General Intro CNS to PPT

Question 1

Where does the spinal cord end?

Answer 1

around L1-L2

Question 2

Are there lymphatics in the CNS?

Answer 2

No

Question 3

What are the meninges?

Answer 3

The meninges are the outer covering of protection for the brain.

Question 4

What is the outermost membrane of the meninges?

Answer 4

The outermost membrane is the dura mater (tough mother), which is the strongest.

Question 5

What is the structure of the dura mater?

Answer 5

The dura mater is a double-layered membrane that is continuous with the periosteum of the cranium.

Question 6

What follows the contour of the dura mater?

Answer 6

The arachnoid membrane follows the contour of the dura mater.

Question 7

What separates the pia mater from the arachnoid mater?

Answer 7

The subarachnoid space separates the pia mater from the arachnoid mater.

Question 8

What is contained in the subarachnoid space?

Answer 8

The subarachnoid space contains cerebrospinal fluid (CSF) that circulates around the brain and spinal cord.

Question 9

What is the function of CSF?

Answer 9

CSF provides further protection to the central nervous system (CNS).

Question 10

What is the innermost layer of the meninges?

Answer 10

The innermost layer is the pia mater (delicate, tender mother), which is a highly vascular layer.

Question 11

How does the pia mater relate to the brain?

Answer 11

The pia mater adheres closely to the contours of the brain.

Question 12

What does BBB stand for?

Answer 12

BBB stands for Blood Brain Barrier.

Question 13

What is the primary function of the BBB?

Answer 13

The primary function of the BBB is to protect the brain from potentially toxic compounds.

Question 14

What type of substances can pass through the BBB?

Answer 14

Substances that can pass through the BBB must be lipid soluble.

Question 15

Why can’t drugs reach tumor cells in healthy brain tissue?

Answer 15

Tumor cells that infiltrate healthy brain tissue cannot be reached by drugs that do not cross the BBB.

Question 16

How is the separation of circulating blood and CSF maintained?

Answer 16

The separation is maintained by the choroid plexus in the CNS.

Question 17

What do endothelial cells restrict?

Answer 17

Endothelial cells restrict the diffusion of microscopic objects (e.g. bacteria) and large or hydrophilic molecules into the CSF.

Question 18

What type of molecules can diffuse through the BBB?

Answer 18

Small hydrophobic molecules can diffuse through the BBB.

Question 19

What substances are actively transported across the BBB?

Answer 19

Cells of the barrier actively transport metabolic products such as glucose across the barrier with specific proteins.

Question 20

CN 1?

Answer 20

Olfactory nerve

Question 21

CN 2?

Answer 21

Optic nerve

Question 22

CN 3?

Answer 22

oculomotor nerve

Question 23

CN 4?

Answer 23

Trochlear nerve

Question 24

CN 5?

Answer 24

Trigeminal nerve

Question 25

CN 6?

Answer 25

Abducens nerve

Question 26

CN 7?

Answer 26

Facial nerve

Question 27

CN 8?

Answer 27

Vestibulocochlear nerve

Question 28

CN 9?

Answer 28

Glossophsryngeal nerve

Question 29

CN 10?

Answer 29

Vagus nerve

Question 30

CN 11?

Answer 30

Accessory nerve

Question 31

CN 12?

Answer 31

Hypoglossal nerve

Question 32

What percentage of all cancers do primary brain tumors account for?

Answer 32

Primary brain tumors account for 1.5% of all cancers.

Question 33

What is the distribution of primary brain tumors between the brain and spinal cord?

Answer 33

80% are brain tumors and 20% are spinal cord tumors.

Question 34

What are the two peak ages for the incidence of primary brain tumors?

Answer 34

The two peak ages are 3-12 years and 50-80 years.

Question 35

What types of tumors are commonly found in children aged 3-12 years?

Answer 35

Common tumors include Medulloblastoma, Cerebellar astrocytoma, and Ependymomas.

Question 36

What types of tumors are commonly found in adults aged 50-80 years?

Answer 36

Common tumors include Malignant gliomas and meningiomas.

Question 37

What percentage of cancer patients eventually develop brain metastasis?

Answer 37

Estimates suggest that 20%-40% of patients with cancer eventually develop brain metastasis.

Question 38

What occupational exposures are associated with higher incidence rates of brain tumors?

Answer 38

Occupational exposure to chemicals, synthetic rubber, and pesticides is associated with higher incidence rates.

Question 39

Which occupations have shown higher incidence rates of brain tumors?

Answer 39

Workers in agriculture and healthcare have shown higher incidence rates than other occupations.

