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Neurological assessment
Anatomic and Physiologic Overview
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The nervous system consists of two divisions:
the central nervous system (CNS) including
the brain and spinal cord
peripheral nervous system, which includes
cranial and spinal nerves.
The peripheral nervous system can be further
divided into the somatic, or voluntary,
nervous system, and the autonomic, or
involuntary, nervous system.
The function of the nervous system is control
of all motor, sensory, autonomic, cognitive,
and behavioral activities.
The nervous system has approximately 10
million sensory neurons that send information
about the internal and external environment
to the brain and 500,000 motor neurons that
control the muscles and glands.
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The brain itself contains more than 100 billion
cells that link the motor and sensory
pathways, monitor the body's processes,
respond to the internal and external
environment, maintain homeostasis, and
direct all psychological, biologic, and physical
activity through complex chemical and
electrical messages
Anatomy of the Nervous System
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Cells of the Nervous System
The basic functional unit of the brain is the
neuron It is composed of a cell body, a
dendrite, and an axon.
The axon is a long projection that carries
impulses away from the cell body. Nerve cell
bodies occurring in clusters are called ganglia
or nuclei.
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Neurotransmitters
Neurotransmitters communicate messages
from one neuron to another or from a neuron
to a specific target tissue .
(In fact, probably all brain functions are
modulated through neurotransmitter receptor
site activity, including memory and other
cognitive processes
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Many neurologic disorders are due, at least in
part, to an imbalance in neurotransmitters—
that is :
an increase in gamma-aminobutyric acid
(GABA) in alcohol withdrawal seizures
(a decrease in dopamine in Parkinson's
disease and a decrease in acetylcholine in
myasthenia gravis
The Central Nervous System
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Brain
The brain is divided into three major areas:
the cerebrum, the brain stem, and the
cerebellum.
The cerebrum is composed of two
hemispheres, the thalamus, the
hypothalamus, and the basal ganglia.
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Each hemisphere has four lobes:
parietal, occipital, temporal, & frontal. The
cerebral lobes control complex problemsolving; value judgments; language;emotions;
interpretation of visual images; &
interpretation of touch, pressure,temperature,
& position sense.
Each hemisphere sends and receives
impulses from the opposite sides of the body
and consists of four lobes "frontal, parietal,
temporal and occipital". The lobes are
composed of a substance known as gray
matter, which mediates higher-level-functions
such as memory, perception, communication,
and initiation of voluntary movements.
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The brain stem includes the midbrain, pons,
medulla, Is a major sensory and motor
pathway for impulses running to and from the
cerebrum. Regulates body functions such as
respiration, auditory and visual reflexes,
swallowing.
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The cerebellum is located under the
cerebrum and behind the brain stem).
contains the major motor and sensory
pathways. It controls smooth, coordinated
muscle movements and helps to maintain
equilibrium.
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The brain accounts for approximately 2% of
the total body weight; in an average young
adult, the brain weighs approximately 1,400 g
whereas in an average elderly person, the
brain weighs proximately 1,200g
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The meninges (fibrous connective tissues
that cover the brain and spinal cord) provide
protection, support, and nourishment to the
brain and spinal cord. The layers of the
meninges are the dura, arachnoid, and pia
mater .
Cerebrospinal Fluid
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CSF, a clear and colorless fluid with a
specific gravity of 1.007, is produced in the
ventricles and is circulated around the brain
and the spinal cord through the ventricular
system. There are four ventricles: the right
and left lateral and the third and fourth
ventricles
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CSF is produced in the choroid plexus of the
lateral, third, and fourth ventricles. The
ventricular and subarachnoid system
contains approximately 150 mL of fluid; each
lateral ventricle normally contains 25 mL of
CSF .
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The composition of CSF is similar to other
extracellular fluids (such as blood plasma), but
the concentrations of the various constituents
are different.
The laboratory report of CSF analysis usually
contains information on color, specific gravity,
protein count, white blood cell count, glucose,
and other electrolyte levels Normal CSF
contains a minimal number of white blood cells
and no red blood cells .
