Reticular Activating System (RAS)

Reticular Activating System (RAS)

• A network of neurons in the brainstem that regulates wakefulness, arousal, and consciousness
• Acts as the brain’s alertness center by filtering sensory input
• Determines which stimuli require attention

Location of the RAS

• Found within the reticular formation in the brainstem, extending from the medulla to the midbrain
• Connects to the thalamus, hypothalamus, and cerebral cortex to regulate consciousness

Functions of the RAS

• Plays a key role in arousal and wakefulness by keeping the cerebral cortex active
• Damage to the RAS can cause coma or prolonged unconsciousness
• Controls transitions between wakefulness, drowsiness, and sleep
• Influenced by light, noise, and external stimuli
• Melatonin and serotonin inhibit RAS activity to promote sleep
• Filters incoming sensory information, allowing the brain to focus on important stimuli, for example, sleeping through background noise but waking up to your name being called
• Determines levels of consciousness (fully awake, drowsy, or unconscious)
• Plays a role in awareness of surroundings

Clinical Significance of the RAS

• Brainstem stroke: Damage to the RAS disrupts consciousness, resulting in coma or altered level of consciousness (LOC)
• Traumatic Brain Injury (TBI): Swelling can suppress RAS function, resulting in loss of consciousness or confusion
• Coma: Severe RAS impairment, resulting in an unresponsive state
• Narcolepsy: Dysregulation of the RAS, resulting in sudden sleep episodes
• ADHD: RAS dysfunction may affect attention regulation, resulting in poor focus or hyperactivity
• Chronic Fatigue Syndrome: Can involve RAS dysfunction, resulting in persistent exhaustion or sleep disturbances

Signs of RAS Dysfunction

• Altered Level of Consciousness (LOC): Lethargy → Stupor → Coma progression
• Coma = Complete loss of RAS function
• Sleep Disturbances: insomnia or excessive sleepiness
• Inattention & Poor Focus: Seen in ADHD and dementia

Overview of the Medulla Oblongata

• Lowest part of the brainstem, connecting the brain to the spinal cord
• Controls vital autonomic functions like breathing, heart rate, and blood pressure
• Damage is often life-threatening

Major Functions of the Medulla

• Contains key autonomic control centers for cardiovascular, respiratory, and reflex functions

Respiratory Control

• Contains respiratory centers that regulate breathing rate and rhythm
• Works with the pons to adjust inhalation and exhalation based on oxygen needs
• Controls chemoreceptors that respond to CO₂ levels in the blood
• Damage → Respiratory arrest, irregular breathing patterns (Cheyne-Stokes, Biot's respirations)

Cardiovascular Control

• Contains the cardiac control center, which regulates heart rate (HR) and force of contraction
• Maintains blood pressure via vasomotor centers that adjust vessel constriction or dilation
• Damage → Severe hypotension, bradycardia, or cardiovascular collapse

Reflex Centers

• Controls several involuntary reflexes: swallowing (CN IX, X), coughing, sneezing, gag reflex, vomiting, hiccuping
• Damage → Aspiration risk, loss of protective airway reflexes

Cranial Nerve Function

• Origin of cranial nerves IX–XII:
• Glossopharyngeal (IX) – Swallowing, taste
• Vagus (X) – Heart rate, digestion, vocal cord function
• Accessory (XI) – Shoulder shrug, head movement
• Hypoglossal (XII) – Tongue movement

Clinical Signs of Medulla Dysfunction

• Respiratory Control: Irregular breathing, respiratory failure
• Cardiovascular Regulation: Severe bradycardia, hypotension
• Swallowing & Gag Reflex: Aspiration risk, dysphagia
• Cranial Nerve Dysfunction: Slurred speech, hoarseness, tongue deviation
• Protective Reflexes: Loss of cough/gag reflex, choking risk

Common Conditions Affecting the Medulla

• Brainstem Stroke (Medullary Infarct)
• Brainstem Tumors
• Neurodegenerative Diseases (ALS, MS)
• Trauma (Cervical Spine Injury)
• Opioid Overdose (Respiratory Depression)

Overview of the Sympathetic Nervous System (SNS)

