Is idiopathic intracranial hypertension without papilledema a risk factor for migraine progression?

Plasma calcitonin gene-related peptide levels in idiopathic intracranial hypertension: an exploratory study

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a debilitating condition characterized by increased intracranial pressure often presenting with chronic migraine-like headache. Calcitonin gene-related peptide (CGRP) plays an important pathophysiological role in primary headaches such as migraine, whilst its role in IIH has not yet been established.

METHODS

This longitudinal exploratory study included patients with IIH, episodic migraine (EM) in a headache-free interval and healthy controls (HC). Blood samples were collected from a cubital vein and plasma CGRP (pCGRP) levels were measured by standardized ELISA.

RESULTS

A total of 26 patients with IIH (mean age 33.2 years [SD 9.2], 88.5% female, median BMI 34.8 kg/m2 [IQR 30.0-41.4]), 30 patients with EM (mean age 27.6 years [7.5], 66.7% female) and 57 HC (mean age 25.3 years [5.2], 56.1% female) were included. pCGRP levels displayed a wide variation in IIH as well as in EM and HC on a group-level. Within IIH, those with migraine-like headache had significantly higher pCGRP levels than those with non-migraine-like headache (F(2,524) = 84.79; p < 0.001) and headache absence (F(2,524) = 84.79; p < 0.001) throughout the observation period, explaining 14.7% of the variance in pCGRP levels. CGRP measurements showed strong intraindividual agreement in IIH (ICC 0.993, 95% CI 0.987-0.996, p < 0.001). No association was found between pCGRP levels and ophthalmological parameters.

CONCLUSIONS

Although interindividual heterogeneity of pCGRP levels is generally high, migraine-like headache seems to be associated with higher pCGRP levels. CGRP may play a role in the headache pathophysiology at least in a subgroup of IIH.

The putative role of trigemino-vascular system in brain perfusion homeostasis and the significance of the migraine attack

Besides representing the place where a migraine attack generates, what is the physiological role of peptidergic control of arteriolar caliber within the trigemino-vascular system? Considering that the shared goal of most human CGRP-based neurosensory systems is the protection from an acute threat, especially if hypoxic, what is the end meaning of a migraine attack? In this paper, we have reviewed available evidence on the possible role of the trigemino-vascular system in maintaining cerebral perfusion pressure homeostasis, despite the large physiological fluctuations in intracranial pressure occurring in daily life activities. In this perspective, the migraine attack is presented as the response to a cerebral hypoxic threat consequent to a deranged intracranial pressure control aimed at generating a temporary withdrawal from the environment with limitation of physical activity, a condition required to promote the restoration of cerebral fluids dynamic balance.

The Pre-Lumbar puncture Intracranial Hypertension Scale (PLIHS): A practical scale to identify subjects with normal cerebrospinal fluid pressure in the management of idiopathic intracranial hypertension

BACKGROUND

Idiopathic Intracranial Hypertension (IIH) diagnosis requires lumbar puncture to measure cerebrospinal fluid (CSF) pressure. The Pre-Lumbar puncture Intracranial Hypertension Scale (PLIHS) is aimed to detect cases that will show raised or normal CSF opening pressure.

METHODS

Retrospective analysis of records of patients who underwent lumbar puncture for suspect IIH. The target was CSF opening pressure ≥ 250 mmH2O, whereas a set of known neurological, neuro-ophthalmological and neuro-radiological parameters, plus obesity, were used as predictors in a logistic regression model. The PLIHS was based on significant predictors and a cut-off was validated using chi-squared test around CSF opening pressure ≥ 250 and < 200 mmH2O.

RESULTS

Records of 162 patients were included: CSF opening pressure was <200 mmH2O in 40 and ≥ 250 mmH2O in 95 patients; 85 fulfilled IIH diagnosis. PLIHS is based on Frisén grade 2 or higher papilledema, tinnitus, empty sella, perioptic subarachnoid space distension, and obesity. Score range is 0-7: correlation with CSF opening pressure is 0.508 (p < .001), and PLIHS score is different between subjects not diagnosed with IIH, and those diagnosed with IIH both with and without papilledema (p < .001). PLIHS score ≤ 2 identifies cerebrospinal fluid pressure < 200 mmH2O; PLIHS score ≥ 3 identifies CSF opening pressure ≥ 250 mmH2O, IIH diagnosis, visual acuity ≤0.7, and optic nerve atrophy.