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Cerebral Circulation
The cerebral circulation receives
approximately 15% of the cardiac output, or
750 mL per minute. The brain does not store
nutrients and has a high metabolic demand
that requires the high blood flow.
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The brain's blood pathway is unique because
it flows against gravity; its arteries fill from
below, and the veins drain from above.
In contrast to other organs that may tolerate
decreases in blood flow because of their
good collateral circulation, the brain has poor
collateral blood flow, which may result in
irreversible tissue damage when blood flow is
occluded for even short time periods
Spinal Cord
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The spinal cord is located in the vertebral
canal and extends from the medulla
oblongata to the first lumbar vertebra,and
serving as the connection between the brain
and the periphery.
Approximately 45 cm (18 in) long and about
the thickness of a finger,
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The spinal cord is an H-shaped structure
with nerve cell bodies (gray matter)
surrounded by ascending and descending
tracts (white matter)
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The spinal cord conducts sensory impulses up
ascending tracts to the brain, conducts motor
impulses down descending tracts to neurons
that stimulate glands and muscles throughout
the body, and is responsible for simple reflex
activity. Reflex activity involves various neural
structures.
Peripheral Nervous System
The peripheral nervous system consists of 12
pairs of cranial nerves and 31 pairs of spinal
nerves
 These nerves are categorized as two types of
fibers: somatic and autonomic. autonomic
nervous system mediates unconsciousness, or
involuntary activities.
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Spinal Nerve
The spinal cord is composed of 31 pairs of
spinal nerves: 8 cervical, 12 thoracic, 5
lumbar, 5 sacral, and 1 coccygeal. Each
spinal nerve has a ventral root and a dorsal
root
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Autonomic Nervous System
The autonomic nervous system regulates the
activities of internal organs such as the heart,
lungs, blood vessels, digestive organs, and
glands. Maintenance and restoration of
internal homeostasis is largely the
responsibility of the autonomic nervous
system.
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There are two major divisions: the
sympathetic nervous system, with
predominantly excitatory responses, most
notably the “fight or flight” response .
and the parasympathetic nervous system,
which controls mostly visceral functions.
Assessment: The Neurologic Examination
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Health History
An important aspect of the neurologic
assessment is the history of the present
illness. The initial interview provides an
excellent opportunity to systematically
explore the patient's current condition and
related events while simultaneously
observing overall appearance, mental
status, posture, movement, and affect.
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Neurologic disease may be stable or
progressive, characterized by symptom-free
periods as well as fluctuations in symptoms
The nurse should be aware of any history of
trauma or falls that may have involved the head
or spinal cord. Questions regarding the use of
alcohol, medications, and illicit drugs are also
relevant.
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The history-taking portion of the neurologic
assessment is critical and, in many cases
of neurologic disease, leads to an
accurate diagnosis. .
Neurological assessment
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The Glasgow Coma Scale
Best Eye-Opening Response
Score
Spontaneously
4
To speech
3
To pain
2
No response
1
Best Motor Response Score
Obeys commands
6
Localizes stimuli: attempt to remove noxious stimuli 5
Withdrawal from stimulus :to avoid noxious stimuli 4
Abnormal flexion (decorticate)
3
Abnormal extension (decerebrate)
2
No response - flaccid
1
The Glasgow Coma Scale
Best Verbal Response
 Oriented
 Confused conversation:
Answer not appropriate to question
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Score
5
4
Inappropriate words: disorganized ,random speech
3
Incomprehensible sounds
2
No response
1
A total score of 3 to 8 suggests severe impairment, 9 to 12
suggests moderate impairment, and 13 to 15 suggests mild
impairment.
Categories of consciousness
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Alert (full consciousness): normal
Awake: may sleep more than usual or be somewhat confused on
first awakening, but fully oriented when Aroused.
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Confused :pt disoriented to time and place put usually oriented
to person ,with impaired judgment and decision making.
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Delirious: pt disoriented to time and place and person with loss
of contact with reality and often has auditory or visual
hallucination.
Lethargic: drowsy but follows simple commands when
stimulated, in which the pt needs an increased stimulus to be
awakened.
Comatose: may have no response to any stimulus.
Clinical Manifestations
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Pain is considered an unpleasant sensory
perception and emotional experience associated
with actual or potential tissue damage or
described in terms of such damage
Seizures are the result of abnormal paroxysmal
discharges in the cerebral cortex, which then
manifest as an alteration in sensation, behavior,
movement, perception, or consciousness
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Dizziness and Vertigo
Dizziness is an abnormal sensation of
imbalance or movement.. About 50% of all
patients with dizziness have vertigo, which is
defined as an illusion of movement, usually
rotation . Vertigo is usually a manifestation of
vestibular dysfunction. It can be so severe as
to result in disorientation, loss of equilibrium
(staggering), and nausea and vomiting.
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Visual Disturbances
Lesions of the eye itself (eg, cataract),
lesions along the pathway (eg, tumor), or
lesions in the visual cortex (from stroke)
interfere with normal visual acuity.
Abnormalities of eye movement can also
compromise vision by causing diplopia or
double vision.
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Weakness
Weakness, specifically muscle weakness, is
a common manifestation of neurologic
disease.
Abnormal Sensation
Numbness, abnormal sensation, or loss of
sensation is a neurologic manifestation of
both central and peripheral nervous system
disease
Diagnostic Evaluation
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Computed Tomography Scanning (CT). The
images provide cross-sectional views of the
brain, with distinguishing differences in tissue
densities of the skull, cortex, subcortical
structures, and ventricles.
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Magnetic Resonance Imaging (MRI) uses a
powerful magnetic field (Can be performed
through magnetic waves which stimulates
nuclei of the atoms in the body ) to obtain
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images of different areas of the body
An MRI scan can be performed with or
without a contrast agent and can identify a
cerebral abnormality earlier and more clearly
than other diagnostic tests .
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It is used to detect CNS tumors, infectious
problem of the CNS
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allowing the clinician to monitor a tumor's
response to treatment. It is particularly useful
in the diagnosis of multiple sclerosis .
Cerebral angiography
1-conventional angiography. For diagnosis of cerebral
aneurysm,, vasospasm, carotid artery disease.
*Complication: cerebral embolus, hemorrhage or
hematoma at the site of catheter insertion,
.vasospasm, thrombosis, allergic reaction
Electrophysiology studies
Electroencephalogram( EEG)
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*It is a recording of electrical impulses
generated by brain.
*Purpose include detection of area of abnormal
.electrical activity
lumber puncture(LP)
*A lumbar puncture (spinal tap) is carried out by inserting a
needle into the lumbar subarachnoid space .
The purpose of lumber puncture is to obtain CSF sample for
analysis ( subarachnoid hemorrhage and infection).
*It is performed by insertion of 20 –22 gauge needle into the
subarachnoid space at L3-L4 or L4 -L5 level by putting
patient in lateral recumbent position .
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Usually, specimens are obtained for cell
count, culture, and glucose and protein
testing. The specimens should be sent to the
laboratory immediately because changes will
take place and alter the result .
Post–Lumbar Puncture Headache
*Bed rest after procedure is very important to
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prevent headache also preventing CSF.
analgesic agents, and hydration. Occasionally,
Other Complications of Lumbar Puncture
Herniation of the intracranial contents results
from shifting of tissue from one compartment of
the brain to another, spinal epidural abscess,
spinal epidural hematoma
Intracranial pressure (ICP):
The main components inside the cranium are: brain tissue (80%), blood (10%), and
cerebrospinal fluid (CSF (10%).
So that any increase in the size of brain tissue or
increase in the volume of the CSF or problem in
the blood vessel (E.g. bleeding into the cranium)
will cause increase in the ICP.
The normal ICP in patients should be less than
15mm Hg.
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The effect of increase in ICP will cause
neurological deficit (sensory, motor,
level of consciousness) or other
problem such as seizure so that it is
important in some patient to monitor
ICP.
Cerebral blood flow
The normal cerebral blood flow (CBF) is 50ml / 100g
of brain tissue.
Although brain makes up to 2% of the body weight
but it required 15% to 20 % of the resting cardiac
output and 15% of the total body’s oxygen demands.
