This handout is for non-aneurysmal perimesencephalic sah. Your care team identified this based on: thunderclap headache in alert (gcs 15) patient with ct showing pretruncal/perimesencephalic blood pattern [rinkel 1991 pmid 1950905; aha/asa 2023].
Other reasons your team may use this plan: ct showing blood centered around midbrain/pons cisterns (interpeduncular / ambient / quadrigeminal); minimal extension into sylvian/interhemispheric fissures [rinkel 1991]; cta negative for aneurysm in patient with sah on ct — pivot toward perimesencephalic pathway [aha/asa 2023]; initial dsa negative for aneurysm in perimesencephalic pattern — repeat dsa at 1–2 wk standard [aha/asa 2023].
Take these medications exactly as prescribed. Do not stop or change a dose without talking to your provider.
| Medication | Starting dose | How | When | What it does |
|---|---|---|---|---|
| nimodipine | 60 mg PO/NG q4h × 21 days | PO | q4h | BRANT 1989 PMID 2496789 — Class I per AHA/ASA 2023 for all SAH (including perimesencephalic); benefit smaller in perimes but recommended. NEVER IV (FDA boxed warning). |
Plan: Perimesencephalic SAH — nimodipine + BP control + observation (low rebleed/DCI risk; AHA/ASA 2023)
Contact your care team if any of the following happen:
Call 911 or go to the nearest emergency room right away if you have:
Follow-up clinic 4–6 wk; cognitive screen if symptomatic; BP optimisation; family aneurysm screening NOT required; resumption of normal activities once cleared [AHA/ASA 2023]
Guideline: 2023 AHA/ASA aSAH Guideline (Hoh et al, Stroke 2023 PMID 37212182) + 2023 NCS aSAH Management (Treggiari et al, Neurocrit Care 2023 PMID 37202712) + Rinkel 1991 perimesencephalic original phenotype