• Part of the autonomic nervous system (ANS) that controls involuntary body functions
• Responsible for the "fight-or-flight" response, preparing the body to respond to stress, danger, or emergencies
• Key Neurotransmitters: Epinephrine (Adrenaline), Norepinephrine (Noradrenaline), Dopamine (in some pathways)
• SNS activation triggers widespread, rapid changes in multiple organ systems to enhance survival

Physiological Changes During SNS Activation & Rationale

• Heart (Cardiovascular System): ↑ Heart Rate (Tachycardia) to increase cardiac output (CO) to supply oxygen & nutrients to vital organs; ↑ Blood Pressure (Hypertension) due to vasoconstriction to maintain perfusion to the brain and muscles
• Respiratory System: ↑ Respiratory Rate (Tachypnea) increases oxygen intake to fuel muscles; Bronchodilation opens airways (bronchioles) to improve oxygen exchange
• Pupils (Ophthalmic Response): Pupil Dilation (Mydriasis) enhances vision to detect threats
• Digestive System: ↓ Gastrointestinal (GI) Motility reduces digestion to divert energy to muscles; ↓ Saliva & Dry Mouth because salivary secretion decreases since digestion is not a priority
• Urinary System: ↓ Urine Output (Urinary Retention) - Blood flow is redirected away from kidneys to vital organs
• Liver & Metabolism: ↑ Glucose Release (Hyperglycemia) because the liver breaks down glycogen (glycogenolysis) to provide quick energy
• Skin & Sweat Glands: ↑ Sweating (Diaphoresis) to help regulate body temperature under stress
• Skeletal Muscles: ↑ Muscle Strength & Blood Flow, blood flow shifts to large muscle groups for quick movement
• Adrenal Glands: ↑ Epinephrine & Norepinephrine Release prolongs SNS effects by enhancing heart rate, BP, and metabolism

Why These Changes Occur (Fight-or-Flight Response)

• SNS activation prepares the body to respond to immediate threats
• Energy is redirected from non-essential functions (digestion, urination) to vital systems (heart, muscles, brain)
• Hormonal responses (epinephrine & norepinephrine) prolong the effects
• Once the threat is gone, the parasympathetic nervous system (PNS) restores balance

Clinical Situations of SNS Activation

• Shock (Compensatory Phase): SNS activation raises BP & HR to maintain perfusion; Prolonged SNS activation → Organ damage (vasoconstriction)
• Pain & Stress Responses: Acute pain → Triggers SNS → Tachycardia, HTN, sweating; Chronic stress → Can lead to hypertension, glucose intolerance, anxiety
• Hypoglycemia (Low Blood Sugar): SNS releases epinephrine → Causes shakiness, sweating, tachycardia
• Trauma, Blood Loss, or Sepsis: SNS tries to compensate by increasing BP & HR
• Exercise & Physical Activity: SNS increases oxygen & glucose delivery to muscles
• Medications That Mimic SNS Activation (Adrenergic Agonists): Epinephrine (anaphylaxis, cardiac arrest), Albuterol (asthma, bronchodilation), Dopamine/Norepinephrine (hypotension & shock)

What Happens When the SNS is Blocked?

• Beta-blockers (e.g., Metoprolol, Propranolol) inhibit SNS effects → ↓ HR & BP, Bronchoconstriction (avoid in asthma patients), Reduced stress response

Overview of the Parasympathetic Nervous System (PNS)

• Part of the autonomic nervous system (ANS) responsible for rest, recovery, and digestion
• Often referred to as the “rest and digest” system because it conserves energy, promotes digestion, and restores normal body functions after stress
• Key Neurotransmitter: Acetylcholine (ACh) (stimulates PNS effects)
• The PNS opposes the effects of the sympathetic nervous system (SNS), promoting relaxation and returning the body to homeostasis

