Chapter 19: Headache Assessment & Diagnosis

Headache Assessment & Diagnosis details the pathophysiology of cranial pain, explaining that while brain tissue is insensitive, pain arises from traction, inflammation, vascular dilation, or muscle contraction affecting sensitive structures like the meninges and blood vessels. The text thoroughly outlines the characteristics of primary headaches, including Tension-Type Headaches (TTH) which manifest as bilateral, band-like pressure; Migraines, characterized by unilateral, throbbing pain often accompanied by nausea, photophobia, and visual auras (scintillating scotoma); and Cluster Headaches, which present as severe, sudden periorbital pain with autonomic symptoms like lacrimation and rhinorrhea. Significant emphasis is placed on diagnostic reasoning to identify "red flags" for life-threatening secondary causes, such as Subarachnoid Hemorrhage (SAH)—described as a sudden "thunderclap" headache—and Meningitis, indicated by fever, nuchal rigidity, and positive Kernig or Brudzinski signs. The summary also covers the evaluation of Temporal Arteritis (Giant Cell Arteritis) in older adults, emphasizing the risk of irreversible blindness and the need for immediate Erythrocyte Sedimentation Rate (ESR) testing. Furthermore, it addresses headaches arising from metabolic issues like carbon monoxide poisoning or hypoglycemia, cranial neuralgias such as Trigeminal Neuralgia, and space-occupying lesions like brain tumors or abscesses which may present with papilledema and progressive neurologic deficits. Finally, the chapter guides practitioners through the physical examination, including a complete neurologic assessment and fundoscopy, and recommends appropriate diagnostic studies such as CT scans for acute hemorrhage or MRI for structural abnormalities.