Transcript Training
Nervous System Emergencies
Nervous System A & P
Nervous System Basics
The
body’s control system
Exerts control through electrochemical
impulses transmitted through nerves
Three subdivisions
Central nervous system (brain and spinal cord)
Peripheral nervous system (cranial, peripheral
nerves)
Autonomic nervous system (sympathetic,
parasympathetic)
Nervous System A & P
A & P of CNS (brain and spinal cord)
Neuron-nerve
cell; fundamental component of
the nervous system
Cell body contains nucleus
Dendrites carry nervous impulses to cell body
Axons transmit nerve impulses away from cell body
Nervous System A & P
A & P of CNS (brain and spinal cord)
Transmission
of impulses in the nervous system
At rest, neuron is positively charged outside,
negatively charged inside
When stimulated, sodium enters cell, potassium
rapidly leaves cell
Activity produces positive charge, called action
potential, at entry site
Nervous System A & P Overview
A & P of CNS (brain and spinal cord)
Transmission
of impulses in the nervous system
(cont.)
Action potential transmitted down neuron to meet
other neurons at junctions called synapses
Axon releases neurotransmitter (acetylcholine or
norepinephrine) that transports impulses across
synapse and stimulates connecting nerve
Nervous System A & P Overview
Protective structures of the CNS
Mostly
protected by body structures (skull,
spinal column)
Also covered by membranes - meninges (pia,
arachnoid, dura)
Brain and spinal cord also bathed in
cerebrospinal fluid (CSF)
Nervous System A & P Overview
The brain
Cerebrum
Diencephalon
Mesencephalon
Pons
Medulla
Oblongata
Cerebellum
Nervous System A & P Overview
Cerebrum
Two
hemispheres joined by corpus callosum
Governs all sensory and motor functions
Responsible for language, learning, analysis,
memory
Cerebral cortex is outermost layer
Nervous System A & P Overview
Diencephalon
Superiormost
portion of brain stem
Contains thalamus, hypothalamus, limbic
system
Responsible for involuntary actions
Major role in regulating autonomic nervous
system
Nervous System A & P Overview
Mesencephalon
Midbrain-located
between mesencephalon and
pons
Responsible for motor coordination and eye
movement
Nervous System A & P Overview
Pons
Located
between midbrain and medulla
Contains connections between the brain and
spinal cord
Nervous System A & P Overview
Medulla Oblongata
Located between pons and spinal cord
Marks division between brain and spinal cord
Controls respirations, cardiac function ,
vasomotor activity
Nervous System A & P Overview
Cerebellum
Located
in posterior fossa of cranial cavity
Coordinates fine motor movement, posture,
equilibrium, muscle tone
Nervous System A & P Overview
Areas of Specialization
Speech-temporal
lobe
Vision-occipital lobe
Personality-frontal lobes
Balance and coordination-cerebellum
Sensory-parietal lobes
Motor-frontal lobes
Nervous System A & P Overview
Vascular supply to brain
Supplied
by two systems: carotid system and
vertebrobasilar system
Both join at the circle of Willis before entering
brain
Interruption of one system will not seriously
affect brain perfusion
Venous drainage through venous sinuses and
internal jugular veins
Nervous System A & P Overview
Spinal Cord
17-18
inches long
Leaves the brain through the foramen magnum
Conducts impulses to peripheral nervous
system
Conducts sensory impulses to the brain and has
reflex arc capability
Nervous System A & P Overview
Spinal Cord (cont.)
Has
31 pairs of nerve fibers
Dorsal roots contain afferent fibers (body to brain)
Ventral roots contain efferent fibers (brain to body)
Nerve
fibers innovate corresponding body areas
called dermatones
Nervous System A & P Overview
A & P of the peripheral nervous system
Basic
information
Consists of cranial and peripheral nerves
Has both voluntary and involuntary components
Nervous System A & P Overview
A & P of the peripheral nervous system
Categories
of the peripheral nerves
Somatic motor-carry impulses to skeletal muscles
Visceral sensory-transmit sensations from visceral
organs (e.g., full bladder need to defecate, etc.)
