Neurological Flashcards
A brain insult that results from a mechanical disruption of brain tissue from an external impact or injury to the head refers to
traumatic brain injury
4 lobes of the brain
frontal, parietal, temporal, occipital
3 points that death occurs at after a TBI?
(1) immediately after injury
(2) within 2 hrs of injury
(3) approx. 3 weeks after injury
4 ventricles containing CSF?
right cerebral hemisphere, left cerebral hemisphere, midbrain, central canal of the spinal cord
“a change in any one of these components must be accompanied by a reciprocal change in one or both of the other components. If this reciprocal change is not accomplished, the result is an increase in intracranial pressure” this is known as
Monroe-Kellie hypothesis
formula for ICP?
Brain volume (80%) + cerebral blood volume (12%) + CSF (8%)
Normal ICP
0 - 15 mmHg
the pressure gradient associated with cerebral blood flow (CBF) that is necessary to supply adequate amounts of blood to the brain refers to
cerebral perfusion pressure (CPP)
CPP must be greater than ____ to ensure adequate cerebral perfusion
70 mmHg
CPP formula
MAP (mean arterial pressure) - ICP = CPP
A brain insult that results from a mechanical disruption of brain tissue from an external impact or injury to the head refers to
TBI
transportation related accidents account for _____ of all TBI’s
50%
3 primary mechanisms of injury associated with TBI?
(1) acceleration/deceleration
(2) rotational
(3) penetration
acceleration injury occurs when
a moving blunt object strikes the head involving transfer of injury along a linear path - causes injury at site of impact
deceleration injury occurs when
the head strikes an immovable object and as the skull ceases movement, the brain continues to move until it hits the skull - force of deceleration causes brain injury as it hits the skull
what is coup-countre coup injury?
occurs when following the initial acceleration (coup) injury, the brain rebounds and sustains additional decelerations (countre coup) injury
rotational injuries occur when
rotational forces cause the brain to twist within the meninges and the skull, resulting in stretching and tearing of blood vessels and shearing of neurons
primary brain injury occurs
at the moment of impact as a result of mechanical forces to the head
secondary brain injury occurs
at the biochemical and cellular response to the initial trauma that can exacerbate the primary injury and cause loss of brain tissue not originally damaged
skull fractures are caused by
substantial force absorbed by the skull with or without underlying brain tissue injury
clinical manifestations associated with a basilar skull fracture
CSF coming out of the ears and nose, racoon eyes, Battle’s sign, positive halo sign
what is a positive halo sign
a clot in the CSF
what is Battle’s sign
bruising / hematoma around the ear
focal brain injuries
injuries localized to the area of direct injury in the brain
cerebral hematoma
- result of injury to a cerebral vein or artery
- a group of focal cerebral injuries associated with the accumulation of blood in the cranial vault
subdural hematoma (SDH)
accumulation of blood between the dura and the arachnoid layers of the meninges
Subdural hematoma is usually secondary to
venous injury in subdural space leading to slow onset of symptoms often not recognized for days or weeks
acute subdural hematoma is less than __ hrs
48
what are the symptoms of acute subdural hematoma
drowsiness, headache, confusion, slowed thinking, agitation, unilateral abnormality
chronic subdural hematoma lasts for ___ weeks
2
symptoms of chronic subdural hematoma
headache, lethargy, absent-mindedness, vomiting, seizures, stiff-neck, pupil changes, hemiparesis
epidural hematoma occurs in
the space between the dura mater and the skull
typical sign of epidural hematoma
brief loss of consciousness followed by an episode of being alert and orient, and then another episode of loss of consciousness
hallmark of epidural hematoma
dilated and fixed pupil on the same side as the impacted area
intracerebral hematoma (ICH)
bleeding directly into the cerebral tissue resulting in destruction of cerebral tissue, cerebral edema and increased ICP
clinical manifestations fo intracerebral hematoma
headache with reduced LOC, unilateral pupil dilation, hemiplegia
contusion
bruising of soft tissue
- commonly seen in TBIs
diffuse head injuries occur in _______ areas of the brain
several
diffuse head injuries include
concussion, diffuse axonal injury (DAI), subarachnoid hemorrhage (SAH)
S&S of concussion
amnesia, headache, dizziness, vertigo, n+v, slurred speech, confusion, inability to function at pre-injury level, might lose consciousness
diffuse axonal injury occurs as a result of
damage to the axons or disruption of axonal transmission to the neural impulses
- stretching and tearing of axons d/t movement of the brain inside the cranium at the time of impact
subarachnoid hemorrhage
accumulation of blood/hematoma between the arachnoid layer of the meninges and brain
complications associated with increased ICP
diabetes insipidus, syndrome of inappropriate antidiuretic hormone, cerebral salt wasting, seizure activity, brain herniation, brain death
spinal cord injury (SCI)
sudden traumatic injury that either results in a bruise, a partial injury or a complete injury to the spinal cord
most common neurological level of SCI
C5
in paraplegia what is the most common level of injury?
