Application of IHS Criteria to Headache Attributed to Spontaneous Intracranial Hypotension in a Large Population

We applied the recent International Headache Society (IHS) criteria for headache related to spontaneous intracranial hypotension (SIH) to 90 consecutive patients with a final diagnosis of SIH confirmed by cerebral magnetic resonance imaging with contrast. Orthostatic headache (developing within 2 h of standing or sitting up) was present in 67 patients (75%) but appeared within 15 min after standing or sitting—as required by point A of the criteria—in only 53 (59%). Forty-four (49%) patients did not satisfy point A, including 22 (24%) with non-orthostatic headache and 14 (16%) with headache developing ≥ 15 min after standing or sitting up; 80 (89%) did not satisfy point D. Only three (3%) patients had headache fully satisfying the IHS criteria. These findings indicate that the current IHS criteria do not capture most patients with SIH-associated headache. Excluding the requirement for response to epidural blood patch (criterion D) and considering headaches appearing within 2 h of sitting or standing up would capture more patients.

Epidemiology of Fixed Unilateral Headaches

A fixed location unilateral headache suggests involvement of a precise nervous structure, and neuroimaging investigations are essential to seek to identify it. Nevertheless, side-locked primary headaches also occur, although they are rare. Side-locked primary headaches are more frequently found in the group of the short-lasting (≤ 4 hours) headaches but long-lasting headache forms may also present with the pain always on the same side, including migraine, tension-type headache, new daily persistent headache and cervicogenic headache. Future studies should address the issue whether patients with side-locked headache form differ from those with non-side-locked form both in terms of natural history and biological markers.

Among 63 consecutive chronic cluster headache patients seen by us from 1999 to 2007, 32 (51±) had side shift. We also found that the duration of the chronic condition was significantly longer in those with side shift than those without. The high frequency of side shift in chronic cluster headache should be considered when proposing surgical treatment for severe intractable forms of the disease.

Validation of AIDA Cefalee, a computer-assisted diagnosis database for the management of headache patients

AIDA Cefalee is a database for the management of headache patients developed on behalf of the Italian Neurological Association for Headache Research (ANIRCEF). The system integrates a diagnostic expert system able to suggest the correct ICHD-II diagnosis once all clinical characteristics of a patient's headache have been collected. The software has undergone a multicentre validation study to assess: its diagnostic accuracy; the impact of using the software on visit duration; the userfriendliness degree of the software interface; and patients' acceptability of computer-assisted interview. Five Italian headache centres participated in the study. The results of this study validate AIDA Cefalee as a reliable diagnostic tool for primary headaches that can improve diagnostic accuracy with respect to the standard clinical method without increasing the time length of visits even when used by operators with basic computer experience.

Deep brain stimulation in craniofacial pain: seven years' experience

Cluster headache (CH) is a primary headache with excruciatingly painful attacks that are strictly unilateral. About 10% of cases experience no significant remission, and about 15% of these do not respond to medication, so surgery is considered. Neuroimaging studies show that the posterior inferior hypothalamus is activated during CH attacks and is plausibly the CH generator. We report on 16 chronic CH patients, with headaches refractory to all medication, who received long-term hypothalamic stimulation following electrode implant to the posterior inferior hypothalamus. After a mean follow-up of 23 months, a persistent pain-free to almost pain-free state was achieved in 13/16 patients (15/18 implants; 83.3%) a mean of 42 days (range 1-86 days) after monopolar stimulation initiation. Ten patients (11 implants) are completely pain-free. A common side effect was transient diplopia, which limited stimulation amplitude. In one patient, a small non-symptomatic haemorrhage into the 3rd ventricle occurred following implant, but regressed 24 h later. Persistent side effects are absent except in one patient with bilateral stimulation, in whom stimulation was stopped to resolve vertigo and worsened bradycardia, but was resumed later without further problems. Hypothalamic stimulation is an effective, safe and well tolerated treatment for chronic drug-refractory CH. It appears as a valid alternative to destructive surgical modalities, and has the additional advantage of being reversible.

