Neuro- Brain Injury, CVA, Guillain Barre Syndrome

Question 1

cranium is made up of (% of each)

Answer 1

• blood 10%
• CSF 10%
• Tissue 80%

Question 2

What is CPP?

How is it calculated?

Answer 2

Cerebral Perfusion Pressure (70-100mmHg) = Mean Arterial Pressure minus Inter Cranial Pressure (5-15mmHg)

Question 3

How do you calculate MAP?

Answer 3

MAP = Systolic + (2x Diastolic) Divided by 3

Example
B/P= 130/60
MAP = 83 3
MAP) 83- 10 (average of 5-10 mmHg) = 73 (is in the average of 70-100mmHg

Question 4

At what CPP is brain schema likely?

Answer 4

Brain ischemia when CPP 40mmhg

Question 5

What is the Monroe-Kellie Hypothesis?

Answer 5

o Physiologic Minor fluctuations in blood, tissue and CSF vol
o Compensate for each other to keep ICP range

Question 6

What are the 3 kinds of compliance to compensate for inc ICP?

Answer 6

• skull is non-expandable
• 1st – compliance = displacement of CSF into spinal cord and then CSF is reabsorbed
• 2nd – compliance = displacement of blood )limited because needs perfusion.
• 3rd – compliance = compression and displacement of brain tissue →causes death! Pushing against the cranium, or the brain stem pushes out through the hole in the bottom hole the foramen magnum

Question 7

How can trauma affect ICP?

Answer 7

trauma→abnormal variation in volume of one or
more components→inc Inner Cranial Pressure
- inc ICP often associated with proliferating lesion (eg/ tumor, hemorrhage)

Question 8

What is Cushing’s Reflex?

Answer 8

• Also brains response to inc ICP
• the body’s response triggered by CPP dropping causing brain ischemia
• inc MAP (up to 270) ∴inc bp and inc heart rate d/t inc blood to area

Question 9

What is Cushing’s Triad?

Answer 9

Cushing’s Triad:

1) widening pulse pressure is difference of systolic and diastolic (often w/ HTN) d/t inc bp
2) Reflexive bradycardia
3) irregular breathing

Question 10

Path of hemorrhage/ hematoma

Answer 10

o Vascular trauma -> hemorrhage -> hematoma
o l/o neural fx (affected area)
• both at site of hemorrhage and at “target” area of neuro

Question 11

Three areas of hemorrhage and Hematoma

Answer 11

• Intracerebral vessel
o Hemorrhage into brain tissue

• Subdural
o Between dura and arachnoid mater
o Encapsulated mass -> cell lysis -> inc -> fluid influx

• Epidural
o Between skull and dura mater
o d/t head injury and fracture
o normally middle meningeal artery

Question 12

What is Guillain Barre Syndrome

Answer 12

Characterized by an autoimmune attack on peripheral nerve myelin causing paralysis. Oddly, is reversible with tx.

Question 13

Etiology of GBS

Answer 13

Idiopathic

Though is autoimmune and preceded by upper respiratory Tract or GI infect (1-4weeks)

Question 14

What Microbe is often responsible for GBS trigger?

Answer 14

Mostly Campylobacter jejuni
• (Poultry, water, unpasteurized milk)
Gram Negative Bacillus

Also, could be Virus as well (eg EBV)
?WHY ALWAYS EBV?

Question 15

Patho of GBS

Answer 15

Preceded by upper respiratory Tract or GI infect (1-4weeks)
Abs and T-cells target myelin sheath (d/t IR)
• Schwann cells (if not dmg by IR, will be by INLFM)

Question 16

MNFTS of GBS

Answer 16

o Those of URT or GI infect (may be present)
o Paresthesias
o Progressive, ascending muscle weakness and paralysis
o Deep muscle pain (in the shoulder and thigh)
o Without intervention complete paralysis will happen
o Can lead to resp. failure (mortality of about 30%)

Question 17

Dx of GBS

Answer 17

o Hx (proceeding inf.?  Ascending paresthesia?)
o Physical exam (is it muscular or neuro or combo?) CHECK Muscle weakness and reflexes

o Measure nerve conduction- Dec nerve conduction

o Inc protein in CSF (3 things you’d see in CSF??)

Question 18

Tx of GBS

Answer 18

o Maintain vital fx (respiratory and heart)
o Plasmapheresis (relates to a self study)
• Remove trouble plasma (removing AB and…) and infuse new plasma)
o IV IgG (provides opportunity for recovery)
o Pain tx
o Most recover fully in 6 -12 months