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neuro.rcvs.v1

Reversible Cerebral Vasoconstriction Syndrome (RCVS / Call-Fleming)

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Start encounter →Print handoutPRODUCTION

Lane F id+neuro-acute campaign new-build (2026-05-26). RCVS is the thunderclap-headache differential pivot vs aneurysmal SAH / CVT / PRES with a reversible string-and-beads angiography signature, distinctive avoid-glucocorticoid pharmacology (Singhal Neurology 2017 PMID 27940651 Class II), and a nimodipine-PO-q4h-anchored treatment ladder. PubMed-MCP verification 2026-05-26 — all 6 evidence PMIDs live-verified clean (17200220 Calabrese 2007 Ann Intern Med; 22995694 Ducros 2012 Lancet Neurol; 18025032 Ducros 2007 Brain 67-patient series; 21482916 Singhal 2011 Arch Neurol 139-patient cohort; 27940651 Singhal 2017 Neurology 162-patient steroid-worsening study; 30635475 Rocha 2019 Neurology RCVSscore). No fabrications detected in the evidence list. RxCUI live-verification (RxNav curl 2026-05-26) — CRITICAL FABRICATION CATCH: orchestrator-supplied candidate 7396 resolves to NICARDIPINE (not nimodipine). Substituted with verified 7426 for nimodipine (the correct dihydropyridine CCB for RCVS). All other candidates verified clean: verapamil 11170 ✓, diltiazem 3443 ✓, magnesium sulfate 6585 ✓, acetaminophen 161 ✓, ondansetron 26225 ✓. Registry-id resolution — used `workup.acute_headache` (existing, RCVS-aware per its description), `workup.sah` (existing, for convexity-SAH parallel rule-out), `workup.acute_stroke` (existing, for watershed-infarct parallel management); calculators `calc.clinical_frailty_scale` + `calc.ckd_epi_2021` + `calc.nihss` resolve; panels `panel.cbc / panel.coag / panel.renal / panel.lft / panel.inflammation` all resolve. No `workup.rcvs` or `protocol.rcvs` in clinical-tools-registry at this build — flagged for future depth-pass registry expansion. Settings shipped: ed / inpatient / icu / outpatient / transition (5). Severity triggers: 10 (lobar ICH / extensive ischemic stroke / status / postpartum-eclampsia / glucocorticoid pre-exposure / persistent-vasoconstriction-12wk / PRES-overlay / recurrent-RCVS / paroxysmal-HTN-pheo / ambiguous RCVSscore-3-4). §5.5.2 Bayesian depth-pass NOT performed at this build — RCVSscore sensitivity / specificity bands (≥5 → 99% spec 90% sens; ≤2 → 100% spec 85% sens; Rocha 2019 PMID 30635475) and nimodipine-effect-size derivations flagged as NEEDS_SOURCE_REVIEW for future depth-pass-2.

Entry points (7)

  • symptom
    Recurrent thunderclap headache (peak <1 min, severe, ≥2 episodes over 1-3 wk) — pathognomonic RCVS entry (Ducros Lancet Neurol 2012 PMID 22995694; Ducros Brain 2007 PMID 18025032 — 94% present with multiple thunderclaps)
    recurrent_thunderclap_headache
  • symptom
    Thunderclap headache provoked by Valsalva / sexual activity / exercise / bathing / sympathomimetic drug ingestion (Calabrese Ann Intern Med 2007 PMID 17200220)
    thunderclap_headache_valsalva_trigger
  • symptom
    Thunderclap headache 4-12 wk postpartum — postpartum cerebral angiopathy / RCVS phenotype (Calabrese 2007 PMID 17200220; Ducros 2012 PMID 22995694)
    thunderclap_headache_postpartum
  • imaging
    Multifocal segmental "string-and-beads" cerebral artery vasoconstriction on CTA / MRA / DSA, multiple vascular territories (Calabrese 2007 PMID 17200220; Ducros 2007 PMID 18025032)
    string_and_beads_angiogram
  • imaging
    Convexity (sulcal / cortical) SAH on CT/MRI — RCVS phenotype distinct from aneurysmal SAH cisternal pattern (Ducros 2007 PMID 18025032 — cSAH 22%)
    convexity_subarachnoid_hemorrhage
  • imaging
    Watershed / cortical ischemic stroke on MRI, often during week 2 — RCVS late-phase complication (Ducros 2007 PMID 18025032 — TIAs 16%, infarcts 4% with later time course)
    watershed_ischemic_stroke
  • symptom
    New seizure in the setting of recurrent thunderclap headache (Ducros 2007 PMID 18025032 — seizure 3%; Singhal 2011 PMID 21482916)
    new_seizure_with_thunderclap_history