Physiological Changes During PNS Activation & Rationale

• Heart (Cardiovascular System): ↓ Heart Rate (Bradycardia) conserves energy by reducing cardiac workload; ↓ Blood Pressure (Hypotension) because blood vessels dilate (vasodilation), promoting relaxation
• Respiratory System: ↓ Respiratory Rate, because the body does not need extra oxygen during rest; Bronchoconstriction because airways return to normal diameter
• Pupils (Ophthalmic Response): Pupil Constriction (Miosis), to prevent excess light exposure, helps near vision
• Digestive System: ↑ GI Motility & Salivation increases digestion and absorption of nutrients; ↑ Digestive Enzyme Secretion helps break down food efficiently
• Urinary System: ↑ Urine Output (Bladder Contraction) because the body is in a relaxed state, promoting waste excretion; ↑ Peristalsis (Bowel Movement) promotes regular bowel movements
• Liver & Metabolism: ↓ Glucose Release, the body stores energy instead of breaking it down
• Skeletal Muscles: ↓ Muscle Readiness , there is no immediate need for fight-or-flight response
• Adrenal Glands: ↓ Epinephrine & Norepinephrine Release reduces stress hormones, promotes relaxation

Function of the Blood-Brain Barrier (BBB)

• Selectively permeable barrier protecting the brain from harmful substances while allowing essential nutrients to pass
• Maintains brain homeostasis by controlling the movement of molecules between the bloodstream and the brain’s extracellular fluid
• Key Functions: Protects the brain from toxins, pathogens, and fluctuations in blood composition; maintains a stable brain environment by regulating ion balance; prevents immune system overreaction; allows selective passage of essential substances (e.g., oxygen, glucose)
• The BBB ensures only necessary molecules enter the brain's highly sensitive neural environment, preventing excitotoxicity and damage

Structure of the BBB

• Formed by specialized endothelial cells in brain capillaries that have: tight junctions which prevent large or harmful molecules from crossing; astrocytes (glial cells) which provide structural support & regulate permeability; pericytes which help control blood flow & vessel integrity
• This unique structure limits the diffusion of most substances while allowing selective transport

Substances That CAN Cross the BBB

• Gases: Oxygen (O₂), Carbon Dioxide (CO₂) via passive diffusion as they are small & nonpolar
• Lipophilic (Fat-Soluble) Substances: Alcohol, Nicotine, Caffeine, Anesthetics via lipid solubility
• Glucose & Amino Acids: Glucose, Essential Amino Acids (e.g., L-DOPA) via active transport (glucose transporters - GLUT1)
• Hormones: some steroids (e.g., cortisol, estrogen) becausethey are lipid-soluble, some drugs (L-DOPA, Benzodiazepines)
• L-DOPA Uses specialized transport systems and is a Parkinson’s drug & Benzodiazepines (e.g., diazepam)

Substances That CANNOT Cross the BBB

• Large Proteins: Albumin, Antibodies, Most Plasma Proteins because they are too large to cross tight junctions
• Hydrophilic (Water-Soluble) Molecules: Most antibiotics (e.g., penicillin), Chemotherapy drugs because they do not dissolve in lipids, lack transporters
• Toxins & Pathogens: Bacteria, Viruses (some exceptions like rabies virus) because the BBB acts as a protective filter
• Neurotransmitters: Dopamine, Serotonin becausethey lack transport systems to enter the brain directly

Clinical Relevance of the BBB

• Infections & the BBB: The BBB blocks most bacteria but also prevents immune cells from reaching infections. Exception: Meningitis can break down the BBB, allowing immune cells in but also making the brain vulnerable.
• Neurological Disorders Affecting the BBB:
• Stroke (Ischemic/Hemorrhagic): BBB damage from lack of oxygen or bleeding, results in brain swelling, neuroinflammation
• Multiple Sclerosis (MS): Autoimmune attack on BBB integrity allows immune cells to attack myelin
• Alzheimer’s Disease: BBB permeability increases with age, allowing toxic proteins (e.g., beta-amyloid) to accumulate
• Traumatic Brain Injury (TBI): Physical damage disrupts the BBB, leading to brain swelling (edema)
• Medication Delivery Challenges: Most drugs cannot cross the BBB, limiting treatment for brain diseases (e.g., Parkinson’s, brain tumors)
• Solutions: Lipid-soluble drugs (e.g., benzodiazepines) can enter, intraventricular drug delivery bypasses the BBB, Nanoparticle technology being explored

Cognitive Time & Aging: Nursing Interventions

• Slower cognitive processing → Increased time for thinking, responding, and problem-solving
• Memory retrieval takes longer, but long-term memory remains intact
• Mild decline in executive function (multitasking, decision-making)
• Appropriate Nursing Interventions: Allow extra time for the patient to process and respond, use clear, simple instructions to aid comprehension, encourage repetition & memory aids (e.g., written reminders), provide a quiet environment to reduce distractions, engage in cognitive exercises (e.g., puzzles, reading, discussions)

