Is there a brainstem generator of chronic daily headache?

Using BOLD-fMRI we have previously documented activation of the red nucleus (RN) and substantia nigra (SN) during spontaneously and visually activated migraine headache. These observations prompted us to study brainstem function in chronic daily headache patients using high-resolution magnetic resonance imaging (MRI) techniques. Seventeen chronic daily headache (CDH) patients, ten episodic migraine (EM) patients and fifteen controls (N) were imaged with a 3 tesla MRI system. For each subject, the relaxation rates R2, R2* and R2' were obtained for RN and SN. There was a significant decrease in R2' and R2* values for RN and SN in CDH compared to N and EM groups (p < 0.05), but no significant difference between the N and EM groups. A decrease in R2' and R2* indicates reduced deoxyhemoglobin and hence persistent activation of the RN and SN in CDH patients most likely secondary to ongoing headache at the time of study. The imaging data provide objective evidence of disturbed central nervous system function in CDH.     

Is Chiari type I malformation a reason for chronic daily headache?

This article briefly reviews the spectrum of headaches associated with Chiari type I malformation and specifically analyzes current data on the possibility of this malformation as an etiology for some cases of chronic daily headache (CDH). Chiari type I malformation is definitely associated with cough headache and not with primary episodic headaches, with the rare exception of basilar migraine-like cases. With regard to CDH, there is no clear evidence supporting an association with this malformation. An MRI study would be justified only in patients showing either a Valsalva-aggravating component or cervicogenic features. Hydrocephalus and low intracranial pressure syndrome should be ruled out in patients showing tonsillar herniation in an MRI study and consulting due to daily headache.     

Phantom headache: pain-memory-emotion hypothesis for chronic daily headache?

The neurobiology of chronic pain, including chronic daily headache (CDH) is not completely understood. “Pain memory” hypothesis is one of the mechanisms for phantom limb pain. We reviewed the literature to delineate a relation of “pain memory” for the development of CDH. There is a direct relation of pain to memory. Patients with poor memory have less chance to develop “pain memory”, hence less possibility to develop chronic pain. Progressive memory impairment may lead to decline in headache prevalence. A similar relation of pain is also noted with emotional or psychiatric symptoms. Literature review suggests that there is marked overlap in the neural network of pain to that of memory and emotions. We speculate that pain, memory, and emotions are interrelated in triangular pattern, and each of these three is related to other two in bidirectional pattern, i.e., stimulation of one of these will stimulate other symptoms/networks and vice versa (triangular theory for chronic pain). Longstanding or recurrent noxious stimuli will strengthen this interrelation, and this may be responsible for chronicity of pain. Reduction of both chronic pain and psychological symptoms by cognitive behavioral therapy or psychological interventions further suggests a bidirectional interrelation between pain and emotion. Longitudinal studies are warranted on the prevalence of headache and other painful conditions in patients with progressive memory impairment to delineate the relation of pain to memory. Interrelation of headache to emotional symptoms should also be explored.     

Is chronic tension-type headache a vascular headache? The relation between chronic tension-type headache and cranial hemodynamics

Twenty-seven patients with chronic tension-type headache were studied as to end-tidal PCO2, heart rate, mean blood pressure, diameter and blood flow of the common carotid arteries, cranial vascular resistance, and headache intensity at supine rest, after administration of nitroglycerin, and at head down tilt. The results were compared to the results of nitroglycerin and head down tilt provocations in age- and sex-matched controls. During supine rest, no change in chronic tension-type headache occurred. Nitroglycerin and tilting induced significant increase of the headache intensity compared to baseline in patients with chronic tension-type headache (P=0.01 and P<0.05, respectively) in contradistinction to controls who did not develop significant headache. Common carotid artery blood flow changes were similar during nitroglycerin provocations in the two groups, but greater (P<0.05) during head down tilt in patients than in controls. Lumbar cerebrospinal fluid pressure was found to be greater than 20 but less than 26 cm H2O in 45% of the 22 patients studied with chronic tension-type headache. The results indicate that the pain in chronic tension-type headache is related to cranial hemodynamics, presumably to distention of intracranial veins.     

Chronic daily headache in the absence of medication overuse: Is daily or continuous pain more treatment-resistant than chronic daily headache with pain-free days?

