MR Imaging in the Evaluation of Chronic or Recurrent Headache

Follow-up care compliance among patients diagnosed with unruptured intracranial aneurysms

OBJECTIVES

Periodic imaging follow-up for patients with unruptured intracranial aneurysms (UIA) is crucial, as studies indicate higher rupture risk with aneurysm growth. However, few studies address patient adherence to follow-up recommendations. This study aims to identify compliance rates and factors influencing follow-up adherence.

METHODS

Patients with a UIA were identified from our institution's database from 2011-2021. Follow-up imaging (CT/MR Angiogram) was advised at specific intervals. Patients were categorized into compliant and non-compliant groups based on first-year compliance. Factors contributing to compliance were assessed through multivariate logistic regression. Phone interviews were conducted with non-compliant patients to understand reasons for non-adherence.

RESULTS

Among 923 UIA diagnosed patients, 337 were randomly selected for analysis. The median follow-up period was 1.4 years, with a 42% first-year compliance rate. The mean aneurysm size was 3.3 mm. Five patients had a rupture during follow-up, of which 4 died. Compared with patients consulting specialists at the initial diagnosis, those seen by non-specialists exhibited lower compliance (OR 0.25, p < 0.001). Loss to follow-up was greatest during transition from emergency service to specialist appointments. Patients who spoke languages other than English exhibited poorer compliance than those speaking English (OR 0.20, p = 0.01).

CONCLUSIONS

Significant amounts of UIA patients at low rupture risk were lost to follow-up before seeing UIA specialists. Main non-compliance factors include inadequate comprehension of follow-up instructions, poor care transfer from non-specialists to specialist, and insurance barriers.

Utility of cranial MRI in non-traumatic headache patients with prior negative head CT within 1 month

AIM

To investigate the importance of additional cranial magnetic resonance imaging (cMRI) in non-traumatic headache patients with a prior negative head computed tomography (CT) examination within 1 month.

MATERIALS AND METHODS

This retrospective study analysed 162 adult patients with non-traumatic headache who underwent cMRI within 1 month of a negative initial head CT at the emergency department (ED). The diagnostic yield and false-referral rate were analysed according to the revisit duration (early [≤1 week] versus late [>1-4 weeks] revisits), patient care settings (ED versus outpatient clinics [OPC]), and clinical variables. Subsequent patient management change (PMC), such as admission and treatment (AT) or outpatient clinic treatment (OT), were also investigated.

RESULTS

The overall diagnostic yield of cMRI was 17.3% (28/162) and the false-referral rate was 1.2% (2/162). The diagnostic yield of cMRI was significantly different according to the patient care settings (ED, 24.7% [21/85] versus OPC, 9.1% [7/77]; p=0.02). The diagnostic yield was highest in the ED-early-revisit group (25.4% [18/71]), 45% (9/20) in those with systemic signs, and 46.7% (14/30) in those with symptom change. Among patients with positive cMRI findings, 90% (27/30) received AT and 3.3% (1/30) received OT. Among OPC-revisit-negative cMRI patients, PMC occurred in 0% (0/50).

CONCLUSION

The diagnostic yield of cMRI was relatively high for headache patients who revisited the ED earlier, especially in those with systemic signs or symptom change. Most positive cMRI cases experienced PMC. Negative cMRI in OPC-revisit patients might help clarify the benign nature of a condition.

MRI findings in children with migraine or tension-type headache

PURPOSE

Migraine and tension-type headache are common primary headaches in children. There is a risk of developing secondary headache in children. The current study was aimed to evaluate magnetic resonance imaging findings (MRI) in children with migraine or tension-type headache.

METHODS

The study was planned in children with migraine or tension-type headaches who have been followed up in the pediatric neurology outpatient clinic with regular office visits for at least two years and had neuroimaging in the last year.

RESULTS

280 patients (187 female patients) datas were studied. 91 (61 female patients) were followed up with the diagnosis of migraine and 189 (126 female patients) with the diagnosis of tension-type headaches. The age of patients was found to be 13.1 ± 3.4 years. Brain tumor was found in one child with tension-type headache who had papilledema. Incidental MRI findings found 7.7% and 12.7% in migraine and tension-type headache, respectively. MRI findings in the study were arachnoid cyst (14), pituitary adenoma (6), mega cisterna magna (6), pineal cyst (3), non-specific gliosis (2) and tumor (1).

CONCLUSION

Arachnoid cysts were found incidental as the most common MRI finding in children with migraine or tension-type headache. The rare life-threatening secondary headache may develop in children. The fundus examination as a complement to the neurological examination can be useful for requesting MRI.

Rimegepant for the treatment of migraine

Migraine is a common form of primary headache, affecting up to 1 in every 6 Americans. The pathophysiology is an intricate interplay of genetic factors and environmental influence and is still being elucidated in ongoing studies. The trigeminovascular system is now known to have a significant role in the initiation of migraines, including the release of pain mediators such as CGRP and substance P. Traditional treatment of migraine is usually divided into acute and preventive treatment. Acute therapy includes non-specific therapy, such as NSAIDs and other analgesics, which may provide relief in mild to moderate migraines. 5-HT1 agonists may provide relief in severe migraine, but are not universally effective and carry a significant side-effect profile with frequent redosing requirement. Prophylactic therapy may reduce the occurrence of acute migraine attacks in selected patients, but does not completely eliminate it. More recently, CGRP antagonism has been studied and shown to be effective in both abortion and prevention of migraine. Novel medications, targeting CGRP, divide into CGRP antibodies and receptor antagonists (gepants). Rimegepant, a second-generation gepant, has shown efficacy in several clinical trials in treating acute migraine. Ongoing trials are also evaluating its role in migraine prophylaxis, and results are promising. It is also generally safer for use than existing options, does not appear to increase the chance of developing chronic migraines, and carries a very tolerable side effects profile. It is a part of a growing arsenal in migraine treatment, and may present the silver bullet for treatment of this disease.

