Anoxia and brain tumors

Question 1

5 causes of anoxia

Answer 1

myocardial infarction; suffocation (e.g. drowning, strangulation); carbon monoxide poisoning; respiratory distress (e.g. severe COVID); respiratory suppression (e.g. fentanyl overdose)

Question 2

Pathophysiology of anoxia

Answer 2

lack of oxygen supply due to insufficient cerebral blood flow or oxygen saturation in blood; multiple complex metabolic pathways to cell death; takes days-weeks to show in brain scan

Question 3

4 brain regions most sensitive to anoxia

Answer 3

basal ganglia (globus pallidus and putamen); hippocampi (CA1 region); cerebellum (purkinje cells); watershed areas of cortex

Question 4

What does severe/prolonged anoxia lead to?

Answer 4

coma or brain death

Question 5

What happens when oxygen supply in the brain is resumed within 5-15 mins?

Answer 5

amnesia; executive dysfunction; ataxia (motor incoordination); proximal limb (shoulder and hips) weakness or person-in-the-barrel; visual agnosia and cortical blindness

Question 6

2 causes of mild hypoxia that can result in reversible damage

Answer 6

being in high altitudes (deprives brains of oxygen); obstructive sleep apnea (secs-mins anoxic episodes wherein a person stop breathing and snores loudly at night)

Question 7

Factors affecting prognosis of anoxia

Answer 7

duration and completeness of oxygen deprivation; predicted by depth of coma at admission

Question 8

Survival/recovery rates for anoxia

Answer 8

10% survive and 5% make full neurological recovery for out-of-hospital cardiac arrests; 50% survival for ICU outcomes

Question 9

4 treatments for anoxia

Answer 9

prevention of further hypoxia (e.g. resuscitation, oxygen); hypothermia (mixed evidence); hyperbaric oxygen therapy for CO poisoning; ECMO

Question 10

Incidence of brain tumors

Answer 10

10-15 cases per 100000 people/year

Question 11

Epidemiology of brain tumors

Answer 11

more common in men (except for meningiomas); mean onset age 75-85 for all types and 50-60 for primary tumors

Question 12

2 origins of brain tumors

Answer 12

primary (brain tissue or brain’s immediate surroundings); metastatic (cancer, usually lung, that spreads to the brain)

Question 13

3 most common types of primary brain tumors

Answer 13

meningiomas (benign/encapsulated), gliomas (malignant/cancerous); pituitary tumors (benign)

Question 14

Origins of 3 most common primary brain tumors

Answer 14

meninges, glial cells, pituitary gland

Question 15

5 pathophysiologies of brain tumors

Answer 15

focal invasion/destruction, local edema, compression, elevated intracranial pressure, hydrocephalus

Question 16

Local edema

Answer 16

irritation and swelling around the site of the tumor

Question 17

Hydrocephalus

Answer 17

tumor pushes brain tissue, obstructing flow of cerebrospinal fluid, leading to build-up in ventricles and making them enlarged

Question 18

Characteristics of onset and symptoms of brain tumors

Answer 18

gradual onset; nature of deficits depend on location; can be focal or generalized if elevated intracranial pressure

Question 19

2 most common initial symptoms of brain tumors

Answer 19

non-pulsing headache and seizures (both in 50% of adults)

Question 20

Tumors with worse prognosis

Answer 20

most malignant; fast growing; highly invasive; higher rate of recurrence; low curative potential and treatment is generally palliative

Question 21

Examples of tumors with worse prognosis

Answer 21

glioblastoma, anaplastic astrocytoma

Question 22

Tumors with best prognosis

Answer 22

least malignant; slow growing; non-invasive; lower rate of recurrence; may be eliminated by surgery alone

Question 23

Examples of tumors with best prognosis

Answer 23

oligoastrocytoma, meningioma

Question 24

3 kinds of diagnostic workup for brain tumors

Answer 24

CT and MRI with enhancement; biopsy for histology; molecular genetic testing

Question 25

4 kinds of treatments for brain tumors

Answer 25

surgery (gold standard), radiation (blasting tumor from different angles); chemotherapy; possibly immunotherapies

Question 26

Surgery for benign vs malignant tumors

Answer 26

benign is removed; malignant is debulked or mass is reduced