Neurological Disorders Flashcards
Increased ICP
pressure greater than 20 mmHg
Cerebral perfusion pressure (CPP)
amount of blood flow from the systemic circulation to provide adequate perfusion to brain tissue - 50-70 mmHg
Mean arterial pressure (MAP)
the average pressure during the cardiac cycle, range from 70-110 mmHg
Describe the Cerebral Hemodynamic relationship
CPP = MAP - ICP
How does the brain adapt to increases in ICP?
a. displacement of CSF into spinal canal
b. reduction of blood volume - alters brain metabolism
- leads to hypoxia and ischemia
c. displacement of brain tissue - herniation
Brain herniation
occurs when the brain shifts across structures within the skull such as the falx cerebri, the tentorium cerebelli and the foraman magnum; occurs late in the course of increased ICP; always constitutes an emergency
Cerebral edema
An increase in the fluid content of brain tissue
Its harmful effects are caused by distortion of the blood vessels, displacement of brain tissues and eventual brain herniation
Describe what can and cannot permeate blood brain barrier
a. O2, CO2, H2O and glucose can easily pass
b. Electrolytes, dyes and organic substances pass more slowly
c. Toxic substances, plasma proteins and other large substances cannot permeate through BBB
Cushing’s Triad
a. Increased SBP with widening pulse pressure
d. Abnormal respiratory patterns
c. Bradycardia
Name the different locations to measure ICP
Ventricular, subarachnoid, intraparenchymal, epidural, subdural
Management of Shock (ABCDEFGHI)
Airway
Blood pressure
Calm
Dim the lights
Elevate the head/Eyes
Fluid and electrolytes/Food/Family
Glasgow Coma Scale
Hyperthermia/Hip flexion
ICP monitoring
Head injuries are most often caused by
Falls
Motor vehicle crashes (MVC)
Sports related injuries
Gun shot wounds
Types of Head Injury
a. Penetrating
b. Coup Contrecoup
c. Scalp injuries
d. Skull fractures
e. Concussions
f. Intracranial hemorrhages
second impact syndrome
a 2nd concussion occurs before the first has healed; rapid and severe brain swelling
Which head injury can cause the following symptoms?
headache, dizziness, vomiting, nausea, lack of coordination, difficulty balancing, may or may not lose consciousness
Concussion
arteriovenous malformation (AVM) is likely to cause which type of bleeding?
Subarachnoid
Intracerebral
Types of Intracranial Hemorrhage
a. epidural
b. subdural
c. subarachnoid
d. intracerebral
e. intraventricular
Penumbra
zone of hypoperfusion around the infarcted area; depends on the amount of collateral circulation present
Primary neuronal injury
cells in the centre of stroke area (core ischemic zone) die almost immediately
What are the two kinds of ischemic stroke?
Thrombotic
Embolic
The extent of an ischemic stroke depends on which 3 things?
a. location of occluded artery
b. size of the occluded artery
c. adequacy of collateral circulation
What causes hemorrhagic stroke?
rupture of weakened blood vessels, commonly caused by aneurysms and AVM
What are some general findings of stroke?
Headache Vomiting Seizures Changes in mental status Motor changes Communication
Management of stroke
a. Identify stroke early
b. Maintain cerebral
c. oxygenation
d. Restore cerebral blood flow
e. Prevent and manage complication
f. Prevent recurrence
g. Rehabilitation
Clinical manifestation specific to ischemic stroke
Transient hemiparesis
Loss of Speech
Hemisensory loss
Clinical manifestation specific to hemorrhagic stroke
Severe occipital and nuchal headaches
Vertigo or syncope (passing out)
Paresthesias and transient paralysis
How does ischemic and hemorrhagic stroke differ in symptom onset?
Ischemic symptoms develop slowly over minutes to hours or days
Hemorrhagic symptoms occur rapidly, typically whilst awake
Transient Ischemic Attack (TIA)
sudden, brief episode of neurologic dysfunction caused by temporary cerebral ischemia
