Pterion

Pterion collects what a pediatric neurosurgery team reaches for on call and in clinic: condition summaries, dosing and physiology calculators, decision pathways, grading scores, templates for operative notes and consultations, and a question bank for revision. It is free, needs no account, and opens in any recent browser on a phone or a computer.

Everything listed below is in the current version (v0.3.3). Each calculator shows its formula and the paper it is taken from.

Topics

68 topics in 7 areas. Each topic links to the calculators, pathways and scores that go with it, and lists its references at the end.

Congenital and developmental (20)

• Arachnoid cyst
• Chiari I malformation
• Chiari II malformation
• Congenital dermal sinus tract
• Congenital hydrocephalus
• Craniosynostosis
• Encephalocele
• ETV vs. shunt — decision-making
• Hydrocephalus (overview)
• Lipomyelomeningocele and spinal lipoma
• Myelomeningocele (open spina bifida)
• Positional (deformational) plagiocephaly
• Post-haemorrhagic hydrocephalus of prematurity
• Shunt hardware — valves, catheters, and configurations
• Shunt infection
• Shunt malfunction
• Slit ventricle syndrome
• Spinal dysraphism — overview and classification
• Split cord malformation (diastematomyelia)
• Tethered cord syndrome

Neuro-oncology (11)

• Atypical teratoid / rhabdoid tumour (ATRT)
• Brainstem glioma and diffuse midline glioma H3 K27-altered (DIPG)
• Choroid plexus tumours (papilloma and carcinoma)
• Craniopharyngioma (pediatric)
• Medulloblastoma
• Optic pathway / hypothalamic glioma
• Pediatric CNS tumours — overview and WHO 2021 framework
• Pediatric ependymoma
• Pediatric high-grade glioma
• Pediatric low-grade glioma
• Pilocytic astrocytoma

Trauma (7)

• Abusive head trauma
• Depressed skull fracture
• Growing skull fracture
• Minor head injury in children
• Pediatric spinal trauma
• Pediatric traumatic brain injury (overview)
• Severe pediatric TBI — management

Vascular (7)

• Cavernous malformation (pediatric)
• Moyamoya disease and syndrome in children
• Pediatric arteriovenous malformation
• Pediatric cerebrovascular disease — overview
• Pediatric dural arteriovenous fistula
• Pediatric intracranial aneurysm
• Vein of Galen malformation

Functional and epilepsy surgery (9)

• Corpus callosotomy
• Deep brain stimulation (DBS) in pediatric epilepsy
• Hemispherotomy and hemispherectomy
• Pediatric epilepsy surgery — overview and framework
• Pre-surgical evaluation in pediatric epilepsy
• Resective epilepsy surgery
• Responsive neurostimulation (RNS)
• Stereo-EEG (sEEG) in pediatric epilepsy
• Vagus nerve stimulation (VNS)

Infection (7)

• Pediatric brain abscess
• Pediatric CNS infection — neurosurgical overview
• Pediatric intracranial tuberculoma
• Pediatric neurocysticercosis
• Pediatric subdural empyema
• Pediatric ventriculitis
• Post-operative wound and bone-flap infection

Perioperative and critical care (7)

• Age-appropriate vital signs and thresholds
• Blood management in pediatric neurosurgery
• Hyponatraemia after pediatric neurosurgery — SIADH, CSW, DI
• Perioperative antibiotic prophylaxis in pediatric neurosurgery
• Perioperative fluid management in pediatric neurosurgery
• Perioperative seizure prophylaxis in pediatric neurosurgery
• Postoperative imaging in pediatric neurosurgery

Calculators, pathways and scores

Calculators (15)

• Age-appropriate vital signs — lookup
• Blood loss warranting transfusion (MABL)
• Cerebral perfusion pressure — pediatric target
• Cranial surgery — antibiotic prophylaxis (pediatric)
• CSF volume — pediatric estimate
• Estimated blood volume — pediatric
• EVD — height and drainage target reference
• Free water deficit — pediatric
• Hypertonic saline 3% — pediatric bolus dose
• Levetiracetam — pediatric loading and maintenance
• Maintenance fluid — pediatric (Holliday-Segar)
• Mannitol — pediatric dose
• Phenytoin — pediatric loading and maintenance
• Shunt surgery — antibiotic prophylaxis (pediatric)
• Sodium correction rate — pediatric

Decision pathways (13)

• Chiari I malformation — management pathway
• Moyamoya — revascularisation decision pathway
• New diagnosis of hydrocephalus — workup
• PECARN — minor head injury imaging decision
• Pediatric brain abscess — management pathway
• Pediatric epilepsy — surgical evaluation pathway
• Post-haemorrhagic hydrocephalus — management
• Postoperative hyponatraemia — workup (SIADH vs CSW vs DI hyponatraemic phase)
• Severe pediatric TBI — tiered ICP management
• Shunt infection — management
• Suspected abusive head trauma — workup
• Suspected shunt malfunction — workup
• Vein of Galen malformation — neonatal management pathway

Scores and grading (6)

• Bicêtre Neonatal Evaluation Score (vein of Galen)
• Endoscopic Third Ventriculostomy Success Score (ETVSS)
• Engel epilepsy surgery outcome classification
• ILAE epilepsy surgery outcome classification
• Pediatric Glasgow Coma Scale
• Spetzler-Martin AVM grading

Study

195 multiple-choice questions grouped by area, with an explanation after each answer, and 17 branching clinical scenarios in which each choice leads to the next step of the case.

Templates

Fill-in templates for operative notes and consultations (9):

• Endoscopic third ventriculostomy (ETV)
• External ventricular drain placement
• Myelomeningocele closure (neonatal)
• Pediatric neurosurgery consultation template
• Posterior fossa craniotomy (midline suboccipital, telovelar approach)
• Posterior fossa decompression for Chiari I
• Shunt malfunction assessment consult template
• Tethered cord release
• Ventriculoperitoneal shunt insertion

Using it

Pterion needs a recent browser: Chrome or Edge 119 or later, Firefox 120 or later, or Safari 18.2 or later. The first visit downloads the whole app, which can take a few seconds on a slow connection. After that the content is kept in the browser and refreshed by itself when a new version is published.

Notes and bookmarks in the notebook are stored only in that browser, on that device. Visits are counted with Microsoft Clarity, as described in the disclaimer.

Pterion is for education and reference. It does not replace clinical judgement, local protocols or the care of a qualified clinician.

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