Headache and spontaneous low cerebrospinal fluid pressure syndrome

We examined 59 consecutive patients presenting between 1993 and 2006 at our centre diagnosed with headache associated with spontaneous intracranial hypotension syndrome (SIH). Thirty-six (61%) patients were women; the mean age was 47 years (range 20-68). Cerebral MRI with contrast confirmed SIH in all patients. Headache characteristics were obtained by direct semistructured interview; in a minority of cases information was completed retrospectively through a phone call. All SIH patients suffered from headache. Early recognition of SIH may avoid dangerous worsening due to delayed diagnosis. Orthostatic headache, the main symptom, suggests the diagnosis.

Functional neuroimaging and headache pathophysiology: new findings and new prospects

In the last ten years pathophysiology of primary headaches has received new insights from neuroimaging studies. Positron emission tomography (PET) showed activation of specific brain structures, brainstem in migraine and hypothalamic grey in trigeminal autonomic cephalalgias. This brain activation suggests it may intervene both in a permissive or triggering manner and as a response to pain driven by the first division of the trigeminal nerve. Voxel-based morphometry has suggested that there is a correlation between the brain area activated specifically in acute cluster headache - the posterior hypothalamic grey matter - and an increase in grey matter in the same region. New insights into mechanisms of head pain have emerged thanks to neuroimaging obtained in experimentally induced headaches, and during peripheral and central neurostimulation.

Acute hypothalamic stimulation and ongoing cluster headache attacks

Long-term hypothalamic stimulation is effective in improving drug-resistant chronic cluster headache (CH). We assessed acute hypothalamic stimulation to resolve ongoing CH attacks in 16 patients implanted to prevent chronic CH, investigating 136 attacks. A pain intensity reduction of > or =50% occurred in 25 of 108 evaluable attacks (23.1%). Acute hypothalamic stimulation is not effective in resolving ongoing CH attacks, suggesting that hypothalamic stimulation acts by complex mechanisms in CH prevention.

Neuroimaging and pain: a window on the autonomic nervous system

Pain is one of the most common experiences of humans. Neuroimaging techniques can visualize the main brain areas involved in pain modulation, the pain matrix. It is noteworthy that many of the brain areas forming the pain matrix are also involved in modulating autonomic nervous system (ANS) activity that in turn plays a major role in determining the best adaptive response to the pain experience. The tight connection between the pain system and ANS is also evident from neuroanatomical studies indicating that the lamina 1 neurons receive both painful and visceral stimuli from all visceral organs giving rise to the spinothalamocortical pathway concerned with conveying interoceptive information to central structures. The resulting interoceptive stream projects to the viscerosensory cortex in the mid-insula and onto the right anterior insula and orbitofrontal cortices. Right anterior insula activation is involved in the sympathetic arousal associated with mental tasks. This brain region receives numerous other inputs including pain and painful stimuli are conveyed somatotopically to both insulae. A similar somatotopic organization of painful stimuli has also been shown in the basal ganglia involved in cognitive, affective, motor and autonomic states. This highly specialized organization of nociceptive information in these brain areas may subserve a number of functions, particularly of coupling pain with the most appropriate autonomic states and affective/emotional states. The anterior cingulated cortex, another brain area playing a crucial role in nociception, is also directly involved in the control of autonomic functions such as arousal during volitional behaviour, including effortful cognitive processing. It is evident that the nociceptive system and ANS closely interact in many processes involved in maintaining internal homeostatis and in order to give the most appropriate biological substrate for cognitive, affective and emotional states.

