMRI in Bell's Palsy: Cortical Activation is Associated with Clinical Status in the Acute and Recovery Phases.

BACKGROUND AND PURPOSE: Using functional magnetic resonance imaging (fMRI), we explored cortical activation in patients with acute Bell's palsy (BP) and analyzed its correlates with clinical status in the acute phase, and with 6-month outcome. METHODS: Twenty-four right-handed patients with acute BP within 15 days of onset and 24 healthy controls underwent fMRI during performance of unilateral active (hemi-smiling) and passive lip movement tasks with both the paretic and the normal lip. The degree of paresis was evaluated during the acute stage and at the 6-month follow up using the House-Brackmann (HB) grading scale. Complete recovery was defined as HB grade II or less at the end of the 6-month period. The difference in the HB grade (ΔHB) between the acute stage and the 6-month follow up was used to evaluate clinical improvement. RESULTS: There were 24 patients with unilateral acute BP. HB grades ranged from III to VI. At 6 months, 11 patients (46%) had completely recovered and 12 (50%) were partially improved. Compared with healthy subjects, BP patients had a significantly greater activation of the frontal areas and the insula ipsilateral to the paretic side. In BP patients, there was an inverse correlation between the activation of the ipsilateral hemisphere when moving the paretic side and the degree of paresis at baseline. An association was also observed between activation and clinical outcome (both complete recovery and ΔHB). CONCLUSIONS: In patients with BP, fMRI may represent a useful tool to predict long-term outcome, guide therapeutic approach, and monitor treatment response.

Haemodynamic activity characterization of resting state networks by fractal analysis and thalamocortical morphofunctional integrity in chronic migraine.

BACKGROUND: Chronic migraine (CM) can be associated with aberrant long-range connectivity of MRI-derived resting-state networks (RSNs). Here, we investigated how the fractal dimension (FD) of blood oxygenation level dependent (BOLD) activity may be used to estimate the complexity of RSNs, reflecting flexibility and/or efficiency in information processing in CM patients respect to healthy controls (HC). METHODS: Resting-state MRI data were collected from 20 untreated CM without history of medication overuse and 20 HC. On both groups, we estimated the Higuchi's FD. On the same subjects, fractional anisotropy (FA) and mean diffusivity (MD) values of bilateral thalami were retrieved from diffusion tensor imaging and correlated with the FD values. RESULTS: CM showed higher FD values within dorsal attention system (DAS) and the anterior part of default-mode network (DMN), and lower FD values within the posterior DMN compared to HC. Although FA and MD were within the range of normality, both correlated with the FD values of DAS. CONCLUSIONS: FD of DAS and DMN may reflect disruption of cognitive control of pain in CM. Since the normal microstructure of the thalamus and its positive connectivity with the cortical networking found in our CM patients reminds similar results obtained assessing the same structures but with the methods of neurophysiology, in episodic migraine during an attack, this may be yet another evidence in supporting CM as a never-ending migraine attack.

Patients with chronic migraine without history of medication overuse are characterized by a peculiar white matter fiber bundle profile.

BACKGROUND: We investigated intracerebral fiber bundles using a tract-based spatial statistics (TBSS) analysis of diffusion tensor imaging (DTI) data to verify microstructural integrity in patients with episodic (MO) and chronic migraine (CM). METHODS: We performed DTI in 19 patients with MO within interictal periods, 18 patients with CM without any history of drug abuse, and 18 healthy controls (HCs) using a 3 T magnetic resonance imaging scanner. We calculated diffusion metrics, including fractional anisotropy (FA), axial diffusion (AD), radial diffusion (RD), and mean diffusion (MD). RESULTS: TBSS revealed no significant differences in the FA, MD, RD, and AD maps between the MO and HC groups. In comparison to the HC group, the CM group exhibited widespread increased RD (bilateral superior [SCR] and posterior corona radiata [PCR], bilateral genu of the corpus callosum [CC], bilateral posterior limb of internal capsule [IC], bilateral superior longitudinal fasciculus [LF]) and MD values (tracts of the right SCR and PCR, right superior LF, and right splenium of the CC). In comparison to the MO group, the CM group showed decreased FA (bilateral SCR and PCR, bilateral body of CC, right superior LF, right forceps minor) and increased MD values (bilateral SCR and right PCR, right body of CC, right superior LF, right splenium of CC, and right posterior limb of IC). CONCLUSION: Our results suggest that chronic migraine can be associated with the widespread disruption of normal white matter integrity in the brain.

