Chapter 25

CHAPTER 25: ASSESSING NEUROLOGIC SYSTEM

STRUCTURE AND FUNCTION

  • The neurologic system is responsible for coordinating and regulating all body functions.

  • It consists of:

    • Central Nervous System (CNS)

    • Peripheral Nervous System (PNS)

CENTRAL NERVOUS SYSTEM (CNS)

  • The CNS is composed of the brain and spinal cord.

    • Meninges:

    • Protective coverings that also nourish the CNS.

    • Subarachnoid Space:

    • Surrounds the brain and spinal cord.

    • Filled with cerebrospinal fluid (CSF) that cushions the brain and spinal cord, nourishes the CNS, and removes waste products.

    • Neurons:

    • Govern electrical activity throughout sensory and motor neural pathways.

    • Upper motor neurons in the CNS influence lower motor neurons in the peripheral nervous system.

BRAIN

  • The brain consists of:

    • Cerebrum:

    • Composed of four lobes:

      • Frontal

      • Parietal

      • Temporal

      • Occipital

    • Diencephalon: consists of thalamus and hypothalamus.

    • Brain Stem: consists of midbrain, pons, medulla oblongata.

    • Cerebellum: divided into two hemispheres.

SPINAL CORD

  • Location: Located within the vertebral canal extending from the medulla oblongata to the first lumbar vertebra.

  • Composition:

    • Consists of two pairs of columns.

    • Features an H-shaped appearance.

  • Neurons:

    • Afferent (sensory) neurons enter through dorsal roots.

    • Efferent (motor) neurons exit through ventral roots.

    • The term synapse refers to the junction between two neurons.

NEURAL PATHWAYS

  • Neural pathways convey sensory and motor impulses throughout the body:

    • Sensory Impulses:

    • Spinothalamic tract: conveys pain, temperature; crude touch.

    • Posterior column: senses position, vibration, fine touch.

    • Motor Impulses:

    • Corticobulbar tract and corticospinal tracts guide voluntary muscle control.

PERIPHERAL NERVOUS SYSTEM (PNS)

  • The PNS carries information to the CNS and consists of:

    • 12 pairs of cranial nerves

    • 31 pairs of spinal nerves

  • **Types of nerves: **

    • Somatic:

    • Carries CNS impulses to voluntary skeletal muscles, mediating conscious activities.

    • Autonomic:

    • Carries CNS impulses to smooth, involuntary muscles, mediating unconscious activities.

CRANIAL NERVES


  • Cranial Nerve Mnemonic:

    Nerve

    Impulse Type

    Mnemonic


    I. Olfactory

    Sensory

    On


    II. Optic

    Sensory

    Old


    III. Oculomotor

    Motor

    Marry


    IV. Trochlear

    Motor

    Money


    V. Trigeminal

    Both

    But


    VI. Abducens

    Motor

    My


    VII. Facial

    Both

    Brother


    VIII. Acoustic/Vestibulocochlear

    Sensory

    Says


    IX. Glossopharyngeal

    Both

    Bad


    X. Vagus

    Both

    Business


    XI. Spinal Accessory

    Motor

    Marries


    XII. Hypoglossal

    Motor

    Money

    SPINAL NERVES

    • Composed of:

      • 8 cervical

      • 12 thoracic

      • 5 lumbar

      • 5 sacral

      • 1 coccygeal nerve

    • Each spinal nerve is named after the vertebra below their exit point along the spinal cord.

    AUTONOMIC NERVOUS SYSTEM

    • The autonomic nervous system carries impulses to smooth, involuntary muscles, maintaining internal homeostasis.

    • Components:

      • Sympathetic Nervous System:

      • Activates during stress ("fight or flight"), arises from T1 to L2.

      • Parasympathetic Nervous System:

      • Restores and maintains normal body functions, comes from S1 to S4 and cranial nerves III, VI, IX, and X.

    BIOLOGICAL (GENETIC) AND CULTURAL BEHAVIOR VARIATIONS

    • Ethnic variations similar to Cardiovascular Disease (CVD) are noted with stroke.