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Assessment and diagnosis
The main signs and symptoms of increased in ICP:
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1- Decreased in the level of consciousness.
2- Cushing’s triad (bradycardia, systolic
hypertension, and bradypnea).
3- Diminished brain stem reflexes.
4- Papilledema.
5- Decerebrate (extension to pain).
6- Decorticate (flexion to pain).
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7- Unequal pupil size.
8- Projectile vomiting.
9- Decreased pupillary reaction to light.
10- Altered breathing pattern.
11- Headache.
Medical and Nursing
management
1-positioning and other nursing activities:
A-Elevation of the bed up to 30 degree will help
to decrease ICP by encouraging the venous
return.
B-Positions that should be avoided are
(trendelenberg, prone, extreme flexion of the
hip
2- hyperventilation: 
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The rational to hyperventilate patient with high ICP
is to reduce the Paco2 from its normal range (3540mm Hg) to a range between 25 and 30 mmHg.wich
lead to cerebral arteries vasoconstriction which lead
to decrease in the CBF and increase in the venous
return.
Also prolonged hyperventilation will lead to ischemia
and infarction, so that the new trend is to maintain
Paco2 in the lower side of the normal (35 ± 2 cm Hg).
4-
Blood pressure control: -
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Maintenance of arterial blood pressure in the high
normal range is essential in head injured patients.
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Sedation is required to control blood pressure in the
initial phase.
If sedative fail to control blood pressure,
antihypertensive should be administered
(e.g.nitroprusside and nitroglycerin), also we will use
B- blockers (e.g. labetalol or metoprolol) may be
used to overcome the effect of vasodilation of
antihypertensive agent.
3- temperature control:
 Cerebral metabolic rate increases 7% per
degree centigrade of increase in the body
temperature.
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Fever should be avoided and treated
aggressively when occurred by using antipyretic
and cooling device until the cause of fever to be
determined
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Hypothermia 32to 35-degree C will decrease the
ICP
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5- Seizure control: -
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The prophylactic use of anticonvulsant is
important in controlling the cerebral metabolic
needs.
The usual medication to be used are phenytoin
and Phenobarbital also lorazepam as a short
and fast acting.
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7-Cerebrospinal fluid drainage
8- diuretic
a-Osmotic diuretic.
 The widely used medication is mannitol (it will
improve perfusion to ischemic areas of the brain
and decrease intracerebral edema that caused
by the injury by its osmotic effect.
 Side effect: electrolyte imbalance
Nonosmotic diuretic:  The most widely used is furosemide
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Maintain euvolemic state to maintain and
optimize cerebral perfusion.
9- control of metabolic demand:
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There are some noxious stimuli that lead to increase
ICP: pain, presence of end tracheal tube, coughing
suctioning, repositioning, bathing.
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There are many agent are used to decrease metabolic
demand : benzodiazepines( midazolam. Lorazepam),
sedative – hypnotic (propofol), opioid narcotic (phentanyl
and morphine), and neuromuscular blocking agents
(atracurium and vecuronium)
Stroke
Is a descriptive term for the onset of acute
neurological deficit
persisting for more than 24 hours and caused by
interruption of blood flow to the brain.
Ischemic Stroke
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An ischemic stroke, cerebrovascular accident
(CVA), or “brain attack” is a sudden loss of
function resulting from disruption of the blood
supply to a part of the brain.
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Modifiable risk factors for ischemic stroke
include
Hypertension
atrial fibrillation
hyperlipidemia
obesity
smoking
diabetes
Clinical Manifestations
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Numbness or weakness of the face, arm, or
leg, especially on one side of the body
Confusion or change in mental status
Trouble speaking or understanding speech
Visual disturbances
Difficulty walking, dizziness, or loss of
balance or coordination
Sudden severe headache
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Motor, sensory, cranial nerve, cognitive, and
other functions may be disrupted
Motor Loss
hemiplegia (paralysis of one side of the
body) caused by a lesion of the opposite side
of the brain. Hemiparesis, or weakness of
one side of the body, is another sign.
Communication Loss
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Other brain functions affected by stroke are
language and communication. In fact, stroke is
the most common cause of aphasia.
