Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

APEX > Neuro > Flashcards

Neuro Flashcards

1
Q

Where is CSF absorbed? Produced?

A

Absorbed in the arachnoid villi in superior saggital sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

CMR02

A

3-3.8mL/02/100 g brain tissue/min

60% electrical activity, 40% cell integrity/housekeeping

CMR02 ↓ 7% for each 1C temp ↓

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Locations of cell bodies of spinothalamic neurons

A

1st order neuron: Dorsal root ganglion

2nd order neuron: Dorsal horn

3rd order neuron: Thalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Posterior circulation of brain

A

Vertebral, basilar a.

Aorta → subclavian → vertebral → basilar → posterior fossa, cervical spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Anterior circulation of brain

A

Carotid

Aorta → carotid → internal carotid → O of Willis → hemispheres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

CBF

A

45-55mL/100g tissue/min (global)

<20= evidence of ischemia
15=complete cortical suppression
<15=membrane failure and cell death

Determined by:
CMR02
CPP
Venous pressure
PaC02
Pa02
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Most common site of transtentorial herniation?

A

Temporal uncus

With ↑ ICP, temporal uncus is forced from supratentorial space → infratentorial space. This ↑ pressure on the midbrain..
..CNIII (oculomotor) originates from the midbrain and crosses near the tentorium. Herniation here puts pressure on the nerve, making it ischemic. Clinically, this manifests as a fixed and dilated pupil.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Cushing’s triad

A

HTN, bradycardia, irregular respiration’s

HTN: ↑ ICP → ↓ CPP. BP ↑ in effort to preserve CPP

Brady: reflex brady from HTN

Irregular resp: Compression of medulla → irregular breathing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Anticonvulsants that → thrombocytopenia, anemia?

A

Thrombocytopenia: Valproic acid (kids>adults), Carbamazepine

Aplastic anemia: Phenytoin, Carbamazepine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Dorsal column (medial lemnsical)

A

SENSORY

Mechanoreceptive sensations:

  • fine touch, proprioception, vibration, pressure
  • capable of 2 point discrimination
  • large, myelinated, fast fibers

Perfused by posterior blood supply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Meds to avoid with Parkinson’s

A

Anything that antagonizes dopamine

Metoclopramide
Butyrophenones (hallow and droperidol)
Phenothiazines (promethazine)

Alfentanil: May cause acute dystonic reaction
Ketamine is controversial

Sux and NDMBs both actually OK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Only 3 conditions definitively linked to MH

A
  • King Denborough syndrome
  • Central core disease
  • Multiminicore disease

ALSO: families from Wisconsin, WV, Michigan appear to be at higher risk. Males, and youth as well.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

4 Determinants of CBF

A

CMR02 (3.5 mL/02/100g brain tissue/min)

CPP [(MAP-ICP or CVP, whichever higher)] - intracranial tumors, head trauma, VAs abolish autoregulation

Venous pressure (↑ VP → ↓ cerebral drainage → ↑ volume)

PAC02

Pa02

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Bleeding, vasospasm with cerebral aneurysm

A

Arterial bleeding is usually subarachnoid

Venous bleeding is usually subdural

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Corticospinal tract (pyramidal)

A

MOTOR: most important motor pathway

  • lateral corticospinal tract decussates in medulla
  • ventral corticospinal tract fibers remain on ipsilateral side as they descend via ventral corticospinal tract, and cross over to the contralateral side of spinal cord in cervical or thoracic area

BABINSKI’S sign is a test of the integrity of the corticospinal tract.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Difference between upper motor neurons and lower motor neurons

A

Upper motor neurons: cortex → ventral horn

  • If an injury occurs above the level of decussation in the medulla, paralysis will be contralateral
  • If an injury occurs below the level of decussation in the medulla, paralysis will be ipsilateral
  • Upper motor neuron injury presents as hyperreflexia and spasticity

Lower motor neurons: ventral horn → NMJ

  • These are the fibers that link the spinal cord to a muscle
  • Injury to lower motor neuron → ipsilateral paralysis
  • Lower motor neuron injury presents with impaired reflexes and flaccid paralysis
17
Q

Spinothalamic tract (anterolateral)

A

SENSORY

Pain, temperature, crude touch, tickle, itch, sexual sensation

  • cannot do 2-point discrimination
  • Smaller, slower fibers, but they are still myelinated
18
Q

Laminae

A

Grey matter is subdivided into 9 laminae

  • Laminae I-VI (1-6) = dorsal = sensory
  • Laminae VII-IX (7-9) = ventral = motor

-pain neurons synapse in the substantia gelatinosa in laminae II, III

19
Q

Types of peripheral mechanoreceptors that comprise dorsal column/medial lemniscal system

A

Meissner’s corpuscles: Two point discriminative touch, vibration
Merkel’s discs: Continuous touch
Ruffini’s endings: Proprioception , prolonged touch and pressure
Pacinian corpuscles: Vibration

20
Q

How can you tell if its neurogenic shock or hypovolemic shock in a trauma?