Prevalence and Risk Factors Associated with Tumors and Other Structural Anomalies in Brain MRI Performed to Rule out Secondary Headache: A Multicenter Observational Study

Headache disorders (HDs) are among the most common conditions of the central nervous system, with an estimated prevalence of 50% in adult population. The aim of this work is to analyze the prevalence of structural anomalies that may explain HDs in MRI exams performed to rule out secondary headache in real-world practice, as well as risk factors associated with these lesions. We conducted a retrospective observational study based on a consecutive case series of all patients that underwent brain MRI due to headache from 1 January 2019 to 31 May 2019. We included patients from six MRI diagnostic centers accounting for four provinces of Andalusia (southern Spain). Bivariate and multivariate logistical regression models were performed to identify risk factors associated with the outcomes (1) presence of a structural finding potentially explaining headache, (2) presence of intracranial space-occupying lesions (SOLs), and (3) presence of intracranial tumors (ITs). Of the analyzed sample (1041 patients), a structural finding that could explain headache was found in 224 (21.5%) patients. SOLs were found in 50 (6.8%) patients and ITs in 12 (1.5%) patients. The main factors associated with structural abnormalities were female sex (OR, 1.35; 95% CI, 1.02–1.85), accompanying symptoms (OR, 1.34; 95% CI, 1.05–1.89), use of gadolinium-based contrast agents (OR, 1.89; 95% CI, 1.31–2.72) and previously known conditions potentially explaining headache (OR, 2.44; 95% CI, 1.55–3.84). Female sex (p = 0.048) and accompanying symptoms (p = 0.033) were also associated with ITs in bivariate analyses. Our results may be relevant for different medical specialists involved in the diagnosis, management and prevention of headache. Moreover, the risk factors identified in our study might help the development of public health strategies aimed at early diagnosis of brain tumors. Future studies are warranted to corroborate our findings.

Updates in the Diagnostic Approach of Headache

PURPOSE OF REVIEW

In this review, we summarize updates in the diagnostic approach of headaches with the aim of facilitating the distinction between primary and secondary etiology in headaches.

RECENT FINDINGS

In the USA, headache is the fifth most common complaint in the emergency department, but only a minority will have a secondary etiology. Initial suspicion and diagnostic workup of secondary headache relies on a patient's medical history due to a scarcity of validated biomarkers. A special interest group under the International Headache Society recently synthesized information on red flags (information that indicates a secondary etiology) and green flags (information that indicates a primary etiology). A systematic diagnostic approach using red flags and green flags can help reduce unnecessary testing and shift attention to patient care. Going forward, further validation of these concepts is needed to properly introduce them for clinical use.

ACR Appropriateness Criteria® Headache

Headache is one of the most common human afflictions. In most cases, headaches are benign and idiopathic, and resolve spontaneously or with minor therapeutic measures. Imaging is not required for many types of headaches. However, patients presenting with headaches in the setting of "red flags" such as head trauma, cancer, immunocompromised state, pregnancy, patients 50 years or older, related to activity or position, or with a corresponding neurological deficit, may benefit from CT, MRI, or noninvasive vascular imaging to identify a treatable cause. This publication addresses the initial imaging strategies for headaches associated with the following features: severe and sudden onset, optic disc edema, "red flags," migraine or tension-type, trigeminal autonomic origin, and chronic headaches with and without new or progressive features. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Magnetic resonance imaging in chronic headache: our experiences and perspectives

Background

Headache is a common symptomatology necessitating hospital consultations. Despite the prohibitive cost to patients in Nigeria, Magnetic resonance imaging (MRI) has become an evaluating tool for headache.

Objectives

To determine the yield of cranial MRI and frequency of significant intracranial lesions among patients with chronic headache.

Methods

A three-year retrospective analysis of cranial MR images and records of patients referred to Medicaid Diagnostic Centre in Abuja, Nigeria on account of chronic headache was done. Data was analyzed using SAS software version 9.3.

Results

150 patients aged 9 to 73 years (mean= 39.5 years) with chronic headache were studied. There were 54 males and 96 females with a ratio of 1:1.8. 48% and 52% had normal and abnormal MRI findings respectively. Although the number with abnormal MRI was higher than those with normal exams, this difference was not significant (p=0.624). The commonest neoplastic and non-neoplastic abnormalities were pituitary macroadenoma (4%) and sinusitis (21.3%) respectively.

Conclusion

In our study, MRI had a low diagnostic yield in patients with chronic headache. Therefore, it is expedient that physicians stratify patients with chronic headache based on red flag signs to determine the need for cranial MRI in view of financial burden.

