Neuro

Question 1

A guy smokes something, goes crazy, acts crazy strong and doesn’t feel pain, and has hallucinations and psychoses. He also has vertical nystagmus. What did he smoke, and what receptor does it work on?

Answer 1

He smoked PCP, and it is an NMDA antagonist. Look for ataxia, horizontal/vertical nystagmus, and delirium.

Question 2

Name a side effect of opoid analgesics that has an impact on smooth muscle in the right upper quadrant.

Answer 2

They can cause contraction of smooth muscle cells in the Sphincter of Odii that cause spasm and an increase in common bile duct pressures. This can be painful.

Question 3

What 3 genes are associated with early onset Alzheimer’s?
What gene is associated with late onset Alzheimer’s?
When gene=decreased risk of Alzheimer’s?

Answer 3

Early=APP, presenilin-1 and presenelin-2
Late=ApoE4
Decreased risk=ApoE2

Question 4

Wernicke encephalopathy commonly causes necrosis of the mammillary bodies and gray matter near the 3rd and 4th ventricles. It is due to decreased levels of thiamine, and thus decreased glucose utilization. Decreased activity of what cofactors of thiamine are key to causing this condition?

Answer 4

1) Pyruvate dehydrogenase
2) Alpha-ketoglutarate dehydrogenase (CA cycle)
3) Branched chain alpha-ketoglutarate dehydrogenase
4) Transketolase (pentose phosphate pathway)

Question 5

What drugs are indicated for:
Absence seizures
ADHD
Tonic Clonic Seizures
Complex Partial Seizures
Anticonvulsant Therapy

Answer 5

Absence Seizures: Ethosuximide/Sodium Valproate
ADHD: Stimulants (Methylphenidate)
Tonic-Clonic Seizures: Phenobarbital
Complex-Partial: Carbamazepine
Anticonvulsant: Benzodiazepines (diazepam, lorazepam, midazolam)

Question 6

On autopsy, a person’s brain has several small cavities filled with clear fluid. What is this called, and what is the likely cause?

Answer 6

This is a lacunar infarct.
Due to small vessel occlusion (lipohyalinosis and microatheroma formation).
Risk factors=DM and uncontrolled hypertension.

Question 7

An axon is accidentally severed during an operation. If you were to examine the cells a few years later, what changes would you expect to see?

Answer 7

Axonal Reaction.
You would expect to see enlarged, rounded cells with peripherally located nuclei and dispersed, finely granular Nissl material/bodies.

Question 8

Woman has a slight tremor in her upper extremities when doing simple tasks. She says her mother and grandfather also had it. She notices that it gets better when she drinks alcohol.
Diagnosis?
Treatment?

Answer 8

Essential tremor.

Rx: Propanolol (the nonspecific Beta adrenergic antagonist).

Question 9

What is the conformation change in Creutzfeldt-Jakob Disease, and what does it cause in the brain?

Answer 9

It’s a change from alpha sheets to beta folding (prions). It results in spongiform change in affected gray matter.

Question 10

Orbital floor fracture. What are 2 common clinical findings?

Answer 10

Vertical gaze limitations due to impaired inferior rectus.

Also, paresthesias of the ipsilateral upper lip and gingiva due to damage to the infraorbital nerve.

Question 11

What is selegiline’s mechanism of action and what is it used to treat?

Answer 11

It’s a MAO-Type B inhibitor, used to treat Parkinson’s.

Question 12

Bupropion is really good for depression, except for a side effect that’s particularly bad in certain populations. What is good about it, and who should not be on it?

Answer 12

Good: No sexual side effects, no weight gain.
Bad: Causes seizures, especially in anorexic/bulimic and those who already suffer from seizures.

Question 13

What is first line treatment for trigeminal neuralgia, and what are potential side effects?

Answer 13

Carbamazepine. It increased sodium channel inactivation and thus inhibits neuronal high-frequency firing.
It does lower bone marrow production, so you need to keep on top of blood cell counts.

Question 14

What drug do you give for opioid overdose, and what receptor(s) does it bind to?

Answer 14

Give naloxone. It binds the mu, kappa, and delta opioid receptors with an affinity for mu receptors.

Question 15

What are cardinal features of narcolepsy, and what compound is low? Treatment?

Answer 15

Excessive daytime sleepiness, hallucinations before (hapnagogic) or after (hypnopompic) sleep, sleep episodes that start with REM sleep, and loss of muscle tone following emotional stimuli (laughing).
Hypocretin is low.
Tx: Day=stimulants. Night=sodium oxybate (GHB)

Question 16

What hormone is similar to endorphins structurally, and thus may be linked to the opioid system?

Answer 16

ACTH. They both come from the same precursor, suggesting a link between the stress response and the body’s opioid response.

Question 17

This drug is prescribed to people who are trying to quit smoking, but they need help preventing cravings.

Answer 17

Varenicline. It’s a partial agonist of nicotine receptors, thus helping with withdrawals and cravings.

Question 18

A local anesthetic has a high arterial/venous concentration gradient. What does this mean in relation to onset of action and solubility in peripheral tissues?

Answer 18

High gradient=high peripheral solubility. This also means a slower onset of action (this is because it keeps it from reaching the brain sooner, and it needs to reach the brain to have its effect).

Question 19

Which protein is involved with retrograde transport of the herpes virus to the neuronal cell bodies?
Which protein is involved in anterograde transport back to the skin?

Answer 19

Retrograde: dynein
Anterograde: Kinesin

Question 20

A patient is on valproate for their bipolar disorder when they become pregnant. What should they take, and if they don’t what is a likely potential issue in their future child?

Answer 20

They should take folate (Vitamin B9) supplementation.

If not, their child has an increased risk of NTDs due to valproate causing a 10-20x increased risk.

Question 21

What are the 1st and 2nd line treatments for nausea (ie from traveler’s diarrhea)?

Answer 21

1) Ondansetron–>it antagonizes the 5-HT3 receptors (serotonin). Increased GI serotonin can lead to vomiting. Ondansetron decreases vagal stimulation. They are well tolerated.
2) Metoclopramide–>a D2 receptor antagonist, these have more GI side effects, are used more for headaches and migraine pain. Good central ones.

Question 22

What does the Romberg sign test? What would a positive romberg sign indicate?

Answer 22

It tests proprioception.
If it’s positive, it would indicate sensory ataxia, which can be caused by defects in the peripheral nerves or posterior column (tabes dorsalis, Vitamin B12 deficiency).
If it’s negative, cerebellar ataxia is more likely, and you can test that with finger to nose or heel to shin testing.

Question 23

A patient needs to be put on atypical antipsychotics. You are deciding between clozapine and olanzapine.

Answer 23

Clozapine-can cause agranulocytosis, need to track WBCs, also can cause metabolic syndrome.
Olanzapine-only need to consider metabolic syndrome.
To track both, monitor BMI, waist circumference, Fasting glucose and lipids, and BP

Question 24

What class and specific drugs are useful to treat spasticity (ie in MS)?

Answer 24

GABAb receptor agonist–>Baclofen

Alpha2 adrenergic agonist–>Tizanidine

Question 25

Which structure in the brain is serotonin released from?

Answer 25

The raphe nuclei