Triggers of migraine: where do we stand?

PURPOSE OF REVIEW: In this review, we illustrate and discuss the recent findings regarding the epidemiology and pathophysiology of migraine triggers and their implications in clinical practice. RECENT FINDINGS: Data from the literature suggest that individual triggers fail to provoke migraine attack in experimental settings. It is therefore possible that more triggers acting in combination are needed to induce an attack by promoting some degree of brain dysfunction and thus increasing the vulnerability to migraine. Caution is however needed, because some of the factors rated as triggers by the patients may actually be a component of the clinical picture of migraine attacks. SUMMARY: Trigger factors of migraine are endogenous or exogenous elements associated with an increased likelihood of an attack in a short period of time and are reported by up to 75.9% of patients. Triggers must be differentiated from premonitory symptoms that precede the headache phase but do not have a causative role in attack provocation, being rather the very first manifestations of the attack. Identification of real triggers is an important step in the management of migraine. Vice versa, promoting an active avoiding behaviour toward factors whose role as triggers is not certain would be ineffective and even frustrating for patients.

Anodal transcranial direct current stimulation in chronic migraine and medication overuse headache: A pilot double-blind randomized sham-controlled trial.

OBJECTIVES: Little evidence is available on the role of transcranial direct current stimulation (tDCS) in patients affected by chronic migraine (CM) and medication overuse headache (MOH). We aim to investigate the effects of tDCS in patients with CM and MOH as well as its role on brain activity. METHODS: Twenty patients with CM and MOH were hospitalized for a 7-day detoxification treatment. Upon admission, patients were randomly assigned to anodal tDCS or sham stimulation delivered over the primary motor cortex contralateral to the prevalent migraine pain side every day for 5 days. Clinical data were recorded at baseline (T0), after 1 month (T2) and 6 months (T3). EEG recording was performed at T0, at the end of the tDCS/Sham treatment, and at T2. RESULTS: At T2 and T3, we found a significant reduction in monthly migraine days (p = 0.001), which were more pronounced in the tDCS group when compared to the sham group (p = 0.016). At T2, we found a significant increase of alpha rhythm in occipital leads, which was significantly higher in tDCS group when compared to sham group. CONCLUSIONS: tDCS showed adjuvant effects to detoxification in the management of patients with CM and MOH. The EEG recording showed a significant potentiation of alpha rhythm, which may represent a correlate of the underlying changes in cortico-thalamic connections. SIGNIFICANCE: This study suggests a possible role for tDCS in the treatment of CM and MOH. The observed clinical improvement is coupled with a potentiation of EEG alpha rhythm.

Pain in focal dystonias - A focused review to address an important component of the disease.

Focal dystonia is characterized by involuntary muscle contractions that cause abnormal postures and/or twisting movements in a segment of the body. Motor symptoms have a major impact on disability in this condition, but the presence of pain represents an additional source of impairment and poor quality of life. Notwithstanding that pain occurs in up to 70% of patients with cervical dystonia and in a relevant proportion of subjects with focal dystonia of the limbs, it has received very little attention from researchers and controlled trials are scant. The aim of this review is to summarize the current knowledge on the clinical assessment and management of pain in focal dystonias. The search results will inform on the types of pain reported in focal dystonias, on the tools that are used to quantify pain and on the efficacy of pharmacological and non-pharmacological approaches. The collated data will hopefully improve the clinical management of focal dystonia and also stimulate future research on dystonia-associated pain. Optimization of the outcome indeed requires the identification and the management of all the factors that determine disability and hence relies on a multidisciplinary approach.

The importance of the reproducibility of oropharyngeal swallowing in amyotrophic lateral sclerosis. An electrophysiological study.

OBJECTIVE: To investigate electrophysiologically the reproducibility of oropharyngeal swallowing in patients with ALS. METHODS: We enrolled 26 ALS patients, both with and without clinical signs of dysphagia, and 30 age-matched controls. The reproducibility of the electrophysiological signals related to the oral phase (electromyographic activity of the submental/suprahyoid muscles) and the pharyngeal phase (laryngeal-pharyngeal mechanogram) of swallowing across repeated swallows was assessed. To do this we computed two similarity indexes (SI) by using previously described mathematical algorithms. RESULTS: The reproducibility of oropharyngeal swallowing was significantly reduced both in patients with and in those without clinical signs of dysphagia, with more marked alterations being detected in the dysphagic group. The SI of both phases of swallowing, oral and pharyngeal, correlated significantly with dysphagia severity and disease severity. CONCLUSIONS: In ALS different pathophysiological mechanisms can alter the stereotyped motor behaviors underlying normal swallowing, thus reducing the reproducibility of the swallowing act. A decrease in swallowing reproducibility could be a preclinical sign of dysphagia and, beyond a certain threshold, a pathological hallmark of oropharyngeal dysphagia. SIGNIFICANCE: Electrophysiological assessment is a simple and useful tool for the early detection of swallowing abnormalities, and for the management of overt dysphagia in ALS.

