DiagnosticTree/FrontalHeadache
{
"tree_id": "frontal-headache", "region": "Frontal Headache", "start": "rom-1",
"redflags": {
"emergency": [
{
"id": "rf-e1",
"label": "Thunderclap headache — subarachnoid haemorrhage",
"question": "Did this headache reach maximum severity within seconds to minutes — described as 'the worst headache of my life'?",
"rationale": "Sudden-onset severe headache is the cardinal symptom of subarachnoid haemorrhage until proven otherwise",
"action": "Call emergency services immediately. Do not proceed."
},
{
"id": "rf-e2",
"label": "Raised intracranial pressure",
"question": "Is the headache worse on waking, accompanied by vomiting, or associated with progressive neurological deficits (visual field loss, diplopia, limb weakness)?",
"rationale": "Morning headache with vomiting and neurological signs suggests raised ICP — space-occupying lesion must be excluded",
"action": "Emergency referral. Do not proceed."
},
{
"id": "rf-e3",
"label": "Meningitis / encephalitis",
"question": "Is there fever, photophobia, neck stiffness, or non-blanching rash?",
"rationale": "Meningism requires immediate medical assessment",
"action": "Call emergency services immediately. Do not proceed."
}
],
"urgent": [
{
"id": "rf-u1",
"label": "Temporal arteritis (Giant cell arteritis)",
"question": "Is the patient aged 50+ with scalp tenderness, jaw claudication (jaw pain that builds with chewing then eases with rest), or visual symptoms such as transient vision loss?",
"rationale": "Temporal arteritis can cause irreversible blindness within hours of visual symptoms. Same-day investigation required.",
"action": "Same-day GP referral + ESR and CRP. Do not delay for further myofascial assessment."
},
{
"id": "rf-u2",
"label": "Acute angle-closure glaucoma",
"question": "Is there sudden severe unilateral eye pain, blurred vision, halos around lights, or a fixed mid-dilated pupil?",
"rationale": "Acute angle-closure glaucoma produces severe frontal and orbital pain and can cause irreversible vision loss within hours",
"action": "Emergency ophthalmology referral. Do not proceed."
},
{
"id": "rf-u3",
"label": "Cervical instability",
"question": "Is there a history of significant head or neck trauma combined with upper cervical pain, arm symptoms, or gait disturbance?",
"rationale": "Cervical instability or fracture can refer pain to the frontal region and must be excluded before any cervical assessment",
"action": "Urgent spinal assessment — no manual therapy until cleared."
}
]
},
"nodes": {
"rom-1": {
"type": "rom",
"question": "Is the frontal headache aggravated, altered, or consistently reproduced by neck movements — rotation, flexion, or sustained postures such as looking down?",
"movement": "Cervical rotation / flexion / sustained posture",
"direction": "aggravating",
"clinical_rationale": "Neck movement implicates cervical muscles (SCM, semispinalis capitis). Absence of neck aggravation with frontal pain points toward facial muscles (frontalis, zygomaticus major) or non-myofascial sources.",
"muscles_implicated": ["SCM (Clavicular head)", "SCM (Sternal head)", "Semispinalis Capitis"],
"muscles_excluded": ["Frontalis", "Zygomaticus Major"],
"yes": "symptom-1",
"no": "rom-2"
},
"symptom-1": {
"type": "symptom",
"question": "Is there postural dizziness, spatial disorientation, unsteadiness when walking, or a veering to one side — independent of any ear symptoms?",
"symptom_name": "Postural dizziness / disequilibrium",
"clinical_rationale": "Postural dizziness without nystagmus or Romberg positivity is the hallmark of SCM clavicular division TrPs. It does not occur with SCM sternal or semispinalis capitis TrPs.",
"muscles_implicated": ["SCM (Clavicular head)"],
"muscles_excluded": ["SCM (Sternal head)", "Semispinalis Capitis"],
"yes": "exam-scm-clav-1",
"no": "symptom-2"
},
"symptom-2": {
"type": "symptom",
"question": "Is there ipsilateral tearing, eye redness, apparent drooping of the eyelid, or a persistent dry tingling cough — on the same side as the headache?",
