Headache
Headaches are among the most frequently named symptoms in general practices.
Epidemiology
Epidemiological analysis has shown that lifetime prevalence of headaches is 93% to 99% 1). In the primary care setting, headaches are the chief complaint in 1.5% of all visits 2).
Pathophysiology
Societies
International Headache Society
Diagnosis
Guidelines suggest that neuroimaging should be ordered only if a stable headache patient displays localizing neurological symptoms or signs 3).
Types
Countless medical textbooks and journal articles provide insight into and guidance on the clinical diagnosis of headache disorders, and most primary headaches can be diagnosed through careful history and physical examination 4).
Differential diagnosis
Differential diagnosis of severe, acute, paroxysmal headache (25% will have SAH):
Subarachnoid hemorrhage, AKA “warning'headache” or sentinel H/A
There is no subarachnoid blood on CT and LP, which should probably be performed on at least the first presentation to R/O SAH. Earlier recommendations to angiogram these individuals have since been tempered by experience
reversible cerebral vasoconstrictive syndrome (RCVS) (AKA benign cerebral angiopathy or vasculitis): severe H/A with paroxysmal onset ± neurologic deficit.
The most common symptom of idiopathic intracranial hypertension (IIH) is headache.
Headache after lumboperitoneal shunt placement for the patients with idiopathic normal pressure hydrocephalus (iNPH) is commonly attributed to intracranial hypotension (IH) due to shunt overdrainage 5).
People with epilepsy experience headaches irrespective of their sex or age. The burden of headaches is very important in patients with epilepsy, since headaches usually cause a moderate or severe burden to their quality of life and suggest a clear clinical need. Clinicians should recognize headache as a common comorbidity of epilepsy, as it may influence antiepileptic drug choice, and may need specific treatment 6).
Management
About 90% of the patients suffer from idiopathic headaches, for example, migraine or tension headaches, which are treated according to guidelines. An acute headache can however also be a symptom of a serious primary disease, such as subarachnoid hemorrhage, arterial dissection, cerebral infarction, cerebral venous thrombosis or acute glaucoma. Patients with suspected symptomatic headaches must be immediately referred to a specialist or hospital for further diagnosis and therapy 7).
Guidelines
Headache is one of the most common human afflictions. In most cases, headaches are benign and idiopathic, and resolve spontaneously or with minor therapeutic measures. Imaging is not required for many types of headaches. However, patients presenting with headaches in the setting of “red flags” such as head trauma, cancer, immunocompromised state, pregnancy, patients 50 years or older, related to activity or position, or with a corresponding neurological deficit, may benefit from CT, MRI, or noninvasive vascular imaging to identify a treatable cause. This publication addresses the initial imaging strategies for headaches associated with the following features: severe and sudden onset, optic disc edema, “red flags,” migraine or tension-type, trigeminal autonomic origin, and chronic headaches with and without new or progressive features. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment 8).