Brain Lobes, Functions, Seizures, Stroke, Brain Injuries, Spinal Cord Injury

BRAIN LOBES + FUNCTIONS

Executive Functions of the Frontal Lobe

  • Frontal Lobe: Often referred to as the executive function center of the brain, responsible for several higher-order cognitive processes.

    • Key Functions:

    • Problem solving

    • Concentration

    • Planning and organizing

    • Reasoning

    • Influences on personality, behavior, and mood regulation

Important Parts of the Frontal Lobe

  1. Broca's Area

    • Function: Controls expressive speech.

    • If Damaged: The individual might understand spoken language but produce disjointed speech, often referred to as "broken speech".

  2. Motor Area (Primary Motor Cortex)

    • Function: Controls voluntary movements.

Parietal Lobe Functions

  • Mnemonic: Think “PIRANHA”

  • Functionality: Significantly sensitive to sensations and body awareness.

    • Key Functions:

    • Processes sensory information (e.g., temperature, pressure, touch, smell, pain, and taste)

    • Body awareness and perception

    • Attention and calculations

Temporal Lobe Functions

  • Mnemonic: Think “TEMPO”

  • Functionality:

    • Involves hearing, attention, and memory.

    • Key Functions:

    • Storing both verbal and visual memories (short-term and long-term)

    • Assists with balance (partially)

    • Understands language and speech

Important Part

  1. Wernicke's Area

    • Function: Controls language comprehension (receptive speech).

    • If Damaged: The individual struggles to understand and respond appropriately to spoken language, leading to nonsensical speech patterns often humorously referred to as “Wernicke is crappy".

Occipital Lobe Functions

  • Mnemonic: Think “OPTIC”

  • Functionality:

    • Central to the visual processing system.

    • Key Functions:

    • Processes visual information

    • Helps in perception of shapes and sizes

Extra: Cerebellum

  • Nickname: Mini brain

  • Functions:

    • Maintains balance and coordination

    • Regulates rhythm and posture

    • Responsible for proprioception (sense of body position)

Brain Stem Functions

  • Functionality:

    • Maintains consciousness

    • Controls basic life processes such as breathing and heart rate

SEIZURES

Definition

  • Sudden and uncontrolled release of electrical activity in the brain, leading to changes in behavior, movements, and loss of consciousness (LOC).

Causes of Seizures

  • Genetics

  • Stroke

  • Head trauma

  • Brain tumors

  • Meningitis or other infections

  • Fetal brain damage (in utero)

  • Drug or alcohol withdrawal

Types of Seizures

  1. Focal (Partial) Seizures

    • Characteristics: Located in one part of the brain.

      • A) Simple Focal Seizures: Do not cause loss of consciousness.

        • Life Threatening:

        • Status Epilepticus: Seizures lasting longer than 5 minutes or consecutive seizures without regaining consciousness can lead to death or permanent brain damage.

        • Symptoms: Altered senses, tingling sensations, jerking movements, and flashing lights.

        • Risk of sudden unexplained death in epilepsy for unmedicated individuals.

        • Particularly dangerous for those with tonic-clonic seizures.

  2. Generalized Seizures

    • Characteristics: Involve all areas of the brain.

      • A) Absence Seizures: Typically seen in children; involves brief loss of awareness or consciousness.

      • B) Complex Focal Seizures: Can cause loss of consciousness or altered awareness, often featuring staring or repetitive movements.

      • C) Tonic Seizures: Characterized by stiffness and complete loss of muscle control.

      • D) Clonic Seizures: Involves jerking movements, often in the face or arms.

      • E) Tonic-Clonic (Grand Mal) Seizures: Most intense type, leading to abrupt LOC, body shaking, and loss of bladder control; may include tongue biting.

Treatment for Seizures

  • Medications: Antiseizure and antiepileptic medications, including anticonsvulsants.

  • Vagus Nerve Stimulation: A device may be implanted under the chest.

  • Emergency Protocols:

    • Do not put anything in the patient’s mouth (risk of aspiration).

    • Ensure the patient is lying on their side to minimize aspiration risks.

    • Monitor LOC and perform neuro checks routinely.

STROKE

Definition

  • The inability of oxygen-rich blood to reach the brain due to blockage or bleeding in a vessel.

Types of Stroke

  1. Ischemic Stroke

    • Characteristics: Narrowing of blood vessels leads to clotting or blockage.

    • How It Occurs:

      • An Embolus travels from another part of the body to the brain.

      • A Thrombus forms from atherosclerosis in the brain.

  2. Hemorrhagic Stroke

    • Characteristics: A broken blood vessel causes bleeding in the brain.

    • How It Occurs:

      • Most commonly caused by an aneurysm; can also be due to trauma or uncontrolled hypertension.

