The evolving role of echocardiography in the assessment of patent foramen ovale in patients with left-side thromboembolism.

Patent foramen ovale (PFO) is the most common congenital cardiac abnormality found approximately in 25% of the adult population The pathophysiological role of paradoxical embolization through the PFO in ischemic stroke is well established. "Self-expanding double disk" and, more recently, suture-based "deviceless" systems are used for PFO closure in the setting of secondary prevention after ischemic stroke likely related to paradoxical embolization. Ultrasound plays a significant role in PFO assessment, indication to treatment, intra-procedural guidance, and follow-up for those undergoing PFO closure. Three different techniques are frequently used for these purposes: transesophageal echocardiography, transthoracic echocardiogram, and transcranial Doppler. In this review, advantages and limits of these techniques are discussed in detail to improve our skills in detection and treatment of this important condition by using ultrasound.

Cognitive Performance in Relapsing-Remitting Multiple Sclerosis: At Risk or Impaired?

INTRODUCTION: Since cognitive impairment (CI) occurs on average in 45% of multiple sclerosis (MS) patients, the early detection of patients "at risk" of CI is important in order to promptly apply preventive strategies. The aim of the present study was to investigate the prevalence and risk factors for CI in MS patients using the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) as a screening test. METHODS: During the 1-year period, CI was evaluated in 82 consecutives mild relapsing-remitting MS (EDSS ≤ 3.5) patients. Patients with 1 altered BICAMS test were defined "at risk." Both "at risk" and CI patients underwent an extensive neuropsychological battery. RESULTS: We found that: (i) 23% had CI, (ii), 25% were "at risk" of CI, and (iii) 76% of the "at risk" patients were already impaired at the NP assessment. In particular, the Symbol Digit Modalities Test was the most compromised (70% of "at risk" and 79% of CI patients). Patients with CI had more frequently an EDSS ≥ 2.5 (p = 0.05), lower education (p = 0.05), and relapses in the last 12 months (p = 0.03). CONCLUSIONS: CI is a significant issue in MS and integration of a screening test, such as the SDMT, into routine clinical practice could be of worth to identify "at risk" patients and to promote an early therapeutic intervention.

Neurophysiological correlates of clinical improvement after greater occipital nerve (GON) block in chronic migraine: relevance for chronic migraine pathophysiology.

BACKGROUND: Therapeutic management of Chronic Migraine (CM), often associated with Medication Overuse Headache (MOH), is chiefly empirical, as no biomarker predicting or correlating with clinical efficacy is available to address therapeutic choices. The present study searched for neurophysiological correlates of Greater Occipital Nerve Block (GON-B) effects in CM. METHODS: We recruited 17 CM women, of whom 12 with MOH, and 19 healthy volunteers (HV). Patients had no preventive treatment since at least 3 months. After a 30-day baseline, they received a bilateral betamethasone-lidocaine GON-B of which the therapeutic effect was assessed 1 month later. Habituation of visual evoked potentials (VEP) and intensity dependence of auditory evoked potentials (IDAP) were recorded before and 1 week after the GON-B. RESULTS: At baseline, CM patients had a VEP habituation not different from HV, but a steeper IDAP value than HV (p = 0.01), suggestive of a lower serotonergic tone. GON-B significantly reduced the number of total headache days per month (- 34.9%; p = 0.003). Eight out 17CM patients reversed to episodic migraine and medication overuse resolved in 11 out of 12 patients. One week after the GON-B VEP habituation became lacking respect to baseline (p = 0.01) and to that of HV (p = 0.02) like in episodic migraine, while the IDAP slope significantly flattened (p < 0.0001). GON-B-induced reduction in headache days positively correlated with IDAP slope decrease (rho = 0.51, p = 0.03). CONCLUSIONS: GON-B may be effective in the treatment of CM, with or without MOH. The pre-treatment IDAP increase is compatible with a weak central serotonergic tone, which is strengthened after GON-B, suggesting that serotonergic mechanisms may play a role in CM and its reversion to episodic migraine. Since the degree of post-treatment IDAP decrease is correlated with clinical improvement, IDAP might be potentially useful as an early predictor of GON-B efficacy.

The Mozart Effect: A quantitative EEG study.