Deep brain stimulation and cluster headache

In recent years, neuroimaging data have greatly improved the knowledge on trigeminal autonomic cephalalgias' (TACs) central mechanisms. Positron emission tomography studies have shown that the posterior inferior hypothalamic grey matter is activated during cluster headache attacks as well as in short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT). Voxel-based morphometric MRI has also documented alteration in the same area in cluster headache patients. These data suggest that the cluster headache generator is located in this region and leads us to hypothesise that stimulation of this brain area could relieve intractable cluster headache just as deep brain stimulation improves intractable movements disorders. This view received support by the observation that high frequency stimulation of the ipsilateral hypothalamus prevented attacks in an otherwise intractable chronic cluster headache patient previously treated unsuccessfully by surgical procedures to the trigeminal nerve. So far, 16 patients with intractable cronic cluster headache (CCH) and one intractable SUNCT patient have been successfully treated by hypothalamic stimulation. The procedures were well tolerated with no significant adverse events. Hypothalamic DBS is an efficacious and safe procedure to relieve otherwise intractable CCH and SUNCT.

Spontaneous low cerebrospinal pressure: a mini review

Spontaneous intracranial hypotension (SIH) is a syndrome of low cerebrospinal fluid (CSF) pressure characterised by postural headaches in patients without any history of dural puncture or penetrating trauma. Described by Schaltenbrand in 1938, SIH is thought to result from an occult CSF leak resulting in decreased CSF volume and, consequently, in low CSF pressure. Magnetic resonance imaging of the head and spine has improved the diagnosis of the syndrome showing peculiar radiographic abnormalities including diffuse pachymeningeal enhancement, subdural fluid collections and downward displacement of the cerebral structures. Treatment of SIH headache should start with conservative, non-invasive therapies while epidural blood patch has emerged as the treatment of choice for those symptomatic patients who have failed medical noninvasive approaches.

Selective vs. complete family interview for detecting those affected by familial cluster headache

This study validates the method of interviewing only the first-degree relatives indicated by the proband as possible cluster headache sufferers. We interviewed essentially all the first-degree relatives (93%) of 87 probands with cluster headache. We found only one new first-degree relative with cluster headache (1/40 = 2.5%). The selective interview may be used with confidence as a means of investigating the hereditary component of cluster headache.

Headache and intracranial hypotension: neuroradiological findings

The cardinal and classic features of postural headache and low cerebrospinal fluid (CSF) pressure in intracranial hypotension may not dominate the clinical picture of the syndrome and may be associated with additional various neurological symptoms and signs. Reports of unusual clinical presentations continue to appear in the literature. Despite the considerable variability of the clinical spectrum, neuroradiological studies reveal more constant and characteristic features. Brain MRI findings include intracranial pachymeningeal thickening and post-contrast enhancement, subdural fluid collections and downward displacement or "sagging" of the brain. Spinal MRI findings include collapse of the dural sac with a festooned appearance, intense epidural enhancement owing to dilatation of the epidural venous plexus, and possible epidural fluid collections. In fact, spinal studies may demonstrate CSF leakage from spinal dural defects, which are considered the most common cause of the syndrome. Myelo-MR may suggest the possible point of CSF leakage, by demonstrating an irregular root sleeve; myelo-CT and radioisotope myelocisternography (RMC) are often needed to confirm the point of CSF leakage. Neuroimaging studies are, therefore, essential for suggesting and confirming the diagnosis.

Strategies for the treatment of autonomic trigeminal cephalalgias

Trigeminal autonomic cephalalgias (TACs) are a group of primary headache syndromes characterised by two main clinical characteristics: pain and oculofacial autonomic phenomena. Three headache forms are grouped as TACs: cluster headache (CH), paroxysmal hemicrania (PH) and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT). These are distinguished mainly on the basis of attack duration. It lasts from 15 to 180 min in CH, from 2 to 30 min in PH and from 5 to 240 s in SUNCT. The most effective drug preventative in PH is indomethacin even if in few cases other non-steroidal anti-inflammatory drugs have been reported to be effective. SUNCT is commonly described as drug resistant. Recent studies report that lamotrigin may be the drug of choice for SUNCT.