Brain Tumors Flashcards
1
Q
Extra axial/extra parenchymal
A
Meninges
2
Q
Intra-axial/intra-parenchymal
A
Brain
3
Q
Carcinogenesis
A
Cellular process by which normal cells become cancerous
- things going awry during cell cycle and the cell will continuously undergo ell division
- oncogenes favor formation of tumors
- tumor suppressor genes: supress entry into cell cycle
- tumor is when cells have aggregated into a single mass
- stop performing normal function usually, but sometimes can go into overdrive. Usually loss of normal function
4
Q
Exceptions of post natal CNS neurons not enter mitosis
A
- only a few isolated regions of the CNS have neural stem cells that continue to produce new neurons (neuro genesis), speicifically in the olfactory bulb and ventricular zone of the CNS (deepest cell layers next to ventricular system)
- glia retina the ability to enter the cell cyl thrghouout adulthood
- neuroantaotmical hotspots for some tumor types e.g. medullablastoma formation in deep white matter of cerebellum, olfactory groove meningioma
5
Q
Meningioma SJS
A
Several common hot spots
Dura mater
6
Q
Nerublastoma
A
From neural stem cells
7
Q
Astrocytoma or gliobastoma
A
Astrocytes can develop these
8
Q
Oligodendroglioma
A
In cerebral white matter
9
Q
Neuromas or schwannoma
A
From Schwann cells in the PNS
10
Q
Ependymomas
A
From ependymal cells lining the ventricular system
11
Q
Choroid plexus cancer
A
Forms benign or malignant tumors (papilloma or carcinoma)
12
Q
Pituitary ademona
A
Pituitary tumor can grow out of sella turcica into the brain
13
Q
Pineal tumor
A
Compression of dorsal midbrain (parinauds syndrome)
14
Q
Meningioma hot spots in the dura mater
A
Flax cerebri External to frontal lobes Olfactory groove over ethmoid bone Patrons ridge of sphenoid bone Clivus region
15
Q
Astrocytoma location
A
In grey and whit matter, can origination essentially from anywhere
16
Q
Mass effect
A
Increased mass/volume and intracranial pressure
Herniations syndromes
17
Q
Tumors and angiogenesis
A
Increased vascularization
- new blood vessles can bleed, causing hematoma
- bleeding can induce seizure activity or cause neurodegeneration locally
- tumors can also undergo necrosis of tumor cells
18
Q
Vasogenic edmea
A
Swelling due to accumulation of extracellular fluid
19
Q
Cytotoxic edema
A
Swelling of dying cells
20
Q
Paraneoplastic syndromes
A
Auto-immun parthology typically caused by antibodies targeted agaisnt the tumor but cross reacts with normal antigens in normal brain tissue, leads to damage or neurodegeneraiton
21
Q
Distribution of tumors
A
Generally focal or multifocal
-tumors can be focal (primary) or multi-focal (usually metastatic)
22
Q
Temporal profile of tumors
A
Chronic/insidious
23
Q
Initial diagnostic confitiomation of tumors
A
Neuroimaging
-tumors visible due to edema, vascularization, high metabolic activity, abnormally tissue intensity, or ring marking boundary, or bleeding
24
Q
Histopathology of tumors
A
Biopsy can be performed, with lab histo analysis
- tumor tissue has a clear structural difference from normal Brain tissue
- specific visual features allow diagnosis and classification of tumor type
- specific visual features determine grade rating
- biopsy can provide genetic analysis
- biopsy can assist in predicting most effective course of treatment
25
Benign vs malignant
- term refer to whether tumor/cancer will progress (grow, metastasize)
- for brain tumors, ay tumor, even “benign” tumors that stop growing can still generate severe neurological problem or become lethal through its effects on the brain (intracranial pressure, herniation, hemorrhage, auto-immune disease, etc)
- brain tumors are generally not called malignant because they do not metastasize outside the cranium
26
Tumor stage vs tumor grade
- stages 1-4 refer to clinical progression
- tumor grades 1-4 refer to histological characteristics related tumor progression and probability of growth, further complications, prognosis for the patient
27
Tumor grades
Grade 1: well differentiated cells (cells appear CI Milan to normal functioning cells)
Grade 2: moderately differentiated cells (some cells appear normal, some dont)
Grade 3: mostly poorly differentiated cells (most cells appear abnormal)
Grade 4: all poorly differentiated (appear abnormal)
Grades 1-2: low grade
Grades 3-4: high grade
28
Focal neuro signs
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Visual disturbances: blurry vision, diplopia
VF loss
Memory loss
Language deficits
Cranial nerve signs
Motor and somatosensory deficits
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29
Diffuse signs and symptoms of tumor
- progressively worsening HA
- difficulty concentrating
- signs of increased intracranial pressure or meninges irritation signs
30
Brain tumor HA
Chronic/insidious onset, steady progression. Can be asymptomatic in many cases until size reaches threshold that irritates dura or causes neuro deficits
31
Tension headache
Chronic and stable.
