Neuro

Question 1

Expected pulmonary function parameters in Guillain-Barre? (FEV1/FVC, TLC, DLCO, NIF)

Answer 1

A restrictive pattern so FEV1 and FVC decreases PROPORTIONALLY but ratio is unchanged
DLCO does not change
TLC is reduced
NIF is reduced

Question 2

Sux and/or volatile anesthetics can trigger which reaction in Duchenne and Becker muscular dystrophy?

Answer 2

Rhabdomyolysis NOT MH

Question 3

Most effective monitor to assess intraoperative ischemia and confirm need for shunt in CEA?

Answer 3

EEG because high specificity for focal and global detection of ischemia.

Question 4

what does NIRS evaluate?

Answer 4

Near infrared spectroscopy (NIRS) evaluates FOCAL brain oxygenation (like a pulse ox)

But can’t detect global ischemia that could benefit from a shunt

Question 5

How are SSEPs utilized during CEA?

Answer 5

A FOCAL measure of brain FUNCTION (will not measure ischemia distant from the monitoring site).

Question 6

Carotid stump pressures are used to….?

Answer 6

Detect GLOBAL ischemia -BUT-

Do NOT correlate with the need for a shunt (because of low sensitivity/specificity) and do NOT detect FOCAL ischemia.

Question 7

Jugular venous oxygen saturation is used to….?

Answer 7

Detect GLOBAL ischemia -BUT-

Does NOT correlate with the need for a shunt (because of low sensitivity/specificity) and does NOT detect FOCAL ischemia.

Indirect assessment of CMRO2 and oxygen delivery to the brain.

Question 8

Confusion assessment method (CAM) requires that a patient?

Answer 8

1: be within 1 week of an anesthetic of any type
2: have an acute onset of neurologic dysfunction WITH A FLUCTUATING COURSE
3: have inattention
4: have at least 1 of the following: disorganized thinking OR alteration of consciousness

**Postop neurocognitive disorders are due to surgically induced systemic inflammation altering brain chemistry, NOT the effects of anesthetic medication

Question 9

QT interval changes with DECREASED calcium, potassium, or magnesium?

Answer 9

Long QT

Question 10

Examples of headaches classified as trigeminal autonomic cephalgias? Common symptoms?

Answer 10

Cluster headaches, paroxysmal hemicrania, short-lasting unilateral neuralgiform headache, hemicrania continua

lacrimation, conjunctival injection, nasal congestion, rhinorrhea, forehead sweating and periorbital edema.

NOT photophobia and phonophobia which can be symptoms of migraines but NOT in trigeminal autonomic cephalgias.

Question 11

Single most important intervention to prevent cerebral ischemia during aortic arch aneurysm repair?

Answer 11

Deep hypothermic circulatory arrest to 17 degrees celsius. (The brain can tolerate circulatory arrest with deep hypothermia for periods of up to 20 minutes before ischemia).

Question 12

The most significant effect of steep Trendelenberg during robotic prostatectomy?

Answer 12

increased intracranial and intraocular pressures – therefore relatively contraindicated in patients with cerebral aneurysms (or those at higher risk such as Marfans, adult polycystic kidney dz, and Ehler-danlos)

Question 13

isoelectric EEG vs burst suppression?

Answer 13

isoelectric EEG: indicates maximal decrease in CMRO2 but time to arousal becomes unpredictable

Burst suppression: allows maximal reduction in CMRO2 with punctuated “bursts” of EEG activity – this indicates regular EEG activity will return predictably following cessation of the infusion

Question 14

Basics of EEG monitor numbering?

Answer 14

odd numbers designate LEFT side of cranium
even numbers designate RIGHT side of cranium
Z designation represents MIDLINE

Question 15

Blood supply to the MEDIAL one-third of the primary motor cortex? This region is responsible for what type of movement?

Answer 15

anterior cerebral artery - lower extremity movement

Question 16

Blood supply to the LATERAL two-thirds of the primary motor cortex? This region is responsible for what type of movement?

Answer 16

Middle Cerebral Artery: region responsible for upper extremity and facial movement

Question 17

Reason why routine use of mild hypothermia in aneurysmal neurosurgery is not recommended?

Answer 17

Despite evidence that the technique suppresses inflammation, there is no evidence for improved neurological outcomes.

Question 18

Mannitol effect on electrolytes?

Answer 18

Causes transient shifts until mannitol clears:
hyponatremia
hypokalemia
hyPERosmolality

Question 19

Treatment for vasogenic edema versus cytotoxic edema in setting of intracranial pathology?

Answer 19

vasogenic edema: likely associated with tumors, give steroids

cytotoxic edema: likely associated with injury or ischemia, give hypertonic saline or mannitol

Question 20

The peak effect of mannitol occurs when?

Answer 20

30-45 mutes after the start of the infusion

Question 21

Medications to avoid during placement of a deep brain stimulator?

Answer 21

beta blockers due to their tendency to decrease tremor

nicardipine is most appropriate if BP needs to be lowered

Question 22

Fluids to avoid in neurosurgery?

Answer 22

glucose-containing or hypOosmolar such as Lacatated Ringer’s with an osmolality of 273

Normal saline and plasmalyte preferred because ISO-osmolar

Question 23

Different types of confirmatory brain death tests?

Answer 23

Cerebral angio - gold standard but invasive
transcranial doppler - bedside, safe, and noninvasive
MR angiography
CT angiography - lower sensitivity, uses iodine

radionuclide brain imaging - tracer penetrates proportional to blood flow so in brain death there is no redistribution - called “hollow skull phenomenon”

EEG - recommended for the very young - electrocerebral silence is present (flat EEG)

Question 24

How does nimodipine improve outcomes and decrease cerebral infarction after SAH?

Answer 24

via fibrinolytic action; NOT cessation of vasospasm

Question 25

It is ok to use corticosteroids for which type of intracranial pathology?

Answer 25

vasogenic edema secondary to a brain tumor

Question 26

A spinal cord injury at or above what level predisposes to autonomic hyperreflexia?

Answer 26

T7

Question 27

transcranial doppler allows intraoperative monitoring of what parameter?

Answer 27

blood flow velocity within the circle of willis - useful in predicting patients at risk for hyperperfusion syndrome

Question 28

Vasopresser that increases CPP and brain oxygenation?

Answer 28

anything that increases MAP will increase CPP.

Vasopressin uniquely does both. increase in oxygenation is thought to be mediated by local nitric oxide release by direct action of vasopressin on cerebral vasculature.

Question 29

Mainstay treatment for botulism < 1 year of age vs > 1 year of age?

Answer 29

<1: human derived immune globulin

>1: equine-derived antitoxin

Question 30

test to differentiate myasthenic crisis from cholinergic crisis in MG?

Answer 30

edrophonium test - edrophonium is a short-acting acetylcholinesterase so weakness improves if myasthenic crisis and worsens in cholinergic crisis

Question 31

GCS correlation with severity of TBI?

Answer 31

mild 13-15
moderate 9-12
severe < 9