Temporal summation of the nociceptive withdrawal reflex involves deactivation of posterior cingulate cortex.

BACKGROUND: Temporal summation of pain sensation is pivotal both in physiological and pathological nociception. In humans, it develops in parallel with temporal summation of the nociceptive withdrawal reflex (NWR) of the lower limb, an objective representation of the temporal processing of nociceptive signals into the spinal cord. METHODS: To study the contribution of cortical and subcortical structures in temporal summation of pain reflex responses, we compared the fMRI signal changes related to the temporal summation threshold (TST) of the NWR with that related to the single NWR response. We studied 17 healthy subjects using a stimulation paradigm previously determined to evoke both the TST of the NWR (SUMM) and the NWR single response (SING). RESULTS: We found a significant activation in left (contralateral) primary somatosensory cortex (SI), bilateral secondary somatosensory cortex (SII), bilateral insula, anterior cingulate cortex (ACC) and bilateral thalamus during both SUMM and SING conditions. The SUMM versus SING contrast revealed a significant deactivation in the posterior cingulate cortex (PCC) and bilateral middle occipital gyrus in SUMM when compared to SING condition. CONCLUSIONS: Our data support the hypothesis that temporal summation of nociceptive reflex responses is driven through a switch between activation and deactivation of a specific set of brain areas linked to the default mode network. This behaviour could be explained in view of the relevance of the pain processing induced by temporal summation, recognized as a more significant potential damaging condition with respect to a single, isolated, painful stimulation of comparable pain intensity. SIGNIFICANCE: The study demonstrated that TST of the NWR involves a selective deactivation of PCC.

Specific patterns of laryngeal electromyography during wakefulness are associated to sleep disordered breathing and nocturnal stridor in multiple system atrophy.

BACKGROUND: Nocturnal stridor and respiratory abnormalities are important features of multiple system atrophy (MSA) with relevance to patient survival, and they are detected and evaluated mainly through video-polysomnography (video-PSG). Diurnal laryngoscopy seems to yield abnormal findings only in the presence of significant vocal cord (VC) dysfunction. AIM: To assess whether specific electrophysiological patterns of diurnal EMG of VC muscles may indicate nocturnal stridor or respiratory dysfunctions in MSA patients. MATERIALS AND METHODS: Seventeen patients with probable MSA were examined. A full-night video-PSG to collect standard breathing parameters (apnea/hypopnea index, mean HbSAO2, oxygen desaturation index, total sleep time with HbSaO2 below 90%) was performed in all the patients. Laryngoscopy and EMG investigation of adductor (thyroarytenoid-TA) and abductor (posterior cricoarytenoid-PCA) muscles of the VCs were also performed. RESULTS: Both the laryngeal EMG abnormalities (based on MUAP analysis and kinesiologic EMG investigation of VC muscles) and the laryngoscopic alterations correlated with video-PSG respiratory abnormalities. Specific patterns of EMG findings were consistently found in MSA subjects with nocturnal stridor detected at PSG. In particular, the following EMG findings were related to the severity of breathing abnormalities and the presence of stridor on video-PSG: neurogenic pattern on MUAP analysis of the PCA, paradoxical activation of the TA during inspiration and tonic EMG activity of the TA during quiet breathing. CONCLUSIONS: Electromyographic/kinesiologic investigation of VC muscles during wakefulness provides additional information on the pathophysiology of the respiratory abnormalities in MSA patients that could be useful for guiding the choice of the best appropriate treatment and care.

Intra- and Extracranial MR Venography: Technical Notes, Clinical Application, and Imaging Development.

Scientific debate over chronic cerebrospinal venous insufficiency (CCSVI) has drawn attention to venous system involvement in a series of pathologic brain conditions. In the last few decades, the MRI venography (MRV) field has developed a number of valuable sequences to better investigate structural anatomy, vessel patency, and flow characteristics of venous drainage in the intra- and extracranial systems. A brief two-tier protocol is proposed to encompass the study of intra- and extracranial venous drainage with and without contrast administration, respectively. Contrast-enhanced protocol is based on time-resolved contrast-enhanced MRV of the whole region plus extracranial flow quantification through 2D Cine phase contrast (PC); non-contrast-enhanced protocol includes intracranial 3D PC, extracranial 2D time of flight (TOF), and 2D Cine PC flow quantification. Total scanning time is reasonable for clinical applications: approximately seven minutes is allocated for the contrast protocol (most of which is due to 2D Cine PC), while the noncontrast protocol accounts for around twenty minutes. We believe that a short though exhaustive MRI scan of the whole intra- and extracranial venous drainage system can be valuable for a variety of pathologic conditions, given the possible venous implication in several neurological conditions.