The aim of this study is to investigate the influence of Mozart's music on brain activity through spectral analysis of the EEG in young healthy adults (Adults), in healthy elderly (Elderly) and in elderly with Mild Cognitive Impairment (MCI). EEG recording was performed at basal rest conditions and after listening to Mozart's K448 or "Fur Elise" Beethoven's sonatas. After listening to Mozart, an increase of alpha band and median frequency index of background alpha rhythm activity (a pattern of brain wave activity linked to memory, cognition and open mind to problem solving) was observed both in Adults and in Elderly. No changes were observed in MCI. After listening to Beethoven, no changes in EEG activity were detected. This results may be representative of the fact that said Mozart's music is able to "activate" neuronal cortical circuits related to attentive and cognitive functions.

A study of migraine characteristics in joint hypermobility syndrome a.k.a. Ehlers-Danlos syndrome, hypermobility type.

Joint hypermobility syndrome (JHS) and Ehlers-Danlos syndrome, hypermobility type (EDS-HT) are two clinically overlapping heritable connective tissue disorders strongly associated with musculoskeletal pain, fatigue and headache. Migraine with or without aura is considered the most common form of headache in JHS/EDS-HT. In this population of chronically ill patients, we investigated whether migraine characteristics were different from those of a control population of migraine patients. The study was carried out on 33 selected JHS/EDS-HT patients, diagnosed according to current criteria. Sixty-six migraine subjects matching age and gender were consecutively selected as controls (MO group) among patients attending our Headache Clinic. JHS/EDS-HT and MO were screened for a series of headache characteristics, such as frequency, intensity, age of onset, level of disability, use of rescue and prophylactic medications. Differences between the two groups were tested by using independent group comparisons. Results showed that in JHS/EDS-HT: (1) migraine has an earlier onset (12.6 vs 17 years of age; p = 0.005); (2) the rate of migraine days/month is higher (15 vs 9.3 days/month; p = 0.01); (3) accompanying symptoms are usually more frequent; (4) HIT-6 and MIDAS scores are higher (p = 0.04 and p = 0.03); (5) efficacy of rescue medication is almost identical, although, total drug consumption is significantly lower (p < 0.04). Joint hypermobility syndrome and Ehlers-Danlos syndrome, hypermobility type patients have a more severe headache syndrome with respect to the MO group, therefore demonstrating that migraine has a very high impact on quality of life in this disease.

Neuroanatomical, Clinical and Cognitive Correlates of Post-Stroke Dysphagia.

BACKGROUND AND PURPOSE: About half of the dysphagic stroke patients have persistent swallowing dysfunction after 7 days from symptom onset. The aim of the study was to evaluate incidence, prognosis, clinical and neuroradiological correlates of post-stroke dysphagia. METHODS: We prospectively examined consecutive patients with acute ischemic or hemorrhagic stroke. Patients' clinical and neuroradiological data were collected. Swallowing function was assessed by the water swallow test upon admission and after 14 days; patients were then classified as persistent dysphagic, non-persistent dysphagic or non-dysphagic. RESULTS: We recruited 275 patients, 121 of whom were dysphagic upon admission and 254 patients attended follow-up at 14 days; 141 never presented dysphagia, 21 had a non-persistent pattern of dysphagia and 92 had a persistent one. Stroke type, leukoaraiosis degree, previous cognitive impairment and stroke severity upon admission independently predicted the occurrence of dysphagia after stroke and its persistence as well. At receiver operating characteristic (ROC) analysis, the National Institutes of Health Stroke Scale (NIHSS) score of 11.5 was the best predictive value of persistent dysphagia, with a specificity of 90.1% and a sensitivity of 72.4%. CONCLUSION: Stroke severity is an important predictor of a persistent pattern of dysphagia, with a suggested NIHSS cutoff value of ≥12. An independent correlation was observed with leukoaraiosis and with previous cognitive impairment.

Cardioembolic stroke: Protective effect of a severe internal carotid artery stenosis in a patient with cardiac embolism.

Cardioembolic stroke is generally caused by intracranial artery occlusion. Clots may be identified in the intracranial vessels by means of conventional neuroimaging in the acute phase. High-resolution ultrasonography may show some features suggestive of cardiac emboli when occluding extracranial carotid arteries. We describe a patient with cardioembolic ischemic stroke in the right hemisphere in whom a left internal carotid artery stenosis paradoxically protected the ipsilateral hemisphere from distal intracranial embolism. The patient also presented multiple acute ischemic embolic lesions in the right middle cerebral artery territory and in the right occipital lobe, which was fed by the posterior cerebral artery, anomally originating from the right carotid siphon. Interestingly, the left internal carotid artery--which showed a severe preexisting stenosis--was occluded by the cardiac clot, whereas the right internal carotid artery only presented a moderate stenosis that had probably allowed the clots to pass. Therefore, the severe left internal carotid artery stenosis may have blocked the cardiac embolus, preventing it from reaching the ipsilateral hemisphere.

Topiramate modulates habituation in migraine: evidences from nociceptive responses elicited by laser evoked potentials.

BACKGROUND: Lack of habituation during repetitive stimulation is the most consistent interictal abnormality of cortical information processing observed in migraine. Preventive migraine treatments might act by stabilizing cortical excitability level and thus the habituation to external stimuli. METHODS: We examined the effects of preventive treatment with topiramate on migraineur's habituation to nociceptive stimulation. Scalp potentials were evoked by Nd-YAP Laser stimulation of the hand dorsum and supraorbital region in 13 patients with migraine without aura (MO) and 15 healthy volunteers (HV). The exam was repeated in MO before and after treatment. RESULTS: We observed a lack of habituation and lower initial amplitudes in MO compared to HV. These abnormalities reached statistical significance for N1 LEPs component, generated in the secondary somatosensory cortex (SII), but not for N2/P2 complex, generated in the insula and anterior cingulated cortex (ACC). Topiramate normalized the N1 habituation pattern in MO, with a significant correlation between clinical effects and normalization of neurophysiological responses. CONCLUSIONS: Our results indicate a modulating action of topiramate on cortical processing of sensorial stimuli, mainly regarding the sensory-discriminative component of pain, elaborated by SII, without a significant effect on the affective dimension of pain, in which the ACC has an important role.

Effects of intermittent theta burst stimulation on cerebral blood flow and cerebral vasomotor reactivity.

OBJECTIVES: To determine whether intermittent theta burst stimulation influences cerebral hemodynamics, we investigated changes induced by intermittent theta burst stimulation on the middle cerebral artery cerebral blood flow velocity and vasomotor reactivity to carbon dioxide (CO(2)) in healthy participants. The middle cerebral artery flow velocity and vasomotor reactivity were monitored by continuous transcranial Doppler sonography. Changes in cortical excitability were tested by transcranial magnetic stimulation. METHODS: In 11 healthy participants, before and immediately after delivering intermittent theta burst stimulation, we tested cortical excitability measured by the resting motor threshold and motor evoked potential amplitude over the stimulated hemisphere and vasomotor reactivity to CO(2) bilaterally. The blood flow velocity was monitored in both middle cerebral arteries throughout the experimental session. In a separate session, we tested the effects of sham stimulation under the same experimental conditions. RESULTS: Whereas the resting motor threshold remained unchanged before and after stimulation, motor evoked potential amplitudes increased significantly (P = .04). During and after stimulation, middle cerebral artery blood flow velocities also remained bilaterally unchanged, whereas vasomotor reactivity to CO(2) increased bilaterally (P = .04). The sham stimulation left all variables unchanged. CONCLUSIONS: The expected intermittent theta burst stimulation-induced changes in cortical excitability were not accompanied by changes in cerebral blood flow velocities; however, the bilateral increased vasomotor reactivity suggests that intermittent theta burst stimulation influences the cerebral microcirculation, possibly involving subcortical structures. These findings provide useful information on hemodynamic phenomena accompanying intermittent theta burst stimulation, which should be considered in research aimed at developing this noninvasive, low-intensity stimulation technique for safe therapeutic applications.

Non-convulsive status epilepticus characterised exclusively by a language disorder induced by non-ketotic hyperglycaemia.

Non-ketotic hyperglycaemia is an endocrine emergency characterised by elevated blood glucose levels and high plasma osmolarity. While hypoglycaemia-induced seizures are usually generalised, hyperglycaemia-induced seizures are often focal and secondary to the presence of brain lesions. Moreover, in the few studies in which language disorders of epileptic origin have been reported as a clinical manifestation of non-ketotic hyperglycaemia, the disorders were usually not isolated but were followed by partial motor seizures. We describe a patient who presented with non-convulsive partial status epilepticus and whose only sign was a fluctuating language disorder induced by non-ketotic hyperglycaemia. There were no accompanying brain lesions and the patient responded optimally to diazepam. Neurophysiological EEG evaluation was fundamental for the diagnosis.

Bilateral spontaneous internal carotid artery dissection with both early and very late recanalization: A case report.

Spontaneous bilateral internal carotid artery dissection has frequently been described in the literature as a cause of stroke. In more than half of the patients with internal carotid artery dissection, recanalization occurs early after the event and is unusual later than 6 months after onset of the dissection. We describe a patient with ischemic stroke due to left internal carotid artery occlusion in the extracranial segment. The patient was treated with anticoagulants and early vessel recanalization did not occur. Ten months later, he developed contralateral internal carotid occlusion in the intracranial tract, which was followed by early complete recanalization. Anticoagulation therapy was continued and, 16 months after the initial event, the left internal carotid artery unexpectedly also reopened.

Cerebral vascular response in airmen exposed to hypobaric hypoxia.

INTRODUCTION: Cerebral vascular response via local and reflex adjustments is part of the integrated response to hypoxia and is coupled with changes in systemic vascular resistances that allow a redistribution of blood flow toward the brain. The cerebral vascular response in airmen exposed to simulated high altitude is not clear, thus we sought to investigate this aspect. METHODS: Four healthy military airmen were exposed to simulated high altitude in a hypobaric chamber according to a standard training protocol. Blood saturation (SpO2) and blood flow velocity with transcranial Doppler from the left middle cerebral artery (Vm) were continuously recorded. Pulsatility Index (PI), resistance index (RI), and systolic/diastolic ratio (S/D ratio) were computed. Alternate hypoxia-hyperoxia trials for 2 and 1 min, respectively, were used to assess the cerebrovascular response. RESULTS: Acute hypoxia induced an increase in Vm that promptly recovered when the oxygen supply was restored (mean increase of 5.5% at 18,000 ft and 17.2% at 25,000 ft). Alternate hypoxia-hyperoxia at 25,000 and 18,000 ft elicited changes in both SpO2 and Vm. In hypoxia, PI significantly decreased (mean decrease o" 25.6% at 18,000 ft and 39.5% at 25,000 ft), as did RI (mean decrease of 18.7% at 18,000 ft and 34.4% at 25,000 ft), while S/D ratio increased. DISCUSSION: The standard altitude training protocol induced a transient cerebrovascular response. The response was as expected, with hypoxia-induced vasodilation and opposite changes when breathing pure oxygen.

Effects of Transcranial Ultrasound Stimulation on Trigeminal Blink Reflex Excitability.

Recent evidence indicates that transcranial ultrasound stimulation (TUS) modulates sensorimotor cortex excitability. However, no study has assessed possible TUS effects on the excitability of deeper brain areas, such as the brainstem. In this study, we investigated whether TUS delivered on the substantia nigra, superior colliculus, and nucleus raphe magnus modulates the excitability of trigeminal blink reflex, a reliable neurophysiological technique to assess brainstem functions in humans. The recovery cycle of the trigeminal blink reflex (interstimulus intervals of 250 and 500 ms) was tested before (T0), and 3 (T1) and 30 min (T2) after TUS. The effects of substantia nigra-TUS, superior colliculus-TUS, nucleus raphe magnus-TUS and sham-TUS were assessed in separate and randomized sessions. In the superior colliculus-TUS session, the conditioned R2 area increased at T1 compared with T0, while T2 and T0 values did not differ. Results were independent of the interstimulus intervals tested and were not related to trigeminal blink reflex baseline (T0) excitability. Conversely, the conditioned R2 area was comparable at T0, T1, and T2 in the nucleus raphe magnus-TUS and substantia nigra-TUS sessions. Our findings demonstrate that the excitability of brainstem circuits, as evaluated by testing the recovery cycle of the trigeminal blink reflex, can be increased by TUS. This result may reflect the modulation of inhibitory interneurons within the superior colliculus.

Extracranial and intracranial sonographic findings in vertebral artery diseases.