Diffusion MRI Findings in Encephalopathy Induced by Immunosuppressive Therapy after Liver Transplantation.

Neurological complications are common after liver transplantation, as they affect up to one-third of the transplanted patients and are associated with significant morbidity. The introduction of calcineurin inhibitors, cyclosporine A and tacrolimus, in immunosuppressive regimens significantly improved the outcome of solid-organ transplantation even though immunosuppression-associated neurotoxicity remains a significant complication, particularly occurring in about 25% of cases after liver transplantation. The immunosuppressant cyclosporine A and tacrolimus have been associated with the occurrence of major neurological complications, diffuse encephalopathy being the most common. The biochemical and pathogenetic basis of calcineurin inhibitors-induced neurotoxicity are still unclear although several mechanisms have been suggested. Early recognition of symptoms could help reduce neurotoxic event. The aim of the study was to evaluate cerebral changes through MRI, in particular with diffusion-weighted images (DWI) and apparent diffusion coefficient (ADC) maps, in two patients undergoing liver transplantation after immunosuppressive therapy. We describe two patients in which clinical pictures, presenting as a severe neurological condition, early after orthotopic liver transplantation during immunosuppression therapy, showed a different evolution in keeping with evidence of focal-multifocal lesions at DWI and ADC maps. At clinical onset, DWI showed hyperintensity of the temporo-parieto-occipital cortex with normal ADC values in the patient with following good clinical recovery and decreased values in the other one; in the latter case, MRI abnormalities were still present after ten days, until the patient's exitus. The changes in DWI with normal ADC may be linked to brain edema with a predominant vasogenic component and therefore reversible, while the reduction in ADC is due to cytotoxic edema and linked to more severe, nonreversible, clinical picture. Brain MRI and particularly DWI and ADC maps provide not only a good and early representation of neurological complications during immunosuppressant therapy but can also provide a useful prognostic tool on clinical outcome of the patient.

Increased neural connectivity between the hypothalamus and cortical resting-state functional networks in chronic migraine.

OBJECTIVE: The findings of resting-state functional MRI studies have suggested that abnormal functional integration between interconnected cortical networks characterises the brain of patients with migraine. The aim of this study was to investigate the functional connectivity between the hypothalamus, brainstem, considered as the migraine generator, and the following areas/networks that are reportedly involved in the pathophysiology of migraine: default mode network (DMN), executive control network, dorsal attention system, and primary and dorsoventral visual networks. METHODS: Twenty patients with chronic migraine (CM) without medication overuse and 20 healthy controls (HCs) were prospectively recruited. All study participants underwent 3-T MRI scans using a 7.5-min resting-state protocol. Using a seed-based approach, we performed a ROI-to-ROI analysis selecting the hypothalamus as the seed. RESULTS: Compared to HCs, patients with CM showed significantly increased neural connectivity between the hypothalamus and brain areas belonging to the DMN and dorsal visual network. We did not detect any connectivity abnormalities between the hypothalamus and the brainstem. The correlation analysis showed that the severity of the migraine headache was positively correlated with the connectivity strength of the hypothalamus and negatively with the connectivity strength of the medial prefrontal cortex, which belongs to the DMN. CONCLUSION: These data provide evidence for hypothalamic involvement in large-scale reorganisation at the functional-network level in CM and in proportion with the perceived severity of the migraine pain.

