Case-Series Trajectory Mapper

Design: Systematic review + individual patient data meta-analysis (case reports/series)
Design classification. PRISMA-IPD systematic review pooling 130 individual patients from 101 case reports/series (no comparison group; each patient's clinical course is reconstructed from a published narrative) — Module A (patient-level trajectory mapper) applies, with univariate OR/CI reported per node rather than a formal meta-analytic pooled effect (Almeida et al., PLoS Negl Trop Dis 2025;19(12):e0013789).
Snakebite96.4% Viperidae Ischemic stroken=80/130 (61.5%) — hub Multifocal / MCA territory58-61% multifocal, MCA 23.1% Conservative tx93.1% overall Survival (textbook path)Ischemic death 13/93=13%Motor sequela 28.8% (survivors) Hemorrhagic stroken=50/130 (38.5%) Thrombocytopenia + sepsisOR 3.97 & 6.21 for death Subarachnoid hemorrhageOR 7.00 for death Death (outlier path)30/128 died (23.4%)Hemorrhagic OR 2.67 vs ischemic Autopsy-confirmed fatal outlier cases (n=6, Table 6) 11M, Notechis scutatusMultiple ICH, no infarctionTibballs et al. 1991 [36] 23M, ViperidNon-bacterial thrombotic endocarditisSingh et al. 1998 [38] 59F, Bothrops atroxVenom detected in brain tissueSilva de Oliveira et al. 2017 [88] 53M, Daboia russeliiBilateral renal petechiae + parietal lesionNamal Rathnayaka et al. 2017 [90]
Hub / textbook-path summary

The dominant (hub) trajectory: Viperidae bite → ischemic stroke → multifocal infarct, often MCA territory → conservative management (no surgery) → survival, frequently with motor sequelae (28.8% of ischemic survivors). This path covers roughly 6 in 10 of the 130 patients (Table 1-2, Almeida et al. 2025).

Outlier / divergence summary
NodeWhy notable
Hemorrhagic + subarachnoid hemorrhage branchOnly 38.5% of cases but carries the largest death risk (OR 7.00 for SAH, OR 2.67 for hemorrhagic vs ischemic stroke type) — the clearest divergence point from the survival-favoring ischemic hub.
Thrombocytopenia + sepsis co-occurrenceSepsis alone raised death odds >6-fold (OR 6.21) — a rare (6.2% of cohort) but decisive branch point.
Six autopsy casesEach shows a distinct fatal mechanism (endocarditis, direct venom detection in brain, multi-organ embolic infarcts) rather than one shared cause — true phase-space edges of the case series rather than noise (Table 6).
References

Almeida T, Priante SP, João GP, Nery Oliveira D, Mouta G, Sachett J, et al. Strokes following snakebite envenomations: A systematic review and individual patient data meta-analysis. PLoS Negl Trop Dis. 2025;19(12):e0013789.
[36] Tibballs J, Henning RD, Sutherland SK, Kerr AR. Fatal cerebral haemorrhage after tiger snake (Notechis scutatus) envenomation. Med J Aust. 1991;154(4):275-6.
[38] Singh S, Dass A, Jain S, et al. Fatal non-bacterial thrombotic endocarditis following viperine bite. Intern Med. 1998;37(3):342-4.
[88] Silva de Oliveira S, Freitas-de-Sousa LA, Alves EC, et al. Fatal stroke after Bothrops snakebite in the Amazonas state, Brazil. Toxicon. 2017;138:102-6.
[90] Namal Rathnayaka RMMK, Kularatne SAM, Kumarasinghe KDM, et al. Ischemic brain infarcts and intracranial haemorrhages following Russell's viper bite in Sri Lanka. Toxicon. 2017;125:70-3.