Pathology of the CNS: Neuronal Reactions
37 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What are the characteristic CSF findings in bacterial meningitis?

  • Normal pressure, normal sugar, high lymphocytes
  • Decreased pressure, increased sugar, normal protein
  • Increased pressure, increased protein, decreased sugar (correct)
  • Normal pressure, decreased protein, increased neutrophils

    • Which organism is primarily associated with meningitis in adolescents and young adults?

  • L.monocytogenes
  • E.coli
  • S.pneumoniae
  • N.meningitidis (correct)

    • Which of the following is NOT a complication associated with N.meningitidis infection?

  • Acute pancreatitis (correct)
  • Waterhouse Friderichsen Syndrome
  • Photophobia
  • Septicemic shock

    • Which condition is primarily associated with caseating granulomas in the brain?

    <p>Tuberculous meningitis</p> Signup and view all the answers

    What is a key characteristic of aseptic (viral) meningitis in terms of CSF analysis?

    <p>Clear CSF with slight increase in protein and normal sugar</p> Signup and view all the answers

    What are the characteristics of red neurons observed after acute injury?

    <p>Shrinkage of the cell body, pyknosis of the nucleus, and intense eosinophilia</p> Signup and view all the answers

    Which of the following is a common reactive change in astrocytes during gliosis?

    <p>Increased number and size of astrocytes</p> Signup and view all the answers

    What is the main function of oligodendrocytes in the CNS?

    <p>Synthesis and maintenance of myelin</p> Signup and view all the answers

    Which of the following best describes central chromatolysis?

    <p>Peripheral displacement of the nucleus and enlargement of the nucleolus</p> Signup and view all the answers

    Which condition is associated with intracellular inclusions seen in neurodegenerative diseases?

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

    Which of the following infections is most commonly associated with hematogenous spread?

    <p>Bacterial meningitis</p> Signup and view all the answers

    What type of cells are Gitter cells associated with in the CNS?

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

    What is the role of ependymal cells in the CNS?

    <p>Line the ventricles and detoxify cerebrospinal fluid</p> Signup and view all the answers

    Which condition is characterized by the accumulation of gangliosides in the CNS?

    <p>Tay-Sachs disease</p> Signup and view all the answers

    What type of infections typically lead to the formation of cytoplasmic inclusions in the CNS?

    <p>Viral infections</p> Signup and view all the answers

    What characterizes paretic neurosyphilis?

    <p>Loss of neurons and proliferation of microglia in the frontal lobe</p> Signup and view all the answers

    Which of the following complications can arise from bacterial meningitis?

    <p>Increased intracranial pressure</p> Signup and view all the answers

    What symptom is indicative of tabes dorsalis?

    <p>Lightning pains and absence of deep tendon reflexes</p> Signup and view all the answers

    What is the typical cause of a brain abscess?

    <p>Bacterial infections via direct implantation or local extension</p> Signup and view all the answers

    What is a common manifestation of meningovascular neurosyphilis?

    <p>Chronic infection in the meninges with plasma cell infiltration</p> Signup and view all the answers

    Which of the following statements about fungal encephalitis is correct?

    <p>It can occur in both normal and immunocompromised patients.</p> Signup and view all the answers

    What leads to increased intracranial pressure in brain abscess patients?

    <p>Localized suppuration and severe edema</p> Signup and view all the answers

    In patients with acute syphilitic meningitis, what is the associated risk?

    <p>Increased risk of complications like obstructive hydrocephalus</p> Signup and view all the answers

    What is the primary characteristic of cryptococcal meningoencephalitis in AIDS patients?

    <p>Formation of multiple micro-abscesses</p> Signup and view all the answers

    Which virus is known to cause temporal lobe encephalitis primarily?

    <p>Herpes Simplex Virus (HSV)</p> Signup and view all the answers

    What type of necrosis is commonly seen in cytomegalovirus infections?

