Brain and Environs

Question 1

Mass effect and types

Answer 1

Distortion of brain geometry
Effacement: flattening
Midline Shift: structures move from side of lesion

Question 2

Consequence of mass effect

Answer 2

Can cause ischemic infarction if there is compression of blood vessels

Can cause headaches if irritates blood vessels or meninges

Question 3

Signs of elevated intracranial pressure

Answer 3

Headache - worse in the morning with reclining position and effects of gravity

Altered mental status - irritability and depressed level of alertness and attention

Nausea and vomiting

Papilledema- takes several days to develop and is often not present in acute setting. Can cause permanent optic nerve injury leading to visual blurring or visual loss - diploid can occur as a result of downward traction on CN VI causing unilateral or bilateral abducens nerve palsy

Question 4

Cushing’s triad

Answer 4

Classic sign of ICP - hypertension, bradycardia, and irregular respirations

Hypertension - to maintain cerebral perfusion pressure
Bradycardia response to hypertension
Irregular respirations due to impaired brain stem function

Question 5

Brain herniation

Answer 5

Occurs when mass effect is severe enough to push intracranial structures from one compartment to another

Question 6

Transtentorial herniation

Answer 6

Herniation of the medial temporal lobe, especially the uncut (uncal herniation)

Clinical triad - blown pupil, hemiplegia, and coma

Blown pupil due to compression of the oculomotor nerve (CNIII) usually ipsilateral to the lesion in 85%) - dilates and then unresponsive and then impaired eye movement

Hemiplegia - contralateral to the lesion because compressing the ipsilateral corticospinal tract in the middle of the brain or direct effects of lesion on motor cortex (sometimes ipsilateral if pushed all the way to the opposite side)

Coma due to disruption of midbrain reticular formation that leads to decreased consciousness

Question 7

Central herniation

Answer 7

Downward displacement of the brain stem - can cause traction on the abducens nerve

Tonsillar herniation associated with compression of the medulla and usually leads to respiratory arrest, blood pressure instability, and death

Question 8

Subfalcine herniation

Answer 8

Unilateral mass lesion that can cause the cingulate gurus and other brain structures to herniate under the falx cerebri

There are usually no clinical signs directly but can lead to occlusion of arteries of the anterior cerebral arteries

Question 9

Petechial hemorrhages

Answer 9

Small spots of blood in the white matter caused by diffuse axonal injury, cerebral edema, and ICP

Question 10

Epidural hematoma

Answer 10

Located between dura and skull due to rupture of the middle meningeal artery

Initially patient presents with no symptoms (lucid interval) within a few hours, hematoma compresses brain tissue causing ICP and herniation

Question 11

Subdural hematoma

Answer 11

Between the dura and the loosely adherent arachnoid - crescent shaped and usually caused by rupture of bridging veins

Question 12

Subarachnoid hemorrhage

Answer 12

CSF filled space between the arachnoid and the pia (contains major vessels)

Question 13

Nontraumatic subarachnoid hemorrhage

Answer 13

Spontaneous - sudden catastrophic headache described as the worst headache of my life or feeling like the head is about to explode

Question 14

Types of nontraumatic subarachnoid hemorrhage by percentage

Answer 14

7 5-80% result from a rupture aneurysm in the subarachnoid space

4-5% result from bleeding of an arteriovenous malformation

Question 15

How are vasospasms treated

Answer 15

Triple H therapy

Question 16

Symptoms of hydrocephalus

Answer 16

Symptoms caused by ICP - can press white matter pathways in the frontal lobe and cause unsteady magnetic gait

Question 17

Hallmark feature of pituitary adnoma

Answer 17

Bitemporal visual defect from compressing on the optic chiasm - also cause endocrine disturbances

Question 18

Percentage of tumors that are located in the posterior fossa and those that are supratentorial

Answer 18

70% are located in the posterior fossa and 30% supratentorially

Question 19

WHO grades

Answer 19

1 is the most benign and IV is the most malignant or glioblastoma multiforme

Question 20

Tumors that can cause bitemporal visual defect

Answer 20

Craniopharyngioma, hypothalamic gloomy, and pituitary adenomas that can be treated with dopaminergic agonist and resection

Question 21

Parinaud’s syndrome

Answer 21

Have limited vertical eye gaze, especially in the upward direction setting sun sign (bilateral deviation of the eyes downward and inward - often reverses with treatment)

Question 22

Paraneoplastic syndromes

Answer 22

Rare neurological disorders caused by remote effects of cancer in the body leading to abnormal autoimmune response (e.g., opsoclonus myoclonus)

Question 23

Signs of meningeal irritation

Answer 23

Headache, lethargy, sensitivity to light and noise, fever, nuchal rigidity

Kernig’s sign: pain in hamstrings when knees are straightened with hips flexed

Brudzinski’s sign: flexion at neck causes hips to flex

Question 24

Signs of brain abcess

Answer 24

Presenting problems are headache, lethargy, fever, nuchal rigidity, nausea, vomiting, seizures, and focal signs depending on location

Much like a tumor but often more rapid course\

Fever is absent in 40%

Depending on size is treated with antibiotics or needle aspiration or surgical removal in addition to antibiotics if the abscess cause mass effect and progressive deterioration