Nursing 302: Central Nervous System Disorders

Disorders of the Central and Peripheral and Neuromuscular Junctions

• This is a nursing 302 course topic.

Traumatic Brain Injury (TBI)

• TBI: An alteration in brain function caused by external force (e.g., motor vehicle accidents, falls).
• Primary Injury: Direct impact (focal or diffuse).
• Secondary Injury: Indirect result of the primary injury.
• Most common injury location: Frontal lobe.
• Focal Brain Injury (Observable Injury): Lesion or contusion.
  • Open (Penetrating) Trauma: Breaks dura, exposing cranial contents to the environment.
  • Closed (Blunt) Trauma: Dura remains intact; brain tissues not exposed.
    • Coup Injury: Injury directly below impact point.
    • Contrecoup Injury: Opposite side injury from impact.
    • Contusions can cause: Epidural, subdural, or intracerebral hematomas.
• Diagnosis: History, GCS score, CT & MRI & PET scan, EEG, ICP.
• Treatment: Goal is to control ICP and manage symptoms; potential surgery.

Hematomas

• Epidural: Bleeding between dura mater and skull (usually due to an artery).
  • Typically associated with loss of consciousness on initial injury.
  • Medical emergency.
  • Symptoms: Worsening headache, vomiting, drowsiness, confusion, seizure, and hemiparesis.
  • Diagnosis: CT, MRI.
  • Treatment: Monitoring, evaluation, pain management, potential surgery.
• Subdural: Bleeding between dura mater and brain.
  • Acts like growing masses; increases ICP, putting pressure on bleeding vessels.
  • Symptoms: Headache, drowsiness, restlessness, slowed thought, confusion, loss of consciousness, breathing pattern changes, pupil changes.
  • Diagnosis: CT, MRI.
  • Treatment: Percutaneous drainage or craniotomy (for chronic bleed).
• Intracerebral: Bleeding within the brain.
  • Increases intracranial pressure (ICP) and decreased level of consciousness (LOC).
  • Treatment: Decreasing ICP and allowing the hematoma to reabsorb slowly.

Open Brain Injury

• Open Brain Injury: Trauma that penetrates the dura mater.
• Compound Skull Fracture: Opens a path between cranial contents and the environment.
• Basilar Skull Fracture: Fracture to the base of the skull.
  • Symptoms: CSF leaking from ear or nose, Battle's sign, periorbital hematoma (racoon eyes).
  • Treatment: Bed rest and close observation for meningitis and other complications.

Diffuse Axonal Injury (DAI)

• Widespread brain injury; severity correlates with shearing force to the brainstem.
• Causes: High levels of acceleration/deceleration or rotational forces (e.g., whiplash).
• Results in:
  • Axonal damage (shearing, tearing, or stretching of nerve fibers).
  • Acute brain swelling.
  • Potential long-term neurodegenerative processes.

Concussion (Interchangeable term for TBI)

• Severity is determined by duration of loss of consciousness, GCS, post-traumatic amnesia & brain imaging.
• Goal of treatment: Maintain cerebral perfusion & oxygenation; promote neuroprotection.
  • Mild Concussion: No or <30 minutes loss of consciousness; GCS 13-15, confusion (< several minutes), amnesia.
  • Moderate Concussion: >30 minutes-6 hours loss of consciousness, GCS 9-12, prolonged confusion &post-traumatic amnesia (>24 hours).
  • Severe Concussion: >6 hours loss of consciousness, GCS 3-8, signs of brainstem damage.

Complications of TBI

• Post-concussion syndrome: Weeks to months after, including headache, fatigue, anxiety, irritability, and insomnia.
• Post-traumatic seizures: Can occur within days or up to 5 years after injury.
• Chronic Traumatic Encephalopathy (CTE): Progressive dementing disease that develops with repeated brain injuries (e.g., sports injuries, military-related trauma).
• Symptoms include violent behaviors, loss of control, depression, memory loss, and changes in motor function.

Spinal Cord Injury

• Causes: Motor vehicle accidents, sports activities, falls (>70 years).
• Risk factors: Male, ages 20-39.
• Primary Spinal Cord Injury: Initial mechanical trauma/immediate tissue destruction.
• Secondary Spinal Cord Injury: Pathophysiological cascade of events (edema, ischemia, excitotoxicity, inflammation, cell death) over weeks following injury.
• Life-threatening if swelling occurs in cervical region (C1 to C4).
• Vertebral Injuries: Acceleration/deceleration/deformation forces causing fractures, dislocations & bone fragments that cause compression.
  • C1-C4 fracture = aspen collar.

