CM neuro 18 and 19- brain tumors
Order by
26 terms
Terms | Definitions |
|---|---|
 astrocytes | brain tumors most commonly arise from this cell type |
| medulloblastoma | most common CNS tumor in children |
| sonic hedgehog | aberrant cerebellar granule cell formation via this pathway predisposes to medulloblastomas |
| somatic mutations | most gliomas are due to this type of mutation |
| meningiomas | most common CNS tumors seen in adults; not considered a malignancy |
| pilocytic grade I | the lowest grade astrocytic tumor -typically indolent, have a limited invasive capacity, and rarely undergo anaplastic progression. |
| no symptoms | most common symptom for meningioma |
| seizures | low grade gliomas cause....... |
| mental status abnormalities | malignant gliomas and primary CNS lymphoma cause....... |
| cranial MRI | the only test needed to diagnose a brain tumor |
| supratentorial | herniations: -uncal -central -cingulate -transcalvarial |
| infratentorial | hernations: -upward -tonsilar |
| uncal herniation | -temporal lobe lesion protrudes through the tentorial notch -structures impinged include the posterior cerebral artery, the contralateral peduncle and the midbrain -neurological findings may be unilateral dilated pupil from ispilateral CN III compression, oculomotor palsy, homonymous hemianopsia, contralateral hemiparesis |
| central herniation | -midline tumor compresses basal ganglia, thalamus and midbrain -neurological findings may be small pupils, lethargy, Cheyne-Stokes respirations |
| cingulate herniation | -medial frontal lobe tissue is pushed under the falx cerebri, anteriorly -critical brain structures are typically not involved early on, and neurological s/s are not well defined -this hernia syndrome is frequently an asymptomatic precursor to the other syndromes |
| transcalvarial herniation | -also called "external" herniation -not usually a neoplastic event, but when generalize brain edema causes outward herniation through a fractured skull, or craniectomy -may prevent closure from taking place |
| upward herniation | -one of the two posterior fossa herniations -also called upward cerebellar hernation -cerebellar signs, and some midbrain effects |
| tonsillar herniation | -AKA downward cerebellar syndrome -posterior fossa tumors compress downward into the foramen magnum -also called Chairi malformation -neurological findings may be posterior headache, cough induced syncope, vomiting, respiratory changes -Lhermittes sign: dysesthesias in the arms and legs with bending the neck forward |
| low grade astrocytoma (LGA) | -most common in young adults, children -seizure is often first sign -non-enhancing lesion on MRI with glucose hypometabolism |
| decision to operate | -age and performance status -proximity to "eloquent" structures -feasability of debulking -feasability of complete resection -in case of recurrence- time since last attempted resection |
| gamma knife, cyberknife, synergy S | -pin point radiation -robotic arm vs. "helmeted" approach vs. computer-aided spin -all intend minimizing collateral damage |
| GB therapeutic dicisions | -resect the resectable -radiation to all (2 Gy fractions, 5 days/week, total of 60 Gy) -Gliadel (biodegradable polymers soaked in carmustine) increased survival 11.6 to 13.0 mo -concomitant XRT temozolmoide (capsules) improves survival. median survival was 16 months with 31% alive at 2 years -stereotactic radiosurgery (3 cm or less) |
| meningioma | -20-25% of all intracranial neoplasms (menigothelial cell origin) -MRI: convexities, parasellar, "dural tail" -surgery for the symptomatic -stereotactic radiosurgery for < 3 cm -commonly found accidentally |
| hedgehog pathway | if this pathway is blocked, results in all translational pathways being turned on, thus leading to tumor formations |
| intracranial germ cell tumors | -pineal region in the majority -signs and symptoms: panhypopituitarism, diabetes insipidus, visual disturbances -egg and sperm malignancy |
| human chorionic gonadotropin (HCG) | if GCT, this hormone will be elevated |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.