CONCLUSIONS

The PLIHS, can be used to identify patients who will particularly need LP, thus helping with the organization of the diagnostic work-up by optimising healthcare resources and potentially limit the likelihood to incur in LP-related adverse events.

The significance of ONSD, ONSD/ETD ratio, and other neuroimaging parameters in idiopathic intracranial hypertension

Background: The measurement of the optic nerve sheath diameter (ONSD) has been suggested to be used in the evaluation of intracranial pressure of several etiologies. However, its potential utility in the clinical evaluation of patients with idiopathic intracranial hypertension (IIH) needs to be clarified.Methods: We recruited all the IIH patients who had been admitted to our neurology clinics and had a cranial MRI before lumbar puncture investigation. A control group of patients with migraine was also included. Studies were reviewed blindly by a radiologist, and ONSD and ONSD/ eyeball transverse diameter (ETD) for both eyes were measured.Results: Ultimately, we have enrolled 50 patients with IIH and 53 migraineurs. The right ONSD values were higher in the IIH group (p = 0.024) whereas the values of ONSD/ETD were found to be both higher in the IIH group (right: p = 0.006, left: p = 0.043). The ROC curve demonstrated an area under the curve of 0.620 (95% CI = 0.508 to 0.731) for ONSD, and it was 0.642 for ONSD/ETD. Using a cut-off of 6.3 mm, ONSD had the following performance characteristics: sensitivity 18%, specificity 81%.Conclusions: The ONSD and ONSD/ETD values may be utilizable in the evaluation processes of IIH patients; however, they do not solely reach sufficient discriminative accuracy. The potential significance of these parameters in rather monitoring the IIH patients may constitute a strictly crucial topic of interest for future research.

Incidence of idiopathic intracranial hypertension in Southern Tasmania, Australia

Introduction

Anecdotally, the incidence of idiopathic intracranial hypertension (IIH) is increasing, linked to an increase in the obesity rate in Australian society. However, formal incidence and prevalence studies are rare. We therefore sought to determine the incidence and clinical features of IIH in Southern Tasmania, Australia.

Method

Neurology discharge summaries and lumbar puncture referrals from the single tertiary referral centre in this region were screened for an IIH diagnosis. All regional neurologists were surveyed to capture patients diagnosed through private neurology clinics. A retrospective review of medical records was conducted to confirm the diagnosis and determine whether patients met the Modified Dandy Criteria (MDC). Patients were included if they were above the age of 18 years and received a new diagnosis of IIH between June 2016 and June 2018. Population statistics were obtained from the Australian Bureau of Statistics.

Results

IIH incidence was 5.4/100 000. All patients were females, aged between 18 and 45 years. Headache was the most commonly reported symptom, with high rates of pre-existing or concurrent migraine diagnoses. Weight loss and commencement of oral acetazolamide were the most common treatment approaches. Four patients were medically refractory and required surgical intervention.

Conclusion

The incidence of IIH in Southern Tasmania is comparable with the incidence reported in subgroups of females of childbearing age in recent prior studies. The demographic, diagnostic and therapeutic data presented can inform future local health service provision and serve as a baseline for ongoing assessment of change in incidence and treatment of IIH at a community level.

An update on idiopathic intracranial hypertension in adults: a look at pathophysiology, diagnostic approach and management

