concept 3

Concepts III Unit 3 Neuro

Alterations and Manifestations of Malfunction of the Nervous System

  • Spinal Cord Injuries

    • Primary: Initial trauma to the spinal cord.
    • Secondary: Processes that occur after initial injury leading to nerve swelling/disintegration, ischemia, hypoxia, and edema destruction.

  • Guillain-Barré Syndrome

    • Description: An acute attack of peripheral nerve myelin that is reversible and constitutes an emergency.
    • Etiology: Most often follows a viral infection.
    • Signs/Symptoms (s/sx):
    • Progression starts in the feet and ascends upward, may then descend.
    • Can target the respiratory system leading to respiratory issues.
    • Pain, diminished or absent reflexes, tachycardia, bradycardia, hypertension (HTN) or hypotension.
    • Medical Management:
    • Require ICU admission for continuous monitoring and respiratory support.
    • Treatments like plasmapheresis and intravenous immunoglobulin (IVIG) are utilized to reduce circulating antibodies.

  • Head Injury

    • Types of Injuries:
    • Open Brain Injury: Requires keeping the patient comfortable.
    • Closed Blunt Brain Injury:
      • Types:
      • Concussion: Temporary loss of brain function.
      • Contusion: Bruising of the brain in a specific area, changes in level of consciousness (LOC), confusion may peak 18-36 hours post-injury.
      • Diffuse Axonal Injury: Widespread shearing and rotation damage to axons between hemispheres, can lead to coma, posturing, and edema; outcomes vary widely.
      • Intracranial Hemorrhage: Symptoms may be delayed and related to increased intracranial pressure (ICP).
        • Epidural Hematoma: Brief change in LOC may occur until ICP increases, emergency situation with rapid onset of neurological damage or respiratory arrest.
        • Subdural Hematoma:
        • Acute (s/sx within 24-48 hours), subacute (2 days to 2 weeks), chronic (3 weeks to months).
        • Intracerebral Hemorrhage: Can be caused by hypertension (HTN), aneurysm, abnormalities, or tumors; treatment is symptomatic.
    • Skull Fracture:
    • Defined by location/type.
    • Basilar Skull Fracture:
      • May have dural tear.
      • Symptoms include Battle sign (bruise behind ears), raccoon eyes (periorbital bruise), and Halo sign (clear fluid leaking from ears/nose).
      • No treatment unless depressed/symptomatic.
    • Posturing:
    • Decorticate Posturing:
      • Limbs bent to the core, indicative of damage above the brainstem.
    • Decerebrate Posturing:
      • Arms and legs extended out, indicating damage at or below the brainstem, considered more severe than decorticate.

Lab/Diagnostic Tests and Medications/Treatments in Patients with Neurological Disorders

  • MRI (Magnetic Resonance Imaging):

    • Utilizes a strong magnetic field and does not involve radiation; duration is approximately 20-60 minutes, with the patient needing to remain still.
    • Commonly used for brain disorders, spinal cord injuries, multiple sclerosis (MS), joint/ligament injuries, heart, and blood vessel diseases.

  • CT Scan (Computed Tomography):

    • X-ray tube rotates around the patient using ionizing radiation, producing cross-sectional images; sometimes uses contrast dye.
    • Effective for diagnosing head injury/brain bleeds, strokes, tumors, bone fractures, internal bleeding, and chest/abdomen diseases.
    • Quick and suitable for emergencies.

  • Lumbar Puncture:

    • Involves a needle inserted into the lower back to collect cerebrospinal fluid (CSF).
    • Indicated for meningitis, subarachnoid hemorrhage, and multiple sclerosis.
    • Patient positions: lateral recumbent (side lying) or sitting.
    • Ensure patient empties bladder, use sterile technique, and keep the patient flat for 4-6 hours post-procedure.

  • Mannitol:

    • Used to reduce pressure in the brain and eyes while increasing urine output.
    • An osmotic diuretic administered intravenously only.
    • Commonly prescribed for increased ICP, cerebral edema, or glaucoma.

  • Intracranial Pressure (ICP):

    • Normal ICP is 0-10 mmHg, with an upper limit of 15 mmHg.
    • Cerebral perfusion pressure (CPP) is calculated as:
      CPP = MAP - ICP
      where normal CPP should be between 70-100 mmHg; values <50 mmHg are devastating.

  • Monro-Kellie Hypothesis: This principle states that the sum of volumes of the brain, blood, and cerebrospinal fluid (CSF) within the skull is constant.

  • Medical Management of ICP:

    • Monitoring: Utilizing intraventricular catheters, subarachnoid bolts, or epidural/subdural catheters.
    • Drainage: Procedures include ventriculostomy or