Symptoms of Stroke

  • Altered LOC, severe headache, facial drooping, one-sided weakness or paralysis, respiratory distress, speech/visual issues, nausea or vomiting, uneven pupils, difficulty swallowing, seizures, and incontinence.

Diagnosis

  • CT Scan: Essential for evaluating stroke type; patients with hemorrhagic strokes cannot be candidates for tPA (tissue plasminogen activator).

Interventions

  • NPO: Patients should not consume food or liquids until swallowing ability is tested, particularly if gag reflex is absent.

  • Baseline Neuro Data: Obtaining assessments using the NIH Stroke Scale.

  • Fluid Electrolyte Management: Essential for maintaining perfusion to the brain.

  • Airway Management: Ensuring dentures are removed.

  • Vital Monitoring: Including pulse oximetry and oxygen levels, intubation if required.

  • IV Fluids: Administer normal saline to maintain or improve BP.

  • Prevent Hyperthermia: Excessive heat can cause vasodilation and increase intracranial pressure (ICP).

  • Use Aspirin: As a preventive measure for ischemic stroke.

  • Risk of Seizures: Increased risk for up to 24 hours post-stroke.

  • Surgeries: Consideration for patients not eligible for tPA, such as removing hematomas.

Remember the Acronym F.A.S.T for Stroke Assessment

  • F: Facial drooping (ask patient to smile)

  • A: Arm weakness (ask patient to raise both arms)

  • S: Speech difficulties (ask patient to repeat a simple phrase)

  • T: Time to call 911

  • Administration Timing for tPA: Must be given within 4.5 hours of symptom onset, ensuring there is a negative hemorrhage evaluation and controlled blood pressure, INR, glucose levels, and no recent use of anticoagulants.

  • Clot Buster Monitoring: Monitor for bleeding, hemoglobin/hematocrit levels, clotting factors, and maintain head midline for perfusion management; avoid new IVs or injections.

PRIMARY TRAUMATIC BRAIN INJURIES

Types

  1. Intracerebral Hemorrhage

    • Location: Bleeding within the brain tissue or ventricles.

    • Common Cause: Penetrating injury; can also result from depressed skull fractures or acceleration/deceleration trauma.

    • Symptoms: Headache, contralateral hemiparesis, loss of consciousness, vomiting, seizures.

    • Treatment: May require an external ventricular drain to relieve pressure; prioritize treating ICP to prevent secondary brain injury.

  2. Cerebral Contusion

    • Location: Small bleeding or bruising on surrounding brain tissue.

    • Cause: Coup, countercoup injury.

    • Symptoms: Range from mild to severe headache, confusion, sleepiness, dizziness, nausea/vomiting, focal changes, and loss of consciousness.

    • Treatment: Severe cases may necessitate external ventricular drains to relieve pressure; ICP management is critical to prevent secondary injury.

  3. Concussion

    • Location: Most commonly affects frontal and temporal lobes.

    • Cause: Result of bump, blow, or jolt to the head.

    • Symptoms: Brief loss of consciousness, headache, dizziness, nausea or vomiting. Considered the mildest form of traumatic brain injury.

SPINAL CORD INJURY

Definition

  • Damage to any area of the spinal cord or nerves that frequently leads to permanent alterations in strength, sensation, and other bodily functions below the site of injury.

Causes of Spinal Cord Injury

  • Trauma leading to fractures, dislocations, crushes, or compressions of vertebrae.

    • Common causes include:

    • Motor vehicle accidents

    • Falls

    • Violence (stabbings, gunshot wounds)

    • Non-traumatic causes such as alcohol, cancer, or arthritis

Symptoms of Spinal Cord Injury

  • Loss of motor and sensory impulses below the injury site.

    • Notable levels:

    • C3-C5 functioning: Potential loss of bladder function, altered vision, inability to feel temperature, changes in mobility, impaired breathing (C3-C5).

    • Symptoms also include flushing skin, feelings of heat, anxiety, and muscle spasms, along with altered sensation to heat, cold, or touch.

    • Neurogenic shock symptoms or autonomic dysreflexia may present.

Treatment

Immediate Response

  • Immobilize the Spine: to prevent further damage.

    • Use of a neck collar and maintaining the head of bed flat.

    • Implement log roll techniques to avoid harm.

Acute Stage

  • Assessment pending determination of SCI.

Ongoing Management

  • Positioning: Rotate every two hours to prevent pressure ulcers; implement passive and active range of motion to prevent blood clots.

  • Encourage physical therapy (PT) and occupational therapy (OT) participation.

  • Provide analgesics and muscle relaxants as needed.

  • Maintain airway especially for C3-C5 injuries due to impact on respiration.

  • Prevent neurogenic shock in the first 24-72 hours.

  • Monitor for autonomic dysreflexia: symptoms may occur at any time with signs including flushed skin and increased temperature.

    • Relationship of clinical signs: Hypertension (HTN), bradycardia (VBP), and variability in heart rate (VHR).