Consensus Guidelines of the French Society of Neuroradiology (SFNR) on the use of Gadolinium-Based Contrast agents (GBCAs) and related MRI protocols in Neuroradiology

Gadolinium-based contrast agents (GBCAs) are used in up to 35% of magnetic resonance imaging (MRI) examinations and are associated with an excellent safety profile. Nevertheless, two main issues have arisen in the last two decades: the risk of nephrogenic systemic fibrosis and the risk of gadolinium deposition and retention. As a first step, this article reviews the different categories of GBCAs available in neuroradiology, their issues, and provides updates regarding the use of these agents in routine daily practice. Recent advances in MRI technology, as well as the development of new MRI sequences, have made GBCA injection avoidable in many indications, especially in patients with chronic diseases when iterative MRIs are required and when essential diagnostic information can be obtained without contrast enhancement. These recent advances also lead to changes in recommended MRI protocols. Thus, in a second step, this review focuses on consensus concerning brain MRI protocols in 10 common situations (acute ischemic stroke, intracerebral hemorrhage, cerebral venous thrombosis, multiple sclerosis, chronic headache, intracranial infection, intra- and extra-axial brain tumors, vestibular schwannoma and pituitary adenoma). The latter allowing the standardization of practices in neuroradiology. Recommendations were also made concerning the use of GBCAs in neuroradiology, based on evidence in the literature and/or by consensus between the different coauthors.

Factors Associated with Incidental Neuroimaging Abnormalities in New Primary Headache Patients

Background and Purpose

Deciding whether or not to perform neuroimaging in primary headache is a dilemma for headache physicians. The aim of this study was to identify clinical predictors of incidental neuroimaging abnormalities in new patients with primary headache disorders.

Methods

This cross-sectional study was based on a prospective multicenter headache registry, and it classified 1,627 consecutive first-visit headache patients according to the third edition (beta version) of the International Classification of Headache Disorders (ICHD-3β). Primary headache patients who underwent neuroimaging were finally enrolled in the analysis. Serious intracranial pathology was defined as serious neuroimaging abnormalities with a high degree of medical urgency. Univariable and multivariable logistic regression analyses were conducted to identify factors associated with incidental neuroimaging abnormalities.

Results

Neuroimaging abnormalities were present in 170 (18.3%) of 927 eligible patients. In multivariable analysis, age ≥40 years [multivariable-adjusted odds ratio (aOR)=3.37, 95% CI=2.07–6.83], male sex (aOR=1.61, 95% CI=1.12–2.32), and age ≥50 years at headache onset (aOR=1.86, 95% CI=1.24–2.78) were associated with neuroimaging abnormalities. In univariable analyses, age ≥40 years was the only independent variable associated with serious neuroimaging abnormalities (OR=3.37, 95% CI=1.17–9.66), which were found in 34 patients (3.6%). These associations did not change after further adjustment for neuroimaging modality.

Conclusions

Incidental neuroimaging abnormalities were common and varied in a primary headache diagnosis. A small proportion of the patients incidentally had serious neuroimaging abnormalities, and they were predicted by age ≥40 years. These findings can be used to guide the performing of neuroimaging in primary headache disorders.

Diagnostic Neuroimaging in Headache Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

Neuroimaging in headache patients identifies clinically significant neurological abnormalities and plays an important role in excluding secondary headache diagnoses. We performed a systematic review and meta-analysis of the existing guidelines and studies surrounding neuroimaging in headache patients.

METHODS

The research question involved determining the prevalence of detecting clinically significant neurological abnormalities using neuroimaging in patients suspected of primary headache. Searches of the PubMed and Embase databases were conducted on English-language studies published from 1991 to 2016, and the reference lists of the retrieved articles were also checked manually. All headache subtypes and patients aged ≥15 years were included in the analysis.

RESULTS

Ten studies met the selection criteria. The pooled prevalence of detecting clinically significant abnormalities in the neuroimaging of headache patients was 8.86% (95% confidence interval: 5.12-15.33%). Subsequently, diverse subgroup analyses were performed based on the detection method, headache type, study type, study region, age group, and disease type.

CONCLUSION

The present findings indicate that limited neuroimaging methods should be carefully considered for headache diagnostic purposes when there are red flag symptoms. Limitations and suggested directions for future studies on neuroimaging in headache patients are described.

"Worst Headache of Life" in a Migraineur: Marginal Value of Emergency Department CT Scanning

PURPOSE

The ACR Appropriateness Criteria recommend performing noncontrast head CT (NCCT) for patients with sudden severe headache ("worst headache of life" [WHOL] or "thunderclap headache" [TCH]). The aim of this study was to assess the value of NCCT scanning in patients with known migraine histories and WHOL or TCH. The hypothesis was that there would be little utility in performing emergency department (ED) NCCT scans in migraineurs without other red flags, even if they had WHOL or TCH.

METHODS

The ED NCCT scans of all patients reporting WHOL or TCH who had established diagnoses of migraine were retrospectively reviewed over a 5-year period. Patients without known intracranial pathology, cancer, or immunocompromising disease or recent head trauma were included as the main study group. For comparison, patients with any of those factors were included as the comparison group. Scans were graded as (1) normal, (2) minor unimportant findings, (3) findings requiring intervention or follow-up, or (4) critical.

RESULTS

Two hundred twenty-four patients with the chief symptom of WHOL or TCH and a history of migraine who underwent ED NCCT were studied. In the main study group, no patients had grade 4 imaging findings (0%), one had a false-positive grade 3 finding (0.8%), and there were no cases of subarachnoid hemorrhage (0%). In the comparison group, six patients had grade 4 imaging findings (6.5%) and three had grade 3 findings (3.3%).