Somatic sensory-transmit sensations of touch,
pressure, pain, temperature, position
Visceral motor-supply nerves to visceral glands and
organs
Nervous System A & P Overview
Autonomic nervous system
Responsible
for unconscious control of body
functions
Made up of two antagonistic, but normally
balanced parts
Sympathetic nervous system controls stress response
Parasympathetic nervous system controls custodial
(vegetative) functions
Assessment of the Neurological
System
Primary Assessment
First
check for responsiveness
Place emphasis on airway maintenance and
cervical spine stabilization
With unconscious patients assume cervical
spinal injury
Use modified jaw thrust maneuvers
Remain
alert for possibility of respiratory arrest
Assessment of the Nervous
System
Secondary Assessment
History
Determine trauma vs medical etiology
If trauma
When did incident occur
Mechanism of injury
Any loss of consciousness
Chief complaint
Complicating factors
Assessment of the Nervous
System
Secondary Assessment (cont.)
History
(cont.)
If nontrauma
Chief complaint
History of present illness
Pertinent underlying medical problems (cardiac disease,
hypertension, diabetes, seizures)
Environmental clues (medications, Medic-alert ID, alcohol
or drug bottles)
Assessment of the Nervous
System
Head to toe survey
Pupils
Check eye movement and pupil reaction
Early indicators of increasing ICP
Cardinal positions of gaze
Fixed, midsize pupils-midbrain
Pinpoint pupils, barely reactive-pons
Unilateral fixed and dilated pupil-third nerve
Fixed or asymmetric pupils-structural lesions
Nonreative pupils-toxic/metabolic states
Assessment of the Nervous
System
Head to toe survey (cont.)
Pupils
(cont.)
Extraocular movements
Disconjugate gaze-structural brainstem lesion
Doll’s eyes-brainstem dysfunction
Assessment of the Nervous
System
Head to toe survey (cont.)
Respiratory
derangements common with CNS
illness or injury
Cheyne Stokes respiration-period of apnea followed
by increasing depth and frequency of respirations
Central neurogenic hyperventilation-rapid, deep,
noisy respirations; lesion in CNS
Ataxic respirations-ineffective thoracic muscular
coordination due to CNS damage
Assessment of the Nervous
System
Head to toe survey (cont.)
Respiratory
derangements common with CNS
illness or injury (cont.)
Apneustic respirations-prolonged inspiration
unrelieved by expiration attempts; damage to upper
pons
Diaphragmatic breathing-caused by intercostal
muscle dysfunction
Assessment of the Nervous
System
Spinal Evaluation-document loss of motor
function or sensation
Evaluate
for pain and tenderness
Observe for bruises
Observe for deformity
Check for motor, sensory and position in each
extremity and bilateral grip strength
Determine response to pain
Note any incontinence
Assessment of the Nervous
System
Vital signs that characterize CNS injury
Increased
blood pressure
Decreased pulse
Decreased respirations
Increased temperature
Assessment of the Nervous
System
Neurological Evaluation - provides baseline
neurological findings for later
comparison/contrast
Determine
level of consciousness
AVPU during primary survey
Note
sensation and motor function in
extremities
Asymmetry-structural lesions
Abnormal posturing
Flaccid paralysis-spinal cord injury
Assessment of the Nervous
System
Glascow Coma Scale
Evaluates
coma patient with CNS injury by
monitoring
Eye openings
Verbal response
Motor response
Nervous System Emergencies
Altered mental status-hallmark of CNS
illness or injury
Basic
mechanisms that can produce altered
mental status
Structural lesions
Toxic-metabolic states
Nervous System Emergencies
Common
causes of altered mental status
Structural
Trauma
Brain tumor
Epilepsy
Intracranial hemorrhage
Other space-occupying lesions
Nervous System Emergencies
Common
causes of altered mental status
Metabolic
Anoxia
Hypoglycemia
Diabetic ketoacidosis
Hepatic failure
Renal failure
Thiamine deficiency
Nervous System Emergencies
Common causes of altered mental status
Drugs
Barbiturates
Narcotics
Hallucinogens
Depressants
Nervous System Emergencies
Common causes of altered mental status
Cardiovascular
Hypertensive encephalopathy
Shock
Anaphylaxis
Dysrhythmias
Cardiac arrest
CVA
Nervous System Emergencies
Common causes of altered mental status
Respiratory
COPD
Toxic gas inhalation
Infectious
Encephalitis
Meningitis
Nervous System Emergencies
Primary Assessment
Special
attention to the airway and c-spine
Consider AEIOU TIPS mnemonic
Early intubation
Nervous System Emergencies
Secondary Assessment
History
Length of alteration in mental status
Onset
History of recent head trauma
patient under medical care
Alcohol or drug use
Preceding symptoms or complaints
Any medications
Medic-Alert tags
Nervous System Emergencies
Secondary Assessment (cont.)