Spinal Cord Injury: Clinical Manifestations

• Spinal Shock: Normal activity of the spinal cord ceases below the injury level; lack of continuous nervous discharges from brain, complete loss of reflex function.
• Neurogenic Shock: Occurs with injuries above T6, caused by absence of sympathetic activity; symptoms include vasodilation, hypotension, bradycardia, & failure of temperature regulation.
• Autonomic Hyperreflexia (Dysreflexia): Massive, uncompensated cardiovascular response to sympathetic nervous system stimulation below the level of injury.
  • Usually caused by distended bladder or rectum.
• Diagnosis: Physical exam, imaging studies.
• Treatment: Immobilization to prevent further injury, Surgical fixation/decompression may be necessary, therapeutic hypothermia, nutrition management, lung function, skin integrity, bladder & bowel management, and rehabilitation.

Degenerative Disorders of the Spine

• Low Back Pain: Primary cause of disability worldwide
  • Risk factors: Occupations requiring repeated lifting/forward bending, exposure to vibrations, obesity, smoking.
• Degenerative Disc Disease (DDD): Normal aging process, vertical compression of the spine.
  • Can lead to disc protrusion, spondylolysis and spinal stenosis.
• Herniated Intervertebral Disc: Displacement of nucleus pulposus or annulus fibrosus.
  • Usually caused by trauma, degenerative disc disease, or both.
  • Symptoms: Radiculopathy, pain, paresthesia.

Stroke

• Stroke: Interruption in blood flow to brain cells (cerebrovascular accident).
• Third leading cause of death in Canada.
• The sooner circulation returns, the greater the chance of recovery.
• Risk Factors: Poorly controlled hypertension, polycythemia, hyperlipidemia, CHF, PVD, atherosclerosis, arrhythmias (atrials fibrillation), diabetes, lack of exercise, hormonal contraceptive use, and smoking
• Classifications:
  • Ischemic (thrombotic or embolic)
  • Hemorrhagic
  • Transient Ischemic Attacks (TIAs)

Ischemic Stroke

• Pathophysiology: Cerebral infarction—area of brain loses blood due to vascular blockage; prompt infusion of thrombolytics may restore perfusion and prevent necrosis.
  • Must be given within 4 hours of onset of symptoms.
• Diagnosis: Cerebral angiography, CT, MRI.
• Treatment: Restoring brain perfusion (tPA), preventing recurrent ischemic events (anticoagulants), physical rehab, and surgery (depending on the extent.)

Hemorrhagic Stroke

• Pathophysiology: Sudden rupture of cerebral artery, leading to diminished blood supply to the affected area.
  • Blood accumulates within the brain, causing greater damage, potentially increasing ICP.
  • Eventually, reabsorption resolves hemorrhage.
• Diagnosis: Cerebral angiography, CT, MRI.
• Treatment: Stopping or reducing the bleed, controlling blood pressure, and surgery (depending on extent.)

Migraines

• Migraines: Repeated episodic headache lasting 4-72 hours.
• Typically in women 25-55 years old.
• Triggers: altered sleep patterns, overexertion, weather change, stress, hormonal changes, excess sensory stimulation, and chemicals (alcohol or nitrates)
• Phases:
  • Premonitory: Tiredness, irritability, inability to concentrate, stiff neck
  • Migraine Aura: Visual, sensory, or motor symptoms last up to 1 hour.
  • Headache: Throbbing, spreading to the whole head; associated with nausea, vomiting, fatigue, dizziness.
  • Recovery: Irritability, fatigue, depression up to days after.
• Diagnosis: History of headaches, medical history (unilateral, throbbing, worsening with movement, moderate or severe).
• Treatment: Avoiding triggers, and pharmacological management.

Headache & Migraines: Cluster Headaches

• Cluster headaches occur in clusters (minutes to hours) followed by a long period of remission.
  • Usually in men aged 20-50 years old.
  • Symptoms: Trigeminal activation, autonomic dysfunction, unilateral pain, ipsilateral autonomic manifestations (tearing, ptosis, nasal congestion).
• Tension-type headaches are most common. Average onset in the second decade.
  • Mild to moderate bilateral pain, tight band sensation. The pain slowly starts.
  • Episodes are hours to days in duration.
  • At least 15 days per month for 3 months.

