Nurs 3366 - Brain Attacks

What is Intracranial Pressure(ICP)?

the totality of pressures in the brain—arterial & venous pressures (blood) + CSF pressure + Brain (tissue)

What is Cerebral Perfusion Pressure(CPP)?

pressure required to get oxygenated blood into the brain to perfuse the cells of the brain

What causes Increased ICP?

cerebral edema

• increased ICP causes a decrease in CPP

What is a Brain Attack?

any interruption of the normal blood supply to a part of the brain or the entire brain, resulting in damaged brain tissue

• ischemic or hemorrhagic

What are the common etiologies of a Brain Attack?

atherosclerosis of cerebral arteries (within the brain) and/or of incoming arteries (carotids & vertebral arteries)

What is an Ischemic brain attack?

the narrowing or blockage of arteries supplying brain(80% of Brain Attacks)

• cellular ischemia leads to edema that leads infarction

thombolic, embolic or TIA

What is TIA—Transient Ischemic Attack?

causes the same S&S as a fully-evolved stroke, but does not damage brain tissue

• transient, i.e., temporary— <24 hours & have no lasting neurologic deficit

warning that more serious, fully-evolved stroke can occur at later date

What is the Hemorrhagic brain attack?

caused by the effects of blood that leaks out directly onto brain tissue

• irritates tissue, initiates inflammation process = cerebral edema

What are the causes of a Hemorrhagic brain attack?

• pressure of hypertension

• congenital vascular malformations—deformities in the arteries that predispose them to bleed

What are the S&S of a Brain Attack?

signs and symptoms will depend on WHERE the brain attack occurs

• Brain stem

• Cerebellum

• Right or left hemisphere of the cerebrum

How do you link S&S to the sight of the BA?

1. assess patient’s autonomic status (includes LOC-- level of consciousness and mental status)

2. assess sensorimotor system

   • below and above the shoulders

3. assess reflexes

How do you assess patient’s autonomic status (includes LOC-- level of consciousness and mental status)?

• check vital signs - if abnormal problem with the brain stem

• check LOC - if issue that is the first sign of a neurological event

How do you interpretate sensorimotor findings above the shoulders?

check the 12 cranial nerves (CNs) - if normal and symmetric no issue with the brain

What occurs when there is abnormalities of CN VII(Facial Nerve)?

if issue with the brain expect to have asymmetric findings, with the defect manifesting unilaterally on the opposite or contralateral side

• ex: if cerebral edema around the right CN VII, that allows a smile, you would see facial drooping on the left side of the mouth

What occurs when there is abnormalities of CN II(Optic Nerve)?

cerebral edema on the right CN II, that transmits visual images to the brain, you would expect visual defects in the two left halves

• called homonymous hemianopia

What occurs when there is abnormalities of the pupillary light reflex?

Cranial nerve II (optic) and CN III (oculomotor) control the pupillary light reflex

• Bilateral loss of the pupillary light response - both pupils either fixed and dilated or fixed and pinpoint - indicates issue with brain stem

How do you interpret sensorimotor findings BELOW the shoulders?

assess the parts that connects brain to spine to muscles in torso, arms, and legs

• the corticospinal tracts & the spinothalamic tracts

What are the Corticospinal tracts?

descending (motor) tracts (“cortico”—cortex of brain); also called pyramidal tracts’

• these axons cross over, or decussate, from their point of origin

What are the Spinothalamic tracts?

carry sensations of pain, temperature, crude and light touch from body to brain (thalamus) for processing

• cross over from one side of the body to the other side(decussate)

What occurs when there is abnormalities with the Corticospinal or Spinothalamic

tracts?

pathologic changes will usually be unilateral, on the contralateral side of the body because of decussation

What are the reflex assessment findings?

brain lesion - reflexes might diminish or become absent:

• deep tendon reflexes might become hyporeactive.

• gag, swallowing, coughing reflexes would fail to protect adequately

positive “Babinski” reflex (AKA plantar reflex) means that stroking plantar surface makes the feet move upwards

What are the issues with a Cerebellar BA?

• vertebral –basilar artery occlusion/near-occlusion

• problems with coordination and balance

• vertigo, nystagmus (rapid eye movement).

What is a Cerebral Hemispheric brain attack?

swelling & edema from hypoxia to the right or left hemisphere of the cerebrum

What are the deficits that are specific to the Left hemisphere?

dysphasia or aphasia

• inability to comprehend,

integrate, and express language

What are the deficits that are specific to the Right hemisphere?

issues with spatiality - recognizing where yourself, things, and others are in a space

• manifests as left-sided neglect – a tendency to completely ignore the environment on the left side

How can you diagnose Hemorrhage BA?

described as “the worse headache” ever experienced.