What is the cause of a headache affecting the whole head, face, occipital region, nape, and extending downwards?

Differential Diagnosis: Diffuse Headache Involving Entire Head, Face, Occiput, Nape, and Descending Pattern

This widespread headache pattern extending from the entire head through the face, occiput, nape, and downward most strongly suggests cervicogenic headache, tension-type headache, or spontaneous intracranial hypotension (SIH), with the descending pattern being particularly characteristic of SIH. 1

Primary Diagnostic Considerations

Spontaneous Intracranial Hypotension (Most Likely Given Descending Pattern)

• The descending distribution from head to nape and downward is highly characteristic of SIH, which presents with orthostatic headache affecting the whole head that worsens within 2 hours of becoming upright and improves >50% within 2 hours of lying flat 1
• Associated symptoms include neck pain, nausea, tinnitus, changes in hearing, and photophobia 1
• The pathophysiology involves compensatory venodilation and downward brain sagging due to CSF volume loss, creating traction on meninges and nerves 1
• If orthostatic features are present (worse when upright, better when lying flat), refer urgently to neurology within 2-4 weeks if self-caring, within 48 hours if requiring help 1

Cervicogenic Headache

• Diagnosed when headache is provoked by cervical movement rather than posture, with reduced cervical range of motion and myofascial tenderness 1
• The whole-head distribution with nape involvement fits this pattern, particularly if pain worsens with neck movement 1
• Examine for cervical pathology, reduced range of motion, and trigger points in cervical musculature 1

Tension-Type Headache

• Presents with bilateral pressing/tightening quality, mild to moderate intensity, not aggravated by routine activity 1
• Lacks nausea/vomiting and photophobia/phonophobia (though may have one or the other) 1
• The whole-head distribution fits, but descending pattern to nape is less typical 1

Migraine (Less Likely But Must Exclude)

• While typically unilateral, migraine can present with bilateral whole-head pain 1
• Key distinguishing features: throbbing quality, moderate-severe intensity, worsening with routine activity, accompanied by nausea/vomiting and/or photophobia/phonophobia 1
• The face and descending nape involvement is atypical for migraine 1

Critical Red Flags Requiring Immediate Evaluation

Assess immediately for these life-threatening causes:

• Thunderclap onset (sudden severe headache): suggests subarachnoid hemorrhage, requires non-contrast CT head immediately 1, 2
• Fever with neck stiffness: suggests meningitis, requires immediate evaluation and lumbar puncture 1, 2
• Focal neurological signs: suggests stroke, tumor, or increased intracranial pressure 1, 2
• Age ≥50 years with new-onset headache: consider giant cell arteritis (check ESR/CRP) or space-occupying lesion 2, 3
• Headache awakening from sleep or worsening with Valsalva/cough: suggests increased intracranial pressure 2, 3
• Progressive worsening over time: suggests secondary cause requiring neuroimaging 2, 4

Diagnostic Approach

History Elements to Clarify

• Orthostatic component: Does headache worsen within 2 hours of standing and improve >50% within 2 hours of lying flat? 1
• Temporal pattern: Sudden vs. gradual onset, constant vs. episodic, duration of episodes 1, 4
• Quality: Pressing/tightening (tension-type), throbbing (migraine), or positional (SIH) 1
• Aggravating factors: Neck movement (cervicogenic), routine activity (migraine), upright posture (SIH) 1
• Associated symptoms: Nausea, photophobia, phonophobia (migraine); autonomic symptoms (cluster); none (tension-type) 1

Physical Examination

• Complete neurological examination including cranial nerves, motor/sensory function, cerebellar testing to rule out secondary causes 2, 4
• Cervical spine examination: range of motion, palpation for tenderness, myofascial trigger points 1
• Fundoscopic examination: check for papilledema suggesting increased intracranial pressure 4
• Vital signs: fever suggests infection; blood pressure abnormalities 4
• Meningeal signs: neck stiffness, Kernig's sign, Brudzinski's sign 1, 2

Neuroimaging Indications

MRI brain is preferred over CT for non-emergent evaluation 1, 4

Obtain neuroimaging if:

• Any red flags present (thunderclap, focal signs, fever, age ≥50 with new headache) 2, 4
• Atypical features not fitting primary headache pattern 1
• Suspected SIH (MRI shows characteristic pachymeningeal enhancement, brain sagging, venous engorgement) 1
• Progressive or changing headache pattern 3, 4

Do NOT obtain neuroimaging for typical primary headache with normal neurological examination 1, 4

Management Based on Diagnosis

If Spontaneous Intracranial Hypotension Suspected

• Refer to neurology urgently (timeframe based on functional status) 1
• Patient should lie flat as much as possible pending evaluation 1
• Specialist center should have capability for epidural blood patch, CT/digital subtraction myelography 1

If Cervicogenic Headache

• Physical therapy focusing on cervical range of motion and posture 1
• NSAIDs for acute pain relief 1
• Address underlying cervical pathology 1

If Tension-Type Headache

• Acute treatment: NSAIDs (aspirin, ibuprofen, naproxen) - acetaminophen alone is ineffective 1
• Preventive treatment if frequent (≥2 attacks/month with ≥3 days disability): consider tricyclic antidepressants 5
• Avoid medication overuse (limit acute treatment to ≤2 days/week) 1

If Migraine Despite Atypical Distribution

• First-line acute treatment: NSAIDs (aspirin, ibuprofen, naproxen, or acetaminophen-aspirin-caffeine combination) 1
• If NSAIDs fail: triptans (contraindicated in uncontrolled hypertension or cardiovascular disease) 1, 6
• Preventive therapy if ≥2 attacks/month with ≥3 days disability: topiramate, beta-blockers, or CGRP antibodies 1, 6

Common Pitfalls to Avoid

• Do not dismiss the descending pattern as benign - this is characteristic of SIH and requires specific evaluation 1
• Do not attribute "sinus headache" to sinusitis - most patients with self-diagnosed sinus headache actually have migraine or tension-type headache 7
• Do not miss medication overuse headache - limit acute medications to ≤2 days/week to prevent transformation 1
• Do not overlook cervicogenic headache - specifically test cervical range of motion and provocation with neck movement 1
• Do not order neuroimaging for typical primary headache with normal examination - this exposes patients to unnecessary radiation and can reveal incidental findings causing alarm 1, 4