CONCLUSIONS

NCCT in known migraineurs with WHOL or TCH who do not have intracranial pathology, cancer, immunocompromising disease, or recent head trauma yielded no critical findings. Therefore, the value of scanning these patients is questionable.

Red and orange flags for secondary headaches in clinical practice: SNNOOP10 list

A minority of headache patients have a secondary headache disorder. The medical literature presents and promotes red flags to increase the likelihood of identifying a secondary etiology. In this review, we aim to discuss the incidence and prevalence of secondary headaches as well as the data on sensitivity, specificity, and predictive value of red flags for secondary headaches. We review the following red flags: (1) systemic symptoms including fever; (2) neoplasm history; (3) neurologic deficit (including decreased consciousness); (4) sudden or abrupt onset; (5) older age (onset after 65 years); (6) pattern change or recent onset of new headache; (7) positional headache; (8) precipitated by sneezing, coughing, or exercise; (9) papilledema; (10) progressive headache and atypical presentations; (11) pregnancy or puerperium; (12) painful eye with autonomic features; (13) posttraumatic onset of headache; (14) pathology of the immune system such as HIV; (15) painkiller overuse or new drug at onset of headache. Using the systematic SNNOOP10 list to screen new headache patients will presumably increase the likelihood of detecting a secondary cause. The lack of prospective epidemiologic studies on red flags and the low incidence of many secondary headaches leave many questions unanswered and call for large prospective studies. A validated screening tool could reduce unneeded neuroimaging and costs.

Unnecessary Neuroimaging for Patients With Primary Headaches

Background - Headache may be due to either a primary or secondary disorder, and neuroimaging assessments can play an important role when differentiating between these types of headache. Although many studies have reported no significant differences between primary headache patients and the general population in terms of abnormal neuroimaging findings, others have shown that neuroimaging may be employed to rule out secondary causes of headache that could impact morbidity and mortality. This issue remains under debate. Thus, the present study compared the neuroimaging findings of headache patients and healthy controls. Methods - This study recruited 1070 healthy controls and 1070 primary headache patients from the Chinese People's Liberation Army General Hospital. The primary headache patients were diagnosed by computerized clinical decision support systems, and re-diagnosed by a specialist. All participants were assessed with either computed tomography or magnetic resonance imaging (MRI) scans. The neuroimaging findings were classified as significant abnormalities, non-significant abnormalities, or normal. Results - All the significant abnormalities were found using MRI scans. Significant abnormalities were identified in 4 primary headache patients (0.58%) and 5 healthy controls (0.73%); the rate of significant abnormalities was not significant different between both groups (P > .05). Conclusions - The present study found that neuroimaging was unnecessary for the primary headache patients.

Occipital Headaches and Neuroimaging in Children

PURPOSE OF REVIEW

The goal of this review is to outline the prevalence and significance of occipital headaches in children and how they relate to neuroimaging findings. We seek to evaluate the concern that occipital headaches in children are indicative of secondary headache pathology by reviewing the yield of neuroimaging in pediatric patients with occipital headache location.

RECENT FINDINGS

Occipital headaches are a common presentation of primary headache disorders in children, seen in 7-16% of children presenting for evaluation of headache and in up to 20% of children diagnosed with migraine in the emergency department. Review of recent literature confirms that in and of itself, occipital location of headache in a child with recurrent headache and a normal physical examination should not be regarded as worrisome. Headaches with associated signs on neurologic examination should be investigated for a secondary cause, regardless of headache location. Occipital headaches that do not meet criteria for a primary headache disorder should be evaluated for site-specific occipital headache conditions. Neuroimaging for recurrent headache in children who have normal neurological examinations has an overall low yield (0-4.1%) for actionable findings in recent studies. Importantly, an abnormal neurologic examination often predicts the presence of neuroimaging abnormalities. In the absence of an atypical history or abnormalities on clinical examination, occipital headaches in children are no more likely to be associated with intracranial pathology than headaches in other locations. If the child's headaches are otherwise consistent with migraine or another primary headache disorder, and the neurologic examination is normal, the yield of neuroimaging is low, and imaging can generally be deferred.

Headache

Headache, an almost universal human experience, is one of the most common complaints encountered in medicine and neurology. Described and categorized since antiquity, with the first classification by Aretaeus of Cappadocia, other classifications followed. The evaluation of this condition may be straightforward or challenging, and, though often benign, headache may prove to be an ominous symptom. This review discusses the current diagnosis and classification of headache disorders and principles of management, with a focus on migraine, tension-type headache, trigeminal autonomic cephalgias, and various types of daily headache.

Evaluation of CT and MRI Findings among Patients Presented with Chief Complaint of Headache in Central India

INTRODUCTION

Headache is one of the most common presenting complaints in day to day medical practice however the secondary causes of headache are uncommon. Thus, appropriate selection of headache patient (Pt) is important to determine those that require neuroimaging due to likely secondary cause. Red flags and Clinical warning criterion (CWC) act as a screening tool to help in identifying those who may get benefit from neuroimaging.

AIM

To evaluate the findings of computed tomography (CT) and Magnetic Resonance Imaging (MRI) among patients presented with the chief complaint of headache and to compare the findings between two groups of patients.