Physical
exam-should include breathing,
response to stimuli, eye response, pupil
response, being particularly alert in suspected
CNS illness or injury cases
Pupillary reflexes-fixed, dilated, or asymmetric
pupils
Extraocular movements-dysconjugate gaze
Nervous System Emergencies
Secondary Assessment (cont.)
Physical
exam-should include breathing,
response to stimuli, eye response, pupil
response, being particularly alert in suspected
CNS illness or injury cases
Motor findings-asymmetry, decorticate or decebrate
posturing, flaccid paralysis
Respiratory patterns
Vital signs-hypertension, bradycardia, unusual body
temperature
Nervous System Emergencies
Management
Immobilization
of the cervical spine
Assure patency and adequate breathing
Draw venous blood sample, check blood sugar
with glucometer or chem strip
IV 5% D5W at TKO rate; related NS or LR if
trauma
Cardiac monitor
Nervous System Emergencies
Drug considerations
50mL
of 50% dextrose (25 grams) IV to correct
hypoglycemia
Naloxone 1-2 mg IV to reverse narcotic
overdose
Thiamine 100mg IV to correct thiamine
deficiency and allow glucose metabolism
Mannitol 25g IV to reduce ICP
Decadron 4-24 mg IV to reduce cerebral edema
Nervous System Emergencies
Management with chronic alcoholism
Many
have thiamine deficiency
Wernicke’s syndrome-memory loss, disorientation
Korsakoff’s psychosis-disorientation,m muttering
delirium, insomnia, delusions painful extremities,
bilateral foot drop, pain on pressure over long
nerves
These patients should receive 100 mg Thiamine IV
or IM
Nervous System Emergencies
Management with ICP
Hyperventilate
patient
Decadron 4-24 mg IV to reduce cerebral edema
Mannitol 25g IV to cause an osmotic diuresis
Nervous System Emergencies
Seizures
Pathophysiology
of seizures
Massive electrical discharge of one or more groups
of neurons in the brain
Can be general or partial
Generalized seizures-grand mal and petit mal
Partial seizures-simple or complex (psychomotor)
Nervous System Emergencies
Seizures (cont.)
Causes
of seizures
Stressors such as hypoxia, sudden elevation in
temperature, or hypoglycemia in healthy persons
Structural diseases such as tumors, head trauma,
eclampsia, vascular disorders
Idiopathic epilepsy is the most common cause
Nervous System Emergencies
Seizures (cont.)
Types
of Seizures
Grand Mal-generalized motor seizure
Produces loss of consciousness from brain hypoxia
Causes uncontrollable tonic/clonic movements of
extremities
Disrupts respirations, producing cyanosis
Often lead to frothing, incontinence, mental confusion
Coma or drowsiness follows (postical period)
Nervous System Emergencies
Seizures (cont.)
Grand-mal
(progression)
Aura-subjective sensation preceding seizure
May be psychic (déjà vu)
May be sensory (a noise, sight, sound, odor)
Loss of consciousness
Tonic phase-continuous motor tension and
contraction of muscles
Nervous System Emergencies
Seizures (cont.)
Grand-mal
(progression cont.)
Hypertonic phase-extreme muscular rigidity,
hyperextension of the back
Clonic phase-extreme muscular rigid
Nervous System Emergencies
Seizures (cont.)
Grand-mal
(progression cont.)
Post-seizure coma
Postictal period-patient awakens confused, fatigued
with some neurological deficits
Nervous System Emergencies
Seizures (cont.)
Focal
motor seizures
Characterized by dysfunction of one area of the
body
Caused by electrical discharge form one part of the
brain
Begin as localized tonic/clonic movements; can
spread and appear s generalized
Nervous System Emergencies
Seizures (cont.)
Psychomotor
(temporal lobe) seizures
Characterized by distinctive pre-seizure aura
Focal seizures lasting 1-2 minutes
Patient experiences loss of contact with
surroundings
Patient may be confused, purposeless, or may show
change in personality or rage abruptly
Nervous System Emergencies
Seizures (cont.)