Aberrant interactions of cortical networks in chronic migraine: A resting-state fMRI study.

OBJECTIVE: We investigated resting-state (RS)-fMRI using independent component analysis (ICA) to determine the functional connectivity (FC) between networks in chronic migraine (CM) patients and their correlation with clinical features. METHODS: Twenty CM patients without preventive therapy or acute medication overuse underwent 3T MRI scans and were compared to a group of 20 healthy controls (HC). We used MRI to collect RS data in 3 selected networks, identified using group ICA: the default mode network (DMN), the executive control network (ECN), and the dorsal attention system (DAS). RESULTS: Compared to HC, CM patients had significantly reduced functional connectivity between the DMN and the ECN. Moreover, in patients, the DAS showed significantly stronger FC with the DMN and weaker FC with the ECN. The higher the severity of headache, the increased the strength of DAS connectivity, and the lower the strength of ECN connectivity. CONCLUSION: These results provide evidence for large-scale reorganization of functional cortical networks in chronic migraine. They suggest that the severity of headache is associated with opposite connectivity patterns in frontal executive and dorsal attentional networks.

H-magnetic resonance spectroscopy: diagnostic tool in recurrent headache in systemic lupus erythematosus. A case report.

We describe serial MR-spectroscopy studies in a patient with systemic lupus erythematosus and headache. We used MR-spectroscopy to monitor disease activity during periods with and without headache. MR-spectroscopy investigates metabolic alterations and was used to explore the pathophysiological mechanism involved in the complications of systemic lupus erythematosus. Our patient underwent serial conventional MRI and MR-spectroscopy at times of controlled and uncontrolled headache, with or without visual aura. MR-spectroscopy showed an increase in the choline/creatine ratio in thalamus and posterior white matter only during periods of uncontrolled headache with visual aura. Conventional MRI scans were normal at all times. MR-spectroscopy should be used in the diagnosis and follow-up of headache in patients with systemic lupus erythematosus.

Resting state connectivity between default mode network and insula encodes acute migraine headache.

Background Previous functional MRI studies have revealed that ongoing clinical pain in different chronic pain syndromes is directly correlated to the connectivity strength of the resting default mode network (DMN) with the insula. Here, we investigated seed-based resting state DMN-insula connectivity during acute migraine headaches. Methods Thirteen migraine without aura patients (MI) underwent 3 T MRI scans during the initial six hours of a spontaneous migraine attack, and were compared to a group of 19 healthy volunteers (HV). We evaluated headache intensity with a visual analogue scale and collected seed-based MRI resting state data in the four core regions of the DMN: Medial prefrontal cortex (MPFC), posterior cingulate cortex (PCC), and left and right inferior parietal lobules (IPLs), as well as in bilateral insula. Results Compared to HV, MI patients showed stronger functional connectivity between MPFC and PCC, and between MPFC and bilateral insula. During migraine attacks, the strength of MPFC-to-insula connectivity was negatively correlated with pain intensity. Conclusion We show that greater subjective intensity of pain during a migraine attack is associated with proportionally weaker DMN-insula connectivity. This is at variance with other chronic extra-cephalic pain disorders where the opposite was found, and may thus be a hallmark of acute migraine head pain.

An Unusual Case of Simultaneous Bilateral Trigeminal Neuralgia Due to Multiple Sclerosis.