MATERIALS AND METHODS

This retrospective observational study was carried out in 500 selected patients, who underwent CT or MRI scan of head in Peoples College of Medical Sciences and Research centre, Bhopal, MP during the period of 2 year in between Jan 2013 to Dec 2014. Siemens Somatom sensation 40 slice MDCT and Siemens magnetom 1.5T MRI scanner were used for imaging. Five hundred patients of 10 to 70 year age were selected for the study based on our criterions of selection.

RESULTS

All 500 patients were divided in to two groups A and B based on presence or absence of red flag signs and CWC signs. Group A consists of 48 patients having one or more red flag or CWC signs and group B consists of 452 patients those don't have any above signs. 29 cases (60.4%) out of total 48 cases of group A is suffering from chronic headache as compared to 97 cases (21.5%) out of total 452 patients of group B is having positive findings (p-value<0.05). Out of 500 patients, only 29 cases (5.8%) revealed some form of brain parenchymal pathology whereas other associated findings were seen in 97 cases e.g. sinusitis in 58 (11.6%), bone related pathology in 26 (5.2%) and chronic suppurative otitis media (CSOM) in 13 (2.6%) patients.

CONCLUSION

CT/MRI in patients without red flag or CWC sign yields very low percentage of clinically significant positive findings in neuroimaging. In the absence of these, the only reason for CT or MRI scan seems to reassure the patients and their loved ones. CT or MRI as a screening tool in these patients has limited value in term of cost effectiveness.

Intracranial abnormalities and headache: A population-based imaging study (HUNT MRI)

Background

Most studies on intracranial abnormalities among headache sufferers were performed in selected clinical populations. The aim of this study was to evaluate the relationship between intracranial abnormalities and headache among middle-aged adults in the general population.

Methods

Participants in a large epidemiological study (the HUNT 3 study; 2006–2008) who answered a headache questionnaire and participated in a population-based imaging study of the head (HUNT MRI; 2007–2009) were included ( n = 864; age, 50–65 at enrollment). Based on the responses to the HUNT 3 questionnaire, respondents were categorized as having migraine, tension-type headache, or unclassified headache. Logistic regression was used to compare the occurrence of intracranial abnormalities between groups.

Results

Intracranial abnormalities were more common in headache sufferers than in headache-free individuals (29% vs. 22%, respectively; p = 0.041). Adjusted multivariate analyses revealed that those with tension-type headache had higher odds of having minor abnormalities (odds ratio, 2.13; 95% confidence interval = 1.18–3.85). This association disappeared when those with only white matter hyperintensities were removed from the analysis.

Conclusions

Headache sufferers had increased odds of minor intracranial abnormalities. The increased odds were primarily related to the presence of white matter hyperintensities.

ACR Appropriateness Criteria Headache

Most patients presenting with uncomplicated, nontraumatic, primary headache do not require imaging. When history, physical, or neurologic examination elicits "red flags" or critical features of the headache, then further investigation with imaging may be warranted to exclude a secondary cause. Imaging procedures may be diagnostically useful for patients with headaches that are: associated with trauma; new, worse, or abrupt onset; thunderclap; radiating to the neck; due to trigeminal autonomic cephalgia; persistent and positional; and temporal in older individuals. Pregnant patients, immunocompromised individuals, cancer patients, and patients with papilledema or systemic illnesses, including hypercoagulable disorders may benefit from imaging. Unlike most headaches, those associated with cough, exertion, or sexual activity usually require neuroimaging with MRI of the brain with and without contrast to exclude potentially underlying pathology before a primary headache syndrome is diagnosed. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Neuro-Behçet's disease: an unusual cause of headache

Neuro-Behçet's disease (NBD) is a potentially fatal complication of Behçet's disease (BD) that can sometimes masquerade as a primary neoplasm, aseptic meningitis or multiple sclerosis. Headache in patients with BD may portend onset of NBD, but the majority of headache in BD is benign. Clinicians who are unaware of the specific neurological manifestations of systemic inflammatory disorders like BD may fail to consider the possibility of serious intracranial pathology. We illustrate these challenges with the case of a 50-year-old woman with a history of BD who presented with headache in the absence of initial focal neurological deficits. The diagnosis of NBD was missed on multiple occasions before the correct diagnosis was made. We describe the etiology of headache in BD, the specific neurological manifestations of BD that suggest NBD, and the utility of routine neurological exams for BD patients with chronic headache. We further discuss the appropriate use of neuroimaging for headache in BD, and we recommend consideration of NBD as a diagnosis for headache in patients suspected of having an underlying systemic disease.

Instrumental exams performance can be a contributing factor to the delay in diagnosis of migraine

BACKGROUND

Diagnostic delay is a recognized drawback for a correct management of migraine patients. The aim of this study was to investigate the possible relationship among number and type of examinations performed and diagnostic delay in migraine diagnosis.

METHODS

We enrolled 500 subjects referred to our Headache Center for a migraine without aura. We analyzed the relationship among diagnostic delay, number of examinations performed and performance of each single test by a Cox regression model and an ordinal logistic regression model.

RESULTS

Each individual exam increased a diagnostic delay of at least 12 months (p < 0.05, Cox regression model). Brain CT as the first diagnostic approach had a reduced risk of delay of more than 5 years (OR 0.632, 95% CI 0.71-0.56, p < 0.05, ordinal regression model).

CONCLUSIONS

The number of instrumental examinations seems to significantly influence the diagnostic delay. This aspect contributes to increase health care costs, the risk of pain chronicization and pharmacological treatment misuse.

