Nervous system

Nervous System Overview

  • Central Nervous System (CNS)

    • Composed of the brain and spinal cord.

  • Peripheral Nervous System (PNS)

    • Divided into:

    • Somatic Nervous System

    • Autonomic Nervous System

      • Further divided into:

      • Sympathetic Nervous System

      • Parasympathetic Nervous System

Anatomy Review

  • Brain:

    • Receives 20% of all cardiac output to the cranium.

    • Connects the cerebrum to the body.

    • Structures include:

    • Cerebrum: Involved in memory, emotion, consciousness.

    • Cerebellum: Coordinates balance and movement.

    • Brainstem: Regulates vital functions (e.g., respiratory rate, heart rate, reflex actions).

    • Meninges: Protective coverings of the brain.

    • Ventricles: Fluid-filled cavities within the brain.

    • Cranium: Bone structure protecting the brain.

Brain Structure Details

  • Cerebrum:

    • Regions include:

    • Frontal Lobe: Involves personality, decision making, voluntary movement.

    • Parietal Lobe: Processes touch and pressure sensations.

    • Temporal Lobe: Associated with auditory information and memory.

    • Occipital Lobe: Processes visual information.

Spinal Cord and Vertebral Anatomy

  • Spinal Cord:

    • Extends from the brainstem down the vertebral column, divided into segments:

    • Cervical Vertebrae: C1—C8 (8 pairs of spinal nerves).

    • Thoracic Vertebrae: T1—T12 (12 pairs of spinal nerves).

    • Lumbar Vertebrae: L1—L5 (5 pairs of spinal nerves).

    • Sacral Vertebrae: S1—S5 (5 pairs of spinal nerves).

    • Coccygeal Nerve: Coccyx region.

    • Key regions include:

    • Conus Medullaris: End of the spinal cord.

    • Cauda Equina: Nerve roots that extend from the lower spinal cord.

    • Note: Motor deficits do not always indicate sensory loss.

Autonomic Nervous System Organs

  • Key Organs:

    • Lacrimal Gland

    • Nasal Mucosa

    • Sublingual and Submaxillary Glands

    • Oral Mucosa

    • Parotid Gland

    • Heart

    • Lungs

    • Stomach

    • Aorta

    • Liver

    • Gall Bladder

    • Pancreas

    • Adrenals

    • Small Intestine

    • Kidneys

    • Large Intestine

    • Reproductive Organs

Patient Interaction Protocol

  • Essential Steps for Patient Interaction:

    • Knock and introduce self.

    • Follow AIDET (Acknowledge, Introduce, Duration, Explanation, Thank you).

    • Conduct primary survey: ensure environment privacy, wash hands, wear gloves.

    • Verify patient's name and date of birth (DOB).

    • Raise the bed to a suitable height for assessment.

Vital Signs Assessment

  • Parameters to Measure:

    • Temperature (T)

    • Pulse (P)

    • Respirations (R)

    • Blood Pressure (BP)

    • Oxygen Saturation (O2 Sat)

    • Pain assessment using PQRSTU method:

    • P: Provocative and Palliative

    • Q: Quality and Quantity

    • R: Region and Radiation

    • S: Severity

    • T: Timing and Treatment

    • U: Understand Patient’s Perception of the Problem

Subjective Findings

  • Key complaints and symptoms that patient may report:

    • Confusion

    • Headache

    • Vertigo

    • Seizures

    • Recent injury or fall

    • Weakness

    • Numbness or tingling (paresthesia)

    • Difficulty swallowing (dysphagia)

    • Difficulty speaking (dysphasia)

    • Lack of coordination of body movements

History Taking

  • Important historical details:

    • Cerebrovascular Accident (CVA): Stroke symptoms without permanent defects that resolve.

    • Transient Ischemic Attack (TIA): Symptoms similar to stroke that resolve quickly.

    • Head Injury: Includes concussion and traumatic brain injury (TBI).

    • Medications, herbs, or supplements that may affect neurological status.

Order of Neuro Assessment

  • Sequence of steps to conduct a neurological assessment:

    1. Inspection

    2. Connection

    3. Cranial Nerves Assessment

    4. Sensory Function Evaluation

    5. Motor Function Evaluation

    6. Balance and Coordination Assessment

    7. Reflexes Testing

Inspection Parameters

  • Aspects to evaluate during inspection:

    • Patient’s alertness (awake/asleep).

    • General appearance, behavior, and communication abilities.

    • Mood/Affect: Noting if flat, labile, or inappropriate.

    • Level of Consciousness (LOC): Categories include acknowledgement of alert, lethargic (somnolent), obtunded, stupor (semi-coma), or coma.

    • Orientation to person, place, time, and situation (AAO x 4). Observe for confusion or restlessness.

    • Examination of incisions, dressings, scars, or shunt sites.

Mental Status Assessment

  • Mini-Mental Status Exam:

    • Comprises 11 questions to evaluate brain function.

    • Delirium often presents alongside confusion and can be temporary, especially in ICU patients.

    • Dementia tends to be progressive and non-reversible.