Although several reports have indicated that trigeminal neuralgia related to multiple sclerosis may occur bilaterally in the orofacial region, trigeminal neuralgia pain usually involves the two sides in different time lapses, and the simultaneous involvement of trigeminal territories on both sides is commonly considered incompatible with its diagnosis. This case report describes a patient with bilateral trigeminal neuralgia related to multiple sclerosis that started simultaneously on both sides of the orofacial region. A 55-year-old man presented with a 16-year history of relapsing/remitting multiple sclerosis. For 1 year, the patient had been complaining of electric shock-like, paroxysmal pain of severe intensity that lasted from a fraction of a second to a few minutes and involved the first and second trigeminal divisions of both sides simultaneously. The neurophysiologic testing of trigeminal reflexes showed bilateral delayed latencies of reflex responses compatible with a trigeminal afferent pathway impairment related to multiple sclerosis. A dedicated 3T magnetic resonance imaging scan revealed pontine demyelinating plaque and a bilateral neurovascular conflict at the trigeminal root entry zone. The finding of an unusual case of simultaneous bilateral trigeminal neuralgia due to multiple sclerosis should prompt neurologists to consider a diagnosis of trigeminal neuralgia in patients with multiple sclerosis in cases of simultaneous involvement of trigeminal territories on both sides.

Cerebral gray matter volume in patients with chronic migraine: correlations with clinical features.

BACKGROUND: To date, few MRI studies have been performed in patients affected by chronic migraine (CM), especially in those without medication overuse. Here, we performed magnetic resonance imaging (MRI) voxel-based morphometry (VBM) analyses to investigate the gray matter (GM) volume of the whole brain in patients affected by CM. Our aim was to investigate whether fluctuations in the GM volumes were related to the clinical features of CM. METHODS: Twenty untreated patients with CM without a past medical history of medication overuse underwent 3-Tesla MRI scans and were compared to a group of 20 healthy controls (HCs). We used SPM12 and the CAT12 toolbox to process the MRI data and to perform VBM analyses of the structural T1-weighted MRI scans. The GM volume of patients was compared to that of HCs with various corrected and uncorrected thresholds. To check for possible correlations, patients' clinical features and GM maps were regressed. RESULTS: Initially, we did not find significant differences in the GM volume between patients with CM and HCs (p < 0.05 corrected for multiple comparisons). However, using more-liberal uncorrected statistical thresholds, we noted that compared to HCs, patients with CM exhibited clusters of regions with lower GM volumes including the cerebellum, left middle temporal gyrus, left temporal pole/amygdala/hippocampus/pallidum/orbitofrontal cortex, and left occipital areas (Brodmann areas 17/18). The GM volume of the cerebellar hemispheres was negatively correlated with the disease duration and positively correlated with the number of tablets taken per month. CONCLUSION: No gross morphometric changes were observed in patients with CM when compared with HCs. However, using more-liberal uncorrected statistical thresholds, we observed that CM is associated with subtle GM volume changes in several brain areas known to be involved in nociception/antinociception, multisensory integration, and analgesic dependence. We speculate that these slight morphometric impairments could lead, at least in a subgroup of patients, to the development and continuation of maladaptive acute medication usage.

Thalamo-cortical network activity during spontaneous migraine attacks.

OBJECTIVE: We used MRI to search for changes in thalamo-cortical networks and thalamic microstructure during spontaneous migraine attacks by studying at the same time structure with diffusion tensor imaging and resting state function in interconnected brain networks with independent component analysis. METHODS: Thirteen patients with untreated migraine without aura (MI) underwent 3T MRI scans during an attack and were compared to a group of 19 healthy controls (HC). We collected resting state data in 2 selected networks identified using group independent component (IC) analysis. Fractional anisotropy (FA) values of bilateral thalami were calculated in the same participants and correlated with resting state IC z scores. RESULTS: Functional connectivity between the executive and the dorso-ventral attention networks was reduced in MI compared to HC. In HC, but not in MI, the higher the IC24 z score, encompassing interconnected areas of the dorso-ventral attention system, the lower the bilateral thalamic FA values. In patients, the higher the executive control network z scores, the lower the number of monthly migraine days. CONCLUSIONS: These results provide evidence for abnormal connectivity between the thalamus and attentional cerebral networks at rest during migraine attacks. This abnormality could subtend the known ictal impairment of cognitive performance and suggests that the latter might worsen with increasing attack frequency.