OBJECTIVE: The aim of this review is to illustrate the sonographic features that can be detected in vertebral artery (VA) diseases. METHODS: We conducted a review of sonographic findings in VA diseases. RESULTS: Various VA diseases are described, and sonographic techniques and features are discussed. CONCLUSIONS: Posterior circulation vascular imaging can be performed by means of various neuroimaging techniques. Intra-arterial angiography remains the reference standard. The use of this technique has become even more widespread since it has become possible to perform endovascular procedures; it is, however, an invasive procedure that is associated with a not irrelevant level of risk. Computed tomographic angiography and magnetic resonance angiography with and without contrast agents have been proposed as less invasive alternatives, although these techniques can only be performed in the radiology unit and may not be readily available in daily clinical management. Sonography, which combines an extracranial and intracranial evaluation, is highly suited to the assessment of the vertebrobasilar system on account of its widespread availability and its unique capacity to study real-time hemodynamics. Furthermore, new sonographic applications and sonographic contrast agents have improved the sensitivity and specificity of this technique with regard to diagnostic accuracy for the posterior circulation.

Noninvasive imaging of carotid arteries in stroke: emerging value of real-time high-resolution sonography in carotid occlusion due to cardiac embolism.

OBJECTIVE: Comprehension of the pathophysiologic characteristics of atherosclerosis has focused its attention on the study of dynamic and metabolic processes involving the vessel wall as possible causes of stroke. When compared with conventional radiologic techniques, sonography has the main advantage of being a real-time imaging modality. We report 2 acute stroke cases in which carotid sonography showed some dynamic features that could not be identified with computed tomography (CT) and magnetic resonance angiography (MRA). METHODS: Carotid sonography with high-resolution probes (9-14 MHz) was compared with CT and MRA findings showing carotid axis occlusion in 2 patients with acute stroke. RESULTS: In case 1, the internal carotid artery occlusion observed on CT and MRA was interpreted as a dissection on a clinical basis, but sonography showed a mobile embolus originating from the heart in the internal carotid artery. In case 2, the occlusion of the whole carotid axis observed on CT and MRA was instead related to a heart-originating embolus floating in the common carotid artery. CONCLUSIONS: The evaluation of dynamic aspects of atherosclerosis is fundamental to understanding the pathophysiologic characteristics of stroke. Sonography is fundamental in carotid artery imaging for its possibility of showing dynamic processes that could be misdiagnosed with "static" imaging. The correct identification of the pathophysiologic characteristics of stroke in these cases could have led to different diagnostic and therapeutic algorithms.

Focus on the "unstable" carotid plaque: detection of intraplaque angiogenesis with contrast ultrasound. Present state and future perspectives.

Over the past 20 years, conventional ultrasonography has identified features of the "unstable" carotid plaque. Histological studies have recognized that plaque inflammation and neoangiogenesis play a pivotal role in the developing of the vulnerable plaque. Hence, the growing interest on the biological activities of atherosclerotic lesions leading to cerebrovascular events. The presence of adventitial vasa vasorum and the occurrence of plaque vascularization have been considered as predictors of unstable lesions in cerebrovascular and/or cardiovascular patients. The advent of ultrasound contrast agents has represented a fundamental step in the up-to-date functional evaluation in several fields with minimally invasive procedures. Contrast specific ultrasound modalities are currently used with excellent results in oncology, in cardiology and in vascular diseases. Contrast carotid ultrasound is an emerging imaging technique, able to depict in vivo new functional information on plaque activity and vascularization that may add further new data on the actual condition and future cerebrovascular risk. Further studies will provide a better clarification of the degree of neo-angiogenesis. A future strategy could be represented by the monitoring of plaque neoangiogenesis in order to detect the possible pharmacological effects on plaque remodeling.

Imaging of carotid plaque angiogenesis.

Currently, characterization of the vulnerable plaque is a hot research topic as a more adequate strategy for preventing cerebrovascular events is being sought. Histological studies have recognized that plaque inflammation and the presence of adventitial vasa vasorum, intimal angiogenesis and plaque neovascularization are strong predictors of instability in atheromatous lesions of cerebrovascular and cardiovascular patients. The in vivo study of these features has been the focus of development of several new radiological imaging methods. Carotid ultrasound, with ultrasound contrast agents, is not only able to provide an enhanced assessment of the arterial lumen and plaque morphology with an improved resolution of the carotid intima-media thickness, but also to directly visualize adventitial vasa vasorum and plaque neovascularization. This technique and its future clinical implications are discussed in the present review.