✅ Model Answer:
• Diagnosis: Increased intracranial pressure due to posterior fossa tumor (medulloblastoma or cerebellar astrocytoma) — morning vomiting, headache, papilledema, hydrocephalus on imaging.
• Any other test: Pediatric neurosurgery consult, CSF cytology if safe (lumbar puncture contraindicated if mass effect), histopathology (biopsy/resection), tumor markers (AFP, beta-HCG for germ cell tumors).
• What to do next: Urgent neurosurgical evaluation. Dexamethasone for cerebral edema. Surgical resection or biopsy. VP shunt if hydrocephalus is severe.
• Follow-up plan: Monitor neurologic status, manage hydrocephalus, oncology follow-up (chemotherapy/radiotherapy if malignant), rehabilitation (physiotherapy, occupational therapy).

✅ Model Answer:
• Classic triad: Headache, vomiting, papilledema.
• Other signs:
- Morning headache (worse on waking, improves during the day)
- Projectile vomiting (without nausea)
- Papilledema (optic disc swelling on fundoscopy)
- Visual changes (diplopia, blurred vision, sixth nerve palsy)
- Behavioral changes (irritability, lethargy, personality changes)
- Seizures
- Bulging fontanelle (in infants)
- Sunsetting sign (in infants)
- Cushing's triad (hypertension, bradycardia, irregular respiration — late sign)

✅ Model Answer:
• Pediatric brain tumors are mostly infratentorial (posterior fossa):
- Medulloblastoma — most common malignant brain tumor in children, arises from cerebellum
- Cerebellar astrocytoma (pilocytic astrocytoma) — most common benign brain tumor, good prognosis
- Ependymoma — arises from ependymal cells, often in 4th ventricle
- Brainstem glioma (diffuse intrinsic pontine glioma — DIPG) — poor prognosis
• Supratentorial tumors:
- Craniopharyngioma — suprasellar, causes visual disturbances and endocrine dysfunction
- Germ cell tumors — pineal region, suprasellar
- Low-grade gliomas (optic pathway gliomas — associated with NF1)

✅ Model Answer:
• Fundoscopy is essential in any child with persistent vomiting and headache.
• Papilledema (optic disc swelling) is the hallmark of increased ICP.
• Findings:
- Disc margins blurred
- Venous engorgement
- Hemorrhages or exudates (late signs)
- Optic atrophy (chronic raised ICP)
• Without papilledema: ICP may still be elevated (especially in early stages or if ventriculoperitoneal shunt is in place).
• Must be done before lumbar puncture to avoid herniation.

✅ Model Answer:
• Emergency management:
- Airway, Breathing, Circulation (ABC) — maintain oxygenation and perfusion
- Elevate head to 30° to promote venous drainage
- Mannitol (0.5-1 g/kg IV) or hypertonic saline (3%) to reduce cerebral edema
- Dexamethasone (0.5-1 mg/kg IV) for peritumoral edema
- Seizure prophylaxis if indicated
- Emergency neurosurgical consult
- Avoid hyperventilation (target PaCO2 35-40 mmHg)
- Monitor ICP if available
- Prepare for surgery (tumor resection, VP shunt)

✅ Model Answer:
• CT Head:
- Initial screening — quick, widely available
- Identifies hemorrhage, calcification, hydrocephalus, mass effect
- Less sensitive for posterior fossa tumors (bone artifacts)
• MRI Brain:
- Gold standard for evaluating brain tumors
- Better soft tissue resolution
- Contrast-enhanced MRI helps characterize tumors
- MR spectroscopy and diffusion-weighted imaging provide additional information
- No radiation — preferred in children
- MRA/MRV for vascular assessment

✅ Model Answer:
• Complications:
- Herniation syndromes (uncal, tonsillar, central) — life-threatening
- Visual loss (optic atrophy, papilledema)
- Neurological deficits (motor, sensory, cranial nerve palsies)
- Cognitive impairment (learning difficulties, memory problems)
- Seizures
- Hydrocephalus (obstructive or communicating)
- Endocrine dysfunction (if hypothalamus/pituitary involved)
- Growth failure (growth hormone deficiency)
- Death (if untreated or progressive)

✅ Model Answer:
• Prognosis depends on:
- Tumor type (benign vs malignant)
- Extent of resection (gross total resection gives best outcomes)
- Histological grade (WHO grade)
- Presence of metastasis
- Age of child (younger age may have better outcomes)
• Specific tumors:
- Pilocytic astrocytoma — excellent prognosis (>90% 5-year survival)
- Medulloblastoma — 70-80% 5-year survival with multimodal therapy
- Ependymoma — 50-70% 5-year survival
- Brainstem glioma (DIPG) — poor prognosis (<10% 2-year survival)
• Long-term sequelae: Cognitive impairment, hearing loss, endocrinopathies, secondary malignancies.