Slower Cognitive Time vs. Neurologic Deterioration

• Memory Loss: Slower recall, but still able to retrieve information with normal aging versus progressive loss, forgets important life events with neurologic deterioration
• Problem Solving: Takes longer but can still reason logically with normal aging versus poor judgment, difficulty planning with neurologic deterioration
• Language: Occasional word-finding difficulty with normal aging versus difficulty forming coherent speech (aphasia) with neurologic deterioration
• Orientation: Remains aware of time, place, and self with normal aging versus disoriented (e.g., confused about location, time) with neurologic deterioration
• ADLs (Activities of Daily Living): Independent, may need minor help with normal aging versus declining ability to perform self-care tasks with neurologic deterioration
• Reversibility?: Normal, can improve with focus with normal aging versus progressive, worsens over time (e.g., Alzheimer’s, stroke) with neurologic deterioration

Why Does a Nurse Ask if a Patient is Right- or Left-Handed During a Neurological Assessment?

• Determines the dominant hemisphere of the brain (90% of right-handed people are left-brain dominant)
• Helps assess stroke impact → If a right-handed patient has left-sided stroke, language and fine motor skills may be severely affected
• Guides functional recovery planning → Affects rehabilitation strategies for mobility and ADLs
• Affects motor strength grading → Dominant hand is naturally stronger, so comparisons should be made accordingly

Order of Assessments for a Patient with Head Trauma & Multiple Injuries

• After stabilizing Airway, Breathing, and Circulation (ABCs) in a trauma patient, the next priority is assessing neurological status to identify brain injury, spinal cord damage, or increased intracranial pressure (ICP)
• Assessment Order After ABCs:
• Level of Consciousness (LOC) – Most Sensitive Indicator of Brain Injury: Use the Glasgow Coma Scale (GCS) (Eye, Verbal, Motor response; Score ≤ 8 = Coma); Assess for confusion, lethargy, stupor, or coma
• Pupillary Response (CN III Assessment): Check for equal, round, reactive pupils (PERRLA); Fixed, dilated pupils = Brainstem herniation (medical emergency!); Unequal pupils = Increased ICP or brain herniation
• Motor Function & Strength: Assess response to pain (localization vs. decorticate/decerebrate posturing); Unilateral weakness or hemiparesis = Stroke or traumatic brain injury (TBI)
• Vital Signs (Cushing’s Triad = Late Sign of Increased ICP): Hypertension (widening pulse pressure), bradycardia, irregular respirations (Cheyne-Stokes, Biot’s breathing)
• Assess for CSF Leakage (Basilar Skull Fracture Signs): Rhinorrhea (CSF from nose) or Otorrhea (CSF from ears) → Test for halo sign (CSF forms a ring around blood)
• Cervical Spine & Spinal Cord Assessment: Assume C-spine injury until cleared by imaging; Assess for paralysis, sensory loss, bladder dysfunction
• Secondary Trauma Survey (Head-to-Toe Exam for Other Injuries): Look for fractures, internal bleeding, abdominal trauma

Key Nursing Actions for Head Trauma

• Monitor GCS trends and repeat neuro exams frequently
• Elevate the head of the bed (HOB) 30° to reduce ICP (unless contraindicated)
• Prepare for emergency interventions (intubation, CT scan, ICP monitoring)

Nursing Techniques/Interventions for a Neurologic Cognitive Exam

• A neurological cognitive exam assesses a patient’s mental status, memory, and higher-level thinking
• Techniques & Interventions:

Assess Orientation (A&O x4)

• Ask: “What is your name? Where are you? What day is it? Why are you here?”
• Disorientation suggests delirium, dementia, or brain injury

Memory Testing

• Immediate recall: Repeat a short list of words
• Recent memory: Ask about today’s events
• Remote memory: Ask about past significant events

Attention & Concentration

• Have patient count backward by 7s (Serial Sevens)
• Ask them to spell “world” backward

Judgment & Reasoning

• Ask: “What would you do if you found an envelope on the ground?”
• Poor judgment may indicate frontal lobe damage (TBI, stroke, dementia)