MRI in headache

Headaches are described as primary, where no contributing cause is found, or secondary, where a discrete lesion or other condition has triggered the phenotype. Primary headache is a common condition; migraine causes much of the morbidity in this population, at great personal and economic cost. The decision to use MRI is a common dilemma facing clinicians, particularly as primary headache phenotypes can be triggered by secondary causes. Studies demonstrate that there is no appreciable difference in the frequency of pathological and incidental findings in common headache populations compared with the general community. Imaging is therefore not routinely required where a primary headache diagnosis can be made. Clinicians must be aware of the risk of manufacturing morbidity in uncovering incidental and nonsignificant imaging changes. However, patients demonstrating 'red flags' on medical history and examination do require imaging to help exclude a secondary cause of symptoms. Other headache phenotypes, such as the trigeminal autonomic cephalalgias, also generally require MRI.

Imaging Features of Cerebral Vascular Malformations

Computed tomography (CT) and magnetic resonance images (MRI) play an important role in the diagnosis of various types of cerebral vascular malformations. To evaluate the imaging features of some of these lesions and compare the results with other studies reported in literature, eight patients (including four cases of cerebral arteriovenous malformation, one case of pial arteriovenous [AV] fistula, two cases of cerebral cavernous malformation [CVM], and one case of developmental venous anomaly [DVA]), with the age range of 28 to 74 years and symptoms ranging from asymptomatic to massive intracranial haemorrhage and coma, were examined by CT, MRI, conventional angiography, or a combination of these. A survey of 11 studies on CVMs, reported from 1981 to 2008, was also done and results were summarized in brief to compare with our study. Noncontrast CT was unable to detect DVA or characterize the lesion in cases of pial AV fistula and cavernous malformations, but MRI was quite successful in detecting cavernous malformations. Computed tomographic angiography (CTA) was highly successful in detecting and characterizing the imaging features of DVA, pial AV fistula, and AVMs. Angiography showed an additional feeding artery in one case of AVM, which CTA failed to show, and endovascular therapy at the time of angiography was also successful to embolize the large intranidal aneurism, providing significant improvement in the patient's condition.

Diagnostics to look beyond the normal appearing brain tissue (NABT)? A neuroimaging study of patients with primary headache and NABT using magnetization transfer imaging and diffusion magnetic resonance

OBJECTIVE

Novel diagnostics can allow us to "look beyond" normal-appearing brain tissue (NABT) to unravel subtle alterations pertinent to the pathophysiology of primary headache, one of the most common complaints of patients who present to their physician across the medical specialties. Using both magnetization transfer imaging (MTI) and diffusion weighted imaging (DWI), we assessed the putative microstructural changes in patients with primary headache who display the NABT on conventional magnetic resonance imaging (conventional MRI).

METHODS

Subjects were 53 consecutive patients with primary headache disorders (40 = migraine with aura; 9 = tension headache; 4 = cluster headache) and 20 sex- and age-matched healthy volunteers. All subjects underwent evaluation with MRI, MTI, and DWI in order to measure the magnetization transfer ratio (MTR) and the apparent diffusion coefficient (ADC), respectively, in eight and six different regions of interest (ROIs).

RESULTS

Compared to healthy controls, we found a significant 4.3 % increase in the average ADC value of the occipital white matter in the full sample of patients (p = 0.035) and in patients with migraine (p = 0.046). MTR values did not differ significantly in ROIs between patients and healthy controls (p > 0.05).

CONCLUSIONS

The present study lends evidence, for the first time to the best of our knowledge, for a statistically significant microstructural change in the occipital lobes, as measured by ADC, in patients with primary headache who exhibit a NABT on MRI. Importantly, future longitudinal mechanistic clinical studies of primary headache (e.g., vis-à-vis neuroimaging biomarkers) would be well served by characterizing, via DWI, occipital white matter microstructural changes to decipher their broader biological significance.

Does health information exchange reduce unnecessary neuroimaging and improve quality of headache care in the emergency department?

BACKGROUND

Health information exchange (HIE) is advocated as an approach to reduce unnecessary testing and improve quality of emergency department (ED) care, but little evidence supports its use. Headache is a specific condition for which HIE has theoretical benefits.

OBJECTIVE

To determine whether health information exchange (HIE) reduces potentially unnecessary neuroimaging, increases adherence with evidence-based guidelines, and decreases costs in the emergency department (ED) evaluation of headache.

DESIGN

Longitudinal data analysis

SUBJECTS

All repeat patient-visits (N = 2,102) by all 1,252 adults presenting with headache to a Memphis metropolitan area ED two or more times between August 1, 2007 and July 31, 2009.

INTERVENTION

Use of a regional HIE connecting the 15 major adult hospitals and two regional clinic systems by authorized ED personnel to access the patient's record during the time period in which the patient was being seen in the ED.

MAIN MEASURES

Diagnostic neuroimaging (CT, CT angiography, MRI or MRI angiography), evidence-based guideline adherence, and total patient-visit estimated cost.

KEY RESULTS

HIE data were accessed for 21.8 % of ED patient-visits for headache. 69.8 % received neuroimaging. HIE was associated with decreased odds of diagnostic neuroimaging (odds ratio [OR] 0.38, confidence interval [CI] 0.29-0.50) and increased adherence with evidence-based guidelines (OR 1.33, CI 1.02-1.73). Administrative/nursing staff HIE use (OR 0.24, CI 0.17-0.34) was also associated with decreased neuroimaging after adjustment for confounding factors. Overall HIE use was not associated with significant changes in costs.

