Neurologic Diseases (Exam III) Flashcards
What vessels provide the blood flow to the brain?
- 80% via the carotid arteries
- 20% via the vertebral arteries
Name the pertinent vasculature of the circle of Willis.
This card is just to look at the picture on the other side.
5 factors
How is cerebral blood flow modulated?
- CMR (cerebral metabolic rate)
- CPP (cerebral perfusion pressure) MAP-ICP
- ICP
- PaCO₂
- PaO₂
How much O₂ is required by the brain per minute?
3 mlO₂ / 100g / min
What is the average cerebral blood blow?
50ml/100g/min
~750ml/min
15% of CO
What drugs and/or metabolic states will decrease CMR?
- Hypothermia
- Anesthetic drugs (VAA, prop, etomidate, etc)
What drugs and/or metabolic states will increase CMR?
- Hyperthermia
- Seizures
- Ketamine
- N₂O
What temperature range do we generally want to keep our patients in?
36 - 38° C
This card previously said 42 which is 107.6F lol
How is Cerebral Perfusion Pressure (CPP) calculated?
CPP = MAP - ICP
Name the three components of the brain that form the Monroe-Kellie Doctrine.
- Brain 80%
- Blood 12%
- CSF 8%
What is the Monroe Kellie Doctrine?
Any increase in one component of the intracranial space (blood, brain tissue, CSF) must be met with an equivalent decrease in another to prevent increased ICP.
What is the normal CPP range?
80 - 100 mmHg
An ICP > ____ mmHg will compromise CPP.
30
What pathologic processes or disease states are known to cause an increase in ICP?
- Tumors
- Hematomas
- Blood in CSF
- Infection
- Aqueductal Stenosis
Tx? Shunts? Shunt malfunction happens when?
Hydrocephalus
- CSF accumulation causing high ICP
- Tx w/ lasix and acetazolamide
- VP shunt or
- endoscopic third ventriculostomy (ETV)
-catheter placed into lateral ventricle –> drains into peritoneal space, r. atrium, or pleural space - Shunt malfunction occurs most frequently in first year
What range is normal for ICP?
5 - 15 mmHg
What symptoms are seen with abnormally high ICP?
- Headache
- N/V
- Papilledema
- ↓LOC
What does Cushing’s Triad indicate?
What is the triad?
↑ICP
- ↑sBP
- ↓HR
- ↓RR (Cheyne-Stokes)
Uncal Herniation
- Subtype of transtentorial herniation
- Medial portion of temporal lobe (uncus) herniates over the tentorium cerebelli
- Sx: Pupillary dilation, ptosis, lateral deviation of affected eye, brain stem compression
What is CN I?
Olfactory - smells
What is CN II?
Optic - vision
What is CN III?
Oculomotor - vision (convergence, pupillary accomodation)
What is CN IV?
Trochlear - vision (convergence, pupillary accommodation)
What is CN V?
Trigeminal - Face