Cost of Chronic and Episodic Migraine. A pilot study from a tertiary headache centre in northern Italy.

BACKGROUND: Chronic migraine (CM) has a high impact on functional performance and quality of life (QoL). CM also has a relevant burden on the National Health Service (NHS), however precise figures are lacking. In this pilot study we compared the impact in terms of costs of CM and episodic migraine (EM) on the individual and on the National Health System (NHS). Furthermore, we comparatively evaluated the impact of CM and EM on functional capability and on QoL of sufferers. METHODS: We enrolled 92 consecutive patients attending the Pavia headache centre: 51 subjects with CM and 41 with episodic migraine (EM). Patients were tested with disability scales (MIDAS, HIT-6, SF-36) and with an ad hoc semi-structured questionnaire. RESULTS: The direct mean annual cost (in euro) per patient suffering from CM was €2250.0 ± 1796.1, against €523.6 ± 825.8 per patient with EM. The cost loaded on NHS was €2110.4 ± 1756.9 for CM, €468.3 ± 801.8 for EM. The total economic load and the different sub-items were significantly different between groups (CM vs. EM p = 0.001 for each value). CM subjects had higher scores than EM for MIDAS (98.4 ± 72,3 vs 15.5 ± 17.7, p = 0.001) and for HIT-6 (66.1 ± 8.4 vs 58.7 ± 10.1, p = 0.001). The SF-36 score was 39.9 ± 14,74 for CM and 66.2 ± 18.2 for EM (p = 0.001). CONCLUSIONS: CM is a disabling condition with a huge impact on the QoL of sufferers and a significant economic impact on the NHS. The adequate management of CM, reverting it back to EM, will provide a dual benefit: on the individual and on the society.

Botulinum toxin type A potentiates the effect of neuromotor rehabilitation of Pisa syndrome in Parkinson disease: a placebo controlled study.

INTRODUCTION: Pisa syndrome (PS) is a tonic lateral flexion of trunk that represents a disabling complication of advanced Parkinson disease (PD). Conventional rehabilitation treatment (CT) ameliorates axial posture and trunk mobility in PD patients, but the improvement tends to wane in 4-6 months. Botulin toxin (BT) may reduce muscle hyperactivity, therefore improving CT effectiveness. We evaluated whether the injection of incabotulinum toxin type A (iBTA) into the hyperactive trunk muscles might improve the effectiveness of rehabilitation in a group of PD patients with PS. METHODS: Twenty-six PD patients were enrolled in a randomized placebo-controlled trial. Group A was treated with iBTA before undergoing CT (a 4-week intensive programme), while Group B received saline before the 4-week CT treatment. Patients were evaluated at baseline, at the end of the rehabilitative period, 3 and 6 months with kinematic analysis of movement, UPDRS, Functional Independence Measure and Visual Analog Scale for pain. RESULTS: At the end of the rehabilitation period, both groups improved significantly in terms of static postural alignment and of range of motion. Group A showed a significantly more marked reduction in pain score as compared with Group B and a more prolonged efficacy on several clinical and kinematic variables. CONCLUSIONS: Our preliminary data suggest that BT may be considered an important addition to the rehabilitation programme for PD subjects with PS for improving axial posture and trunk mobility, as well as for a better control of pain.

A consensus protocol for the management of medication-overuse headache: Evaluation in a multicentric, multinational study.

INTRODUCTION: The management of medication-overuse headache (MOH) is often difficult and no specific guidelines are available as regards the most practical and effective approaches. In this study we defined and tested a consensus protocol for the management of MOH on a large population of patients distributed in different countries. SUBJECTS AND METHODS: The protocol was based on evidence from the literature and on consolidated expertise of the members of the consensus group. The study was conducted according to a multicentric interventional design with the enrolment of 376 MOH subjects in four centres from Europe and two centres in Latin America. The majority of patients were treated according to an outpatient detoxification programme. The post-detoxification follow-up lasted six months. RESULTS: At the final evaluation, two-thirds of the subjects were no longer overusers and in 46.5% of subjects headache had reverted back to an episodic pattern of headache. When comparing the subjects who underwent out-patient detoxification vs those treated with in-patient detoxification, both regimens proved effective, although the drop-out rate was higher in the out-patient approach. CONCLUSIONS: The present findings support the effectiveness and usability of the proposed consensus protocol in different countries with different health care modalities.