Glasgow Coma Scale (GCS)

  • Scoring criteria for assessing consciousness levels:

    • Eye Opening Response:

    • 4: Spontaneous

    • 3: To speech

    • 2: To pain

    • 1: No response

    • Motor Response:

    • 6: Obeys verbal commands

    • 5: Localizes pain

    • 4: Flexion-withdrawal

    • 3: Flexion-abnormal

    • 2: Extension-abnormal

    • 1: No response

    • Verbal Response:

    • 5: Oriented x3 (appropriate)

    • 4: Conversation confused

    • 3: Speech inappropriate

    • 2: Speech incomprehensible

    • 1: No response

    • Total score interpretation:

    • 13-14: Mild TBI/concussion

    • 9-12: Moderate TBI

    • 3-8: Severe TBI

    • 8 or less: Indicates intubation may be necessary.

Posturing in Motor Response

  • Decorticate posturing:

    • Characterized by hands moving to the core; feet crossed.

    • Indicative of a better prognosis.

  • Decerebrate posturing:

    • Characterized by extension of the arms and feet uncrossed, shows wrist flexion.

Morse Fall Scale

  • Assessment criteria for fall risk:

    • History of falls in the last 3 months.

    • Check for secondary diagnoses (e.g., CVA, Parkinson’s, Alzheimer's/Dementia).

    • Evaluate use of assistive devices and environmental safety.

    • Bedrest patients are generally not at risk unless indicated otherwise.

National Institutes of Health Stroke Scale (NIHSS)

  • Assessment components:

    • Balance

    • Eyes

    • Face

    • Arm

    • Speech

    • Time

Cranial Nerves Assessment

  • Cranial Nerves and Functions:

    1. Olfactory (I): Smell

    2. Optic (II): Vision (Snellen chart)

    3. Oculomotor (III), Trochlear (IV), Abducens (VI): PERRLA (Pupils Equal, Round, Reactive to Light and Accommodation) and Extraocular Movements (EOMs).

    4. Trigeminal (V): Assessment involves sensory (Stroke and Poke test) and motor (Clenching Jaw) components.

    5. Facial (VII): Facial expression assessment.

    6. Acoustic (VIII): Hearing; Romberg test.

    7. Glossopharyngeal (IX) and Vagus (X): Gag reflex and swallowing assessment.

    8. Spinal Accessory (XI): Strength of the Trapezius and Sternocleidomastoid muscles.

    9. Hypoglossal (XII): Tongue movement.

PERRLA Assessment in Eye Examination

  • PERRLA Criteria:

    • Pupil size: Equal versus unequal.

    • Roundness: Pupil shape should be round.

    • Reactivity to Light: Must constrict in light and dilate in darkness.

    • Consensual Response: Both pupils should react together.

    • Accommodation: Pupil dilates when looking away and constricts when looking close.

    • Reaction time should be evaluated as brisk or sluggish.

Sensory Function Assessment

  • Dermatome levels:

    • Each spinal nerve has a specific area of sensory control, represented acrss various levels (e.g., C5: Anterolateral shoulder, C6: Thumb, T4: Nipple line).

    • Graphesthesia: Ability to recognize numbers or letters drawn in the hand.

    • Stereognosis: Ability to identify objects through touch with eyes closed.

    • Sensory impairment correlates with levels of spinal cord injury.

Motor Function Assessment

  • Evaluation of:

    • Hand grasps and strength.

    • Foot pumps against resistance.

    • Upper and lower extremity strength documentation.

Cerebellar Function: Balance and Coordination

  • Assessed through:

    • Ability to perform rapid, rhythmic, alternating movements.

    • Accuracy of movements, such as finger to nose movement.

    • Balance tests including: Romberg test, gait and ataxia assessments, pronator/ palmar drift tests, and heel-to-toe walking.

Superficial and Deep Tendon Reflexes (DTRs)

  • Assessment involves:

    • Brachioradialis (C5-6)

    • Triceps (C6-7)

    • Patellar (L2-4)

    • Plantar aka Babinski (L5, S1)

    • Scoring responses:

    • 0: No response; absent

    • 1+: Sluggish or diminished; hyporeflexive

    • 2+: Active or expected response; normoreflexive

    • 3+: Hyperactive without clonus; hyperreflexive

    • 4+: Hyperactive with clonus.

Special Considerations for Older Adults

  • Notable changes include:

    • Slower motor and sensory reaction times.

    • Impairment in fine coordination, balance, and reflex activity.

    • Diminished cerebral blood flow and oxygen use, leading to dizziness or loss of balance.

    • Pupils may appear smaller, irregular, and demonstrate decreased response to light.

Documentation of Neuro Assessment

  • Key documentation elements:

    • Patient is alert and oriented x4 (to person, place, time, and situation).

    • Affect is appropriate for situation.

    • Patient is cooperative and follows commands.

    • Dress and hygiene are appropriate, including the use of bilateral hearing aids or corrective lenses.

    • PERRLA evaluation indicates pupils are 4 mm in diameter, equal, and reactive.

    • Document strength of hand grips as strong and equal.

Patient Safety Measures

  • Essential safety procedures include:

    • Setting the bed in a low position.

    • Locking the bed wheels.

    • Ensuring side rails are up on both sides.

    • Placing call light within reach.

    • Instructing patient to call for help when needed.

    • Ensuring bedside table is within reach before leaving the room.