Meningitis

• Meningitis: Inflammation of the meninges in brain and spinal cord.
  • Blood flow to the brain is reduced, tissues swell causing increased intracranial pressure (ICP).
  • Spreads through droplets (bacterial), and quickly due to CSF circulation.
• Causes: Bacteria, viruses, fungi, parasites, or toxins.
• Risk Factors: Malnourishment, immunosuppression, CNS trauma.
• Clinical Manifestations (Children <2 vs. Adults): Fever, anorexia, vomiting, diarrhea, listlessness, and bulging fontanels, cry vs adults (fever, chills, headache, photophobia, neck stiffness, positive Kernig's & Brudzinski sign, tachycardia, LOC deterioration.)

Brain or Spinal Cord Abscess

• Abscess: Localized collection of pus in brain or spinal cord.
• Brain Abscess: Epidural, subdural, or intracerebral.
• Spinal Cord Abscess: Rare; epidural, or intramedullary.
• Risk Factors: Immunosuppressed individuals, IV drug users.
• Pathophysiology: Microorganisms entering the CNS via direct extension along vein walls or via infective emboli.
• Clinical Manifestations: Early (low-grade fever, headache, nausea, vomiting, stiff neck), and then later (confusion, decreased attention span, memory deficits, decreased visual acuity, papilledema, ocular palsy, ataxia, seizures, dementia).

Encephalitis

• Encephalitis: Acute febrile illness usually viral, with nervous system involvement.
• Causes: Mosquito/tick/fly bites, Herpes Simplex type 1, live attenuated vaccines.
• Clinical Manifestations:
  • Minor: Malaise, headache, body aches, nausea, and vomiting.
  • Major: Fever, delirium, decreased LOC, seizures, paralysis, increased ICP signs.
• Diagnosis: History, CSF examination & culture, WBC count, CT or MRI.
• Treatment: Specific to the type of virus.

Multiple Sclerosis (MS)

• MS: Progressive, inflammatory demyelination of the white matter of the CNS; leading to acquired autoimmune response; loss of myelin disrupts nerve conduction and brain atrophy.
• Characterized by exacerbations and remissions.
• Clinical Manifestations: Vision problems (optic neuritis), paresthesia, emotional lability, dysphagia, muscle weakness/spasticity, hyperreflexia, urinary & bowel problems, gait ataxia, fatigue.
• Diagnosis: History and clinical exam, MRI for lesions, CSF analysis for elevated IgG levels.
• Treatment: Preventing exacerbations, damage, and symptomatic relief (medications like steroids, bed rest, massage, bowel/bladder training, physical therapy).

Myasthenia Gravis

• Myasthenia Gravis: Acquired chronic autoimmune disease producing sporadic/progressive muscular weakness.
• Autoimmune response to acetylcholine receptors.
• Clinical Manifestations: Weakness and fatigue of eye and throat muscles (diplopia, chewing/swallowing problems), drooping jaw, bobbing head.
• May result in myasthenia or cholinergic crisis
• Myasthenia Crisis: Increased symptoms (respiratory distress, tachycardia, decreased gag reflex, visual changes)
• Cholinergic Crisis: Due to anticholinesterase medication toxicity, with symptoms like hypotension, bradycardia, diarrhea, & increased respiratory secretions
• Diagnosis: Tensilon test, Electromyography, Nerve conduction studies.
• Treatment: Anticholinesterase drugs, steroids, and IVIG.

Alterations of Neurological Function in Children

• This is a chapter 17 topic about neurological disorders in children.

Defects of Neural Tube Closure

• Spina Bifida: Vertebrae fail to close; genetic, and folic acid deficiency cause.
• Types: Anencephaly, encephalocele, meningocele, and myelomeningocele.

Encephalopathies

• Encephalopathy: brain tissue abnormality.
• Static encephalopathy: Fixed lesion due to brain injury or disease (not progressing.)
  • Causes: Brain malformations, brain injury during gestation/birth, anoxia, trauma, infections, toxins, and metabolic disturbances.
• Cerebral Palsy: Movement and muscle tone disorder occurring due to prenatal or perinatal cerebral hypoxia, hemorrhage, infection or genetic abnormalities, and low birth weight.
  • Types: Spasticity, dystonia, ataxia, mixed.