Headache in idiopathic intracranial hypertension. A CGRP-dependent head pain?

Headache is the most frequent and often the most severe symptom of idiopathic intracranial hypertension (IIH) clinical presentation, although pain characteristics are very variable among sufferers and the pain may even lack in some cases. Whatever the headache features, refractoriness to treatments, pain worsening in the recumbent position, and frequent awakenings with severe headache late in the night are the specific complains of such patients. However, a migraine or probable migraine headache, mostly with a chronic headache pattern, can be diagnosed in about 2/3 of the cases. In IIH cases without papilledema (IIHWOP), this leads to a high rate of misdiagnosis with primary chronic migraine (CM). Mechanisms responsible for the shared migrainous presentation of CM and IIH/IIHWOP may rely on a pathologic CGRP release from the rich trigemino-vascular innervated dural sinuses, congested in the course of raised intracranial pressure. The possible role of IIHWOP as a powerful and modifiable risk factor for migraine progression is discussed. Further studies investigating the possible efficacy of anti CGRP/receptor antibodies in IIH/IIHWOP headache treatment are needed.

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.

Pain cognition in migraine: from basic neurophysiology to a behavioral paradigm.

Most of the data in this review have been already reported by the authors in Neurological Science, but the goal of the present paper is to realize an integrated lecture of all the available data and look to the last achievements in pain cognition, with a special focus on migraine and chronic migraine. According to the proposed integrated perspective, migraine can be viewed as an adaptive behavioral response with evolutionistic advantages.

Starling resistors, autoregulation of cerebral perfusion and the pathogenesis of idiopathic intracranial hypertension.

Two critical functions for the control of intracranial fluids dynamics are carried on the venous side of the perfusion circuit: the first is the avoidance of cortical veins collapse during the physiological increases of cerebrospinal fluid (CSF) pressure in which they are immersed. The second, is the generation of an abrupt venous pressure drop at the confluence of the cortical veins with the dural sinuses that is required to allow a CSF outflow rate balanced with its production. There is evidence that both of these effects are ensured by a Starling resistor mechanism (a fluid dynamic construct that governs the flow in collapsible tubes exposed to variable external pressure) acting at the confluence of cortical veins in the dural sinus. This implies that, in normal circumstances of perfusion balance, a certain degree of venous collapse physiologically occurs at the distal end of the cortical vein. This is passively modulated by the transmural pressure of the venous wall (i.e. the difference between internal blood pressure and external CSF pressure). The mechanism provides that the blood pressure of the cortical vein upstream the collapsed segment is dynamically maintained a few mmHg higher than the CSF pressure, so as to prevent their collapse during the large physiological fluctuations of the intracranial pressure. Moreover, the partial collapse of the vein confluence also generates a sharp pressure drop of the blood entering into the sinus. The CSF is drained in dural sinus through arachnoid villi proportionally to its pressure gradient with the sinus blood. The venous pressure drop between cortical veins and dural sinus is therefore needed to ensure that the CSF can leave the cranio-spinal space with the same speed with which it is produced, without having to reach a too high pressure, which would compress the cortical veins. Notably, the mechanism requires that the walls of the dural sinuses are rigid enough to avoid the collapse under the external cerebrospinal fluid pressure, and predicts that in the presence of excessively flexible dural sinuses, the system admits a second point of balance between cerebral fluid pressure and dural sinus pressure, at higher values. The second balance state is due to the triggering of a self-limiting venous collapse feedback loop between the CSF pressure, that compresses the sinus, and the subsequent increase of the dural sinus pressure, that further raises the intracranial pressure. The loop may stabilize only when the maximum stretching allowed by the venous wall is reached. Then, a new relatively stable and self-sustaining balance state is achieved, at the price of a higher CSF and dural sinus pressure values. We propose that this model is crucially involved in Idiopatic Intracranial Hypertension pathogenesis with and without papilledema, a condition that could be described as a pathological new balance state, relatively stable, between intracranial and dural venous pressure, at higher absolute values.

No evidence for an effect on brain atrophy rate of atorvastatin add-on to interferon ß1b therapy in relapsing-remitting multiple sclerosis (the ARIANNA study).

BACKGROUND: A previous phase 2 trial has suggested that statins might delay brain atrophy in secondary progressive multiple sclerosis. OBJECTIVES: The objective of this study was to evaluate the effect of atorvastatin add-on therapy on cerebral atrophy in relapsing-remitting multiple sclerosis. METHODS: This randomised, placebo-controlled study compared atorvastatin 40 mg or placebo add-on therapy to interferon ß1b for 24 months. Brain magnetic resonance imaging, multiple sclerosis functional composite score, Rao neuropsychological battery and expanded disability status scale were evaluated over 24 months. RESULTS: A total of 154 patients were randomly assigned, 75 in the atorvastatin and 79 in the placebo arms, with a comparable drop-out rate (overall 23.4%). Brain atrophy over 2 years was not different in the two arms (-0.38% and -0.32% for the atorvastatin and placebo groups, respectively). Relapse rate, expanded disability status scale, multiple sclerosis functional composite score or cognitive changes were not different in the two arms. Patients withdrawing from the study had a higher number of relapses in the previous 2 years (P=0.04) and a greater probability of relapsing within 12 months. CONCLUSIONS: Our results suggest that the combination of atorvastatin and interferon ß1b is not justified in early relapsing-remitting multiple sclerosis and adds to the body of evidence indicating an absence of significant radiological and clinical benefit of statins in relapsing-remitting multiple sclerosis.

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 pregnancy: an internet survey.