Question 40

What lifestyle and dietary factors are associated with brain tumors?

Answer 40

Factors include cell phones, nitrates, hair dyes, and smoking.

Question 41

What medical conditions are associated with brain tumors?

Answer 41

Conditions include viral infections, certain drugs, and AIDS.

Question 42

What genetic factors are linked to brain tumors?

Answer 42

Genetic factors include Neurofibromatosis (less than 5%), tuberous sclerosis, LI-Fraumeni syndrome, and von Hippel-Lindau syndrome.

Question 43

What symptoms do benign tumors generally cause?

Answer 43

Benign tumors generally cause symptoms produced by pressure.

Question 44

What can malignant tumors cause?

Answer 44

Malignant tumors can cause pressure and destruction of the CNS tissue.

Question 45

What is intracranial pressure (ICP) caused by?

Answer 45

ICP is caused by the growth of the tumor itself, swelling of the brain, or blockage of the flow of CSF.

Question 46

What is an initial symptom of increased intracranial pressure?

Answer 46

The initial symptom may be a headache, which is usually worse in the mornings.

Question 47

What are some signs of increased intracranial pressure?

Answer 47

Signs of ICP include seizures and difficulties with balance, gait, and ambulation.

Question 48

What symptoms may occur with glioma of the optic nerve?

Answer 48

Symptoms may include vision loss.

Question 49

What symptoms can occur in the spinal cord?

Answer 49

Symptoms include pain, weakness, numbness in extremities, and bowel and bladder control problems.

Question 50

What is necessary for patients with a sudden onset of symptoms of a spinal cord tumor?

Answer 50

Immediate treatment is necessary to prevent permanent paralysis.

Question 51

How can ICP symptoms be managed?

Answer 51

Symptoms can be managed with corticosteroids.

Question 52

What is the role of steroids in treating ICP?

Answer 52

Steroids help reduce swelling.

Question 53

What are some neurological exam findings in CNS tumors?

Answer 53

Findings may include decreased level of alertness, poor memory, hyperactive reflexes, muscle weakness in extremities, visual field defects, and cranial nerve abnormalities.

Question 54

What is the most important tool in diagnosis and grading of brain conditions?

Answer 54

MRI (with or without contrast) is the most important tool due to its superior image quality and ability to show chemical changes within the brain.

Question 55

What is the contrast agent used in MRI for brain tumors?

Answer 55

The contrast agent used is gadolinium, which is a noniodine-based intravenous contrast agent.

Question 56

What is the role of MRI contrast agents?

Answer 56

They help differentiate between edema and the tumor and can detect surface seeing.

Question 57

What is the advantage of CT scans?

Answer 57

CT scans are more cost-effective and are used in follow-up after treatment.

Question 58

What radionuclide does PET use?

Answer 58

PET uses the radionuclide F-fluorodeoxyglucose (FDG) to help detect lesions.

Question 59

What is the utility of PET scans?

Answer 59

PET scans are useful in determining differences between necrosis and malignancy.

Question 60

What are some other imaging studies?

Answer 60

Other imaging studies include arteriogram, EEG, MEG, and stereotactic biopsy.

Question 61

What is the universal staging system for CNS tumors?

Answer 61

No universal staging system is currently used, leading to problems due to lack of standardization.

Question 62

What are the routes of spread for tumors?

Answer 62

Local invasion, along pre-existing pathways defined by white matter tracts, and spread via the CSF. ## Footnote Tumors do not spread hematogenously.

Question 63

What is the treatment of choice for most brain and spinal cord tumors?

Answer 63

Surgery. ## Footnote The primary goal for surgery is to remove the tumor and obtain a histologic diagnosis.

Question 64

What factors can limit surgery for brain and spinal cord tumors?

Answer 64

Tumor location and extent, patient status, and risk of debilitating neurological deficits.

Question 65

Does partial removal of a tumor enhance the patient's chances for survival?

Answer 65

No, the patient's chances for survival are not enhanced with partial removal of the tumor.

Question 66

What follows surgery to prevent tumor regrowth or recurrence?

Answer 66

Adjuvant Radiation Therapy.

Question 67

What is an important option for patients with isolated CNS tumors and solitary brain metastases?

Answer 67

Stereotactic Radiosurgery (SRS).

Question 68

What factors have limited the use of chemotherapy in CNS treatment?

Answer 68

The presence of the BBB, the low number of effective drugs, lack of change in progression of disease with introduction of adjuvant therapy, and lack of adjuvant chemotherapy to increase the survival rate.