Pediatric Brain Tumors (and other stuff)!

Common presenting symptoms

• Most common symptom reported by children with a newly diagnosed brain tumor is headache. Occurs in 1/3 of patients

• Nausea and vomiting occur in 1/3 of children newly diagnosed

• New onset seizure can be seen in up to 40% of children diagnosed with cortical based tumor

• Young children can present with macrocephaly, vomiting, irritability and lethargy

Headache

• Many benign causes of headache: tension headache, migraine headache, viral syndrome, etc

• Not benign causes: Brain mass, ruptured SAH, meningitis, obstructive hydrocephalus (e.g. due to VP shunt malfunction)

• How do you differentiate the benign vs not benign headaches?

• Red flag headache findings:

  • SNOOPY IS WET

    • Systemic signs/symptoms

    • Neurological signs (ataxia, focal deficits, papilledema)

    • Occipital headache

    • Occurring in high risk groups (sickle cell disease, VP shunts, malignancy)

    • Postural (worse leaning forward/bending)

    • Younger age (2-3 years old)

    • Infectious signs

    • Squint (new onset)

    • Waking from sleep

    • Early morning vomiting

    • Thunderclap headache

​Examination	Pertinent findings suggestive of a tumor
Mental Status	Encephalopathy, progressive neurocognitive decline
Cranial Nerve II	Visual field defects, papilledema
Cranial Nerves III, IV, VI	Nystagmus (particularly upgaze), gaze paralysis, mid-position, poorly reactive pupils
Cranial Nerve VII	Facial Weakness (upper vs. lower motor neuron distributions
Cranial Nerve VIII	Decreased hearing, vertiginous symptoms
Cranial Nerves IX, X, XII	Drooling, dysphaiga, uvula deviation, tongue protrusion deviation
Motor exam	Early handedness, delayed motor milestones, pronator drift, focal changes in tone with associated atrophy
Reflexes	Hyperreflexia, babinski sign, hofmann's sign
Cerebellar function	Dysmetria, overshooting/missing on finger-to-nose and/or heel-to-shin test, asymmetry of finger and/or toe tapping
Gait	Wide based unsteady gait, inability to perform straight-line test, circumduction of gait
Sensory	sensory deficits in focal anatomic distribution

Medulloblastoma

• Most common malignant brain tumor of childhood

• Derived from tumor stem cells of the external granular layer of the cerebellum

• Generally presents as a posterior fossa mass, often associated with obstructive hydrocephalus

Ependymomas

• Derived from ependymal cells within the CNS

• Most commonly in posterior fossa

• Can also occur in supratentorial region and spinal cord

Astrocytoma

• Juvenile pilocytic astrocytoma most common

• Associated with Neurofibromatosis Type 1

• Usually arise in cerebellum, near the brain stem, in hypothalamic region or optic chiasm

Craniopharyngioma

• Suprasellar mass

• Can present with bitemporal hemianopsia and pituitary insufficiency

​Signs and Symptoms	Tumor Location
Early morning vomiting, recurrent vomiting, enlarged head	Posterior fossa, ventricular system
Failure to thrive, Anorexia	Suprasellar, hypothalamic
Visual compaints, abnormal extraocular movements	Optic Pathway, suprasellar, brain stem, posterior fossa
Tics, tremors, movement disorders	basal ganglia, thalamus, midbrain
Early handedness	Cortex, subcortical, brain stem, spinal cord
Facial nerve palsy	Brain stem, cerebellar pontine angle
Hearing loss	cerebellar pontine angle
Precocious puberty, nocturnal enuresis	suprasellar
head tilt, torticollis	Cerebellar pontine angle, cervicomedullary junction

ICP Management

1. Evacuate mass occupying lesions (e.g., hemorrhage, tumor, abscess, etc)

2. Patient Positioning: Head up 30 degrees and midline, neck position neural. Enhances cerebral venous outflow and maximizes CPP.

3. CSF drainage: Decreases volume, effective however associated with bleeding risk, infection

4. Mannitol & Hypernatremia:

   1. Mannitol: 0.5 - 2 g/kg up to Osm of 320. Increases intravascular oncotic pressure.

   2. Hypertonic Saline (3%):

      1. 5-10 ml/kg 3% NaCl up to [Na] of 145-180 meq/L – may bolus 5-10 ml/kg and start a sliding scale gtt @ 0.5-2 ml/kg/hr. (Learn PICU)

      2. 2 to 5 mL/kg administered over 10 to 20 minutes (Lexicomp)

      3. Increases intravascular oncotic pressure, volume expander.

5. Craniectomy: resection of large flap of skull, changes the “volume” part of the compliance equation.

6. Sedation & Analgesia: Benzos, narcs, barbiturates, Lido pETT/IV; possibly premedicate before stimulation; cluster nursing activity; calm environment. Decrease CNS metabolic demand

7. Seizure Control: Aggressively treat and consider prophylaxis, numerous choices of AED (phenobarb, dilantin).Decrease CNS metabolic demand

8. Antipyresis:Tylenol, paralysis, cooling measures, caution with NSAIDS. Metabolic demands increase 5-10% per 1 degree C.

9. Ventilation: Normoventilate if able, +/- Hyperventilation temporarily if necessary.

   1. Hypocapnia leads to cerebral vasoconstriction, decreased cerebral blood flow -> decreased volume -> decreased ICP.

10. Glucose Control: Glucose control with prudent dextrose administration and insulin gtt if needed. Hypo-and hyperglycemia in the setting of cerebral ischemia leads to enhanced anaerobic metabolism.

Masooma Kazmi, MD