Data in the literature show that migraine tends to improve during pregnancy in most migrainous women. The aim of this Internet survey was to obtain the most likely cross section of the situation in the general population with respect to the presence and course of migraine in pregnancy. All women who participated were asked to answer questions pertaining to their history of pregnancy and headache. One thousand and eighteen women participated in the survey; only 775 met the eligibility criteria for inclusion. One hundred and ninety-five women (25.2 %) reported having had a headache only before pregnancy, 425 (54.8 %) before and during pregnancy, and 155 (20.0 %) only during pregnancy. Women suffering from headache before and/or during pregnancy were much more likely to have headaches with more migrainous features at the ID Migraine Screener test when compared to women whose headache began during pregnancy. "Definite migraines" were 277/620 (44.7 %) and 26/155 (16.8 %), respectively, in the two groups (p < 0.0001). Among the 620 females that suffered from headache before pregnancy, 375 (60.5 %) improved, 195 (31.5 %) showed complete resolution of the disorder, and 180 (29.0 %) had a reduction in headache frequency. Moreover, the multinomial logistic model (with headache pattern as dependent variable) proved fetal presentation as significant (p = 0.0042). Women with "new headache" (No/Yes pattern) had an OR (95 % CI) of 1.9 (1.2-3.0) of breech presentation at delivery versus those with a stable pattern of headache (Yes/Yes). Finally, women with not recent pregnancy stated they suffered from headache less than the women with recent pregnancy.

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.

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.

Position paper of the Italian Society for the study of Dementias (SINDEM) on the proposal of a new lexicon on Alzheimer disease.

A panel of Italian neurologists of the Italian Society for the study of Dementias (SINDEM) discussed the recently proposed new lexicon for Alzheimer disease (AD) and the related diagnostic criteria for the different phases of the disease (Preclinical AD, prodromal AD and Alzheimer's dementia) (Dubois et al. in Lancet Neurol 6:734-746, 2007; in Lancet Neurol 9:1118-1127, 2010). The aim of this discussion was to reach a consensus, among the Italian neurologists involved in the study and care of persons with dementia, in particular in reference to the potential use of the proposed diagnostic criteria in clinical practice. After having critically revised the scientific evidence related to the new lexicon and to the new proposed diagnostic criteria, the panel concluded that the proposed new diagnostic criteria and the new proposed lexicon for AD are conceptually attractive. However, the evidence about the instrumental and laboratory markers for the diagnosis of the preclinical and asymptomatic states of the disease are, until to now, insufficient to support the routine clinical use of these investigations.

Chronic migraine classification: current knowledge and future perspectives.

In the field of so-called chronic daily headache, it is not easy for migraine that worsens progressively until it becomes daily or almost daily to find a precise and universally recognized place within the current international headache classification systems. In line with the 2006 revision of the second edition of the International Classification of Headache Disorders (ICHD-2R), the current prevailing opinion is that this headache type should be named chronic migraine (CM) and be characterized by the presence of at least 15 days of headache per month for at least 3 consecutive months, with headache having the same clinical features of migraine without aura for at least 8 of those 15 days. Based on much evidence, though, a CM with the above characteristics appears to be a heterogeneous entity and the obvious risk is that its definition may be extended to include a variety of different clinical entities. A proposal is advanced to consider CM a subtype of migraine without aura that is characterized by a high frequency of attacks (10-20 days of headache per month for at least 3 months) and is distinct from transformed migraine (TM), which in turn should be included in the classification as a complication of migraine. Therefore, CM should be removed from its current coding position in the ICHD-2 and be replaced by TM, which has more restrictive diagnostic criteria (at least 20 days of headache per month for at least 1 year, with no more than 5 consecutive days free of symptoms; same clinical features of migraine without aura for at least 10 of those 20 days).

The Italian neurological schools of the twentieth century.

This lecture is not a historical lecture, but rather a journey through the "story" of neurology in Italy from its "prehistoric" beginning in the 19th century. The birth of a neurological school is that magical moment in which a founder attracts disciples: the more capable this founder is of transmitting methodology and allowing his pupils intellectual freedom, the longer his memory will live on. On the basis of this idea, the scientific biography of a few leading Italian neurologists of the 20th century is outlined, starting from Leonardo Bianchi, founder of the Italian Neurological Society in 1907.

Advancement in idiopathic intracranial hypertension pathogenesis: focus on sinus venous stenosis.

Idiopathic intracranial hypertension is consistently associated with venous outflow disturbances. Sinus venous stenosis are found at magnetic resonance venography in the large majority of IIH patients and may have various conformations, ranging from functional smooth narrowings of sinus segments associated or not with definite flow gaps, to segmental hypoplasia or aplasia of one or more central venous collectors. Stenosis are currently believed to be a consequence of a primary altered cerebrospinal fluid (CSF) pressure since it may normalize after CSF subtraction with lumbar puncture or shunting procedures. In this paper a "self-sustained venous collapse" is proposed as a crucial causative mechanism in predisposed subjects, leading to a self-sustained intracranial hypertension in presence of a wide range of triggering factors. The proposed mechanisms predict the long-term remission of IIH syndromes frequently observed after a single or few serial CSF subtractions by lumbar puncture.

Is chronic migraine a primary or a secondary condition?

In the light of the pathophysiologic knowledge acquired in recent years, a tentative redefinition of some types of headache, until now defined as primary, is now possible. Chronic migraine is proposed here as the consequence of "processes" to be ascribed to mechanisms activated by comorbid conditions. The observations supporting the possibility that allodynia represents the process leading to pain progression, which occurs in some migraineurs, are discussed.

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

The association of chronic migraine (CM) with an idiopathic intracranial hypertension without papilledema (IIHWOP), although much more prevalent than expected in clinical series of CM sufferers, is not included among the risk factors for migraine progression. We discuss the available evidence supporting the existence of a pathogenetic link between CM and idiopathic intracranial hypertensive disorders and suggest a causative role for IIHWOP in migraine progression.