Idiopathic intracranial hypertension is a neurological syndrome determined by a rise in intracranial pressure without a detectable cause. Course and prognosis may be changeable, requiring a multidisciplinary approach for its diagnosis and management. Although its precise pathogenesis is still unknown, many studies have been carried out to define the possible causal and associated factors, such as retinoids, steroid hormones, body mass index and recent weight gains, cytokines and adipokines levels. The clinical presentation can be variable including chronic headache, disturbance of vision, diplopia and tinnitus. Even if papilloedema is considered the most specific sign, it could not be observed in more than 5% of patients during the evaluation of the fundus oculi. Neuroradiological signs acquire greater importance in patients who do not present papilloedema and may suggest the diagnosis of idiopathic intracranial hypertension. Other assessments can be useful in the diagnostic process, such as optical coherence tomography, visual evoked potentials, ocular ultrasonography and fundus fluorescein angiography and autofluorescence. Nonetheless, cerebrospinal fluid pressure measurement is required to establish a definite diagnosis. Management may be different, since surgical procedures or lumbar punctures are often required when symptoms develop rapidly leading to a loss of visual function. Apart from these cases, patients can be treated with a pharmacological approach and low-calorie diet, but they also need to be monitored over time since relapses years later are not uncommon.

The prevalence of papilledema in patients with migraine: a crucial cooccurrence of migraine and idiopathic intracranial hypertension

OBJECTIVE

We aimed to investigate the prevalence of idiopathic intracranial hypertension (IIH) in patients with migraine by screening for papilledema.

MATERIALS AND METHODS

We have included all the patients with migraine who applied to our neurology clinic during December 2019 and accepted to participate in the study. The demographic and clinical characteristics including migraine subtype (episodic/chronic), headache frequency per month, and headache characteristics of all patients were interrogated. Besides, the presence of fibromyalgia (FM) and chronic fatigue syndrome (CFS) was noted. Fundus examination was performed in all of the patients and the presence of papilledema was noted.

RESULTS

Overall, 158 consecutive migraineurs were included in this study. The mean age of the group was 35.9 ± 9.9 and the female/male ratio was 134/24. Papilledema was determined in 10 (6%) patients. There was a past medical history of having IIH in one of these patients. In four of the patients, the diagnosis of IIH was newly established. Comparative analyses between episodic migraineurs and chronic migraineurs revealed that female gender was more prevalent in chronic migraineurs (p = 0.00) and the comorbidities of FM and CFS were more common in chronic migraineurs. Remarkably, papilledema was found to be more common in chronic migraineurs. The results of the logistic regression analyses revealed that obesity was the only predictor for the presence of papilledema (p = 0.014).

CONCLUSION

Our results may suggest that IIH should be kept in mind as a notable comorbidity in migraineurs, particularly in the subgroup of obese patients with chronic migraine.

Dural sinus collapsibility, idiopathic intracranial hypertension, and the pathogenesis of chronic migraine

Available evidences suggest that a number of known assumption on idiopathic intracranial hypertension (IIH) with or without papilledema might be discussed. These include (1) the primary pathogenetic role of an excessive dural sinus collapsibility in IIH, allowing a new relatively stable intracranial fluids pressure balance at higher values; (2) the non-mandatory role of papilledema for a definite diagnosis; (3) the possibly much higher prevalence of IIH without papilledema than currently considered; (4) the crucial role of the cerebral compliance exhaustion that precede the raise in intracranial pressure and that may already be pathologic in cases showing a moderately elevated opening pressure; (5) the role as "intracranial pressure sensor" played by the trigeminovascular innervation of dural sinuses and cortical bridge veins, which could represent a major source of CGRP and may explain the high comorbidity and the emerging causative link between IIHWOP and chronic migraine (CM). Accordingly, the control of intracranial pressure is to be considered a promising new therapeutic target in CM.

Cerebral venous hemodynamic abnormalities in episodic and chronic migraine

Alterations of cerebral venous drainage have been demonstrated in chronic migraine (CM), suggesting that cerebral venous hemodynamic abnormalities (CVHAs) play a role in this condition. The aim of the present study was to look for a correlation between CM and CVHAs. We recruited 33 subjects suffering from CM with or without analgesic overuse, 29 episodic migraine (EM) patients with or without aura, and 21 healthy subjects as controls (HCs). CVHAs were evaluated by transcranial and extracranial echo-color Doppler evaluation of five venous hemodynamic parameters. CVHAs were significantly more frequent in the CM and EM patients than in the HCs. In the migraine patients, CVHAs were not correlated with clinical features. The significantly greater frequency of CVHAs observed in the migraineurs may reflect a possible relationship between migraine and these abnormalities. Prospective longitudinal studies are needed to investigate whether CVHAs have a role in the processes of migraine chronification.