T12
a secondary SCI occurs as a result of
vascular injury to the cord
primary SCI
neurological damage that occurs at the moment of impact
what are the goals of nursing care for SCI
- Maximize potential for neurological recovery
- Prevent or minimize complications
- Regain life skills and independence
neurogenic shock occurs with
SCI above T6
spinal shock usually occurs ______ mins after injury
30 - 60 mins
clinical manifestations of acute SCI
muscle weakness, loss of voluntary muscle movement and/or feeling in chest/arms/legs, breathing problems, loss of bowel and bladder function, changes in fertility (more in men than women), inability to regulate BP effectively, reduced control of body temperature, inability to sweat below level of injury, chronic pain
signs of autonomic dysreflexia
increased BP (vasoconstriction), increased blood sugar, decreased elimination, flushing (vasodilation), bradycardia (below 40)
brain volume remains constant through the blood brain barrier unless
disrupted by trauma or metabolic abnormalities (should be 80% of ICP)
epidural hematoma is common with high impact to
temporal area
unstable SCI
damage to two or more spinal columns
cerebral blood volume is maintained at a
constant level through cerebral blood flow (should be 12% of ICP)
classifications of diffuse axonal injuries
mild - coma less than 24 hrs
moderate - coma more than 24 hrs with transient flexor or extensor posturing
severe - coma prolonged, fever, diaphoresis, severe extensor posturing
3 types of subdural hematoma
acute - symptoms within 24-48 hrs of injury
subacute - symptoms within 2-14 days of injury
chronic - symptoms after 2+ weeks after injury
___% of SCI pts develop persistent neuropathic pain
40%
sympathetic nervous system responses in autonomic dysreflexia
increased perfusion and ventilation - increases BP, increased blood sugar, decreased elimination and digestion
how do you assess cerebral tissue perfusion
LOC, PERRLA, oculomotor responses, vitals, CN reflexes, ICP monitoring, cerebral oxygenation monitoring, CT, MRI, EEG, cerebral angiography, lumbar puncture, transcranial doppler
what are the parasympathetic nervous system responses in autonomic dysreflexia
massive vasodilation - causes flushing, bradycardia - below 40
management of subdural hematoma
surgical evacuation of hematoma, possible placement of subdural drain, monitoring LOC and neurological assessments
upper motor neurons of the _______ and lower motor neurons of _______ in the central horn of the spinal cord carry impulses that affect _______________
brain
cell bodies
movement
intracranial pressure is the pressure exerted by:
the CSF within the ventricles
CSF should make up how much of the ICP
8%
motor neurons regulate
visceral organs, innervate smooth and cardiac muscles, and glands
peripheral sensory nerves transmit stimulation from
sensory receptors in the skin, muscles, sensory organs, and viscera to the dorsal horn of the spinal cord
auto regulation of blood flow
constant supply of blood to the brain regardless of systemic BP changes (matching CBF with metabolic needs leads to auto regulation)
S&S of subarachnoid hemorrhage
severe headache, intracranial hypotension, neck stiffness (nuchal rigidity)
management of epidural hematoma
- surgical evacuation of the hematoma
- possible placement of ICP monitor
- admission to ICU for neurological checks and ICP monitoring
- observe for sudden changes in LOC or a unilateral, fixed, and dilated pupil
what is considered a first-line treatment for neuropathic pain?
gabapentin
management of diffuse head injuries
- not localized to a particular area so it is difficult to diagnose and treat
- recovery depends on severity of injury
- neurological assessments and pain management
- in moderate to severe injury you want to decreased ICP, increase CPP, and stabilize VS
- rehabilitation may be required
the brain attempts to meet metabolic demands by increasing or decreasing ____________________________ as required
cerebral blood flow
functions of CSF
- cushioning and supporting the brain/ spinal cord
- nourishing brain tissue
- removal of wastes
- monitoring carbon dioxide levels
management of intracerebral hematoma
- manage cerebral edema
-promote adequate cerebral perfusion - hemorrhage may be reabsorbed over a period of time
- surgical evacuation usually not possible due to location
CSF is produced by
the choroid plexus
what arteries are included in the circle of willis?
- Anterior Cerebral
- Anterior Communicating
- Posterior Communicating
- Posterior Cerebral
autonomic dysreflexia occurs more often if injury is
T6 and above
CSF is comprised of what
mainly water in addition to protein, sodium, chloride, potassium, bicarbonate & glucose
CSF should not contain
RBC
