Medical-Surgical Nursing: An Integrated Approach, 2E

Chapter 25

NURSING CARE OF THE CLIENT: NEUROLOGICAL SYSTEM

The Human Nervous System Its purpose is to control all motor, sensory,

autonomic, cognitive, and behavioral activities.

This is accomplished by coordination and initiation of cellular activity through the transmission of electrical impulses and various hormones.

The Nervous System: Structure The nervous system is divided into:

The central nervous system, consisting of the brain and spinal cord.

The peripheral nervous system, which consists of the cranial nerves and spinal nerves.

Basic functional unit—neuron The autonomic nervous system, which is part of

the peripheral nervous system and consists of sympathetic and para-sympathetic systems.

The Brain Composed of gray

matter and white matter, the brain controls, initiates, and integrates body functions through the use of electrical impulses and complex molecules.

Physiology of the Brain The brain is contained

within the skull, or cranium.

Three coverings of the brain, called the meninges. They are the dura mater, arachnoid mater, and pia mater.

The Brain Hemispheres The right side receives information from

and controls the left side of the body. Specializes in perception of physical environment, art, music, nonverbal communication, spiritual aspects.

The left receives information from and controls the right side of the body. Specializes in analysis, calculation, problem solving, verbal communication, interpretation, language, reading, & writing.

The Spinal Cord A continuation of the brain stem. Exits the skull through the foramen

magnum, an opening in the base of the skull.

Cerebrospinal Fluid Provides for shock absorption and bathes

the brain and spinal cord.

Peripheral Nervous System:Cranial Nerves

Twelve pairs of cranial nerves have sensory, motor, or mixed functions.

Cranial NervesOlfactorySensory;smell

OpticSensory;Vision

OculomotorMotor; PupilConstriction

TrochlearMotor;upper eyelid elevation

Trigeminalcornea, nose, oral mucosa; mastication

AbducensMotor; Extraocular eye movement

FacialMotor (facial muscles); Sensory (taste)

AcousticSensory;Hearing; Equilibrium

Glosso-PharyngealTaste; Swallowing

VagusMotor and Sensory

Spinal AccessoryMotor

HypoglossalTongue Movement

Peripheral Nervous System:Spinal Nerves

Cervical 8 Thoracic 12 Lumbar 5 Sacral 5 Coccyx 1

NERVES NUMBER OF PAIRS

Peripheral Nervous System:Autonomic Nervous System

Main function is to maintain internal homeostasis.

Two subdivisions of ANS: The sympathetic system (activated by stress,

prepares body for “fight or flight” response). The parasympathetic system (conserves,

restores, and maintains vital body functions, slowing heart rate, increasing gastrointestinal activity, and activating bowel and bladder evacuation).

Neurologic Assessment: Health History

Pain Seizures Dizziness (abnormal sensation of imbalance

or movement) and vertigo (illusion of movement, usually rotation)

Visual disturbances Weakness Abnormal sensations

Neurologic Assessment

Cerebral function; mental status, intellectual function thought content, emotional status, perception, motor ability, and language ability Note the impact of any neurologic impairment on

lifestyle and patient abilities and limitations Agnosia is the inability to interpret or recognize

objects seen through the special senses. Motor system; posture, gait, muscle tone and strength,

coordination and balance, Romberg test Sensory system; tactile sensation, superficial pain,

vibration and position sense Reflexes; DTRs, abdominal, and plantar (Babinski)

Techniques Eliciting Major Reflexes

(A) Biceps reflex. (B) Triceps reflex. (C) Patellar reflex. (D) Ankle or Achilles reflex. (E) Babinski response.

Figure Used to Record Muscle Strength

5, full range of motion against gravity and resistance; 4, full range of motion against gravity and a moderate amount of resistance; 3, full range of motion against gravity only; 2, full range of motion when gravity is eliminated; 1, a weak muscle contraction when muscle is palpated, but no movement; and 0, complete paralysis.

Gerontological Considerations Important to distinguish normal aging changes

from abnormal changes Determine previous mental status for

comparison. Assess mental status carefully to distinguish delirium from dementia.

Normal changes may include: Losses in strength and agility; changes in gait,

posture and balance; slowed reaction times and decreased reflexes; visual and hearing alterations; deceased sense of taste and smell; dulling of tactile sensations; changes in the perception of pain; and decreased thermoregulatory ability

Pupil Size Normal range: 2 - 6 mm

Drugs: pinpoint pupils Increased intracranial pressure: pupils begin

to dilate• Dilated and fixed, poor prognosis

Glascow Coma Scale

Score BEST response in each category

Highest score = 15 (normal)

Lowest score = 3 (deep coma)

Eye OpeningSpontaneous                      

4To Voice                           

3To Pain                              

2None                                  

1 Best Verbal

Oriented                             5

Confused                            4

Inappropriate Words          3

Incomprehensible Sounds 2

None                                  1

Best MotorObeys Commands            

6Localizes Pain                    

5Withdraws to Pain             

4Flexion to Pain (decorticate)              

3Extension to Pain (decerebrate)         

2None                                 

1

Computed tomography(CT) Magnetic resonance imaging (MRI) Cerebral angiography Myelography Noninvasive carotid flow studies Transcranial doppler Electroencephalography (EEG) Electromyography (EMG) Lumbar puncture and analysis of cerebrospinal

fluid

Diagnostic Tests