    • U.S. identified regions:

      • Stroke belt: NC, SC, GA, AL, MS, LA, AR, TN.

      • Stroke buckle: NC, SC.

    • Culture-bound syndrome example: "ataque de nervios" in Latina Americans, expressing symptoms akin to anxiety.

    OLDER ADULT CONSIDERATIONS

    • Normal decrease in sensory abilities (hearing, seeing, tasting, smelling).

    • May exhibit:

      • Intentional tremors when extending hands.

      • Reduced muscle mass through muscle fiber degeneration.

      • Hand or head tremors or dyskinesia.

    • Gait changes: wider, shorter base; difficulty in heel-to-toe walks.

    • Risk in performing mobility tests (hopping, standing on one foot) due to the risk of falling.

    • Decreased deep tendon reflexes with age, may indicate peripheral neuropathy.

    COLLECTING SUBJECTIVE DATA: NURSING HEALTH HISTORY

    • History of Present Health Concern:

      • Headaches, seizures, dizziness, numbness/tingling (paresthesias).

      • Changes in senses, speaking, swallowing (dysphagia), muscle control, memory loss.

    • Past Health History:

      • Important to gather information on family history, lifestyle, and health practices.

    GENERAL VS. FOCUSED ASSESSMENTS

    • General Routine Screening:

      • Not all aspects of a full neurologic exam are performed.

    • Focused Specialty Assessment:

      • More detailed neurologic examinations in specialized settings (e.g., ICUs).

    COLLECTING OBJECTIVE DATA: PHYSICAL EXAMINATION

    • Comprehensive neurologic assessment includes:

      • Evaluating mental status, cranial nerves, motor systems, sensory systems, and reflexes.

    • Important metrics:

      • Level of consciousness, pupillary checks, and extremities' movement and strength.

    • Note any changes in vital signs which may indicate increased intracranial pressure (ICP).

    GLASGOW COMA SCALE

    • The Glasgow Coma Scale is implemented to assess a client’s responsiveness to stimuli:

      • A score of 10 or lower requires emergency attention.

      • A score of 7 or lower generally indicates coma status.

    CEREBROVASCULAR ACCIDENT (STROKE)

    • Overview:

      • A stroke occurs when blood flow to a portion of the brain is interrupted or stopped, leading to brain cell death.

    • Types of Stroke:

      • Hemorrhagic Stroke: occurs from ruptured or leaking blood vessels.

      • Ischemic Stroke: occurs due to a clot blocking blood vessels (from emboli or thrombi).

      • Transient Ischemic Attack (TIA): considered a mini-stroke and serves as early warning.

    • Statistics:

      • Stroke is the fifth leading cause of death and the leading cause of disability in the United States.

    CEREBROVASCULAR ACCIDENT (STROKE) RISK FACTORS

    • Key risks include:

      • Hypertension, diabetes, heart disease, smoking, brain aneurysms, younger age, gender, race, personal/family history of stroke.

    CLIENT EDUCATION FOR STROKE PREVENTION

    • Avoid smoking and manage cholesterol/blood pressure/diabetes through lifestyle and medication.

    • Exercise and maintain a balanced diet rich in fruits and vegetables, low in saturated fats and sodium.

    • Recognize stroke symptoms using the "Act FAST" acronym:

      • F: Face drooping

      • A: Arm weakness

      • S: Speech difficulties

      • T: Time to call 911!

    ABNORMAL MUSCLE MOVEMENTS & GAITS

    • Abnormal movements may include atrophy, fasciculations, and various types of tremors (static, postural, intention).

    • Gait abnormalities include cerebellar ataxia, Parkinsonian gait, and scissor gait.

    • Abnormal postures in unconscious clients include decorticate and decerebrate posturing, indicating different forms of brain damage.

    VALIDATING AND DOCUMENTING FINDINGS

    • It is essential to validate all assessment data collected to verify its reliability and accuracy.