Neuro Emergencies

Question 1

Monroe-Kellie Hypothesis

Answer 1

“We have a perfect environment inside our cranium”
Cranial vault is a fixed space. If we had any increase in one component(blood, brain, CSF) there has to be a decrease in another component.

Question 2

Normal ICP measurement

Answer 2

0-15mmHg

Question 3

What is CBF

Answer 3

Cerebral Blood Flow- requires 15-20% of cardiac output to meet metabolic demands and is maintained by cerebral autoregulation

Question 4

What is CPP

Answer 4

Cerebral Perfusion Pressure- Gradient that drives CBF and is calculated as follows: CPP=MAP-ICP
Normal CPP 60-80mmHg
Brain requires 60-70 for optimal CBF
Adult goal = >70mmHg
Peds goal = >60mmHg
CPP <50mmHg = infarction

Question 5

MAP and Pulse pressure calculations

Answer 5

MAP=[(DBPx2)+SBP]/3
Pulse pressure= SBP-DBP

Question 6

How to maintain CBF

Answer 6

increase MAP and decrease ICP
*CO2 affects chemical regulation is cerebral vascular resistance
Hypocapnia will cause Vasoconstriction(could lead to infarct)
Hypercapnia will cause Vasodilation(causes an increase in ICP)
**New standard is to prevent the 3 H’s( Hypoxia, Hypotension, Hyperventilation)

Question 7

Causes of secondary TBI

Answer 7

Hypoxia, Hypo/Hypertension, Hypo/Hypercapnia, Ischemia, Edema, Vasodilation, and increased ICP

Question 8

Signs of increased ICP

Answer 8

Change in LOC, pupil size/reaction, motor response, signs of herniation(decorticate/decerebrate/blown pupils), and Cushings Triad( HTN/widening pulse pressure, bradycardia, Cheyne-Stokes respirations) Standard ICP patient will initially see tachycardia instead of brady.

Question 9

Elevated ICP treatment

Answer 9

limit suction, noise, and atmospheric pressure changes.
Fluid balance
Normothermia
Normal electrolytes
Sedation and analgesia(consider long acting paralysis)
head to bed elevated to 30 degrees
Osmotherapy with mannitol or hypertonic saline

Question 10

Concave vs Convex CT head scans

Answer 10

Concave always means an Epidural bleed.
Convex is always a Subdural bleed.

Question 11

Subdural bleed

Answer 11

40-60% mortality rate.
VENOUS BLEED
Causes: HTN, ruptured aneurysm, and trauma.
Occurs between dura and arachnoid.
typically have immediate LOC

Question 12

Subdural bleed treatment

Answer 12

advanced airway management(maintain ETCO2 35-50mmHg)
adeqaute fluid resuscitation
osmotherapy (mannitol, lasix, 3% saline)
maintain serum Na+ at upper limit of 155mEq/L
higher serum osmolarity(<320mOsm)
anticonvulsants for seizure prevention

Question 13

CT findings

Answer 13

If the bleed is lighter in color(white) then its fairly new. Darker in color(grey or black) its an older bleed

Question 14

Epidural Bleed

Answer 14

ARTERIAL BLEED(usually from middle meningeal artery) temporal lobe damage(side of the head)
occurs between cranium and dura
often associated with skull Fx
**classic presentation is initial LOC with a lucid interval, followed by neurological deterioration
causes rapid compression of the brain stem

Question 15

Epidural Bleed treatment

Answer 15

Decrease ICP
Evacuate bleed ASAP
Low mortality if treated in timely fashion

Question 16

Subarachnoid Bleed treatment

Answer 16

Treatment: Maintain SBP<140mmHg and decrease ICP
Complications: rebleed, cerebral ischemia, vasospasm, hydrocephalus
Overall morbidity/mortality is high

Question 16

Subarachnoid Bleed

Answer 16

ARTERIAL BLEED
occurs between arachnoid and Pia
Causes: Trauma, ruptured cerebral aneurysm, rupture of arteriovenous malformation(AVM)
S/S: AMS-coma, Seizures, sudden onset of severe HA, N/V

Question 17

Intraventricular Bleed

Answer 17

Primary sources: trauma(shearing forces), anuerysm, and vascular malformation
Usually a secondary bleed
Found in frontal and temporal lobe injuries

Question 18

Intraventricular Bleed Treatment

Answer 18

Prevent further insult, maximize CPP > 70mmHg, maintain SBP < 160mmHg, and control ICP. Hypertonic saline

Question 19

Diffuse Axonal Injury(DAI)

Answer 19

Often not fatal
clinical signs of TBI
small tears(petechial hemorrhage) from cu contra cu(frontal-occipital impacts)
Treatment: prevent secondary injuries, avoid the following: hypotension, hypoxia, cerebral edema, and elevated ICP.

Question 20

Brown-Sequard Syndrome

Answer 20

Ipsolateral cord legion(TEST Q)*
Hemisection of the cord(usually cervical region) that is very rare, reduced or loss of motor/power on side of lesion however pain and temperature are preserved, reversed on opposite side.

Question 20

Central Cord Syndrome

Answer 20

Greater motor weakness in upper extremities than the lower with varying degree of sensory loss

Question 20

Anterior Cord Syndrome

Answer 20

Complete motor, pain, and temp loss below the legion with sparing proprioception, vibration and touch.(most common)

Question 20

SCIWORA syndrome

Answer 20

Spinal cord injury without radiograph abnormality
(spinal shock or spinal contusion)

Question 21

Neurogenic shock symptoms

Answer 21

Hypotnsion, Peripheral vaso-dilation(flushed/red skin), and bradycardia

Question 22

Autonomic dysreflexia

Answer 22

Potentially life threatening HTN occurs in individuals with spinal cord injury above T6 causes imbalance in reflex sympathetic discharge check foley cath for kinks and drain slowly think of other noxious stimuli that may be the cause(could be a neurogenic bladder)

Question 23

Neurgenic bladder

Answer 23

Urinary bladder malfunction due to neurogenic dysfunction

Question 24

Little tidbits of neurogenic shock info

Answer 24

One episode of hypoxia or hpypotension increases mortality by 50%, CPP is the key end point for resuscitation efforts, Hypercarbia leads to increased cerebral blood flow and increased ICP, and Hypocarbia leads to decreased cerebral blood flow and possible cerebral ischemia.

Question 25

**Quiz question** How does an epidural hematoma present?

Answer 25

Answer: unconsciousness, followed by a brief period of lucidity, and a period of rapid decrease in LOC

Question 26

**Quiz question** How does a patient with Brown-Sequard syndrome present?

Answer 26

Answer: Ipsilateral motor loss, contralateral pain loss Explanation: results from loss of sensation and motor function caused by a lateral hemi section of the spinal cord