Required inputs (17)

  • agerequired
    demographic • used at CONTEXT
    Reproductive-to-middle-age predominant; mean 42 y (Singhal Arch Neurol 2011 PMID 21482916; Ducros Brain 2007 PMID 18025032)
  • sex_pregnancy_postpartumrequired
    demographic • used at CONTEXT
    Female 75-81% predominance; postpartum 4-12 wk window is a high-incidence trigger (Singhal 2011 PMID 21482916; Calabrese 2007 PMID 17200220)
  • sbprequired
    vital • used at TREATMENT
    BP control informs treatment — but AVOID hypotension (perfusion-pressure-dependent vasoconstricted territories may infarct on aggressive lowering); also screen for postpartum HTN / eclampsia overlay (Ducros 2012 PMID 22995694)
  • gcsrequired
    vital • used at RED_FLAGS
    Mental-status decline triggers ICU + repeat imaging; catastrophic RCVS with massive edema/ICH is rare but devastating (Ducros 2012 PMID 22995694)
  • ct_or_mri_brainrequired
    imaging • used at INITIAL_WORKUP
    CT/MRI brain to rule SAH / ICH / infarct + look for convexity SAH / watershed infarct / PRES overlay; initial brain imaging normal in 55% (Singhal 2011 PMID 21482916)
  • cta_or_mra_intracranialrequired
    imaging • used at INITIAL_WORKUP
    CTA / MRA / DSA for "string-and-beads" segmental multifocal vasoconstriction — diagnostic anchor (Calabrese 2007 PMID 17200220); MRA may miss early distal-vessel involvement — DSA is gold standard when high suspicion + non-invasive negative
  • mrv_to_exclude_cvt
    imaging • used at BRANCHING_WORKUP
    MRV gradient-echo to exclude CVT in postpartum / OCP / thrombophilia thunderclap-headache patient (Ducros 2012 PMID 22995694; per neuro.cerebral-venous-thrombosis.v1)
  • cbc_with_plateletsrequired
    lab • used at INITIAL_WORKUP
    Baseline + screen for sympathomimetic-drug-induced thrombocytopenia / coagulopathy / postpartum HELLP overlay
  • coag_pt_inr_apttrequired
    lab • used at INITIAL_WORKUP
    Baseline coags pre-LP and to inform anticoagulation contraindication in convexity-SAH or ICH RCVS-complication phenotypes
  • creatininerequired
    lab • used at INITIAL_WORKUP
    Baseline eGFR; nimodipine extensively hepatic-metabolised (not renal-dose-adjusted) but renal panel informs antihypertensive selection / contrast safety
  • lft_alt_ast
    lab • used at INITIAL_WORKUP
    Baseline LFT — nimodipine hepatic metabolism + monitor for hepatic-impairment dose reduction (Ducros 2012 PMID 22995694)
  • urine_drug_screen
    lab • used at CONTEXT
    Cocaine, amphetamine, cannabis, MDMA, ergotamines are major RCVS triggers; Ducros 2007 (PMID 18025032) — 37/67 had vasoactive substance exposure (cannabis, SSRIs, decongestants predominant)
  • bhcg_pregnancy_testrequired
    lab • used at CONTEXT
    Identify postpartum-RCVS phenotype + exclude eclampsia overlay (Ducros 2007 PMID 18025032 — postpartum 5/67)
  • sympathomimetic_serotonergic_exposurerequired
    medication • used at CONTEXT
    SSRIs / SNRIs / triptans / ergots / nasal decongestants / pseudoephedrine / MDMA / cocaine / cannabis / TCAs — DISCONTINUE on RCVS suspicion (Calabrese 2007 PMID 17200220; Singhal 2011 PMID 21482916 — 42% had vasoconstrictive-drug exposure)
  • recent_transfusion_or_immunosuppressant_exposure
    medication • used at CONTEXT
    Erythropoietin, IVIG, tacrolimus, cyclosporine, intra-arterial contrast and recent blood-product transfusion are recognised RCVS triggers (Calabrese 2007 PMID 17200220)
  • prior_migraine_history
    history • used at CONTEXT
    Prior migraine present in ≈40% of RCVS cohorts — but migraine alone does NOT diagnose RCVS and triptan use during RCVS can precipitate strokes (Singhal 2011 PMID 21482916 — 40% prior migraine)
  • pheochromocytoma_or_catecholamine_secreting_tumor
    history • used at BRANCHING_WORKUP
    Catecholamine-secreting tumour (pheochromocytoma / paraganglioma) is a rare but reversible RCVS trigger — screen if hypertensive / paroxysmal symptoms (Calabrese 2007 PMID 17200220)

12-phase flow (12)

  1. 1FRAME
    Adult (or postpartum) patient with recurrent thunderclap headache (or single thunderclap with vasoconstrictive trigger / cortical SAH / watershed infarct); RCVS diagnostic framework requires reversibility on follow-up imaging at 6-12 wk (Calabrese Ann Intern Med 2007 PMID 17200220)
    advance: RCVS clinically suspected on thunderclap-headache phenotype
  2. 2ENTRY
    Recurrent thunderclap headaches over 1-3 wk (94% of Ducros 2007 cohort PMID 18025032) ± Valsalva/sex/exercise/bathing/sympathomimetic trigger ± convexity SAH ± watershed infarct ± seizure — STAT non-contrast CT + CTA / MRA (Calabrese 2007 PMID 17200220)
    inputs: age, sex_pregnancy_postpartum
    advance: RCVS entry trigger captured + initial vascular imaging ordered
  3. 3CONTEXT
    Identify trigger: sympathomimetic / serotonergic drug exposure (SSRIs, triptans, ergots, decongestants, cocaine, cannabis, MDMA); postpartum 4-12 wk; recent transfusion; immunosuppressants (tacrolimus, cyclosporine, IVIG); pheochromocytoma screen if HTN paroxysms (Calabrese 2007 PMID 17200220; Singhal 2011 PMID 21482916; Ducros 2007 PMID 18025032)
    inputs: sympathomimetic_serotonergic_exposure, recent_transfusion_or_immunosuppressant_exposure, bhcg_pregnancy_test, urine_drug_screen, prior_migraine_history
    advance: Substrate / mechanism mapped + offending agents removed
  4. 4RED_FLAGS
    GCS decline, new focal deficit, status epilepticus, malignant cerebral edema, large lobar ICH, basilar / brainstem ischemic stroke → STAT ICU + neurosurgery / neurointerventional (Ducros 2012 PMID 22995694)
    inputs: gcs, cbc_with_platelets
    advance: ICU triage complete; severe-RCVS phenotype documented or excluded
  5. 5INITIAL_WORKUP
    STAT non-contrast CT (rule SAH/ICH) + CTA OR MRA (string-and-beads); CBC + coags + CMP + LFT + urine drug screen + β-hCG; reserve LP for high-suspicion SAH with negative CT (≥6 h pre-LP per Perry Ottawa SAH pathway sibling) (Calabrese 2007 PMID 17200220)
    inputs: ct_or_mri_brain, cta_or_mra_intracranial, cbc_with_platelets, coag_pt_inr_aptt, creatinine, lft_alt_ast, urine_drug_screen
    actions: workup.acute_headache, panel.cbc, panel.coag, panel.renal, panel.lft
    advance: CTA/MRA findings reviewed; SAH/CVT/PRES/PACNS provisionally excluded or pursued
  6. 6BRANCHING_WORKUP
    Negative CT but high suspicion → LP for SAH (xanthochromia / RBC count); MRV to exclude CVT in postpartum / OCP / thrombophilia; DSA if CTA/MRA equivocal (DSA is gold standard for distal segmental beading); ESR/CRP + CSF cell count to screen PACNS (high-pleocytosis suggests vasculitis); pheochromocytoma screen if paroxysmal HTN (Calabrese 2007 PMID 17200220; Rocha 2019 PMID 30635475 — RCVSscore for differentiation)
    inputs: mrv_to_exclude_cvt, pheochromocytoma_or_catecholamine_secreting_tumor
    advance: Definitive vascular imaging + CSF reviewed; RCVS confirmed (RCVSscore ≥5) or alternative entertained
  7. 7DIFFERENTIAL
    RCVS (recurrent thunderclap + reversible multifocal beading + normal CSF) vs aneurysmal SAH (cisternal blood + aneurysm) vs CVT (MRV defect) vs PRES (parenchymal posterior edema — frequent OVERLAP ~10-30%) vs PACNS (insidious onset + CSF pleocytosis + biopsy + NOT reversible) vs intracranial atherosclerosis (older + smooth concentric narrowing) vs fibromuscular dysplasia vs cervical artery dissection vs migraine with prolonged aura (Calabrese 2007 PMID 17200220; Rocha 2019 PMID 30635475)
