Neuropathology Lecture 4

Definition: Neuropathology is the study of diseases or disorders affecting the nervous system, particularly the brain.
Focus: Understanding brain injuries and their implications on functionality.
Importance of prefixes: Understanding terms through prefixes like "neuro" relating to the nervous system.

Different sections of the brain are responsible for various functions. For instance:
- Frontal Lobe: Related to personality, movement, and sense of smell. Injury here may lead to:
- Changes in personality or behavior.
- Altered eating experience due to smell impairments.
- Loss of movement control.
- Temporal Lobe: Associated with speech. Injury may result in:
- Difficulty speaking in a typical manner.
Understanding these anatomical functions is crucial for diagnosing brain injuries.

Examination of types of brain injuries.
Discussion of three representative diseases:
- Stroke: Mechanisms, types, signs, and management.
- Seizures: Nature of the electrical injuries to the brain.
- Parkinson's Disease: Neuropathological effects and management.
Clarification of brain death as a terminal event in severe brain injuries.

Definition: Injuries arising indirectly from other systemic conditions affecting the brain.
Underlying conditions may include:
- Hypoxia: Lack of oxygen reaching the brain due to respiratory disorders.
- Symptoms and potential for hypoxic brain injury.
- Infections leading to fever, which the brain cannot withstand at high temperatures (e.g., above 103°F).
- Edema: Swelling due to excess fluid that disrupts the brain's water balance.

Ischemic Stroke
- Definition: Occurs due to a blockage in an artery supplying blood to the brain.
- Mechanism: Often linked to blood clots that prevent adequate blood flow.
- Signs: Sudden neurological deficits manifest, reflecting affected brain areas (
  ) e.g., motor deficits or speech difficulties.
- Pathophysiology: Cellular death occurs rapidly due to lack of blood flow; the concept of "time is brain".
Hemorrhagic Stroke
- Definition: Results from ruptured blood vessels in the brain, leading to bleeding.
- Cause: Often due to aneurysms or other vascular malfunctions.
- Complications: Can create considerable pressure within the skull, leading to further injury.

Hypertension: High blood pressure may weaken arterial walls, promoting rupture risk.
Smoking: Increases inflammation and overall vascular risk.
Diabetes and Hyperlipidemia: Related to clotting mechanisms and overall vascular health.
Atrial Fibrillation: Disorganized heart activity can lead to stroke by promoting clot formation.

Definition: Abnormal bursts of electrical activity in the brain, leading to varying behavioral symptoms.
Types of seizures include:
- Focal Seizures: Affect a specific area of the brain, possibly leading to sensory or motor deficits localized to that area.
- Generalized Seizures: Involve the entire brain, leading to loss of consciousness and convulsions.

Prodromal Phase: Signs or symptoms that occur before the seizure; may include auras.
Ictal Phase: The actual seizure event; characterized by abnormal electrical discharge.
Post-Ictal Phase: Recovery period post-seizure; may include confusion or fatigue.

Time document: Important to record when the seizure started to evaluate duration and effect.
Ensure patient safety: Clear surrounding hazards and place patients on their side to maintain airway.
Administer oxygen if necessary.
Call for medical assistance if seizure lasts longer than five minutes (status epilepticus).

Definition: A progressive neurodegenerative disorder primarily affecting dopamine production in the substantia nigra.
Symptoms include:
- Bradykinesia: Slowed movement.
- Tremors: Typically observed at rest.
- Rigidity: Muscle stiffness impacting movement and coordination.
Diagnosis may involve a review of symptoms and medical history,
- Hypothetical Tests: Look for lewy bodies in neuro cells to differentiate from other diseases.

Levodopa Carbidopa Therapy: Used to replenish dopamine levels.
Anticholinergics: To combat acetylcholine imbalances.
Physical Therapy and Exercise: To maintain mobility and quality of life.
Patient Support: Importance of emotional support from family and groups due to the disease's impact over time.

Definition: Irreversible cessation of all brain activity and functions.
Criteria for documentation of brain death include:
- Evidence of irreversible condition.
- Neurological assessments to confirm loss of brainstem reflexes and functions.
- Verification of absence of spontaneous respiratory efforts despite elevated levels of carbon dioxide in the blood.
Collaboration within the medical team is vital for care and ethical considerations in brain death scenarios.