Language & Communication

• Assess for aphasia (speech difficulty) by asking the patient to name objects, follow commands, and read/write sentences
• Expressive aphasia = Broca’s area damage (difficulty speaking); Receptive aphasia = Wernicke’s area damage (difficulty understanding)
• Mood & Behavior: Look for agitation, flat affect, or inappropriate responses
• Suggests psychiatric or neurological disorder
• Abstract Thinking: Ask the patient to interpret a proverb (e.g., “A rolling stone gathers no moss”)

Key Nursing Actions During Neurological Cognitive Exam

• Be patient; allow extra time for older adults
• Use a calm, reassuring tone to reduce anxiety
• Document changes in mental status carefully for early intervention

Glasgow Coma Scale (GCS)

• A neurological assessment tool used to evaluate a patient’s level of consciousness (LOC) after a traumatic brain injury (TBI) or other neurological event
• Evaluates three components: eye opening (E), verbal response (V), motor response (M)
• Each category is scored separately, and the total score ranges from 3 (worst) to 15 (best)

Glasgow Coma Scale (GCS) Breakdown

• Eye Opening (E): 4 = Spontaneous, 3 = To verbal command, 2 = To pain, 1 = No response
• Verbal Response (V): 5 = Oriented, 4 = Confused, 3 = Inappropriate words, 2 = Incomprehensible sounds, 1 = No response
• Motor Response (M): 6 = Obeys commands, 5 = Localizes pain, 4 = Withdraws from pain, 3 = Abnormal flexion (decorticate posturing), 2 = Abnormal extension (decerebrate posturing), 1 = No movement (flaccid)

When Should the GCS Be Used?

• TBI (Traumatic Brain Injury), Stroke, Seizures, Increased Intracranial Pressure (ICP), Altered Mental Status (AMS), Sedation Monitoring (ICU patients under anesthesia or mechanical ventilation)

Are There Situations Where GCS Should NOT Be Used?

• Intubated or Non-Verbal Patients, GCS verbal score cannot be assessed in intubated patients, instead, document “T” (tracheostomy) or “ETT” (endotracheal tube)
• Severe Facial Trauma, If the patient cannot open eyes due to swelling, the eye-opening score is not reliable
• Spinal Cord Injury (SCI) or Paralysis, Motor response may not be accurate due to loss of limb movement

Interpreting GCS Scores

• GCS Score 13-15 = Mild brain injury (concussion, brief LOC), 9-12 = Moderate brain injury (confusion, possible LOC), ≤ 8 = Severe brain injury (coma, high mortality risk), 3 = Deep coma or brain death

Changes That Indicate Neurologic Deterioration

• Drop in GCS of ≥ 2 points indicates worsening brain function
• Loss of verbal response or new confusion
• New onset of abnormal motor posturing (decorticate or decerebrate)
• Unresponsive to pain (GCS ≤ 6 = severe brain injury); GCS < 8 = Intubate! (Loss of airway protective reflexes)
• Reassess GCS every hour in critical patients and notify the provider immediately if GCS drops by 2 or more points
• Prepare for possible airway management (intubation, ICP monitoring)

Earliest Sign of Neurologic Deterioration

• Change in Level of Consciousness (LOC) is the Earliest Indicator of Brain Injury
• Subtle confusion, restlessness, or lethargy can be the first sign of worsening brain function
• Patient may become drowsy, disoriented, or difficult to arouse
• Slowed Verbal Responses or Inappropriate Speech, Example: Patient starts using the wrong words, answering slowly, or becoming incoherent
• Subtle Motor Weakness, Pronator Drift Test: Patient holds arms out with palms up → If one arm drifts downward, it may indicate early stroke or ICP changes
• New Onset of Headache or Vomiting: Unrelieved headache and projectile vomiting suggesting increased ICP
• Pupil Changes (Late Sign): Sluggish pupils or unequal pupils indicate increasing ICP

Stroke Management: First Priority Action & Nursing Interventions

• Perform a rapid neurologic assessment using the FAST exam:
• F – Facial droop
• A – Arm weakness
• S – Speech difficulty
• T – Time to call 911 (Stroke Team)