CONCLUSIONS

HIE is associated with decreased diagnostic imaging and increased evidence-based guideline adherence in the emergency evaluation of headache, but was not associated with improvements in overall costs. Controlled trials are needed to test whether specific HIE enhancements to increase HIE use can further reduce potentially unnecessary diagnostic imaging and improve adherence with guidelines while decreasing costs of care.

Primary care direct access MRI for the investigation of chronic headache

AIM

To assess the efficacy of a primary-care imaging pathway for neurology outpatients, from inception to deployment, compared with traditional outpatient referral.

MATERIALS AND METHODS

After local agreement, guidelines were generated providing pathways for diagnosis and treatment of common causes of headache, highlighting "red-flag" features requiring urgent neurology referral, and selecting patients for direct magnetic resonance imaging (MRI) referral. In addition, reports were clarified and standardized. To evaluate the efficacy of the access pathway, a retrospective sequential review of 100 MRI investigations was performed comparing general practitioner (GP) referral, with traditional neurology referral plus imaging, acquired before the pathway started.

RESULTS

No statistically significant difference in rates of major abnormalities, incidental findings or ischaemic lesions were identified between the two cohorts. Reported patient satisfaction was high, with a cost reduction for groups using the pathway.

CONCLUSION

The findings of the present study suggest that a defined access pathway for imaging to investigate chronic headache can be deployed appropriately in a primary-care setting.

Why do GPs with a special interest in headache investigate headache presentations with neuroradiology and what do they find?

The general practitioner with a special interest in headache offers an important contribution to the management of headache in primary care where the majority of presentations take place. A number of guidelines have been developed for neuroradiological investigation of headache, but their clinical utility and relevance is not known. Fourteen general practitioners with a special interest in headache recorded consecutive headache consultations over a 3-month period, whether patients were investigated with neuroradiology and if so the reason for investigation and outcome. Reason for investigation was compared to the guidelines published for the use in primary care. 895 patients were seen, of whom 270 (30.1%) were investigated. 47% of indications were outside the guidance framework used, the most common reason for investigation being reassurance. Of those investigated, 5.6% showed positive findings but only 1.9% of findings were felt to be of clinical significance. General practitioners with a special interest investigated with neuroradiology a greater level than general practitioners, but less than neurologists. However, yields of significant findings are broadly comparative across all groups. This report confirms other studies that suggest that even when there is a high level of clinical suspicion, yields of significant findings are very low.

Primary care access to computed tomography for chronic headache

BACKGROUND

The diagnostic yield of neuroimaging in chronic headache is low, but can reduce the use of health services.

AIM

To determine whether primary care access to brain computed tomography (CT) referral for chronic headache reduces referral to secondary care.

DESIGN OF STUDY

Prospective observational analysis of GP referrals to an open access CT brain scanning service.

SETTING

Primary care, and outpatient radiology and neurology departments.

METHOD

GPs in Tayside and North East Fife, Scotland were given access to brain CT for patients with chronic headache. All referrals were analysed prospectively over 1 year, and questionnaires were sent to referrers to establish whether imaging had resulted in or stopped a referral to secondary care. The Tayside outpatient clinic database identified scanned patients referred to the neurology clinic for headache from the start of the study period to at least 1 year after their scan.

RESULTS

There were 232 referrals (55.1/100 000/year, 95% confidence interval = 50.4 to 59.9) from GPs in 59 (82%) of 72 primary care practices. CT was performed on 215 patients. Significant abnormalities were noted in 3 (1.4%) patients; there were 22 (10.2%) non-significant findings, and 190 (88.4%) normal scans. Questionnaires of the referring GPs reported that 167 (88%) scans stopped a referral to secondary care. GPs referred 30 (14%) scanned patients to a neurologist because of headache. It is estimated that imaging reduced referrals to secondary care by 86% in the follow-up period.

CONCLUSION

An open access brain CT service for patients with chronic headache was used by most GP practices in Tayside, and reduced the number of referrals to secondary care.

Neuroimaging in chronic migraine

In chronic migraine, many neuroimaging studies with advanced techniques showed abnormalities in several brain areas involved in pain processing. The structural and functional dysfunctions are reported in cerebral areas localized in the brainstem and in the lateral and medial pain pathways. Using the advanced technique of volumetric MRI (voxel-based morphometry), reduction in the grey and white matter in brain areas of the pain network and increased density of the structures of the brainstem were observed in patients with episodic or chronic migraine. Most of the studies of functional anatomy in chronic migraine uses positron emission tomography (PET) and functional RM. These techniques could detect cerebral areas with regional cerebral blood flow and blood level oxygenation-dependent (BOLD) signal changes. Several PET and functional MRI experiments in patients with chronic migraine and drugs overuse before and after the withdrawal showed hypometabolism and hypoactivation in cortical areas involved in pain processing. These areas normalize their activity after detoxification, indicating reversible metabolic changes and BOLD signal changes as observed in other chronic pain. Functional and structural alterations observed in the cerebral areas of the pain network could be a result of a selective dysfunction of these regions due to cortical overstimulation associated with chronic pain. Advanced neuroimaging techniques have revolutionized the knowledge on chronic migraine, determining specific cortical substrate that could explain different forms of chronic migraine and perhaps the predisposition of patients to different therapeutic responses and to possible relapse in drug abuse.

