Nervous system

• Alzheimer's


  • Neurodegenerative disorder
  • Progressive loss of cognitive function
  • Affects brain
• Etiology of Alzheimer's


  • Neurochemical factors
  • Viral factors
  • Trauma
  • Genetic factors
• Neurochemical factors in Alzheimer's

  • Deficiencies in neurotransmitters acetylcholine, somatostatin, substance P, and norepinephrine
• Viral factors in Alzheimer's

  • Slow-growing CNS viruses
• Genetic factors in Alzheimer's

  • APOE, APOE-e4
• Familial Alzheimer's


  Occurs very rarely on people with alzheimer’s
• Sporadic Alzheimer's


  Most common
• Pathogenesis of Alzheimer's


  • Neurofibrillary tangles formed from fibrous proteins in neurons
  • Beta-amyloid plaques (protein deposits)
  • Abnormal protein concentration and new protein formation
  • Granulovacuolar degeneration of neurons
• Signs and Symptoms of Alzheimer's


  • Insidious onset
  • Extend over 10-20 years
  • Behavioral changes (early)
  • Irritability, hostility, mood swings (early)
  • Gradual loss of memory, lack of concentration (early)
  • Impaired learning, poor judgment (early)
  • Decline of cognitive function, memory, language (late)
  • Change in food intake (late)
  • Inability to recognize family, lack of environmental awareness, incontinence, inability to function, Urinary incontinence (late)
• Treatment of Alzheimer's


  • Current drugs can't alter progressive loss of brain cells
  • Cholinesterase inhibitors prevent breakdown of acetylcholine
  • Possible vaccine in clinical trials to stimulate immune system against beta-amyloid plaques
• Amyotrophic Lateral Sclerosis (ALS)


  • Progressive neurodegenerative disorder
  • Affects nerve cells in brain and spinal cord
  • Cognitive function remains normal
• Etiology of ALS


  • Gene mutation
  • Chemical imbalance with high glutamate levels
  • Accumulation of abnormal proteins
  • Autoimmune disorders
  • Precipitating factors like trauma, viral infection, physical exhaustion
• Familial ALS


  Rare (5-10%)
• Sporadic ALS


  Most common (90-95%)
• Signs and Symptoms of ALS

  • Onset between 40-70 years old
  • Motor neurons gradually die, cannot produce or transport signals to muscles
  • Leads to weakness, paralysis, muscle atrophy in upper limbs
• Treatment of ALS


  • Patients may require gastric feedings, tracheostomy and mechanical ventilation
• Bell's Palsy


  • Most common facial nerve disorder
  • Mild weakness to total paralysis on one side of face
  • Considered benign, most patients recover
• Etiology of Bell's Palsy


  • Inflammation or compression of facial nerve
  • Acute demyelination of nerves
  • Reactivation of herpes simplex virus (HSV-1) or herpes zoster virus (HZV)
  • Viral infections causing nerve inflammation and compression
• Risk Factors for Bell's Palsy

  • Pregnant women in 3rd trimester
  • Early postpartum
  • Older adults
  • People with diabetes or hypothyroidism
• Signs and Symptoms of Bell's Palsy

  • Facial droop and trouble making facial expressions
  • Drooling
• Epilepsy


  Neurologic disorder with abnormal brain activity causing seizures
• Etiology of Epilepsy


  • Genetic influences
  • Perinatal injuries
  • Metabolic abnormalities
  • Brain conditions
  • Infections
  • Traumatic brain injury
  • Ingestion of toxins
  • High fever in young child
• Pathogenesis of Epilepsy


  • Seizures are paroxysmal events with abnormal electrical discharges in the brain
  • Status epilepticus can lead to severe hypoxia, acidosis, and brain damage
• Signs and Symptoms of Epilepsy


  • Seizures can trigger convulsive movements, interruption of sensation, or alteration in level of consciousness
  • Affects people of all ages, races, and backgrounds
  • Absence seizures common in children
  • Does not usually affect intelligence
• Diagnosis of Epilepsy


  EEG is used to confirm diagnosis and classify seizures
• Treatment of Epilepsy


  • Drug therapy to reduce seizure frequency and prevent occurrence
  • Surgery for drug-resistant cases to remove localized epileptic area
• Guillain-Barré Syndrome


  • Acute inflammatory demyelinating polyneuropathy
  • Autoimmune process following viral or bacterial infection
• Pathogenesis of Guillain-Barré Syndrome


  • Rapidly progressing acute autoimmune processes leading to segmented demyelination of peripheral nerves
• Epidemiology of Guillain-Barré Syndrome


  • Occurs equally in both sexes, usually between ages 30-50
• Phases of Guillain-Barré Syndrome

  • Acute phase (1-3 weeks)
  • Plateau phase (several days to 2 weeks)
  • Recovery phase (4 months to 3 years)
• Meningitis


  Inflammation of the meninges (membranes surrounding the brain and spinal cord)
• Causes of Meningitis


  • Escherichia coli (neonates)
  • Haemophilus influenzae (young children)
  • Neisseria meningitidis (children/young adults)
  • Streptococcus pneumoniae (older adults)
• Pathogenesis of Meningitis


  • Microorganisms reach the brain via blood, nearby tissue, or direct access
  • Infections spread rapidly through the meninges
  • Inflammatory response leads to increased intracranial pressure
• Signs and Symptoms of Meningitis


  • Sudden onset
  • Severe headache, back pain, photophobia
  • Nuchal rigidity, Kernig sign, Brudzinski sign
  • Vomiting, irritability, lethargy, fever, chills with leukocytosis
  • Progression to stupor or seizures
• Diagnosis of Meningitis


  Examination of cerebrospinal fluid to identify causative organism
• Treatment of Meningitis


  • Aggressive antimicrobial therapy
  • Specific treatment for increased intracranial pressure and seizures
  • Glucocorticoids to reduce inflammation
  • Vaccines available for some types
• Migraine


  Episodic neurological disorder characterized by headaches
• Etiology of Migraine


  • May involve changes in blood flow to the brain, brain metabolism, vascular, hormonal, or neurotransmitter components
• Types of Migraine


  • Migraine with aura (visual, sensory, or motor symptoms)
  • Migraine without aura (more common)
• Diagnosis of Migraine


  Made from medical history and physical examination, EEG and imaging may be used to rule out other diagnoses