What negative findings are pertinent in headache evaluation?

From the Guidelines

Negative findings in headache evaluation are crucial for effective management. When evaluating headaches, it is essential to consider negative findings, such as the absence of certain symptoms or signs, to rule out underlying conditions that may require specific treatments.

• Medication overuse headache is a critical consideration, and screening for high-risk factors, including headache frequency, migraine diagnosis, medication use, history of anxiety or depression, physical inactivity, and smoking, is vital 1.
• Lack of response to treatment should prompt a thorough review of the underlying reasons, including poor adherence, suboptimal dosing, or incorrect diagnosis 1.
• Normal physical examination findings do not necessarily rule out underlying conditions, and further evaluation may be necessary to determine the cause of headaches 1.
• Negative findings on imaging studies do not always exclude underlying conditions, and clinical correlation is essential to determine the cause of headaches 1.
• Absence of certain symptoms, such as aura or photophobia, does not necessarily rule out migraine or other primary headache disorders 1.
• Failure to respond to first-line treatments should prompt consideration of alternative treatments or specialist referral 1. In summary, negative findings in headache evaluation are essential to consider, as they can help rule out underlying conditions, guide further evaluation, and inform treatment decisions. By considering these negative findings, clinicians can provide more effective management and improve patient outcomes.

From the Research

Negative Findings in Headache Evaluation

• The yield of neuroimaging in the evaluation of patients with headache and a normal neurologic examination is quite low, with overall percentages of various pathologies as: brain tumors, 0.8%; arteriovenous malformations, 0.2%; hydrocephalus, 0.3%; aneurysm, 0.1%; subdural hematoma, 0.2%; and strokes, including chronic ischemic processes, 1.2% 2
• EEG is not useful in the routine evaluation of patients with headache 2
• The yield of neuroimaging in the evaluation of migraine is quite low, with overall percentages of various pathologies as: brain tumor, 0.3%; arteriovenous malformation, 0.07%; and saccular aneurysm, 0.07% 2
• Cerebral atrophy has been variably reported as more frequent and no more frequent in migraineurs compared with controls 2
• The probability of detecting an aneurysmal hemorrhage on CT scans performed at various intervals after the ictus is low, with a probability of: day 0,95%; day 3,74%; 1 week, 50%; 2 weeks, 30%; and 3 weeks, almost nil 2
• The management of thunderclap headaches with normal CT scan and CSF examinations is controversial, and most patients have a benign course but an unruptured saccular aneurysm occasionally may be responsible for the headache 2
• Up to 15% of patients 65 years and over who present to neurologists with new-onset headaches may have serious pathology such as stroke, TA, neoplasm, and subdural hematoma 2
• The erythrocyte sedimentation rate can be normal in 10% to 36% of patients with TA, and a superficial temporal artery biopsy can give a false-negative result in 5% to 44% of patients 2

Limitations of Current Diagnostic Approaches

• The current diagnosis and classification of headache disorders may be straightforward or challenging, and though often benign, headache may prove to be an ominous symptom 3
• The distinction between a primary and secondary headache with potentially life-threatening implications can be difficult 4
• Documentation of red flags and clinical characteristics is inadequate and does not allow proper diagnostic categorization 4
• A structured and standardized form for documenting the headache history and red flags in the ED may facilitate concise documentation and rapid decision making 4