Immediate Nursing Actions for Stroke

• Ensure Airway, Breathing, Circulation (ABCs)
• Maintain oxygenation (keep O₂ Sat > 94%) and protect the airway (risk of aspiration if dysphagia is present)
• Check Blood Glucose, Hypoglycemia mimics stroke symptoms – correct low glucose first
• Initiate Stroke Protocol & Activate Rapid Response/Stroke Team, Time = Brain! Early intervention reduces disability
• Obtain a STAT Non-Contrast CT Scan, Determines ischemic vs. hemorrhagic stroke
• Assess for tPA (Tissue Plasminogen Activator) Eligibility (Ischemic Stroke Only)
• tPA must be given within 3-4.5 hours of symptom onset
• Contraindications: Bleeding risk, recent surgery, uncontrolled hypertension (>185/110)
• Monitor Neurological Status Frequently, Check Glasgow Coma Scale (GCS) and NIH Stroke Scale (NIHSS)

For Hemorrhagic Stroke

• Avoid tPA (worsens bleeding)
• Prepare for possible surgery or BP management

Pre-Assessment for the Dull and Sharp Pain Test

• Assess the Patient’s Cognitive Ability, ensure the patient can understand and follow instructions
• Check for Any Nerve Injuries or Sensory Deficits, pre-existing conditions like diabetic neuropathy, spinal cord injuries, or strokes may impair sensation
• Inspect the Skin & Test for Light Touch First, check for wounds, burns, or pressure ulcers that could affect sensation, and start with light touch before testing pain perception
• Ensure the Patient’s Eyes are Closed During Testing, this prevents visual compensation, ensuring an accurate response
• Explain the Procedure Clearly, tell the patient they will feel a dull or sharp sensation and should indicate when they feel each one
• Always compare sensations bilaterally to detect asymmetry (e.g., stroke, neuropathy)

How to Assess Cerebral Motor or Brainstem Integrity

• Motor Response to Commands & Strength Testing: Ask the patient to follow simple motor commands (e.g., “Lift your arm,” “Squeeze my hand”); Assess for weakness, asymmetry, or involuntary movements
• Reflex Motor Responses (Brainstem Function)
• Gag Reflex (CN IX, X), gagging response that is present shows brainstem function, absent gag reflex means there is brainstem dysfunction
• Pupil Response (CN III), PERRLA (equal, round, reactive) brainstem function, fixed, dilated pupils show brainstem herniation
• Corneal Reflex (CN V, VII), blink response is present shows brainstem function, no blink means there is severe brainstem injury
• Oculocephalic Reflex (Doll’s Eye Test), eyes move opposite to head turn shows brainstem function, no movement show brainstem damage
• Oculovestibular Reflex (Cold Water Test), eyes move toward cold water shows brainstem function, no movement says brainstem damage

Posturing (Late Sign of Brainstem Dysfunction)

• Decorticate (Flexor Posturing): Arms flexed, hands curled inward and indicates damage to cerebral cortex
• Decerebrate (Extensor Posturing): Arms stiffly extended, wrists outward and indicates severe brainstem damage (worse prognosis

Why You Don’t Need to Assess Both Pain and Temperature for Nerve Integrity

• Pain and temperature sensations are transmitted by the same nerve pathway (spinothalamic tract) in the spinal cord
• If a patient can feel pain, their temperature sensation is also intact, and vice versa
• If pain sensation is absent, assume temperature sensation is also impaired without needing further testing
• If pain is absent, document the deficit and assess for underlying neuropathy, stroke, or spinal cord injury

Recommended Stimuli for Glasgow Coma Scale (GCS) Testing & Escalation Steps

• Order of Stimuli (From Least to Most Invasive)
• Verbal Stimuli (Soft to Loud): Say the patient’s name and Progress to louder calling if no response
• Tactile Stimuli: Light touch on the patient’s arm and progress to vigorous shaking of the shoulder
• Painful Stimuli (If No Response to Verbal/Tactile): Apply a central pain stimulus by using trapezius squeeze (pinching trapezius muscle) or supraorbital pressure (pressing above the eye) or sternal rub (knuckles pressed firmly on sternum)

Signs, Symptoms, and Cause of Trigeminal Neuralgia

• A chronic pain disorder affecting the trigeminal nerve (CN V)
• Causes sudden, severe, stabbing facial pain
• Trigger points can cause attacks (e.g., chewing, speaking, wind on the face)