A

Neurogenic → bradycardia, hypotension, hypothermia with pink, warm extremities

Hypovolemic → tachycardia, hypotension, cool clammy extremities

21
Q

Where is the BBB not present/not great?

A 
ANATOMY:
CRTZ
Posterior pituitary
Pineal gland
Parts of hypothalamus
PATHOLOGY:
Tumor
TBI
Infection
Ischemia
Poorly developed in neonates
22
Q

Order of CSF flow

A 
Lateral ventricles → 
Foramen of Monro → 
3rd ventricle → 
Aqueduct of Sylvius → 
4th ventricle → 
BLL paired foramen of Luschka, midline foramen Magendie → subarachnoid space (brain and SC) + central canal of SC → 
superior saggital sinus (absorption)
23
Q

Relationship between PaC02 and CBF

A

Linear.

PH of the CSF around the arterioles controls the CVR.

  • at PaC02 40mmHg, CBF = 50mL/100g/min
  • 1mmHg ↑ = CBF ↑ 1-2 (max vasodilation at PaC02 80-100)
  • 1mmHg ↓ = CBF ↓ 1-2 (max vasoconstriction at PaC02 25)

Metabolic acidosis does not affect CBF because H+ does not pass thru BBB. Only C02 does.

24
Q

How does Pa02 affect CBF?

A
  • Pa02 below 50-60mmHg → cerebral vasodilation → ↑ CBF

- Pa02 above 60mmHg, no effect on CBF.

25
Q

Anticoagulated patient with head injury

A
  • Warfarin can be reversed with FFP, prothrombin complex concentrate, and/or recombinant factor VIIa.
  • Plavix, aspirin or both can be reversed with platelet transfusion. Possibly recombinant VIIa too.
26
Q

Drugs that can help with locating seizure foci during cortical mapping

A

Methohexital
Etomidate
Alfentanil

All ↑ EEG activity

27
Q

Levodopa + carbidopa

A

Together they ↑ [] of dopamine in basal ganglia.
→ levodopa is a dopamine precursor. Normally it’s metabolized to dopamine in the circulation, and dopamine in the circulation does not penetrate the CNS. Carbidopa is a decarboxulase inhibitor that prevents levodopa metabolism in the blood, letting more levodopa enter the CNS.

SE: ↑ inotropy, tachycardia, orthostatic hypotension, dyskinesia, N/V

28
Q

Anterior spinal artery syndrome (Beck’s syndrome)

A

AoX placed above Artery of Adamkiewicz → ischemia to lower portion of anterior spinal cord.
→ flaccid paralysis of lower extremities (corticospinal tract)
→ bowel and bladder dysfunction (autonomic fibers)
→ loss of temperature and pain sensation (spinothalamic)
→ preserved touch and proprioception (dorsal column)

Corticospinal tract, autonomic fibers, and spinothalamic tract are all perfused by anterior blood supply.

29
Q

Tensilon test

A

Diagnostic test used to determine cholinergic crisis from myasthenic crisis

1-2mg edrophonium is administered

  • If muscle weakness is worse, then the patient has a cholinergic crisis and needs an anticholinergic.
  • If muscle strength improves, then the patient has an exacerbation of myasthenic symptoms.
30
Q

NMBs with myasthenia gravis

A

-NDMBS: ↑ sensitivity, reduce dose by at least 1/2

-Sux: ↑ resistance, increase dose
→ may have ↑ duration of sux if on pyridostigmine however, because it messes with psuedocholinesterase

31
Q

Eaton Lambert syndrome

A

-High correlation with small cell carcinoma of lung (oat cell carcinoma). Consider this disorder in all patients with suspected lung cancer presenting for mediastinoscopy, bronch, or thoracoscopy.

  • IgG mediated destruction of PRESYNAPTIC voltage-gated calcium channel.
  • Postsynaptic nicotinic receptor is present in normal amount and function.
  • Weakness is generally worse in the morning and improves as the day goes on. (Reverse with MG)
32
Q

Cyclosporine

A

Prolongs duration of sux

33
Q

Things that can exacerbate SLE

A

Pregnancy, infection, surgery, stress, enalapril, d-pencillamine

Captopril, hydralazine, isoniazid, methyldopa, procainamide

“PISSED CHIMP”

34
Q

Things that can exacerbate MS

A

Stress, ↑ body temp, spinal anesthesia

Sux can cause life threatening hyperkalemia

35
Q

MOA of Dantrolene, dose

A

2 MOAs:
→ Halts calcium release from RyR1 receptor
→ prevents calcium entry into the myocyte, which ↓ the stimulus for calcium-induced calcium release

  • 2.5mg/kg IV q5min
  • continue in ICU @ 1mg/kg q6hr for 48-72 hrs
36
Q

What would the earliest sign of MH be in an SPONTANEOUSLY VENTILATING patient be?

A

Tachypnea (↑ MV)

37
Q

Benefits of epidural anesthesia

A
  • ↓ gluconeogenesis
  • ↑ glucose sensitivity
  • improved glucose utilization
  • improved post op glucose tolerance
38
Q

Cardiac risks of RA

A

Aortic regurg as a function of dilated aortic root

APEX (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions