CNS Pathology Lecture 4: Demyelinating Diseases
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Questions and Answers

Which disease is associated with mutation in the tau protein?

  • Huntington's disease
  • Alzheimer's disease
  • Pick's disease (correct)
  • Parkinson's disease

    • What is a common gross appearance associated with Alzheimer's disease?

  • Cerebral calcifications
  • Cerebral atrophy of the cerebellum
  • Enlargement of the lateral ventricles only
  • Cerebral atrophy of the frontal, temporal, and parietal lobes (correct)

    • Which of the following best describes the clinical feature of deterioration in Alzheimer's disease?

  • Immediate loss of motor function
  • Instant personality changes and aggression
  • Sudden onset of hallucinations
  • Progressive memory loss and inability to recognize family members (correct)

    • What is the inheritance pattern of Huntington's disease?

    <p>Autosomal Dominant</p> Signup and view all the answers

    Identify the type of inclusions found in the cortex in Pick's disease.

    <p>Pick bodies</p> Signup and view all the answers

    What type of movements are associated with Huntington's disease?

    <p>Choreiform movements</p> Signup and view all the answers

    What is the primary cause of death in patients with Alzheimer's disease?

    <p>Aspiration pneumonia</p> Signup and view all the answers

    What type of degeneration is characterized by fragmentation of neurites?

    <p>Neuronal processes fragmentation</p> Signup and view all the answers

    Which characteristic is NOT associated with active plaques in multiple sclerosis?

    <p>No inflammation</p> Signup and view all the answers

    Which marker is indicative of disease activity in multiple sclerosis?

    <p>Oligoclonal bands in immunoglobulin</p> Signup and view all the answers

    Which symptom is NOT commonly associated with acute disseminated encephalomyelitis (ADEM)?

    <p>Myelopathy</p> Signup and view all the answers

    Which of the following describes acute necrotizing hemorrhagic encephalitis?

    <p>Is characterized by hemorrhagic necrosis of white and gray matter</p> Signup and view all the answers

    Which statement about degenerative diseases of the CNS is accurate?

    <p>They result in neuron atrophy and loss.</p> Signup and view all the answers

    Acute disseminated encephalomyelitis is most commonly reported in which age group?

    <p>Children and adolescents</p> Signup and view all the answers

    Which of the following viral infections is NOT commonly associated with acute necrotizing hemorrhagic encephalitis?

    <p>Respiratory syncytial virus (RSV)</p> Signup and view all the answers

    What type of cellular infiltration is observed in acute disseminated encephalomyelitis?

    <p>Mononuclear and polymorph nuclear leukocytes</p> Signup and view all the answers

    What distinguishes demyelinating diseases from degenerative diseases in the context of CNS pathology?

    <p>Demyelinating diseases are characterized by myelin damage with relative preservation of axons.</p> Signup and view all the answers

    What is the predominant accepted cause of Multiple Sclerosis?

    <p>Immune-mediated mechanisms</p> Signup and view all the answers

    At what age range is Multiple Sclerosis most clinically apparent?

    <p>Ages 20 to 50 years</p> Signup and view all the answers

    Which of the following factors significantly increases the risk of developing Multiple Sclerosis?

    <p>Having a first-degree relative with the condition</p> Signup and view all the answers

    What is the role of oligodendrocytes in the context of Multiple Sclerosis?

    <p>They form the myelin sheath around neurons.</p> Signup and view all the answers

    What is a characteristic feature of the progression of Multiple Sclerosis?

    <p>It begins as a relapsing and remitting illness before stabilizing.</p> Signup and view all the answers

    What type of hypersensitivity reaction is involved in the immunopathogenesis of Multiple Sclerosis?

    <p>Type IV hypersensitivity reaction</p> Signup and view all the answers

    What is the consequence of myelin loss in neurons due to Multiple Sclerosis?

    <p>Breakdown of axons and possible neuronal death</p> Signup and view all the answers

    Which of the following diseases is characterized by the presence of neurofibrillary tangles and senile plaques?

    <p>Alzheimer's disease</p> Signup and view all the answers

    What is a key distinguishing feature in the brain morphology of Huntington's disease?

    <p>Loss of neurons in the caudate and putamen</p> Signup and view all the answers

    In Pick's disease, what is the primary cause linked to the observed neuronal degeneration?

    <p>Mutation in the tau protein</p> Signup and view all the answers

    What is the most common age range for the onset of symptoms in Huntington's disease?

    <p>20 to 50 years</p> Signup and view all the answers

    Which of the following statements accurately describes a clinical feature of Alzheimer’s disease?

    <p>Inability to recognize family members</p> Signup and view all the answers

    What type of degeneration is primarily seen in Pick's disease?

    <p>Marked loss of cortical neurons</p> Signup and view all the answers

    Which of the following is NOT a characteristic finding in the pathology of Alzheimer’s disease?

    <p>Pick bodies</p> Signup and view all the answers

    What is the most common inheritance pattern for Pick's disease?

    <p>Sporadic cases</p> Signup and view all the answers

    Which protein is characterized by an abnormality in Huntington's disease?

    <p>Huntingtin</p> Signup and view all the answers

    Which of the following described features is least likely associated with Alzheimer's disease?

    <p>Choreiform movements</p> Signup and view all the answers

    What primarily characterizes inactive plaques in multiple sclerosis?

    <p>Unmyelinated axons</p> Signup and view all the answers

    Which symptom is characteristic of acute necrotizing hemorrhagic encephalitis?

    <p>Seizures</p> Signup and view all the answers

    What type of immune response is involved in the development of acute disseminated encephalomyelitis (ADEM)?

    <p>Immune-mediated response post-infection</p> Signup and view all the answers

    In the context of multiple sclerosis, what is indicated by the presence of oligoclonal bands in laboratory results?

    <p>Abnormal immune activity</p> Signup and view all the answers

    What is the significance of high CSF protein levels in diagnosing multiple sclerosis?

    <p>Indicates abnormal immune response</p> Signup and view all the answers

    What type of lesions are characteristic of acute disseminated encephalomyelitis?

    <p>Multiple inflammatory lesions</p> Signup and view all the answers

    Which demographic group is primarily affected by acute necrotizing hemorrhagic encephalitis?

    <p>Previously healthy children</p> Signup and view all the answers

    Which pathology is observed in the morphology of acute necrotizing hemorrhagic encephalitis?

    <p>Hemorrhagic necrosis of gray and white matter</p> Signup and view all the answers

    What is a common clinical presentation symptom of multiple sclerosis?

    <p>Varied neurological manifestations</p> Signup and view all the answers

    What morphological feature distinguishes active plaques in multiple sclerosis?

    <p>Loss of axonal integrity</p> Signup and view all the answers

    What is the primary mechanism by which damage occurs in Multiple Sclerosis?

    <p>T-cell-mediated immune response leading to myelin destruction</p> Signup and view all the answers

    How does the risk of developing Multiple Sclerosis change with family history?

    <p>It increases significantly if present in a first-degree relative</p> Signup and view all the answers

    What characterizes the initial phase of Multiple Sclerosis?

    <p>Relapsing and remitting episodes</p> Signup and view all the answers

    What results from the breakdown of myelin in the context of Multiple Sclerosis?

    <p>Formation of scar tissue around damaged axons</p> Signup and view all the answers

    What is the concordance rate for Multiple Sclerosis among monozygotic twins?

    <p>Approximately 25%</p> Signup and view all the answers

    What is NOT a suspected contributing factor to the pathogenesis of Multiple Sclerosis?

    <p>Direct bacterial infection</p> Signup and view all the answers

    Which age range is most commonly affected by Multiple Sclerosis?

    <p>Between 20 and 50 years old</p> Signup and view all the answers

    What type of hypersensitivity reaction is primarily involved in the immunopathogenesis of Multiple Sclerosis?

    <p>Type IV hypersensitivity</p> Signup and view all the answers

    Which of the following infections is included among the viral infections considered a potential trigger for Multiple Sclerosis?

    <p>Mumps virus</p> Signup and view all the answers

    What happens to the oligodendrocytes in Multiple Sclerosis?

    <p>They are destroyed, leading to myelin loss</p> Signup and view all the answers

    Study Notes

    CNS Pathology Lecture (4)

    • Lecture covers Demyelinating and Degenerative Diseases

    Demyelinating Diseases

    • Demyelinating diseases of the central nervous system (CNS) are characterized by myelin damage, with axons relatively preserved.
    • These diseases include:
      • Multiple Sclerosis (MS)
      • Acute Disseminated Encephalomyelitis (ADEM)
      • Acute Necrotizing Hemorrhagic Encephalitis

    Multiple Sclerosis (MS)

    • Definition: An autoimmune demyelinating disorder characterized by distinct, separate episodes of neurological deficits in time, and lesions in different locations in space(separated in space) within the CNS white matter.

    • This involves inflammation and damage to the myelin sheath surrounding nerve cells in the brain and spinal cord.

    • Prevalence: Approximately 1 per 1000 people in the USA and Europe.

    • Clinical Onset: Clinically apparent at any age, but relatively rare in childhood and after age 50.

    • Course: Typically begins as a relapsing and remitting illness, progressing to a steady state later.

    • Age of Onset: Most common between ages 20 and 50.

    • Gender Predominance: More common in women (2:1 ratio).

    • Causes:

      • Immune-mediated disease (most accepted).
      • Viral infection (unproven, examples include: mumps, rubella, herpes simplex, and measles).
      • Genetic defects: Abnormalities in the HLA region of chromosome 6 increase the likelihood of developing MS.

    • Pathogenesis: A combination of environmental and genetic factors leads to a loss of tolerance towards self proteins.

      • Concordance rate for monozygotic twins is approximately 25% and lower for dizygotic twins.
      • The risk of developing MS is 15-fold higher if a first-degree relative has the disease.

    • Experimental Allergic Encephalomyelitis (EAE): An animal model of MS, where inflammation and demyelination are induced by immunizing the animal with myelin or myelin peptides.

      • Damage is caused by the delayed T-cell mediated type IV HSR.
      • Toxic effects of released molecules from immune cells (lymphocytes/macrophages) play a significant role in axonal damage and neuronal death.

    • Pathogenesis (MS): involves the loss of oligodendrocytes, the cells responsible for myelin sheath formation leading to interruption of nerve signal transmission. This is followed by breakdown of axons and scar tissue (sclerosis) formation in multiple plaques throughout the CNS.

    • Morphology (Active Plaques):

      • Gross: Well-circumscribed plaques with loss of myelin.
      • Microscopic: Myelin breakdown, lipid-laden macrophages, and lymphocytes at the edges of the plaques; relative preservation of axons.

    • Morphology (Inactive Plaques):

      • No inflammation.
      • Axons remain unmyelinated.
      • Sclerosis (scar tissue).

    • Clinical Manifestations:(Multiple Sclerosis): Neurological symptoms vary according to the affected areas including autonomic, motor, and sensory abnormalities.

    • Clinical Manifestations (Example Symptoms):

      • Central: fatigue, cognitive impairment, depression, unstable mood
      • Visual: nystagmus, optic neuritis, diplopia
      • Throat: dysphagia
      • Musculoskeletal: weakness, spasms, ataxia
      • Sensation: pain, hypoesthesias, paraesthesias
      • Bowel: incontinence, diarrhea or constipation
      • Urinary: incontinence, frequency or retention
      • Speech: dysarthria

    • Diagnosis (MS):

      • Clinical evaluation
      • Laboratory analysis: high CSF protein, mostly gamma globulin, oligoclonal bands of immunoglobulin. Antibodies present are a marker of disease activity.

    Acute Disseminated Encephalomyelitis (ADEM)

    • Characteristics: Immune-mediated disorder.
    • Cause: Usually follows a viral infection, or rarely, viral immunization.
    • Onset: Affects all ages, but most cases are in children and adolescents.
    • Morphology: Multiple inflammatory lesions in white matter of the brain and spinal cord, demyelination, and accumulation of lipid-laden macrophages. Mononuclear and polymorphonuclear leukocyte infiltration.
    • Clinical Manifestations: Fever, headache, lethargy, and coma.

    Acute Necrotizing Hemorrhagic Encephalitis

    • Characteristics: More severe and abrupt than MS or ADEM.
    • Onset: Seen in young, previously healthy children.
    • Causes: Influenza A virus, mycoplasma, Herpes Simplex Virus (HSV), and human herpes virus 6 - potential causative agents.
    • Morphology: Hemorrhagic necrosis of white and gray matter.
    • Clinical Manifestations: High fever, seizures, and rapidly progressing neurological disturbances.

    Degenerative Diseases of CNS

    • A group of disorders with unknown etiology and pathogenesis.
    • There's degeneration in specific neuronal populations leading to atrophy and neuronal loss.
    • Often, gliosis (scarring) follows.

    Demyelinating Diseases II

    • Associated with mutations affecting myelin formation or synthesis/degradation.
    • These diseases include:
      • Alzheimer's disease
      • Pick's disease
      • Huntington's disease
      • Parkinson's disease

    Alzheimer's Disease (AD)

    • Definition: Senile dementia characterized by progressive memory loss, difficulty with tasks of daily living, and difficulty recognizing familiar individuals.
    • Cause: Unknown, but some familial cases are linked to abnormalities on chromosomes 21, 14, 1, and 19.
    • Onset: Usually after 50 years of age. Mostly sporadic (90-95%), but some cases run in families.
    • Gross Appearance: Cerebral atrophy, predominantly in the frontal, temporal, and parietal lobes. MRI/diagnostics can show these changes.
    • Microscopic Features:
      • Fragmentation of neurites (production of "senile plaques"): degenerative synaptic endings.
      • Amyloid material (AB) deposited outside the neurons. Insoluble intracellular twisted filaments (neurofibrillary tangles).
      • Cerebral amyloid angiopathy (CAA).
    • Clinical features: Progressive memory loss(dementia), inability to participate in daily activities, and inability to recognize family members.
    • Cause of death: Typically aspiration pneumonia.

    Pick's Disease

    • A frontotemporal neurodegenerative disease, similar to AD.
    • Cause: Mutations in the tau protein, which stabilizes microtubules within neurons.
    • Gross Appearance: Cerebral atrophy, predominantly affecting the frontal and temporal lobes. The atrophy may be asymmetrical.
    • Microscopic Features: Marked loss of cortical neurons with gliosis. Presence of cytoplasmic inclusions (Pick bodies).

    Huntington's Disease

    • An autosomal dominant disorder.
    • Cause: Abnormalities on chromosome 4 (mutation in the huntingtin gene).
    • Onset: Typically between ages 20 and 50.
    • Morphology: Loss of neurons in the caudate and putamen, with subsequent gliosis. Enlargement of the anterior horns of the lateral ventricles.
    • Clinical features: Choreiform movements (involuntary, jerky movements), personality changes.

    Parkinson's Disease

    • Characteristics: A progressive neurodegenerative disorder.
    • Causes: Sporadic (most common) and familial cases with mutations in the alpha-synuclein gene (autosomal dominant) or in the parkint gene (autosomal recessive).
    • Morphology:
      • Pallor of the substantia nigra and locus ceruleus.
      • Loss of pigmented neurons.
      • Gliosis.
      • Lewy bodies (abnormal protein aggregates within nerve cells).
    • Clinical Features: Diminished facial expression, slow movements, festinating gait, cogwheel rigidity, pill-rolling tremors.

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    Cns Pathology Lecture (4)-Demyelinating & Degenerative Diseases PDF

    Description

    This quiz covers critical concepts related to demyelinating and degenerative diseases of the central nervous system, focusing specifically on Multiple Sclerosis and related conditions. You will explore the characteristics, prevalence, and clinical impact of these disorders on patients, enhancing your understanding of CNS pathology.

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