Neurology

Neurological System - Week 7 Lecture Notes

Lecturer Information

  • Farzana Sarder, MS, PA-CArizona State University (ASU)

Assigned Reading

  • McCance, K.L. & Huether, S.E. (2019). Pathophysiology: The biologic basis for disease in adults and children (8th ed). Elsevier.Chapters to read:

    • Chapter 17: Alterations in Cognitive Systems, Cerebral Hemodynamics, and Motor Function

    • Chapter 18: Disorders of the Central and Peripheral Nervous System

Key Concepts

Neurological Alterations in Movement

  • Key terms and movement alterations:

    • Alterations in Muscle Tone:

      • Hypotonia: Decreased muscle tone

      • Hypertonia: Increased muscle tone

        • Spasticity: Hyperexcitability of stretch reflexes leading to uncontrolled movements

        • Dystonia: Increased voluntary muscle contraction causing repetitive movements

        • Rigidity: Firm, tense muscles resisting movement

Upper and Lower Motor Neurons

  • Upper Motor Neurons (UMN):

    • Origin: Brain, travel to brainstem and spinal cord.

    • Injury leads to hypertonia (e.g., spasticity, rigidity).

  • Lower Motor Neurons (LMN):

    • Origin: Spinal nerves, travel to muscles.

    • Injury leads to hypotonia (e.g., weakness, atrophy, fasciculations).

Parkinson's Disease

  • Pathophysiology: Loss of dopamine neurotransmitter affecting basal ganglia, leading to excess movement control loss.

  • Symptoms:

    • Hallmarks: Resting tremors, cogwheel rigidity, bradykinesia (slow movements).

    • Increased tone causes difficulty walking; common symptoms include unblinking stare and drooling.

  • Treatment:

    • Medications (e.g., Carbidopa, Levodopa, Amantadine).

    • Rehabilitation therapies to address symptoms.

Spinal Cord Injuries

  • Causes: Trauma (e.g., falls, vehicle accidents).

  • Clinical Manifestations:

    • Loss of function below the injury level, initial hypotonia followed by hypertonia.

  • Complications:

    • Spinal Shock: Loss of motor/sensory function/ reflexes at injury level.

    • Neurogenic Shock: Occurs in higher spinal injuries, causing hypotension and bradycardia.

    • Autonomic Dysreflexia: Hypertension and possible bradycardia in response to stimuli, common after T6 injury.

Demyelinating Disorders

  • Multiple Sclerosis (MS):

    • Autoimmune disorder causing demyelination in CNS, producing sclerotic plaques.

    • Symptoms: Weakness, sensory deficits, gait issues, visual disturbances.

  • Guillain-Barre Syndrome:

    • Post-infection demyelinating disorder leading to ascending paralysis and potential respiratory failure.

Neuromuscular Junction Disorders

  • Myasthenia Gravis:

    • Autoimmune destruction of acetylcholine receptors, causing muscle weakness that improves with rest.

    • Symptoms: Diplopia, ptosis, impaired swallowing.

Traumatic Brain Injury (TBI)

  • Glasgow Coma Scale (GCS):

    • Assessment tool for traumatic brain injury severity based on eye opening, verbal response, and motor response.

    • GCS score range: 3 (severe) to 15 (healthy).

  • Posturing:

    • Decorticate: Flexion indicative of cortical injury.

    • Decerebrate: Extension indicative of brainstem injury.

Hematomas

  • Epidural Hematoma:

    • Bleeding between the skull and dura mater, often following skull fractures. Symptoms can evolve.

  • Subdural Hematoma:

    • Bleeding beneath the dura but above brain tissue, generally related to venous bleeding.

  • Subarachnoid Hematoma:

    • Bleeding in subarachnoid space compressing brain tissue, producing various symptoms.

Cerebrovascular Accident (CVA)

Types

  • Ischemic Stroke:

    • Thrombotic and Embolic categories; require rapid intervention to restore blood flow.

  • Hemorrhagic Stroke:

    • Spontaneous bleeding, requiring careful management.

Warning Signs

  • Use F.A.S.T. to identify potential stroke symptoms:

    • Face drooping

    • Arm weakness

    • Speech difficulty

    • Time to call 911

Meningitis

  • Definition: Inflammation of the meninges, commonly due to infections.

  • Symptoms: Fever, headache, neck stiffness, photophobia. Lumbar puncture for diagnosis.

  • Key Signs: Brudzinski and Kernig signs indicate irritation.

Encephalitis

  • Inflammation of brain tissue, often viral, leading to more severe deficits.

  • Similar diagnostic procedures as for meningitis.

Final Notes

  • For further in-depth details, refer to Chapters 17 and 18 of the assigned textbook.

  • Important assignments are available in the Canvas platform.