"symptom_name": "Autonomic features — tearing / rhinitis / palpebral ptosis / cough",
"clinical_rationale": "These autonomic phenomena are characteristic of SCM sternal division TrPs. The sternal division refers to cheek, orbit, occiput, and vertex; the clavicular division does not produce these autonomic features.",
"muscles_implicated": ["SCM (Sternal head)"],
"muscles_excluded": ["Semispinalis Capitis"],
"yes": "exam-scm-sternal-1",
"no": "rom-3"
},
"rom-3": {
"type": "rom",
"question": "Is there significant posterior head or occipital pain accompanying the frontal headache — i.e. pain that wraps from the back of the head through to the forehead?",
"movement": "Posterior head / occipital component",
"direction": "location",
"clinical_rationale": "Semispinalis capitis TrPs refer from the occipital region through the cranium to the forehead. The pain wraps around the head rather than originating in the frontal region. SCM sternal division also refers to the occiput but with the autonomic features screened above.",
"muscles_implicated": ["Semispinalis Capitis"],
"muscles_excluded": ["SCM (Clavicular head)", "SCM (Sternal head)"],
"yes": "exam-semispinalis-1",
"no": "exam-scm-clav-1"
},
"exam-scm-clav-1": {
"type": "examination",
"question": "Does flat palpation of the clavicular head of the SCM — from the medial clavicle upward toward the mastoid — reproduce the patient's frontal headache or dizziness?",
"exam_type": "palpation",
"landmark": "Clavicular head: lies deep and posterior to the sternal head. Palpate with flat pressure from the medial third of the clavicle upward toward the mastoid. TrPs typically found in the mid-belly.",
"positive_finding": "Reproduces frontal headache, or provokes or worsens dizziness / spatial disorientation",
"muscles_implicated": ["SCM (Clavicular head)"],
"yes": "result-scm-clavicular",
"no": "result-overlap"
},
"exam-scm-sternal-1": {
"type": "examination",
"question": "Does pincer palpation of the sternal head of the SCM reproduce the patient's facial pain, orbital pain, or familiar headache — or does pressing the central muscle belly reproduce a sore throat on swallowing?",
"exam_type": "palpation",
"landmark": "Sternal head: encircle the muscle belly between thumb and forefinger from mastoid to sternum. For the sore throat test (SCM Compression Test): grasp the SCM firmly in a pincer grip and ask the patient to swallow — positive if throat pain resolves with compression.",
"positive_finding": "Reproduces facial pain, orbital pain, or sore throat resolves with SCM compression",
"muscles_implicated": ["SCM (Sternal head)"],
"yes": "result-scm-sternal",
"no": "result-overlap"
},
"exam-semispinalis-1": {
"type": "examination",
"question": "Does deep flat palpation of the posterior neck muscles — midway between the midline and the mastoid, at the level of C1–C2 — reproduce the patient's head pain or refer pain through the cranium toward the forehead?",
"exam_type": "palpation",
"landmark": "Semispinalis capitis: deep posterior cervical muscle. Palpate approximately 2–3 cm lateral to the midline at the level of C1–C2, pressing firmly against the cervical laminae. TrPs are deep and may require sustained pressure.",
"positive_finding": "Reproduces occipital-to-frontal wrap-around head pain, or localised occipital tenderness with frontal referral",
"muscles_implicated": ["Semispinalis Capitis"],
"yes": "result-semispinalis",
"no": "result-overlap"
},
"rom-2": {
"type": "rom",
"question": "Is jaw opening restricted — less than approximately 40 mm between the upper and lower incisors — or is there pain along the side of the nose or cheek accompanying the frontal headache?",
"movement": "Jaw opening / nasal arc pain",
"direction": "aggravating",
"clinical_rationale": "Zygomaticus major TrPs refer pain in an arc from the cheek along the lateral nose to the mid-forehead. TrP tightness can restrict jaw opening by 10–20 mm. This distinguishes zygomaticus major from frontalis, which refers locally over the forehead only.",
"muscles_implicated": ["Zygomaticus Major"],