Medication overuse headache - An under-diagnosed problem in shunted idiopathic intracranial hypertension patients

PURPOSE

Management of headache in a subgroup of shunted idiopathic intracranial hypertension (IIH) patients is a well- described and difficult task. We present our series of shunted IIH patients with medication overuse headache (MOH) and discuss the role of careful pain management in this group of patients.

MATERIALS AND METHODS

A retrospective review of shunted IIH patients with headache, who had their shunt function assessed by monitoring their intracranial pressure and were subsequently diagnosed with MOH.

RESULTS

A total of 15 patients were identified. The mean time between the diagnosis of IIH and the diagnosis of medication overuse headache was 6 years (standard deviation 4.9, range 2-18 years). The majority of patients in this group (12/15) had undergone multiple shunt revisions.

CONCLUSIONS

Medication overuse headache in shunted IIH patients can lead to the requirement of hospital admission, investigations and procedures. We suggest that opiates and non-steroidal anti-inflammatory analgesics (NSAIDs) are used for a specified duration post-operatively and reviewed regularly. We suggest that patients are counselled regarding medication overuse headache in a multidisciplinary setting.

Pseudotumor cerebri associated with modified Fontan anatomy

Surgical treatment of functional single-ventricle heart disease with a modified Fontan procedure results in elevated central venous pressure. The case report describes a 19-year-old boy with hypoplastic left heart syndrome and Fontan palliation that resulted in frequent debilitating headaches after transcatheter closure of systemic venous-to-pulmonary venous collaterals. Measured increased intracranial pressure and prompt relief of the headaches with lumbar puncture favored a diagnosis of pseudotumor cerebri. After implantation of a lumboperitoneal shunt, the patient's headaches improved dramatically. Headaches are frequent in patients with Fontan circulation. The current literature supports a pivotal role of elevated dural venous sinus pressure in the pathogenesis of pseudotumor cerebri. The high superior and inferior vena caval pressures characteristic of modified Fontan anatomy may account for headaches in some of these patients.

Intracranial pressure in unresponsive chronic migraine

To assess the prevalence and possible pathogenetic involvement of raised intracranial pressure in patients presenting with unresponsive chronic migraine (CM), we evaluated the intracranial opening pressure (OP) and clinical outcome of a single cerebrospinal fluid withdrawal by lumbar puncture in 44 consecutive patients diagnosed with unresponsive chronic/transformed migraine and evidence of sinus stenosis at magnetic resonance venography. The large majority of patients complained of daily or near-daily headache. Thirty-eight (86.4 %) had an OP >200 mmH₂O. Lumbar puncture-induced normalization of intracranial pressure resulted in prompt remission of chronic pain in 34/44 patients (77.3 %); and an episodic pattern of headache was maintained for 2, 3 and 4 months in 24 (54.6 %), 20 (45.4 %) and 17 (38.6 %) patients, respectively. The medians of overall headache days/month and of disabling headache days/month significantly decreased (p < 0.0001) at each follow-up versus baseline. Despite the absence of papilledema, 31/44 (70.5 %) patients fulfilled the ICHD-II criteria for “Headache attributed to Intracranial Hypertension”. Our findings indicate that most patients diagnosed with unresponsive CM in specialized headache clinics may present an increased intracranial pressure involved in the progression and refractoriness of pain. Moreover, a single lumbar puncture with cerebrospinal fluid withdrawal results in sustained remission of chronic pain in many cases. Prospective controlled studies are needed before this procedure can be translated into clinical practice. Nonetheless, we suggest that intracranial hypertension without papilledema should be considered in all patients with almost daily migraine pain, with evidence of sinus stenosis, and unresponsive to medical treatment referred to specialized headache clinics.

Migraine and obesity, is there a link?

Obesity and migraine are two frequent conditions found in the general population. In the past years, large-scale studies have established epidemiological links between the two conditions. Migraine prevalence appears to be increased in the obese population, and some characteristics of migraine are affected in the overweight population. More recent but limited data point out an improvement of migraine in the obese population after weight loss. Obesity may facilitate migraine progression to chronic daily headache or chronic migraine. Common physiological mechanisms that would be responsible for both conditions are not fully established. Several hypotheses suggest a common etiological factor for obesity and migraine. This work proposes to review the epidemiological data and to highlight the main hypotheses currently discussed.

