I asked

Create a case of a patient with cavernous sinus thrombosis, including all clinical, laboratory, and imaging details, so I can use it to train residents on making the diagnosis.

ChatGPT answered

Below is an unfolding clinical case you can run as a step‑by‑step diagnostic exercise. It’s written so you can hand residents the data in “cards.” The diagnosis is not named in the case text; an educator key with references sits at the end.

Case Title

Fever, “sinus infection,” and a painful eye

Card 1 – Triage note (ED, Day 0 – 10:20 a.m.)

  • Patient: 29‑year‑old woman

  • Chief concerns: 3 days of severe right retro-orbital headache and eyelid swelling; fever since last night; double vision since this morning

  • Context: 8‑day history of “sinusitis” (nasal congestion, purulent rhinorrhea). Took OTC ibuprofen; started leftover amoxicillin 500 mg BID yesterday without relief. Admits she “popped” a painful pimple inside right nostril 4–5 days ago.

  • Past history: Healthy; on oral contraceptive; no diabetes; no recent trauma or surgery

  • Allergies: NKDA

  • Vitals: T 39.1 °C; HR 115; BP 104/66; RR 20; SpO₂ 98% RA

  • Pain: 8/10, worse with eye movement and bending forward

  • Initial orders placed (but results not back): CBC, CMP, ESR, CRP, two sets of blood cultures prior to antibiotics

Card 2 – Focused exam (Day 0 – 10:45 a.m.)

  • General: Ill‑appearing, photophobic

  • Face/Nose: Crusted lesion at right nasal vestibule with surrounding erythema; purulent rhinorrhea; tenderness over right ethmoid/sphenoid region

  • Orbit/Eyelids: Right upper/lower lid edema and erythema; conjunctival chemosis

  • Ocular motility:

    • Right eye (OD): -4 abduction, -3 adduction/elevation, -2 depression (painful)

    • Left eye (OS): Full at this time

  • Ptosis: Partial on the right

  • Sensation: Decreased pinprick/light touch in right V1 (supraorbital/supratrochlear) and V2 (infraorbital) distributions; corneal reflex absent OD

  • Auscultation over orbit: No bruit

  • Neuro otherwise: No limb deficits; no meningeal signs

Card 3 – Ophthalmic details (Day 0 – 11:05 a.m.)

  • Visual acuity: OD 20/80 (pinhole 20/60); OS 20/20

  • Pupils: OD 6→5 mm sluggish (relative mydriasis); OS 3→2 mm brisk; no RAPD detected

  • Intraocular pressure (applanation): OD 26 mmHg; OS 14 mmHg

  • Color plates (Ishihara): OD 8/14; OS 14/14

  • Exophthalmometry (Hertel, base 100 mm): OD 21 mm; OS 16 mm (asymmetry 5 mm)

  • Fundus: Venous engorgement OD, mild disc edema (Frisén grade 1) OD; OS normal

Teaching note for facilitator: An asymmetry >2 mm on exophthalmometry is abnormal; typical adult “normal” ranges ~12–21 mm and vary by sex and ethnicity. EyeWiki

Card 4 – Initial labs (Day 0 – 11:40 a.m.)

  • CBC: WBC 19.8 × 10⁹/L (neutrophils 90%), Hgb 13.2 g/dL, Plt 335 × 10⁹/L

  • CMP: Na 132 mmol/L, K 3.8, Cr 0.8 mg/dL, Glucose 108 mg/dL

  • Inflammation: CRP 210 mg/L, ESR 64 mm/h

  • Coag/others: D‑dimer 1,950 ng/mL FEU; lactate 2.0 mmol/L

  • Micro: Two sets blood cultures drawn (pending)

Teaching note: Leukocytosis with high CRP/ESR is common; blood cultures are positive in ~60–70% of septic cases. emergencymed.org.il+1

Card 5 – Non‑contrast CT head & orbits (Day 0 – 12:20 p.m.)

  • Brain: No acute hemorrhage or territorial infarct

  • Paranasal sinuses: Complete opacification of right sphenoid and anterior ethmoid cells with air–fluid level

  • Orbits: Mild right proptosis; preseptal/orbital fat stranding on the right; no subperiosteal abscess seen

Teaching note: Early CT can be non‑diagnostic for cavernous sinus thrombosis (CST); sinus disease plus orbital changes should prompt contrast venography or MRI/MRV. MDPI

Card 6 – Contrast CT venography (Day 0 – 1:05 p.m.)

  • Cavernous sinuses: Asymmetric enlargement of the right cavernous sinus with convex lateral wall; central non‑opacifying filling defect and peripheral enhancement

  • Veins: Right superior ophthalmic vein (SOV) enlarged and poorly opacified; left SOV normal caliber

  • Arteries: Right cavernous ICA flow‑void preserved on this study

  • Paranasal sinuses: As above, with inflamed mucosa

Teaching note: CT venography/MR venography are appropriate to confirm venous sinus thrombosis; engorged or thrombosed SOV is a supportive sign. PubMed+1

Card 7 – MRI brain & orbits with contrast + MRV (Day 0 – 3:40 p.m.)

Sequences & key measurements

  • T1/T2: Right cavernous sinus bulky with loss of normal flow void; heterogeneous T1/T2 signal

  • Post‑contrast T1: Peripheral dural enhancement of the right cavernous sinus with a central non‑enhancing thrombus; subtle dural enhancement at the right orbital apex

  • DWI/ADC: Restricted diffusion within the right cavernous sinus and a segment of the right SOV

  • MRV (contrast‑enhanced): Non‑opacification of the right cavernous sinus; left cavernous sinus opacifies

  • SOV diameter (coronal): Right 5.1 mm; left 2.2 mm

  • Cavernous sinus maximal coronal diameter: Right 11.8 mm; left 6.4 mm

  • Cavernous ICA flow‑void diameter: Right 3.7 mm (slightly narrowed); left 4.9 mm

  • Sinuses: Marked mucosal disease in right sphenoid/ethmoid with air–fluid level; no intracranial abscess

Teaching notes & evidence anchors: Loss of flow void, bulging/convex lateral wall with peripheral enhancement and central filling defect are classic MRI features. SOV dilation ≥2.9–3.0 mm and cavernous sinus diameter ≥10 mm support CST; diffusion restriction can appear in acute intravascular thrombus. PubMed+3PubMed+3AJR Online+3
Normal SOV mean diameter is ~2 mm; values ≥2.5–3 mm are often used as abnormal cutoffs. Radiopaedia+1

Card 8 – Course check (Day 0 – 8:10 p.m.)

  • New finding: Left CN VI palsy (–2 abduction), otherwise left eye remains normal

  • Right eye: Motility deficits persist; pain improved slightly after analgesia

Teaching note: Spread to the contralateral eye within 24–48 h is characteristic due to intercavernous connections; VI palsy is frequently observed. JAMA Network

Card 9 – Microbiology (Day 1 – 10:30 a.m.)

  • Blood cultures (2/2 sets): Methicillin‑resistant Staphylococcus aureus (MRSA); PBP2a/mecA positive

  • Nasal vestibule culture: S. aureus (same susceptibility pattern)

  • MRSA susceptibilities: Sensitive to vancomycin, linezolid, daptomycin; resistant to oxacillin, clindamycin (D‑test positive)

Teaching note: S. aureus (often MRSA) is the most frequent pathogen in septic CST; streptococci, oral anaerobes and Gram‑negative bacilli are also reported—especially with sinus or dental sources. NCBI+2ScienceDirect+2

Card 10 – Optional tests (release only if residents ask)

  • Lumbar puncture: Deferred initially because imaging already confirmed venous sinus thrombosis and there were no meningitic signs

  • Thrombophilia panel: Not sent acutely (no prior thrombosis; clear septic trigger)

What you should hear from residents (diagnostic reasoning prompts)

  • The constellation of fever, sinus/vestibular infection, painful ophthalmoplegia, V1/V2 sensory loss/corneal areflexia, proptosis/chemosis, and rapid spread to the fellow eye should trigger suspicion for cavernous‑sinus pathology. Imaging then confirms cavernous sinus thrombosis with SOV involvement. NCBI+1

  • Labs support sepsis but do not rule in/out CST; blood cultures help guide therapy. emergencymed.org.il

  • Best first imaging when available is contrast‑enhanced MRI/MRV; CT/CTV is acceptable if MRI is not readily available. Radiopaedia

Compact differential (useful during the discussion)

Condition Clues for / against Orbital cellulitis: Fever, Orbital cellulitis. Fever, lid edema, and pain, but classically lacks V1/V2 sensory loss and multi‑CN palsies; venous sinus findings are absent on MRV/CTV.Carotid–cavernous fistulaPulsatile bruit, corkscrew conjunctival vessels, elevated IOP, enlarged SOV with arterialized flow, not a filling defect; often subacute after trauma.Tolosa–Hunt (idiopathic orbital apex/cavernous inflammation)Painful ophthalmoplegia; typically steroid‑responsive; no septic source, normal labs/cultures; MRI shows inflammation but no venous filling defect.Pituitary apoplexy/parasellar tumorAcute headache/ophthalmoplegia possible; endocrine findings; mass on MRI, not venous thrombus.Invasive fungal sinusitis (mucor/aspergillus)Immunocompromised/diabetic ketoacidosis; black eschar, necrotic turbinates; MRI may show “black turbinate” sign; can cause CST as a complication.