Trigeminal Neuralgia Symptoms

• Paroxysmal (Sudden) Sharp, shooting, or electric shock-like pain on one side of the face that is caused by Light touch, cold air, eating, talking, pain follows one or more branches of CN V and has pain-free intervals with sudden recurrence, and muscle spasms may occur
• Involuntary facial twitching

Cause of Trigeminal Neuralgia

• Compression of CN V by a blood vessel (vascular compression) or multiple sclerosis (MS) (damage to myelin sheath) or trauma, tumors, or unknown causes
• Manage pain with carbamazepine (first-line drug), nerve blocks, or surgery (rhizotomy)

Earliest & Most Reliable Sign of Central Neurologic Function Decline

• Change in Level of Consciousness (LOC) is the earliest and most sensitive sign of brain function decline

Signs of Neurologic Deterioration

• Confusion, Restlessness, Irritability: Patient becomes slow to respond or inappropriately answers questions
• Lethargy, Difficulty Arousing: More effort is needed to wake the patient and disorientation occurs as patient loses sense of time, place, or person
• Slurred or Delayed Speech: May struggle to find words or form coherent sentences

Late Signs (Indicative of Severe Brain Dysfunction)

• Pupil Changes (Sluggish, Fixed, Unequal)
• Abnormal Motor Posturing (Decorticate, Decerebrate)
• Cushing’s Triad: (HTN, Bradycardia, Irregular Breathing) → Late sign of brain herniation

Cerebral Angiography: Procedure & Patient Education

• Diagnostic imaging to visualize the cerebral blood vessels
• Uses contrast dye and fluoroscopy (X-ray) to detect aneurysms, stroke, tumors, or vessel blockages

Procedure Overview:

• Catheter Insertion: A catheter is inserted into the femoral or radial artery and guided to the cerebral arteries
• Contrast Dye Injection: Iodine-based contrast is injected to highlight blood flow
• Fluoroscopy Imaging: X-ray images track cerebral circulation in real time

Patient Education:

• NPO for 4-6 hours before the procedure and may feel a warm or flushing sensation when contrast is injected
• Mild headache or metallic taste is common during the procedure
• Remain still to ensure clear imaging and let provider know of Iodine/shellfish allergies
• Assess for kidney disease or diabetes—contrast dye can worsen renal function

Post-Procedure Care for Cerebral Angiography

• Monitor for Bleeding or Hematoma (Insertion Site): Apply pressure for 15-30 minutes at the puncture site; Assess for swelling, bruising, or bleeding
• Assess Neurovascular Status of the Affected Limb: Check distal pulses, skin color, temperature, capillary refill; Weak pulses, cold limb, or numbness → Notify the provider!
• Monitor for Signs of Stroke: Sudden confusion, weakness, slurred speech, vision changes; Perform frequent neurological assessments
• Encourage Hydration to Flush Out Contrast Dye: IV fluids or oral fluids promote dye excretion; Monitor for urine output (risk of contrast-induced nephropathy)
• Monitor Bed Rest & Leg Immobilization: Keep the affected leg straight for 4-6 hours to prevent bleeding; Elevate the head of the bed no more than 30°
• Report signs of bleeding, stroke, or renal dysfunction immediately

Electroencephalography (EEG): Procedure & Preparation

• A non-invasive test that measures electrical activity in the brain
• Used to diagnose seizures, epilepsy, brain death, and sleep disorders

Procedure Overview:

• Small electrodes (sticky patches) are attached to the scalp; Records electrical signals (brain waves) for 30-60 minutes; Stimuli like flashing lights or deep breathing may be used to trigger brain responses

Patient Preparation:

• Wash hair before the test (No oils, gels, or conditioners); Avoid caffeine or stimulants for 8 hours before the test; Continue taking medications unless told otherwise; May be asked to sleep-deprive the night before (for seizure monitoring); Painless & no electrical shocks—reassure the patient
• Monitor for seizure activity if the patient has epilepsy.