Diagnostic testing for migraine and other primary headaches

Most primary headaches can be diagnosed using the history and examination. Judicious use of neuroimaging and other testing, however, is indicated to distinguish primary headaches from the many secondary causes that may share similar features. This article evaluates the reasons for diagnostic testing and the use of neuroimaging, electroencephalography, lumbar puncture, and blood testing. The use of diagnostic testing in adults and children who have headaches and a normal neurologic examination, migraine, trigeminal autonomic cephalalgias, hemicrania continua, and new daily persistent headache are reviewed.

Migraine and stroke: current perspectives

OBJECTIVE

The purpose of this article is to review the latest concepts regarding migraine and ischemic stroke. In addition, focal neurological deficits and MRI changes in migraine patients will be reviewed.

METHODS

A PubMed search of neurological literature pertaining to this study was conducted using specific keyword search terms pertaining to migraine and ischemic stroke.

RESULTS

Migraine, especially with aura, is a relative risk factor for stroke. Neuroimaging demonstrates the posterior circulation as being most vulnerable, although the reason for this distribution is unclear. Factors that may contribute to stroke in migraine include changes during cortical spreading depression with hyper- or hypoperfusion of neural tissue, vasospasm and endothelial dysfunction. Estrogen affects migraine expression as well as cerebral circulation, yet most women with migraine without aura are not at increased risk. Co-morbidity with patent foramen ovale can be mechanism of both disorders via presumed lack of filtration of microemboli or toxic substances; however, closure with reversal of right to left shunt seems to be more beneficial for cryptogenic stroke than migraine. Migraine and stroke are found in specific genetic disorders such as CADASIL, HERNS and MELAS giving clues to genetic factors. Stroke associated with migraine treatments such as ergots or triptans is rare, and usually associated with special circumstances such as overuse or concomitant thrombogenic conditions.

CONCLUSION

Although true migrainous infarction is rare, our understanding of the subtle associations between migraine and cerebrovascular behavior is expanding.

Overuse or underuse of MRI scanners in private radiology centers in Tehran

Objectives:The semiprivate health system in Iran has created an opportunity for unnecessary uses of advanced medical equipments including magnetic resonance imaging (MRI). This study aimed to evaluate the evidence for MRI overuse in private diagnostic imaging centers in Tehran, Iran. The objectives of this study were to determine the frequency of use of MRI scans for different complaints and to explore frequency of normal MRI findings as a function of unnecessary MRI use.

Methods:We conducted a survey among private MRI centers in Tehran, Iran, to study the proportion of MRI scans that may result in significant clinical finding. All MRI reports at a specific point in time at selected MRI centers were reviewed by a physician and the findings were recorded as normal, abnormal, or substantial changes.

Results:Of all the MRI reports, 17.2 percent had resulted in normal findings; 9.8 percent ordered for examination of headache, and 4.8 percent for lower back pain.

Conclusion:Unnecessary MRIs are most likely to result in normal finding; although not all the MRI with normal results could be identified as unnecessary. Negative findings from MRI scans may be reassuring to both clinicians and patients. The proportion of normal findings in MRI scans did not provide evidence of MRI overuse in Iran. The results of this study warrant formation of guidelines for the use of MRIs for headache and low back pain disorders.

Diagnostic testing for chronic daily headache

Primary chronic headaches of long duration include chronic migraine, chronic tension-type headache, new daily persistent headache, and hemicrania continua. This article reviews the utility of neuroimaging and other testing for diagnosis of these headaches. The presentation and diagnosis of the many secondary headaches that can mimic primary headache types are also discussed, including arteriovenous malformations, spontaneous intracranial hypotension, neoplasms, pseudotumor cerebri, cervical artery dissections, cerebral venous thrombosis, Chiari I malformation, and temporal arteritis. Although the yield of diagnostic testing is low, serious pathology as a cause of chronic headaches can be easily overlooked.

Brain MRI white matter lesions in migraine patients: is there a relationship with antiphospholipid antibodies and coagulation parameters?

Brain magnetic resonance imaging (MRI) studies in migraine patients have demonstrated lesions consisting of focal regions of increased signal intensity within the white matter. Antiphospholipid antibodies are known to have a role in many diseases including migraine. The aim of the present study was to ascertain the relationship between MRI-visualized cerebral focal hyperintense lesions and serum antiphospholipid antibody levels, as well as blood coagulation parameters in migraine patients. One hundred and two (77 females, 25 males, mean age 33.8 +/- 11.1) consecutive migraine patients and a control group of 94 (70 females, 24 males, mean age 33.2 +/- 10.8) healthy subjects were enrolled. All individuals underwent brain MRI. Complete blood examinations, autoantibodies, antiphospholipids antibodies including anticardiolipin and lupus anticoagulant (aCL, LAC), antithrombin III, Protein C and S serum levels were ascertained in the subjects who presented white matter lesions on MRI. Twenty-seven (26.4%) migraine patients and six (6.3%) healthy subjects in the control group showed focal regions of increased intensity signal within cerebral white matter (odds ratio 5.3, 95% CI: 1.98-16.36). In migraine patients with white matter lesions, antiphospholipid antibodies were not detected and serum levels of antithrombin III, and proteins C and S were normal. White matter lesions in migraine patients are fairly common. This finding is not associated with antiphospholipid antibodies or abnormal coagulation parameters. The significance of such lesions at present remains unclear.