(Evidence for patterns and imaging distinctions above: NCBI+1)

Educator key (do not hand to learners)

Working diagnosis: Septic cavernous sinus thrombosis (right‑sided) with thrombosed/enlarged right superior ophthalmic vein, secondary to right sphenoid/ethmoid sinusitis and manipulated nasal vestibular furuncle; early contralateral spread (CN VI).
Microbiology: MRSA bacteremia fits epidemiology of septic CST (S. aureus often predominant). NCBI+1

Why the data point that way

  • The clinical tetrad: fever, painful ophthalmoplegia (III/IV/VI), V1/V2 sensory loss/corneal areflexia, and orbital signs (proptosis/chemosis) + rapid bilateral progression. NCBI+1

  • MRI/MRV hallmarks: enlarged cavernous sinus with bulging convex lateral wall, peripheral enhancement with central non‑enhancing thrombus, loss of flow void, SOV thrombosis/dilation, and absent cavernous‑sinus opacification on MRV; diffusion restriction can be seen acutely. Objective thresholds (helpful for teaching): CS diameter ≥10 mm, SOV diameter ≥2.9–3.0 mm, cavernous ICA flow‑void ≤4.2 mm. PubMed+1

  • Labs support sepsis (leukocytosis, high CRP/ESR); blood cultures positive in up to ~70%. emergencymed.org.il+1

If management comes up (optional teaching sidebar)

  • Start empiric IV antibiotics urgently after cultures; cover MRSA, streptococci, Gram‑negatives, and anaerobes. Typical duration 3–4 weeks IV; tailor to cultures and source control (e.g., ENT drainage). Medscape

  • Anticoagulation in septic CST remains controversial but is often considered unless contraindicated; evidence base suggests possible benefit and reasonable safety in selected cases. Medscape+2PubMed+2

Selected, high‑yield references for your facilitator notes

  • StatPearls: Cavernous Sinus Thrombosis (clinical features, pathogens). NCBI

  • StatPearls: Cavernous Sinus Syndromes (neuro‑oph findings & differential). NCBI

  • MR imaging of cavernous sinus thrombosis (diagnostic MRI criteria; numeric cutoffs). PubMed

  • Radiopaedia/EyeWiki on SOV size & venous signs. Radiopaedia+1

  • Classic review on bilateral progression within 24–48 h. JAMA Network

  • Medscape Treatment & Workup (duration of antibiotics; AC controversy). Medscape+1

Printing/Running Tips (optional)

  • Hand out Cards 1–4 together; pause for differential and first‑line tests.

  • Release Card 5 (non‑contrast CT) if they ordered CT first, otherwise skip to Card 6/7 if they request CTV or MRI/MRV.

  • Use Card 8 to test whether learners anticipate contralateral involvement.

  • Close with Card 9 (cultures) to anchor the septic etiology.

If you want this adapted into a one‑page PDF or a slide deck with “click‑to‑reveal” cards, I can package it.

I said:

Can you provide me with images that would be similar to your descriptions?

ChatGPT said:

Request for GPT-5 Pro

Reasoned for 8m 30s

Here are four solid, representative images you can show alongside the case. Use them as “spot the signs” prompts—ask residents to name what they see before you reveal the label.

What to notice (quick cues for you):

  1. Post‑contrast MRI of the cavernous sinus — peripheral dural enhancement with a central non‑enhancing filling defect; convex/bulging lateral wall. Classic for CST.

  2. Axial orbital MRI — enlarged, thrombosed superior ophthalmic vein (SOV) on the involved side; supportive sign that pairs with CST.

  3. Axial CT — dilated/hyperdense SOV with concurrent pansinusitis; good for linking sinus source → orbital venous congestion.

  4. MR venography (TOF MRV) — absent flow signal in the cavernous sinus (non‑opacification) that lines up with the clinical picture.

How to run them with your case

  • Before showing #1, ask: “What specific MRI findings would make you call CST?” Then reveal the peripheral enhancement + central defect.

  • With #2, have learners trace the SOV and estimate its caliber; ask what else (IOP, chemosis) should co‑travel clinically.

  • For #3, tie the sinus disease to mechanism; ask when CT alone is insufficient and why you’d escalate to MRI/MRV.

  • End on #4 and ask them to name two pitfalls of TOF MRV and when they’d prefer contrast‑enhanced MRV.

Licensing note: these images live on their publishers’ sites; for teaching, link/credit the source on your slide. For anything beyond classroom use, check the site’s permission terms first.