To our patients, their families, and treatment providers who may not be headache specialists, chronic daily headache (CDH) would appear to refer to headache disorders marked by the presence of daily pain over an extended period of time. To the headache specialist, in contrast, CDH represents a family of headache disorders in which pain occurs from 15 to 30 days each month [1], now reflected in the International Headache Society (IHS) criteria for chronic migraine (CM) or chronic tension-type headache [2]. The IHS classification does not distinguish between daily CM and intermittent CM marked by at least some pain-free days [3]. Research studies and clinical reports of the diagnostic entities subsumed under CDH often include patients with pain-free days and those with true daily pain.     

Is there hope for chronic pain and headache?

Currently the clinical needs for pain and headache management are not met. Despite the numerous and exciting recent advances in understanding the molecular and cellular mechanisms that originate pain, we cannot yet fully explain the mechanism underlying the biology of chronic pain. Pain is a natural mechanism preserving our species survival; however, when the protective quality is lost, physiologic changes to the peripheral and central nervous systems result in the formation of chronic pain states. Once we understand how this chronic pain state is created, either through genetic, environmental, therapeutic, or other triggers we may be able to enhance our species existence, limiting maladaptive pain and suffering. The future therapeutic targets will need to address the genetics, neurophysiologic changes of the neurons and brain as well as help control immune systems including the glia. The key to successful headache and pain therapy is research aimed at prevention and minimizing the plastic changes triggering chronic pain.     

The patients’ perceptions of migraine and chronic daily headache: a qualitative study

This study aimed to gain insight into the management of migraine and chronic daily headache (CDH) from the patients perspective. This article outlines the patients perceptions of migraine and chronic daily headache. Thirteen semi–structured interviews were carried out with patients suffering from IHS migraine. Five patients, due to their headache frequency of more than 15 headache days per month, were classed as CDH patients. The data were transcribed verbatim and analysed in accordance with the grounded theory methodology. The main themes were: headaches, impact and headaches related to health issues. The theme headaches was sub-divided into their pain and symptoms, differentiating between their headaches and perceptions of headaches as barriers and facilitators to management. The patients perceptions of migraine and CDH were sometimes conflicting and influenced the patients management behaviours. The qualitative methodology may help to inform doctors, other healthcare professionals and headache researchers about the patients perspective and possibly develop future headache research, care and education.     

Does chronic daily headache arise de novo in association with regular use of analgesics?

BACKGROUND: The prevalence of chronic daily headache in association with regular use of analgesics is about 2%. Whether regular use of analgesics has a causal or consequential relationship to daily headache has not been established. A causal relationship has been suggested consequent to the observation of improvement or resolution of headache following analgesic withdrawal in patients attending headache clinics, but this observation has not been validated by controlled trials. PURPOSE: The aim of our investigation was to determine whether regular use of analgesics is associated with the development of chronic daily headache de novo and to characterize the clinical phenotype of those headaches by carefully studying chronic daily headache in patients with regular use of analgesics for a nonheadache indication. METHODS: Patients attending a rheumatology-monitoring clinic of second-line agents were interviewed by a training neurologist with regard to their analgesic and headache history. Headache classification was according to the criteria of the International Headache Society. Daily headache characteristics were surveyed via a standardized questionnaire, and headache features were further explored by a trained medical interviewer. RESULTS: Of 110 patients presenting to a rheumatology-monitoring clinic, 73% had a diagnosis of rheumatoid arthritis, 23% had seronegative arthritis, and 4% comprised a miscellaneous group. One hundred three were using one or more analgesics regularly for their arthritis. Of this group, 8 (7.6%) reported a history of chronic daily headache, each of whom reported a history of migraine. The onset of migraine occurred before the onset of chronic daily headache in 7 patients and at about the same time as the chronic daily headache in 1 patient. In those with onset of migraine prior to chronic daily headache, the mean interval before the onset of headache was 30 years (range, 10 to 50 years). Regular use of analgesics preceded the onset of daily headache in 5 patients by a mean of 5.4 years (range, 2 to 10 years). In 1 patient, analgesic use and the development of daily headache occurred at about the same time. In 1 patient, the onset of daily headache preceded regular use of analgesics by almost 30 years. Five of those with regular use of analgesics had been taking an opiate-based preparation in combination with a nonsteroidal anti-inflammatory agent in 4. Two had been on a combination of acetaminophen (paracetamol) and a nonsteroidal anti-inflammatory drug. The minimum number of tablets per week was 7, and the mean was 48 (range, 7 to 87). Of those patients who did not have daily headache, 41% had a history of migraine and 27% reported a history of tension-type headache. CONCLUSION: These findings suggest that individuals with primary headache, specifically migraine, are predisposed to developing chronic daily headache in association with regular use of analgesics.     