"muscles_excluded": ["Frontalis"],
"yes": "exam-zygomaticus-1",
"no": "exam-frontalis-1"
},
"exam-zygomaticus-1": {
"type": "examination",
"question": "Does pincer palpation of the zygomaticus major — with one gloved digit inside the cheek and one outside, running from the zygomatic bone toward the angle of the mouth — reproduce the patient's pain or refer pain upward along the nose toward the forehead?",
"exam_type": "palpation",
"landmark": "Zygomaticus major: patient supine or seated with jaws comfortably propped open. Pincer palpation from zygomatic bone (origin) toward corner of mouth (insertion). Taut band is palpable chiefly by the outside finger.",
"positive_finding": "Reproduces cheek-to-nasal-arc-to-forehead pain pattern, or spot tenderness in a taut band",
"muscles_implicated": ["Zygomaticus Major"],
"yes": "result-zygomaticus",
"no": "exam-frontalis-1"
},
"exam-frontalis-1": {
"type": "examination",
"question": "Does flat palpation above the medial end of the eyebrow — pressing the fingertip crosswise over the frontalis muscle fibres against the underlying frontal bone — reproduce the patient's forehead pain?",
"exam_type": "palpation",
"landmark": "Frontalis: flat palpation against the frontal bone, above the medial end of the eyebrow. Press firmly and run the fingertip crosswise over the thin, superficial muscle fibres. The TrP is a spot of focal tenderness in a taut band.",
"positive_finding": "Reproduces localised forehead pain spreading upward and over the ipsilateral forehead",
"muscles_implicated": ["Frontalis"],
"yes": "result-frontalis",
"no": "result-overlap"
},
"result-scm-clavicular": {
"type": "result",
"diagnosis": "SCM — Clavicular Division Trigger Point",
"confidence": "high",
"wiki_page": "Muscle:Sternocleidomastoid",
"chapter_ref": "Travell & Simons Vol.1 — Ch.7 Sternocleidomastoid",
"notes": "The clavicular division produces three dominant presentations, any one of which may predominate: (1) ipsilateral frontal headache — commonly mistaken for tension or sinus headache; (2) postural dizziness and disequilibrium — veers toward the TrP side on straight-line walking; (3) dysmetria — same object feels heavier when held on the unaffected side. In rare cases, hearing may be impaired on the same side.",
"treatment_hint": "Correct forward head posture first — the single most important perpetuating factor. Flat palpation of the clavicular head from medial clavicle upward. Spray and stretch (superior to inferior), ischemic compression. Treating SCM often resolves satellite TrPs (frontalis, orbicularis oculi) without direct treatment.",
"also_consider": ["Scalene muscles", "Splenius cervicis", "Semispinalis capitis"],
"less_likely": [
{ "muscle": "SCM Sternal Division", "reason": "Autonomic features (tearing, rhinitis, palpebral fissure narrowing) absent" },
{ "muscle": "Semispinalis Capitis", "reason": "No posterior head wrap-around pain" },
{ "muscle": "Frontalis", "reason": "Frontalis TrPs are satellites of clavicular division — treat SCM first" },
{ "muscle": "Zygomaticus Major", "reason": "No jaw restriction or nasal arc pain" }
],
"confirmatory": [
"Straight-line walking test — patient veers toward the side of active clavicular TrP while walking toward a fixed point",
"Romberg's sign is NEGATIVE — distinguishes from vestibular pathology",
"Nystagmus absent — presence of nystagmus indicates vestibular pathology, not myofascial",
"Dysmetria test — same object may feel heavier when held on the unaffected side",
"Hearing restoration manoeuvre — rotate head toward affected side and tilt chin down; any hearing change confirms clavicular division involvement"
],
"satellite_trps": ["Frontalis", "Orbicularis oculi", "Scalene muscles", "Sternalis", "Pectoralis major"],
"landing_page_topics": [
"Full dizziness differentiation protocol — Romberg, nystagmus, straight-line walking",
"Neurological screen — postural BP, carotid auscultation",
"Hearing restoration manoeuvre",
"Dysmetria — weight perception test",
