Headache in Children

1. THE 2-MINUTE PHYSIOLOGY (Rapid Pathophysiology)

• The Classification Paradigm: According to the International Headache Society (IHS), pediatric headaches are fundamentally divided into primary headaches (migraines, tension, and cluster headaches), secondary headaches (which can be benign or life-threatening), and cranial neuralgias/facial pain.
• The Statistical Breakdown: The vast majority of pediatric headaches are secondary to a benign cause (60%), followed by primary headaches (25%), unclassified causes (10%), and strictly life-threatening secondary causes (5%).
• The Mechanical Breakdown (Raised ICP): The core pathophysiology driving life-threatening secondary headaches is increased intracranial pressure (ICP) resulting from space-occupying lesions (tumors, hematomas), infections (abscesses, meningitis), or cerebral venous sinus thrombosis. When ICP critically rises, it compresses CN III and the brainstem, leading to acute brain herniation. The body attempts to compensate and maintain Cerebral Perfusion Pressure (CPP) by initiating the Cushing reflex, manifesting as paradoxical hypertension and bradycardia.

2. THE BEDSIDE ACTION PLAN (Rapid ER Management)

• Immediate Stabilization for Herniation: If a patient with a headache exhibits signs of acute brain herniation (bradycardia, hypertension, and a unilaterally dilated, nonreactive pupil), elevate the head of the bed to 30 degrees and utilize controlled ventilation to maintain ETCO2 at approximately 35 mm Hg.
• Hyperosmolar Therapy: Immediately administer Mannitol or 3% hypertonic saline IV to acutely reduce intracranial pressure. Consider intravenous phenytoin for seizure prophylaxis.
• Abortive Analgesia: For mild to moderate primary headaches, administer oral NSAIDs or acetaminophen. For severe, intractable headaches, utilize parenteral NSAIDs with or without an IV antiemetic.
• Discharge Counseling: For patients discharged after successful treatment of a primary headache, prescribe the SMART lifestyle modifications to prevent recurrence: Sleep (adequate), Meals and activity (regular), Relaxation techniques, and Trigger avoidance.

3. THE DIAGNOSTIC GRID (Differential Diagnosis & Workup)

• Top "Can't-Miss" Differential Diagnoses:
• Arterial Ischemic Stroke: Routinely missed in pediatric patients on initial presentation.
• CNS Infection: Meningitis, encephalitis, or brain abscess.
• Intracranial Hemorrhage: Subarachnoid or subdural hematomas, especially post-traumatic.
• Carbon Monoxide Poisoning: An often-overlooked toxicological cause of severe headache.
• Prioritized Diagnostic Workup:
• Tier 1 (Targeted History): The history is the most important component for differentiating benign from life-threatening headaches. Rapidly assess the time of onset, duration, laterality, quality (throbbing vs. dull), relieving/exacerbating factors, and associated symptoms like photophobia or intractable vomiting.
• Tier 2 (Directed Labs): Obtain a complete blood count, blood and urine cultures, and a lumbar puncture (LP) to analyze cerebrospinal fluid (CSF) if an infectious etiology like meningitis or encephalitis is suspected.
• Tier 3 (Definitive Imaging): Non-contrast cranial CT is the initial gold standard to evaluate for intracranial bleeding, masses, or traumatic brain injury.

4. THE VISUAL BOARD (ECG / POCUS / Imaging)

• CT Head Checklist: Scrutinize the cranial CT for loss of gray-white differentiation, midline shift, and effacement of the basilar cisterns or ventricles, which are radiographic hallmarks of elevated ICP and impending herniation.
• The Pupillary Exam: The resident must actively assess for a dilated, nonreactive pupil, which, in the setting of severe headache and bradycardia, definitively signals CN III compression and acute brain herniation.

5. THE SCORING MATRIX (Risk Stratification & Guidelines)

• PECARN Head Trauma Rules: Used for risk stratification in children presenting with a post-traumatic headache.
• High Risk: Infants and children with a Glasgow Coma Scale (GCS) of 14, altered mental status, or palpable skull fractures have a high risk of clinically important traumatic brain injury (TBI) and require immediate cranial CT.
• Moderate Risk: For a neurologically intact child (GCS 15) presenting with a headache strictly due to a severe mechanism of injury, shared decision-making with the parents regarding ED observation versus immediate cranial CT is recommended.

6. THE DANGER ZONE (Pitfalls & Critical Actions)

• The Hemiplegic Migraine Trap: Pitfall: Diagnosing a child with "hemiplegic migraine" and discharging them without imaging. Critical Action: Hemiplegic migraine classically presents with sudden hemiparesis or hemisensory loss followed by a contralateral headache. Because pediatric stroke is routinely missed, immediate neuroimaging is absolutely mandated to rule out an arterial ischemic stroke before attributing the focal deficit to a migraine.
• The Antihypertensive Fallacy: Pitfall: Administering antihypertensives (e.g., a nicardipine infusion) to a child presenting with a severe headache, bradycardia, and hypertension. Critical Action: This hemodynamic triad is the Cushing reflex, a physiologic mechanism to maintain cerebral perfusion against rising ICP. Lowering the blood pressure will catastrophically drop cerebral perfusion. You must target the ICP with hyperosmolar therapy instead.

7. MCQ MASTERCLASS (Written Exam Tips)

• Buzzwords: "Sudden onset of hemiparesis followed by headache in the contralateral hemisphere"
• Diagnosis: Hemiplegic migraine. Exam Tip: Always choose the option that includes neuroimaging to rule out stroke first.
• Buzzwords: "Child with headache, sudden unresponsiveness, dilated left pupil, bradycardia, and hypertension."
• Diagnosis: Acute brain herniation secondary to raised ICP.
• Common Distractor: A post-traumatic pediatric patient with a GCS of 14 and a severe headache. An option will suggest "Observe in the ED for 4 hours."
• Differentiate: According to PECARN rules, a GCS of 14 carries a 4% risk of a clinically important TBI. Observation is incorrect here; this patient strictly requires a cranial CT scan.

8. THE BOARDROOM SCRIPT (OSCE & Oral Board Tips)

• The Opening Salvo: "This child is presenting with a severe headache. Because only 5% of pediatric headaches are life-threatening, my immediate priority in the ED is to differentiate a primary benign headache from a secondary intracranial catastrophe. I will initiate a meticulous history exploring the headache's onset, quality, and any associated intractable vomiting or photophobia, followed immediately by a comprehensive neurologic examination.".
• Addressing Focal Deficits: "The patient is exhibiting left-sided weakness following a right-sided headache. While this is classic for a hemiplegic migraine, pediatric stroke is frequently missed. I am ordering an immediate cranial CT scan and consulting pediatric neurology to rule out an arterial ischemic stroke.".
• Articulating the Resuscitation: "The patient has become bradycardic and hypertensive with a newly dilated pupil, indicating acute brain herniation. I am immediately elevating the head of the bed to 30 degrees, taking control of the airway to maintain an ETCO2 of 35 mm Hg, and ordering STAT intravenous 3% hypertonic saline to decrease intracranial pressure.".