Sinus venous stenosis-associated idiopathic intracranial hypertension without papilledema as a powerful risk factor for progression and refractoriness of headache

Data from two recent studies strongly support the hypothesis that idiopathic intracranial hypertension without papilledema (IIHWOP) could represent a powerful risk factor for the progression of pain in primary headache individuals. The first study highlights that an asymptomatic IIHWOP is much more prevalent than believed in the general population and occurs only in central venous stenosis carriers. In the second study, about one half of a large consecutive series of unresponsive primary chronic headache patients shows significant sinus venous stenosis. A continuous or intermittent IIHWOP was detectable in 91% of this subgroup and in no patient with normal venography. Moreover, after the lumbar puncture, a 2- to 4-week improvement in headache frequency was observed in most of the intracranial hypertensive patients. These findings strongly suggest that patients prone to primary headache who carry central venous outflow abnormalities are at high risk of developing a comorbid IIHWOP, which in turn is responsible for the progression and the unresponsiveness of the pain. Based on the available literature data, we propose that central sinus stenosis-related IIHWOP, although highly prevalent among otherwise healthy people, represents an important modifiable risk factor for the progression and refractoriness of pain in patients predisposed to primary headache. The mechanism could refer to up to one half of the primary chronic headache patients with minimal response to treatments referring to specialized headache clinics. Due to the clinical and taxonomic relevance of this hypothesis further studies are urgently needed.

Sinus venous stenosis, intracranial hypertension and progression of primary headaches

The recently advanced hypothesis that idiopathic intracranial hypertension without papilledema (IIHWOP) is a powerful risk factor for the progression of pain in individuals prone to episodic primary headache implies that IIHWOP is much more prevalent than it is believed to be in the general population and that it can run almost asymptomatic in most of the affected individuals. In this review, we discuss the evidence available supporting that: (a) sinus venous stenosis-associated IIHWOP is much more prevalent than believed in the general population and can run without symptoms or signs of raised intracranial pressure in most of individuals affected, (b) sinus venous stenosis is a very sensitive and specific predictor of intermittent or continuous idiopathic intracranial hypertension with or without papilledema, even in asymptomatic individuals, (c) in primary headache prone individuals, a comorbidity with a hidden stenosis-associated IIHWOP represents a very common, although largely underestimated, modifiable risk factor for the progression and refractoriness of headache.

Cerebral transverse sinus morphology as detected by MR venography in patients with chronic migraine

OBJECTIVE

To clarify the frequency and characteristics of altered transverse sinus morphology in a series of consecutive patients with chronic migraine.

BACKGROUND

As terminology, neuroradiological techniques and patient selection differ widely across various studies, reliable, reproducible information is lacking on the frequency of cerebral transverse sinus asymmetry as measured by cerebral magnetic resonance venography in patients with chronic migraine.

METHODS

We assessed the frequency and characteristics of transverse sinus asymmetries and their correlation with the chronic migraine phenotype in a blind, cross-sectional magnetic resonance venographic study in a series of 83 consecutive patients with chronic migraine.

RESULTS

After excluding mild (≤ 10%) physiological differences in transverse sinus diameter, we found magnetic resonance venographic evidence of altered transverse sinus morphology in 50.6% of the patients: 16.9% had moderate transverse sinus asymmetry (≤ 50%), 24.1% severe asymmetry (>50%), and 9.6% aplasia. Among the tested risk factors for migraine chronification, analgesic consumption, anxiety, and high systolic blood pressure were more frequent in patients with transverse sinus aplasia than in those without.

CONCLUSIONS

Advanced magnetic resonance venographic techniques used in strictly selected subjects disclose transverse sinus asymmetries in as many as 50.6% of patients with chronic migraine, even when mild differences in physiological caliber are excluded. The unexpected correlation between transverse sinus aplasia and some risk factors for migraine chronification requires confirmation in larger studies.