Petit
mal seizures
Generalized seizures with 10-30 second loss of
consciousness
Patient may stare and flutter eyelids
Observers may be unaware of seizure
Nervous System Emergencies
Seizures (cont.)
Hysterical
seizures
Psychological disorders
Patient presents with sharp and bizarre movements
Curt commands can curtail seizure
No postical period
Use of aromatic ammonia may differentiate
hysterical from true seizure
Nervous System Emergencies
Assessment
rule
out other causes of coma
Obtain history including:
History of seizure
Alcohol/drug abuse
Current medications
Recent history of head trauma
Description of seizure
Past medical history (diabetes, cardiac, strokes)
Differentiate
true seizure vs. syncope
Nervous System Emergencies
Management
Protect
patient from self-harm; do not restrain
Maintain airway
Administer oxygen
Establish IV access
Determine blood glucose; D50W if needed
Protect body temperature
position patient on side after tonic/clonic phase
Nervous System Emergencies
Management (cont.)
Suction
if required
Monitor cardiac rhythm
Provide quiet rest, reassuring atmosphere
Transport in supine or lateral recumbent
position
Nervous System Emergencies
Status Epilepticus
Description
Series of two or more seizures without lucid period
Most common cause is failure to take anticonvulsant
medications
Can lead to brain injury from anoxia
Nervous System Emergencies
Status Epilepticus (cont.)
Management
Establish and protect airway
Assist ventilations with 100% oxygen
Establish IV access with NS TKO
Monitor cardiac rhythm
Administer 50% dextrose 25gm IV
Administer diazepam 5-10 mg IV
Nervous System Emergencies
Stroke (cerebrovascular accident - CVA)
Pathophysiology
injury or death to brain tissue from interruption of
blood
Can by caused by ischemic or hemorrhagic lesions
commonly secondary to atherosclerosis or
hypertension
Sudden loss of consciousness followed by paralysis
which may be caused by hemorrhage, embolism or
thrombus
Nervous System Emergencies
Strokes (cont.)
Categories
Infarction
of stroke
Inadequate blood supply to limited prtion of the brain
caused by embolism or blood vessel occlusion usually due
to thrombus
Hemorrhage
Intracerebral or subarachnoid bleeding
Marked by sudden onset of headache and stiff neck
Can cause increased intracranial pressure
Nervous System Emergencies
Strokes (cont.)
Clinical
presentation of a stroke
Symptoms depend on area of brain injured
Motor, speech, and sensory centers most commonly
affected
Onset of symptoms is acute and may include:
Unconsciousness
Stertorous breathing
Unequal pupils
Unilateral paralysis
Speech disturbances
Nervous System Emergencies
Strokes (cont.)
Distinguishing
CVA from transient ischemic
attacks (TIA’s)
Temporary stroke symptoms
Usually caused by small emboli
Can last several minutes to hours
No evidence of neurological deficient after attack
Abrupt onset with symptoms depending on area of
brain affected
Nervous System Emergencies
Strokes (cont.)
Symptoms
Monocular blindness
Hemiplegia
Inability to recognize by touch
Staggering
Difficulty in swallowing, aphasia
Hemiparesis
Dizziness
Numbness, paresthesia
Nervous System Emergencies
Strokes (cont.)
History
- Determine:
Previous neurological symptoms
Initial symptoms and their progression
Chanbes in mental status Precipitating factors
Dizziness
Palpitations
History of hypertension, cardiac disease, sickle cell
disease, previous TIA or stroke
Nervous System Emergencies
Strokes (cont.)
Physical
Exam - Be alert for:
Hemiparesis, hemiplegia
Unilateral facial droop
Speech disturbances
Gait problems
Altered mental status
Vision problems
Nervous System Emergencies
Strokes (cont.)
Management
of CVA and TIA
Maintain patient supine with 15 degree head
elevation to maximize venous drainage
Maintain c-spine integrity if trauma suspected
Maintain a patent airway, assisting ventilation PRN
Administer oxygen, hyperventilation if patient
unresponsive
Draw venous blood sample and test for blood sugar
Nervous System Emergencies
Strokes (cont.)
Management
Start IV with NS or LR TKO
Monitor cardiac rhythm
If patient hypoglycemic, give D50W
Protect paralyzed extremities
Reassure patient and transport quietly to hospital
Nervous System Emergencies
Judy Dyke, RN, NREMT-P
Rogers State University
Paramedic Technology Program