Headaches Attributed to Disorders of Homeostasis.

Headaches attributed to disorders of homeostasis include those different headache types associated with metabolic and systemic diseases. These are headache disorders occurring in temporal relation to a disorder of homeostasis including hypoxia, high altitude, airplane travel, diving, sleep apnea, dialysis, autonomic dysreflexia, hypothyroidism, fasting, cardiac cephalalgia, hypertension and other hypertensive disorders like pheochromocytoma, hypertensive crisis, and encephalopathy, as well as preeclampsia or eclampsia. The proposed mechanism behind the causation of these headache subtypes including diagnostic criteria, evaluation, treatment, and overall management will be discussed.

Metabolic headaches.

This article discusses headaches secondary to disorders of homeostasis, which include headaches attributed to (1) hypoxia and/or hypercapnia (high-altitude, diving, or sleep apnea), (2) dialysis, (3) arterial hypertension (pheochromocytoma, hypertensive crisis without hypertensive encephalopathy, hypertensive encephalopathy, preeclampsia or eclampsia, or autonomic dysreflexia), (4) hypothyroidism, (5) fasting, (6) cardiac cephalalgia, and (7) other disorder of homeostasis. Clinical features and diagnosis as well as therapeutic strategies are discussed for each headache type.

Patterns of care and outcomes after computed tomography scans for headache.

BACKGROUND: concerns exist about potential overuse of computed tomography (CT) scans for headache in ambulatory care. METHODS: we sought to examine health services use, brain tumor diagnosis, and death during the year after CT scanning for headache by linking records of an audit of 3930 outpatient CT brain scans performed in 2005 in Ontario, Canada, to administrative databases. RESULTS: of 623 patients receiving CT scans for a sole indication of headache, few (2.1%) scans contained findings potentially causing their headache. For most patients, the index CT scan was the only one received over an 11-year period. However, 28.4% of patients received 1 or more CT brain scans during the preceding decade and 6.7% received 1 or more CT brain scans during the subsequent year. Of the 473 patients (75.9%) whose index scan was ordered by a primary care physician, most (80.3%) did not see a specialist during follow-up. One patient with an indeterminate finding on the index scan was diagnosed with a malignant brain tumor (0.2%), and 6 patients (1.0%) died during follow-up. Among the 4 deaths in which the cause could be determined, none were due to central nervous system causes. CONCLUSION: because of the potential risk of cancer from exposure to ionizing radiation, efforts should be made to avoid CT scanning for headache when the likelihood of serious illness is low. Evidence-based decision rules that identify which patients with headache do not require neuroimaging may decrease the use of CT scans in situations of little benefit.

Headaches attributable to infectious diseases.

Headache is the most common symptom that humans experience. While the vast majority of headaches are due to benign primary headache disorders, a small but important minority of headaches are due to secondary causes. Whereas significant emphasis is placed on educating physicians regarding prompt recognition of subarachnoid hemorrhage and headaches secondary to brain tumors, attention toward headaches secondary to infectious causes is often neglected. Unfortunately, a missed or delayed diagnosis of a headache secondary to meningitis, encephalitis, brain abscess, subdural empyema, or other infectious etiologies can lead to dire consequences for both the patient and physician. Accordingly, this article provides an overview of headaches attributed to systemic and intracranial infectious causes.

An approach to the patient with painful ophthalmoplegia, with a focus on Tolosa-Hunt syndrome.

The differential diagnosis of painful ophthalmoplegia is extensive and consists of numerous sinister etiologies, including neoplasms (ie, primary intracranial tumors, local or distant metastases), vascular (eg, aneurysm, carotid dissection, and carotid-cavernous fistula), inflammatory (ie, orbital pseudotumor, giant cell arteritis, sarcoidosis, and Tolosa-Hunt syndrome), and infectious etiologies (ie, fungal and mycobacterial), as well as other miscellaneous conditions (ie, ophthalmoplegic migraine and microvascular infarcts secondary to diabetes). A systematic approach to the evaluation of painful ophthalmoplegia can lead to prompt recognition of serious disorders that can be associated with significant morbidity or mortality if left untreated. Inflammatory conditions such as Tolosa-Hunt syndrome and orbital pseudotumor are highly responsive to corticosteroids but should be diagnoses of exclusion.

Migraine and white matter hyperintensities.

Patients with migraine are at increased risk for white matter hyperintensities detected on magnetic resonance imaging. The presence of nonspecific white matter hyperintensities may cause uncertainty for physicians and anxiety for patients. The pathophysiology and long-term consequences of these lesions are unknown. Occasionally, white matter lesions in a migraineur may indicate an underlying disease such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS), or central nervous system vasculitis. The ability to distinguish between nonspecific and disease-specific patterns of white matter hyperintensities in migraine sufferers is important for the practicing clinician.

Painful ophthalmoplegia: overview with a focus on Tolosa-Hunt syndrome.

Painful ophthalmoplegia is an important presenting complaint to emergency departments, ophthalmologists, and neurologists. The etiological differential diagnosis of painful ophthalmoplegia is extensive and consists of numerous sinister etiologies including vascular (eg, aneurysm, carotid dissection, carotid-cavernous fistula), neoplasms (eg, primary intracranial tumors, local or distant metastases), inflammatory conditions (eg, orbital pseudotumor, sarcoidosis, Tolosa-Hunt syndrome), infectious etiologies (eg, fungal, mycobacterial), and other conditions (eg, microvascular infarcts secondary to diabetes, ophthalmoplegic migraine, giant cell arteritis). A systematic approach to the evaluation of painful ophthalmoplegia can lead to prompt recognition of serious disorders that if left untreated, can be associated with significant morbidity or mortality. Inflammatory conditions such as Tolosa-Hunt syndrome and orbital pseudotumor are highly responsive to corticosteroids, but should be diagnoses of exclusion.