Dysarthria (difficulty in speaking), caused by
paralysis of the muscles responsible for
producing speech
Dysphasia (impaired speech) or aphasia (loss
of speech), which can be expressive aphasia,
receptive aphasia, or global (mixed) aphasia
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Apraxia (inability to perform a previously
learned action)
 Visual-perceptual dysfunctions. hemianopsia
(loss of half of the visual field)
 Sensory Loss
 Agnosias are deficits in the ability to
recognize previously familiar objects
perceived by one or more of the senses.
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Assessment and Diagnosis
1- The characteristics signs of an ischemic stroke is a
sudden onset of focal neurologic signs persisting for more
than 24 hours.
2- Presence of hemiparesis, aphasia, hemanopsia.
3-Change in level of consciousness usually occur with
brainstem or cerebellar involvement ,seizure, hypoxia,
hemorrhage, increased ICP.
4-Brain CT without contrast.
5- ECG, chest X-ray, continuous cardiac monitoring,
arterial blood gases.
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Assessment and Diagnostic Findings
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Any patient with neurologic deficits needs a
careful history and a complete physical and
neurologic examination.
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The characteristics signs of an
ischemic stroke is a sudden onset of
focal neurologic signs persisting for
more than 24 hours
- Presence of hemiparesis, aphasia,
hemanopsia.
-Change in level of consciousness usually
occur with brainstem or cerebellar
involvement ,seizure ,hypoxia, increased ICP.
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Initial assessment focuses on airway
patency, which may be compromised by loss
of gag or cough reflexes and altered
respiratory pattern; cardiovascular status
(including blood pressure, cardiac rhythm and
rate) and gross neurologic deficits
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Patients may present to the acute care facility
with temporary neurologic symptoms.
A transient ischemic attack (TIA) is a
neurologic deficit lasting less than 24 hours,
with most episodes resolving in less than 1
hour
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. A TIA is manifested by a sudden loss of
motor, sensory, or visual function. The
symptoms result from temporary ischemia
(impairment of blood flow) to a specific region
of the brain.
A TIA may serve as a warning of impending
stroke. Lack of evaluation and treatment of a
patient who has experienced previous TIAs
may result in a stroke and irreversible deficits
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The initial diagnostic test for a stroke is a
noncontrast (CT) scan performed emergently
to determine if the event is ischemic or
hemorrhagic .
A 12-lead (ECG) and a carotid ultrasound are
standard tests
Medical Management
· *Thrombolytic agent( rt-PA)which is given intravenously is
recommended within 3 hours of onset of ischemic stroke, also age should
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be greater than 18 years old according to the national institute of
neurologic disorders and stroke( NINDS).
· * The recommended dose is 0.9 mg / Kg up to the maximum dose of 90
mg, 10% of the dose is administered as an initial intravenous bolus over 1
minute, the remaining 90% is administered by intravenous infusion over
60 minute.
· * Patient who receive thrombolytic therapy for stroke should not
receive aspirin, heparin, warfarin, ticlodipine for at least 24 hours after
treatment.
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Platelet-inhibiting medications, including
aspirin, clopidogrel (Plavix), and ticlopidine
(Ticlid), decrease the incidence of cerebral
infarction in patients who have experienced
TIAs and stroke from suspected embolic or
thrombotic causes .
Therapy for Patients With Ischemic Stroke
Not Receiving t-PA
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Other treatments may include anticoagulant
administration (IV heparin or low-molecularweight heparin).
Interventions during this period include
measures to reduce ICP, such as
administering an osmotic diuretic (eg,
mannitol), maintaining the partial pressure of
carbon dioxide (PaCO2) within the range of
30 to 35 mm Hg, and positioning to avoid
hypoxia
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*Blood pressure in some cases must not be lowered because it
will affect the cerebral perfusion pressure.
· * antihypertensive therapy is considered only if the diastolic
blood pressure is greater than 120 mmHg or the systolic BP is
greater than 220mmHg.
· * Blood pressure should be 180/105 mmHg to prevent
intracranial hemorrhage.
· * Intravenous labetalol and nitroprusside is used to achieve BP
control.