"Forward head posture correction — axial extension exercise",
"Sleep posture and workstation setup"
],
"related_pages": [
{ "label": "Scalene TrPs →", "page": "Muscle:Scalene" },
{ "label": "Frontalis TrP →", "page": "Muscle:Frontalis" }
]
},
"result-scm-sternal": {
"type": "result",
"diagnosis": "SCM — Sternal Division Trigger Point",
"confidence": "high",
"wiki_page": "Muscle:Sternocleidomastoid",
"chapter_ref": "Travell & Simons Vol.1 — Ch.7 Sternocleidomastoid",
"notes": "The sternal division refers to cheek, temple, supraorbital ridge, occiput, and vertex. The autonomic phenomena (tearing, conjunctival redness, rhinitis, palpebral fissure narrowing) are often more alarming to the patient than the pain itself. A dry tingling cough TrP near the sternal attachment and sore throat on swallowing (resolved by SCM compression) are pathognomonic of central sternal division involvement. The forehead and orbital pain pattern is frequently diagnosed as sinusitis, tension headache, or trigeminal neuralgia.",
"treatment_hint": "Pincer palpation of the sternal head. Spray and stretch (superior to inferior). Correct forward head posture — essential for lasting relief. Address satellite TrPs only after SCM TrPs are resolved.",
"also_consider": ["SCM Clavicular Division", "Scalene muscles", "Splenius capitis"],
"less_likely": [
{ "muscle": "SCM Clavicular Division", "reason": "Autonomic features present — more consistent with sternal division" },
{ "muscle": "Semispinalis Capitis", "reason": "Autonomic features and orbital referral absent in semispinalis" },
{ "muscle": "Frontalis", "reason": "Frontalis TrPs are satellites of sternal division — treat SCM first" },
{ "muscle": "Zygomaticus Major", "reason": "No jaw restriction or nasal arc pain" }
],
"confirmatory": [
"SCM Compression Test positive — pharyngeal pain resolves when sternal head is compressed in a pincer grip during swallowing",
"Apparent ptosis (palpebral fissure narrowing) without miosis or enophthalmos — excludes true Horner syndrome",
"Autonomic phenomena ipsilateral to TrP — tearing, rhinitis, conjunctival redness",
"Visual symptom: venetian blinds / window frame phenomenon — contrast sensitivity disturbance distinct from blurred or double vision",
"Dry tingling cough triggered by palpation near sternal attachment"
],
"satellite_trps": ["Scalene muscles", "Sternalis", "Pectoralis major", "Orbicularis oculi", "Frontalis", "Zygomaticus Major"],
"landing_page_topics": [
"Full sternal vs clavicular division comparison",
"Horner syndrome exclusion protocol",
"SCM Compression Test technique",
"Autonomic phenomena — differential from true neurological signs",
"CN XI entrapment and trapezius weakness"
],
"related_pages": [
{ "label": "Scalene TrPs →", "page": "Muscle:Scalene" },
{ "label": "Zygomaticus Major TrP →", "page": "Muscle:Zygomaticus_Major" }
]
},
"result-semispinalis": {
"type": "result",
"diagnosis": "Semispinalis Capitis Trigger Point",
"confidence": "high",
"wiki_page": "Muscle:Semispinalis_Capitis",
"chapter_ref": "Travell & Simons Vol.1 — Ch.16 Semispinalis Capitis",
"notes": "TrPs in the semispinalis capitis refer pain diffusely over the back of the head and through the cranium, producing an intense ache or pressure deep in the forehead and behind the eye. The pain wraps around the head from occiput to frontal region. Greater occipital nerve entrapment by semispinalis capitis TrP taut bands produces a superficial scalp tingling and hot prickling quality that is distinct from the deep aching referral — patients with nerve entrapment cannot tolerate heat and prefer an ice pack, whereas TrP referral patients find moist heat provides relief.",
"treatment_hint": "Spray and stretch with the neck in flexion. Deep ischemic compression. Address perpetuating forward head posture. Check for satellite TrPs in the occipitalis and splenius capitis.",
"also_consider": ["Occipitalis", "Splenius Capitis", "SCM Sternal Division", "Posterior Digastric"],
"less_likely": [