32
Migraine
Irregualr pattern with variable remission periods
33
Cluster HA
Tends to occur in several daily bouts with long remission periods
34
Sensory (pain) innervation of dura, falx, tentorium
CN 5/10, cervical nerves
35
Increased ICP: origins
- hemorrhage (hematoma)
- tumor or other mass
- hydrocephalus
- brain edema (swelling)
36
Syndrome/symptoms of increased ICP
- headache: mechanical stress on dura (intensified by coughing straining)
- papilledema: gradual protrusion of optic disc forward, elevation and blurring of optic disc on examination
- Nausea and vomiting: pressure stimulates vomiting center in medulla. Beware: vomitting can occur in the absence of nausea
- impaired consciousness (involves many systems in cerebrum and brainstem)
- skull: bulging Fontaelles in infants, suture separation in children
- increased systemic BP-compensatory mechanism
- bradycardia: slowing of heart rate, disruption of medulla function
37
Normal ICP
<20cm (200mm) H20 or <15cm (150mm) Hg
These values are upper limit of normal range
38
ICP measured by
- lumbar puncture (subarachnoid space around cauda equina)
| - neurosurgical insertion of intracranial monitors/catheters
39
Contra-indications of lumbar puncture for ICP
- suspected increased supratentorial pressure, can cause herniation
- infection or mass in the path of manometer needle insertion
40
Meningeal irritation syndrome
1. HA/pain: activation of novice-time fibers in dura. Pressure, chemical signals, inflamamtion
2. Neck stiffness or “nuchal rigidity”. Mechanism might be cervical spinal reflex circuit: sensory input activates motorneurons and increases muscle tone in neck
3. Carious causes
4. Impairment or loss of consciousness
41
VF of pituitary tumor
Bitemporal hemianopia
42
VF from oligodentrioma or meningioma
Bitemporal hemianopia
Left hemianopia in right eye
Left homonymous hemianopia
43
VF loss due to oligodendrioma, astrocytoma, ependymoma
- quadrantoanopias
| - left homonymous heminaopia
44
Pituitary and the optic chiasm
Proximity of infundibulum to optic chiasm
-pituitary tumors can compress optic chiasm, leading to bitemporal hemianopsia. Aneurysms at these locations can also lead to the various visual syndromes
45
Parinauds sydnrome and pineal tumor
-pineal tumor expands downward to compress the dorsal midbrain, specifically the pre-recital nuclei-bilateral impairment of pupillary light reflex
Potential compression of LGN-hemianopia or blindness
46
Disruption of oculomotor system at level of peripheral nerves
CN 3/4/6
Neuroma (nerve sheath, oligodendrocytoma or schwannoma)
Meningioma from clivus, sella turcica, tentorium
47
Cerebellopontine angle tumors
Location, not type of tumor
- meningioma, cerebellar astrocytoma, or acoustic neuroma
- acoustic neuroma: Schwann cell tumor, forms on cochlear or vestibular nerves, grows and expands through internal acoustic meatus into subarachnoid space at cerebellopontine angle
- also can originate from metastatic cancer and other origins
48
Cerebral tumors
Medullablastoma
| Astrocytoma
49
Symptoms of cerebrall tumors
Ataxia, nystagmus, papilledma
50
Medullablastoma
Deep, midline tumor in cerebellum, NOT medulla
- originations from neural stem cells located close to the 4th ventricle
- epidemiology: typically in kids
- neuroanatomy: primarily impacts floccular-nodular love, ie. vestibulo-cerebellar system
- focal neuro signs: impaired balance, nystagmus
- diffuse neuro signs: papilledema, increased ICP
51
Astrocytoma
- within cerebellar hemispheres
- adults
- initally affects spinal cerebellar and cerebral-cerebellar systems, potential expansion to the floccular-nodular lobe (vestibulo-cerebellar system)
- neuro signs: impaired balance, nystagmus, papilledema
- diffuse neurological signs: papilledelma, increased ICP