    advance: RCVS vs PACNS distinguished (RCVSscore ≥5 — 99% specificity); mimics excluded
  8. 8RISK_STRATIFICATION
    Severity drivers: convexity SAH, lobar ICH, posterior-circulation ischemic infarct, status migrainosus/epilepticus, postpartum RCVS, atypical trajectory >12 wk without reversibility, glucocorticoid pre-exposure (Singhal Neurology 2017 PMID 27940651 — glucocorticoids independently predict worsening + poor mRS); severe-RCVS = ICU candidate (Ducros 2012 PMID 22995694)
    inputs: gcs
    actions: calc.clinical_frailty_scale
    advance: Severity tier assigned (mild / moderate / severe)
  9. 9TREATMENT
    Step 1 — REMOVE TRIGGER (stop SSRI/triptan/ergot/decongestant/sympathomimetic). Step 2 — nimodipine 60 mg PO q4h × 4-12 wk first-line (Ducros 2007 PMID 18025032 — 61/67 received nimodipine); alternatives verapamil 240-480 mg/day or diltiazem 240 mg/day. Step 3 — BP control (avoid hypotension — vasoconstricted territories perfusion-pressure-dependent). Step 4 — magnesium IV in postpartum / eclampsia-feature overlay. Step 5 — analgesia with acetaminophen + ondansetron (NO triptans — vasoconstrictors that may precipitate stroke). Step 6 — AED for clinical seizure (levetiracetam 1 g IV + 500-1000 mg q12h; NOT routine prophylaxis). Step 7 — AVOID GLUCOCORTICOIDS (Singhal Neurology 2017 PMID 27940651 Class II — independent predictor of clinical / imaging / angiographic worsening and poor discharge mRS). Step 8 — repeat MRA at 6-12 wk to confirm reversibility (Calabrese 2007 PMID 17200220)
    inputs: sbp, creatinine, lft_alt_ast, bhcg_pregnancy_test
    advance: Trigger removed + nimodipine initiated + steroid contraindication documented + follow-up imaging scheduled
  10. 10DISPOSITION
    Neuro-ICU for severe RCVS (large lobar ICH / extensive watershed infarction / status epilepticus / GCS decline); stroke-unit floor or short ED observation otherwise; ambulatory discharge possible for mild RCVS with reliable follow-up + nimodipine adherence + clear trigger removal (Ducros 2012 PMID 22995694)
    inputs: gcs
    advance: Bed allocated or ambulatory plan documented
  11. 11MONITORING
    Daily neuro-checks during inpatient phase; nimodipine BP / HR monitoring (caution if SBP<120); repeat MRA at 6-12 wk to confirm reversibility (gold-standard diagnostic confirmation per Calabrese 2007 PMID 17200220); headache diary; if late ischemic stroke (typical week 2 timing per Ducros 2007 PMID 18025032) → re-image + escalate
    inputs: sbp
    advance: Monitoring plan documented
  12. 12FOLLOWUP
    Headache clinic / vascular neurology at 6-12 wk for repeat MRA (reversibility = diagnostic gold standard); discontinue nimodipine when angiogram normalises and headache resolves (typically 1-3 mo); LIFELONG avoidance of SSRIs/triptans/sympathomimetics during high-risk windows; counsel re: future-pregnancy postpartum-RCVS recurrence; recurrence ≈5% (Ducros 2012 PMID 22995694; Singhal 2011 PMID 21482916)
    advance: Reversibility confirmed + trigger avoidance plan documented + recurrence counselling complete