{ "muscle": "SCM Clavicular Division", "reason": "No postural dizziness; posterior head wrap-around pain more consistent with semispinalis" },
{ "muscle": "SCM Sternal Division", "reason": "No autonomic features; occipital origin of pain argues against sternal division" },
{ "muscle": "Frontalis", "reason": "No neck movement aggravation; pain wraps from occiput rather than originating frontally" },
{ "muscle": "Zygomaticus Major", "reason": "No jaw restriction or nasal arc; no cheek TrP" }
],
"confirmatory": [
"Pain quality distinction — deep aching TrP referral (patient prefers moist heat) versus superficial hot prickling nerve entrapment (patient prefers ice pack)",
"Greater occipital nerve entrapment suspected if pain is superficial, tingling, and heat-intolerant — caused by TrP taut band compressing the nerve",
"TrP located approximately 2–3 cm lateral to the midline at C1–C2 level — deep palpation against the cervical laminae required",
"Sustained neck flexion reproduces or worsens the occipital-to-frontal pain"
],
"satellite_trps": ["Occipitalis", "Splenius Capitis", "Trapezius/Upper"],
"landing_page_topics": [
"Greater occipital nerve entrapment — heat vs cold preference as diagnostic sign",
"Distinction from occipital neuralgia",
"Posterior digastric as co-involved muscle",
"See also Ch.16 for full semispinalis cervicis detail"
],
"related_pages": [
{ "label": "Occipitalis TrP →", "page": "Muscle:Occipitofrontalis" },
{ "label": "Splenius Capitis TrP →", "page": "Muscle:Splenius_Capitis" }
]
},
"result-zygomaticus": {
"type": "result",
"diagnosis": "Zygomaticus Major Trigger Point",
"confidence": "high",
"wiki_page": "Muscle:Zygomaticus_Major",
"chapter_ref": "Travell & Simons Vol.1 — Ch.13 Cutaneous I: Facial Muscles",
"notes": "TrPs refer pain in a curving arc from the cheek along the lateral side of the nose, across the nasal bridge, and up to the mid-forehead. TrP tightness can restrict jaw opening by 10–20 mm — this is reversible on TrP inactivation. Pain is commonly misattributed to sinusitis (nasal arc component) or tension headache (forehead component). Palpebral fissure narrowing may be present — exclude Horner syndrome by confirming normal pupillary reactivity.",
"treatment_hint": "Patient supine, jaws propped open. Pincer palpation and injection (pincer grasp, 25g needle, 0.5% procaine) are more effective than spray and stretch for this muscle — stretch is difficult to achieve adequately. Inactivate SCM and masticatory TrPs as key drivers.",
"also_consider": ["Masseter", "Temporalis", "SCM Sternal Division", "Buccinator"],
"less_likely": [
{ "muscle": "SCM Clavicular Division", "reason": "No dizziness; no neck movement as primary aggravator" },
{ "muscle": "SCM Sternal Division", "reason": "No autonomic features; nasal arc and cheek TrP present" },
{ "muscle": "Semispinalis Capitis", "reason": "No posterior head component; no neck movement aggravation" },
{ "muscle": "Frontalis", "reason": "Pain follows nasal arc rather than remaining local to forehead; jaw restriction present" }
],
"confirmatory": [
"Measure jaw opening — restriction of 10–20 mm below normal (36–44 mm) that improves after TrP inactivation confirms zygomaticus major contribution",
"Pain arc confirmed by palpation — pressing on the mid-muscle belly between zygomatic bone and corner of mouth reproduces the nasal arc and forehead referral",
"Palpebral fissure narrowing without miosis — exclude Horner syndrome",
"Masticatory dysfunction (trismus) present or in history — primary activating mechanism"
],
"satellite_trps": ["Zygomaticus Minor", "Orbicularis Oculi", "Buccinator", "Platysma"],
"landing_page_topics": [
"Jaw opening measurement and re-measurement after TrP release",
"Palpebral fissure narrowing — Horner exclusion",
"Spray and stretch technique with eye protection",
"Injection technique — pincer grasp"
],
"related_pages": [
{ "label": "Buccinator TrP →", "page": "Muscle:Buccinator" },
{ "label": "Masseter TrP →", "page": "Muscle:Masseter" }
]
},
"result-frontalis": {
"type": "result",
"diagnosis": "Frontalis Trigger Point",
"confidence": "high",