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* Treatment should include controlling cerebral edema or
seizure activity. but prophylaxis for these complication is not
recommended.
Hemorrhagic Stroke
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Hemorrhagic strokes account for 15% to 20%
of cerebrovascular disorders and are
primarily caused by intracranial or
subarachnoid hemorrhage. Hemorrhagic
strokes are caused by bleeding into the brain
tissue, the ventricles, or the subarachnoid
space .
Intracerebral hemorrhage
· *Is a bleeding directly into the brain tissue.
· * It will destroys cerebral tissue causes cerebral edema, and
increaseICP.
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*Causes include
1- the most important cause is hypertension
2- rupture of AVM or aneurysm.
3-. rupture of small artery
4-patients who receive anticoagulant or thrombolytic therapy.
5-coagulation disorders.
6-drug abuse
7-hemorrhage into cerebral infarct or brain tumor
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An intracerebral
hemorrhage (ICH) is
bleeding within brain
tissue.
An ICH may be
associated with other
brain injuries, particularly
contusions .
Assessment and Diagnostic Findings
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Any patient with suspected stroke should
undergo a CT scan to determine the type of
stroke, the size and location of the
hematoma, and the presence or absence of
ventricular blood and hydrocephalus.
CT scan and cerebral angiography confirm
the diagnosis of an intracranial aneurysm or
AVM
Clinical Manifestations
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Clinical Manifestations
The patient with a hemorrhagic stroke can
present with a wide variety of neurologic
deficits, similar to the patient with ischemic
stroke.
Medical Management
1. airway , breathing, and circulation.
2. reduction of blood pressure is necessary to decrease ongoing
bleeding, but lowering blood pressure too much or too rapid may
compromise cerebral perfusion pressure(CPP).
3. MAP should be below 130 mmHg in patients with a history of
hypertension, and 110 mmHg after surgical treatment of ICH.
4. if there is increase in ICP, recommended therapy is mannitol,
hyperventilation, neuromuscular blockade with sedation.
Subarachnoid hemorrhage
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it is the bleeding into the subarachnoid
space( CSF circulation).
causes of subarachnoid hemorrhage:1- rupture of cerebral aneurysm.
2- Arteriovenous malformation.
3- Trauma.
Risk factors: hypertension, smoking,
alcohol abuse , and stimulants use.
Subarachnoid hemorrhage
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Traumatic subarachnoid
hemorrhage (SAH) is
caused by bleeding into
the subarachnoid space.
Etiology
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Cerebral aneurysm rupture account 85% of
subarachnoid hemorrhage. Also 90% of
aneurysms are congenital.
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Rupture of cerebral aneurysm occur during
the fifth and sixth decades of life.
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arteriovenous malformation(AVM) rupture is
responsible for less than 10% of
subarachnoid hemorrhage.
Assessment and diagnosis
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1-HEADACHE( “ WORST HEADACHE IN
MY LIFE”)
2-BRIEF LOSS OF CONSCIOUSNESS.
3-NAUSEA AND VOMITING
4-FOCAL NEUROLOGICAL DEFICIT.
5-STIFF NECK
6-PHTOPHOBIA
DIAGNOSTIC TESTS
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1- CT scan initially done to verify diagnosis.
2- lumbar puncture to take CSF sample for
analysis if the CT scan is negative.
3- magnetic resonance angiogram(MRA)and
magnetic resonance venogram(MRV).
4- catheterization cerebral angiography.
Medical management
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the goal of treatment is preservation neurological
function.
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Airway management and ventilatory assistance may
be necessary.
Venticulostomy is performed to control ICP if the
patients develop deterioration in the level of
consciousness with hydrocephalus.
Control of blood pressure by maintaining systolic
blood pressure no greater than 150mmHg and
prevent hypotension.
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prophylactic anticonvulsants must be
prescribed.
Maintain normal blood volume by giving
intravenous fluid to expand blood volume to
prevent vasospasm, and maintain adequate
cerebral perfusion.
Nimodipine: cause vasodilatation of cerebral
vessel , in doses 60 mg every 4 hours for 21
days