12-phase flow (12)

1. 1FRAME
   Acute encephalopathy with parieto-occipital vasogenic edema; recognise trigger-removal-reversibility paradigm and avoid BP-overcorrection ischemic risk (Fugate Lancet Neurol 2015 PMID 26184985)
   advance: PRES suspected on syndromic + imaging grounds
2. 2ENTRY
   Headache + altered mental status + visual disturbance + seizures (often severe HTN OR drug trigger OR eclampsia) → STAT MRI brain FLAIR/DWI (Hinchey NEJM 1996 PMID 8559202; Fugate Lancet Neurol 2015 PMID 26184985)
   inputs: age, sex_pregnancy_postpartum, sbp, dbp
   advance: Clinical syndrome + STAT imaging ordered
3. 3CONTEXT
   Trigger identification: severe HTN, calcineurin inhibitor (cyclosporine/tacrolimus), chemotherapy (bevacizumab/sorafenib/sunitinib/oxaliplatin/cisplatin), eclampsia, autoimmune flare, transplant rejection, hypocalcemia/hypomagnesemia, sepsis, HUS/TTP, blood transfusion (Fugate Lancet Neurol 2015 PMID 26184985; Triplett Pract Neurol 2022 PMID 35046115)
   inputs: calcineurin_inhibitor_or_chemo_exposure, bhcg_pregnancy_test, autoimmune_flare_history, kidney_transplant_rejection, sepsis_or_active_infection
   advance: Trigger / substrate captured
4. 4RED_FLAGS
   Status epilepticus, GCS<13, cerebral hemorrhage, cytotoxic-PRES (DWI restriction), brainstem involvement, refractory severe HTN, eclampsia overlay → ICU + neurosurgery / OB consult (Fugate Lancet Neurol 2015 PMID 26184985)
   inputs: gcs
   advance: ICU triage + airway plan documented
5. 5INITIAL_WORKUP
   STAT MRI brain FLAIR/DWI (parieto-occipital vasogenic edema classic; cytotoxic restriction = worse prognosis); CBC, CMP (Ca/Mg), LFT, coags, β-hCG, MRV/CTV to exclude CVT (Bartynski AJNR 2008 PMID 18403560; Fugate Lancet Neurol 2015 PMID 26184985)
   inputs: mri_brain_FLAIR_DWI, cbc_with_platelets, cmp_renal_electrolytes, lft, coag_pt_inr_aptt, mrv_or_ctv_exclude_CVT
   actions: workup.encephalopathy, panel.cbc, panel.lft, panel.renal, panel.coag
   advance: Imaging confirms vasogenic edema; biochemical triggers screened
6. 6BRANCHING_WORKUP
   EEG (NCSE rule-out if AMS persists post-seizure); LP if encephalitis still on differential; ADAMTS13 + schistocytes if TMA suspected; autoimmune panel if flare phenotype (Fugate Lancet Neurol 2015 PMID 26184985)
   actions: workup.first_seizure
   advance: Mimics + secondary triggers excluded
7. 7DIFFERENTIAL
   PRES vs cerebral venous thrombosis (MRV defect) vs RCVS (thunderclap + vasospasm beading on CTA) vs top-of-basilar stroke (DWI restriction in arterial territory) vs autoimmune encephalitis (CSF NMDAR/LGI1) vs HSV encephalitis (CSF HSV PCR; bilateral temporal) vs CNS vasculitis vs hypoglycemia vs drug intoxication (Fugate Lancet Neurol 2015 PMID 26184985)
   advance: PRES confirmed + mimics excluded
8. 8RISK_STRATIFICATION
   Severity tier: status epilepticus, GCS<13, cytotoxic-PRES on DWI, brainstem / atypical imaging, refractory HTN, intracranial hemorrhage complication, eclampsia (Triplett Pract Neurol 2022 PMID 35046115)
   inputs: gcs
   advance: Severity tier assigned
9. 9TREATMENT
   Step 1 — Identify + remove trigger (halt offending chemo / immunosuppressant; switch CNI → mTOR e.g. sirolimus/everolimus); Step 2 — BP control with nicardipine 5-15 mg/h IV titrate OR labetalol 20 mg IV bolus q10min → infusion; target SBP 140-150 first 24h, AVOID over-correction + AVOID nitroprusside (intracranial steal); Step 3 — Seizure management with levetiracetam 1500 mg IV load → 1000 mg q12h; second-line fosphenytoin/phenytoin (avoid in hepatic dysfunction); benzodiazepines for status; Step 4 — Eclampsia overlay → MgSO4 4-6 g IV load → 1-2 g/h × 24h post-delivery + deliver; Step 5 — NO routine corticosteroids; Step 6 — Plasmapheresis if HUS/TTP-driven; Step 7 — ICU monitoring + airway if status / GCS<13 / hemorrhage (Fugate Lancet Neurol 2015 PMID 26184985; Triplett Pract Neurol 2022 PMID 35046115; Hinchey NEJM 1996 PMID 8559202)
   inputs: sbp, dbp, cmp_renal_electrolytes, bhcg_pregnancy_test
   actions: protocol.ich
   advance: Trigger removed + BP controlled + AED started if seizure
10. 10DISPOSITION
    Neuro-ICU if status epilepticus, GCS<13, cytotoxic-PRES, hemorrhage, refractory HTN, eclampsia; floor neuro-checks otherwise (Fugate Lancet Neurol 2015 PMID 26184985)
    inputs: gcs
    advance: Bed level allocated
11. 11MONITORING
    Hourly BP early; daily neuro exam; serial Ca/Mg/Cr; cEEG if AMS persists; repeat MRI at 1-3 mo to confirm edema resolution (radiologic confirmation of diagnosis) (Bartynski AJNR 2008 PMID 18403560; Fugate Lancet Neurol 2015 PMID 26184985)
    advance: Monitoring plan documented
12. 12FOLLOWUP
    Neurology clinic 4-6 wk; repeat MRI 1-3 mo for resolution; long-term recurrence prevention (BP control if HTN-PRES, avoid CNI re-challenge or use mTOR alternative, avoid future bevacizumab if oncology-PRES, pre-pregnancy counselling if eclampsia-PRES); AED duration 3-12 mo per seizure recurrence + EEG; mood / cognition screen — post-PRES cognitive deficits described in cytotoxic variant (Triplett Pract Neurol 2022 PMID 35046115; Fischer/Schmutzhard J Neurol 2017 PMID 28054130)
    advance: Long-term anti-trigger plan documented