"wiki_page": "Muscle:Frontalis",
"chapter_ref": "Travell & Simons Vol.1 — Ch.14 Cutaneous II: Occipitofrontalis",
"notes": "TrPs in the frontalis belly refer pain locally — spreading upward and over the ipsilateral forehead. The referred pain remains in the region of the muscle, similar to the deltoid pattern, and does not radiate to the nose or orbit. Frontalis TrPs are most commonly satellites of TrPs in the clavicular division of the SCM. Active TrPs in the medial half of the frontalis belly can entrap the supraorbital nerve, producing a unilateral frontal headache with a neuritic quality (tingling, burning) rather than the dull aching of TrP referral. Habitual frowning and raised-eyebrow expressions in anxious patients are the dominant perpetuating postural factor.",
"treatment_hint": "Pressure release is the treatment of choice — spray and stretch is unsatisfactory because the frontalis is so difficult to stretch. Deep massage is also effective. Dry needling with acupuncture needle is effective if local twitch response is elicited. Needle: 2.5 cm (1 inch), 24- or 25-gauge, directed across the fibres nearly tangent to the skin. First inactivate SCM clavicular division TrPs — frontalis TrPs often resolve spontaneously.",
"also_consider": ["SCM Clavicular Division", "Occipitalis", "Zygomaticus Major"],
"less_likely": [
{ "muscle": "SCM Clavicular Division", "reason": "Treat SCM clavicular TrPs first — frontalis is typically a satellite; check whether clavicular TrPs are active" },
{ "muscle": "SCM Sternal Division", "reason": "No autonomic features; pain remains local to forehead" },
{ "muscle": "Semispinalis Capitis", "reason": "No posterior head component; no neck movement aggravation" },
{ "muscle": "Zygomaticus Major", "reason": "No nasal arc; no jaw restriction; pain is local to forehead only" }
],
"confirmatory": [
"TrP located above the medial end of the eyebrow — flat palpation against the frontal bone",
"Supraorbital nerve entrapment suspected if pain has a neuritic quality (tingling, burning) rather than dull aching — TrP in medial half of frontalis; relieved by TrP inactivation",
"Habitual frowning or raised-eyebrow posture observed on patient examination",
"SCM clavicular division TrPs active on the same side — confirms satellite relationship; treat SCM first and reassess"
],
"satellite_trps": ["Occipitalis", "SCM Clavicular Division (as key TrP)"],
"landing_page_topics": [
"Supraorbital nerve entrapment — neuritic vs myofascial pain quality",
"Satellite TrP relationship with SCM clavicular division",
"Biofeedback monitoring of frontalis — anxiety and muscle tension",
"Injection technique — tangential needle approach"
],
"related_pages": [
{ "label": "SCM TrP →", "page": "Muscle:Sternocleidomastoid" },
{ "label": "Occipitalis TrP →", "page": "Muscle:Occipitofrontalis" }
]
},
"result-overlap": {
"type": "overlap",
"text": "Findings are inconclusive. Multi-muscle involvement or atypical presentation is likely. Perform a full palpation screen of all muscles in this region.",
"screen_these": [
"SCM — Clavicular head (flat palpation from medial clavicle upward)",
"SCM — Sternal head (pincer palpation full length)",
"Semispinalis capitis (deep flat palpation at C1–C2, 2–3 cm lateral to midline)",
"Frontalis (flat palpation above medial eyebrow against frontal bone)",
"Zygomaticus major (pincer palpation with jaws propped open)"
],
"wiki_page": "Differential:FrontalHeadache"
}
},
"broad_differential": [
{
"id": "bd-1",
"condition": "Tension-type headache",
"confidence": "common",
"mimics": "Bilateral or unilateral frontal pressure — the most common misdiagnosis for frontalis and SCM clavicular TrP headache",
"distinguishing_feature": "Myofascial frontal headache responds to TrP treatment and has identifiable taut bands with spot tenderness. Tension headache is a diagnosis of exclusion — always examine the SCM clavicular division and frontalis before applying this label.",
"action": "Full TrP palpation screen before accepting tension headache diagnosis."