Are there predictive factors for long-term outcome after withdrawal in drug-induced chronic daily headache?

OBJECTIVES: To investigate prognostic factors for long-term outcome of patients after inpatient withdrawal because of drug-induced chronic daily headache. PROCEDURES: Fifty-five patients (36 females) were re-examined by means of a standardized interview after inpatient withdrawal. The mean observation period was 9.28 +/- 2.85 years (mean +/- SD; median 8.58; range 5.00-13.50). RESULTS: Five years after withdrawal, one-third of the patients (34.6%) had an overall favourable outcome, one-third (32.7%) had no recurrent drug overuse and reported a clear-cut improvement of headache, and one-third (32.7%) developed recurrent drug overuse. Most relapses occurred within 2 years, and a small percentage within 5 years. No predictors for long-term outcome after inpatient withdrawal were found. CONCLUSIONS: All patients with drug-induced chronic daily headache should be considered as good candidates for inpatient withdrawal, and no patient should be excluded from that therapy.     

Post-infectious headache: a reactive headache?

Post-infectious disease syndrome includes both neurological and non-neurological disorders. However, headache as an isolated or a presenting complaint of post-infectious illness has not been well acknowledged in the literature. In this retrospective observation, patients having daily headache of more than 1 week and <4 weeks duration were included. We divided this group into patients having headache with preceding history of febrile illness in the recent past and patients without such history of febrile illness. We compared clinical features and therapeutic responses of various drugs between the groups. There were no significant differences in demographic features in these groups. However, associated neck pain, nausea, photophobia and meningeal signs were more prevalent in patients having history of preceding infection. A relatively lower proportion of subjects showed complete response to drugs at 3 months in post-infectious group. Good responses were noted to steroids in post-infectious group. In conclusion, a subset of patients with daily headache may be because of post-infectious pathology and treatment in the early stage may prevent it from becoming chronic. Large prospective studies are required to confirm these observations.     

Alternative therapies in headache. Is there a role?

Alternative or complementary modes of treatment often lack scientific proof of efficacy. This is true for many drugs that are used for prophylaxis of headaches as well. Many of these complementary modes are inexpensive, harmless, and possibly effective. Patients can be given a list of options in the following order of clinician preference: aerobic exercise; isometric neck exercise; biofeedback; a combination product containing magnesium, riboflavin, and feverfew; and acupuncture. The patient must decide which of these approaches is appealing, affordable, and realistically doable.     

Is field intubation useful?

The establishment and maintenance of an adequate airway is often the single most important initial therapy provided to a victim of severe injury. This may be accomplished by simple techniques such as placement of an oral or nasopharyngeal airway as well as bag-mask ventilation techniques. More advanced techniques such as endotracheal intubation require a higher level of training and expertise for both prehospital and hospital providers. Although paramedics routinely practice endotracheal intubation in the field, there are increasing reports on the many potential risks associated with these procedures as well as increased morbidity and mortality in both pediatric and adult patients. These data have important implications for field airway management in the critically ill trauma patient.     

Is headache related to asthma, hay fever, and chronic bronchitis? The Head-HUNT Study

OBJECTIVES: To examine the relationship between migraine and nonmigrainous headache and asthma, hay fever, and chronic bronchitis in a large cross-sectional population-based study. BACKGROUND: Associations between prevalence of migraine and asthma or allergy have been demonstrated in clinic-based and epidemiologic studies whereas studies on chronic bronchitis are scarce. METHODS: A total of 51,383 subjects completed a headache questionnaire and constituted the "Head-HUNT" Study. Of these 50,401 (98.1%) answered the questions about asthma and chronic bronchitis, and 47,029 (91.5%) answered the question about hay fever. Associations were assessed in multivariate analyses, estimating prevalence odds ratios (ORs) with 95% confidence intervals (CI). RESULTS: Both migraine and nonmigrainous headache were approximately 1.5 times more likely among those with current asthma, asthma related symptoms, hay fever, and chronic bronchitis than those without. The association increased with increasing headache frequency. CONCLUSIONS: This large questionnaire-based study confirms that migraine and other headaches are associated with respiratory and allergic disorders. The magnitude of the association between headache and asthma, hay fever, and chronic bronchitis tended to be in the same order. Headache frequency seems to have a greater impact on the association with respiratory or allergic conditions than headache diagnoses. Whether it is a causal relationship is uncertain, but the results underline the importance of considering comorbid disorders among patients with frequent headache.