Potential Complications from Contrast Dye Use

• Allergic Reaction (Anaphylaxis): Signs & symptoms are rash, itching, wheezing, hypotension, angioedema. Nursing interventions include, stopping infusion and administer Epinephrine, oxygen, antihistamines
• Nephrotoxicity (Kidney Damage): Signs & symptoms are urine output is low, creatinine/BUN is rising. Nursing interventions include, encourage fluids, monitor kidney function
• Contrast-Induced Neurotoxicity: Confusion, seizures, coma (rare) nursing interventions, monitor neuro status with seizure precautions
• Extravasation (Leakage into Tissues): Signs & symptoms are swelling, pain with skin necrosis, nursing interventions stop IV, apply warm compress, elevate the limb

MRI vs. CT Scan

• CT Scan (Computed Tomography) – Best For: Quick imaging, bone injuries & fractures (Skull, spine, extremities), acute bleeding & trauma (Hemorrhagic stroke, subdural hematoma), lung and chest abnormalities (Pneumonia, PE), kidney stones or calcifications (Hard tissue visualization)

• Advantages of CT: Fast (Used in emergencies like stroke & trauma) with better imaging for bone & bleeding and can be used with metal implants & pacemakers

• MRI (Magnetic Resonance Imaging) – Best For: Soft tissue & organ imaging (Brain, spinal cord, nerves), multiple sclerosis (MS), tumors, and nerve damage, ligament, tendon, and muscle injuries (Rotator cuff tear, ACL tear), detailed brain imaging (Ischemic stroke, brain tumors), spinal cord diseases (Herniated discs, cord compression)

• Advantages of MRI: Better for soft tissue & nerves and no radiation exposure is safe for repeated use, and it detects strokes earlier than CT (especially ischemic strokes)

• Contraindications for MRI: Metal implants, pacemakers, and claustrophobia

Lumbar Puncture: Indications & What It Detects

• Indications where one is typically performed are when a doctor is assessing for Meningitis, Subarachnoid Hemorrhage, Multiple Sclerosis (MS), Guillain-Barré Syndrome (GBS), and Pseudotumor Cerebri
• Position patient in fetal position to open up the intervertebral spaces.

What Provider Looks for in CSF Analysis

• High WBCs indicates Meningitis/Encephalitis
• High Protein indicates Guillain-Barré, MS
• Low Glucose indicates Bacterial Meningitis
• Xanthochromia (Yellow CSF) indicates Subarachnoid hemorrhage

Contraindications for a Lumbar Puncture

• DO NOT Perform a Lumbar Puncture If increased Intracranial Pressure (ICP)
• Risk of Brain Herniation!
• Symptoms: Severe headache, vomiting, altered LOC, Cushing’s triad
• DO NOT Perform a Lumbar Puncture If patient has has a Coagulopathy - Risk of spinal hematoma
• Check INR, platelets
• DO NOT Perform a Lumbar Puncture If skin is infected - Risk of introducing bacteria into the CSF
• DO NOT Perform a Lumbar Puncture If spinal cord is compressed - May exacerbate neurological symptoms

Where Are Calcium & Phosphorus Stored? Their Functions?

• 99% of Calcium & 85% of Phosphorus are stored in the bones & teeth.
• Calcium Functions: Bone strength & formation, muscle contraction, nerve conduction & neurotransmitter release, blood clotting
• Phosphorus Functions: Bone mineralization, energy production, acid-base balance, cell membrane integrity

Ethnicities at Greatest Risk for Osteoporosis & Why

• Caucasian & Asian Women; lower bone density, smaller bone structure
• Hispanic & African American Women; higher bone mass, but still at risk with aging
• Risk Factors for Osteoporosis:
• Age > 50 Female sex Low calcium Sedentary lifestyle Smoking & alcohol

Bowing of Bones in Both Lower Limbs: Causes & Treatment

• Bowing of the legs is a deformity of long bones where the legs curve outward or inward and it suggests weakened bones due to defective mineralization

Causes of Bowing in Both Lower Limbs

• Rickets: defective mineralization due to Vitamin D, calcium, or phosphate deficiency, and they are correctable if treated early
• Osteomalacia: defective mineralization due to vitamin D deficiency and is partially correctable with treatment
• Paget’s Disease: caused by bone remodeling and weak bone formation that can be managed but deformities may persist
• Blount’s Disease: growth Plate disorder in children that may need surgery
• Encourage vitamin D & calcium intake, monitor growth in children, and provide orthopedic support if needed