},
{
"id": "bd-2",
"condition": "Sinusitis (maxillary / frontal)",
"confidence": "common",
"mimics": "Frontal and nasal pain from zygomaticus major and SCM sternal TrPs is consistently misdiagnosed as sinusitis",
"distinguishing_feature": "Sinusitis requires fever, purulent nasal discharge, or radiographic sinus opacification. Absence of these features with frontal/nasal pain should prompt TrP examination.",
"action": "Examine zygomaticus major and SCM sternal division before prescribing antibiotics for recurring sinus pain."
},
{
"id": "bd-3",
"condition": "Migraine",
"confidence": "common",
"mimics": "Unilateral frontal/orbital headache from SCM sternal division TrPs closely resembles migraine — especially with the autonomic accompaniments (tearing, rhinitis, light sensitivity)",
"distinguishing_feature": "Classic migraine has prodrome, nausea, photophobia, and phonophobia in combination. Myofascial headache from SCM is postural, reproduced by neck movement and palpation, and lacks nausea and GI symptoms. However, SCM TrPs can trigger genuine migraines in susceptible individuals.",
"action": "Examine SCM in all headache patients. Migraine and myofascial pain frequently co-exist."
},
{
"id": "bd-4",
"condition": "Temporal arteritis (Giant cell arteritis)",
"confidence": "uncommon — but critical",
"mimics": "Temporal and frontal headache in patients over 50",
"distinguishing_feature": "Jaw claudication, scalp tenderness, ESR markedly elevated (often >50 mm/hr). Visual symptoms demand same-day assessment.",
"action": "Same-day GP referral + ESR and CRP in any patient aged 50+ with new frontal or temporal headache."
},
{
"id": "bd-5",
"condition": "Occipital neuralgia",
"confidence": "uncommon",
"mimics": "Wrap-around occipital-to-frontal head pain from semispinalis capitis TrPs",
"distinguishing_feature": "Neuralgic pain is superficial, tingling, hot prickling quality — patient prefers ice pack and cannot tolerate heat. Myofascial TrP referral is deep aching — patient prefers moist heat. Greater occipital nerve block produces temporary relief in true occipital neuralgia.",
"action": "Use heat/cold preference test as bedside screen. Distinguish from greater occipital nerve entrapment by semispinalis capitis TrP bands."
},
{
"id": "bd-6",
"condition": "Acute angle-closure glaucoma",
"confidence": "rare — but emergency",
"mimics": "Severe unilateral frontal and orbital pain",
"distinguishing_feature": "Fixed mid-dilated pupil, decreased visual acuity, nausea, halos around lights. Immediate ophthalmology referral required.",
"action": "Examine pupils in all severe unilateral headache presentations."
},
{
"id": "bd-7",
"condition": "Cervicogenic headache",
"confidence": "common",
"mimics": "Frontal headache referred from upper cervical joints (C0–C2) — overlaps significantly with semispinalis capitis and SCM TrP patterns",
"distinguishing_feature": "Cervicogenic headache is typically unilateral, non-throbbing, with ipsilateral neck stiffness and restricted cervical ROM. Diagnostic cervical nerve block produces temporary headache relief. Myofascial and cervicogenic components frequently coexist.",
"action": "Examine cervical ROM and upper cervical joint tenderness alongside TrP palpation."
},
{
"id": "bd-8",
"condition": "Intracranial space-occupying lesion",
"confidence": "rare — but must be excluded",
"mimics": "Progressive unilateral frontal headache",
"distinguishing_feature": "Headache worse in the morning, worse on Valsalva (coughing, sneezing, straining), progressive neurological deficits, papilloedema.",
"action": "Refer for neuroimaging if headache is progressive, positional (worse lying flat), or accompanied by any neurological signs."
}
]
}