    <p>Hemorrhagic necrosis</p> Signup and view all the answers

    Which condition is characterized by the presence of Negri bodies?

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

    Which of the following is NOT a feature common to most viral infections of the CNS?

    <p>Necrotizing inflammation</p> Signup and view all the answers

    What characterizes the neural degeneration seen in rabies?

    <p>It is most severe in the midbrain and fourth ventricle.</p> Signup and view all the answers

    Which virus primarily affects anterior horn cells of the spinal cord?

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

    What is a characteristic histological finding in Creutzfeldt-Jakob Disease?

    <p>Multifocal spongiform transformation</p> Signup and view all the answers

    In patients with HIV, what is the most common cause of dementia?

    <p>HIV-associated neurocognitive disorder (HAND)</p> Signup and view all the answers

    Which fungal infection is specifically noted for causing hematogenous or direct spread?

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

    Which condition is associated with large cytoplasmic and intranuclear inclusions in AIDS patients?

    <p>Cytomegalovirus infection</p> Signup and view all the answers

    What is the consequence of JC virus infection in immunosuppressed patients?

    <p>Progressive multifocal leukoencephalopathy (PML)</p> Signup and view all the answers

    What is the typical age of onset for sporadic Creutzfeldt-Jakob Disease cases?

    <p>Usually seen in the elderly, around the 7th decade</p> Signup and view all the answers

    Which virus is known for having the potential to cause encephalitis in immunosuppressed patients, particularly AIDS patients?

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

    Study Notes

    Pathology of the CNS: Neuronal Reactions to Injury

    • Acute Injury: Necrosis

      • Occurs within 12 hours of ischemia/hypoxia
      • Red neurons show cell shrinkage, nuclear pyknosis, and cytoplasmic eosinophilia
      • Spheroids result from axonal injury, cell body enlargement, and peripheral displacement of the nucleus and Nissl bodies (central chromatolysis)

    • Apoptosis

      • Neuronal death during development and aging processes

    • Chronic/Subacute Injury (Degenerative Diseases)

      • Neuronal loss and replacement by gliosis occurs in progressive diseases
      • Some diseases show intracellular inclusions (e.g., thickened and tortuous neurites in Alzheimer's and Parkinson's diseases)

    • Axonal Injury

      • Leads to cell body swelling
      • Central chromatolysis (nuclear displacement)
      • Peripheral dispersion of Nissl substance

    • Inclusions

      • Can be nuclear or cytoplasmic
      • Seen in viral infections (e.g., Negri bodies in rabies)

    • Accumulations

      • Lipofuscin (aging pigments)
      • Ganglioside accumulation (e.g., Tay-Sachs disease)

    Glial Cells

    • Astrocytes

      • Increase in number and size in gliosis
      • Gemistocytes are swollen, reactive astrocytes with acidophilic cytoplasm
      • GFAP (glial fibrillary acidic protein) increases
      • Rosenthal fibers are aggregates of thick eosinophilic astrocytic fibers in chronic conditions or tumors

    • Oligodendrocytes

      • Synthesize and maintain myelin
      • Inclusions in demyelinating diseases (e.g., PML, JC virus infections)

    • Ependymal Cells

      • Line the ventricles and detoxify cerebrospinal fluid (CSF)
      • Ependymal granulations are areas of ependymal lining sloughing (may be normal or pathologic, ventriculitis)
      • Inclusions characteristic of CMV

    • Microglia

      • Macrophages in infarction (gitter cells)
      • Elongated cells in syphilis (rod cells)
      • Aggregates of microglia around injured cells (microglial nodules)
      • Aggregate around dead neurons (neuronophagia)

    CNS Infections

    • Routes of Infection

      • Hematogenous (most common)
      • Direct (trauma, iatrogenic)
      • Local extension from adjacent foci (air sinuses, congenital abnormalities, peripheral nerves)

    • Epidural/Subdural Infections

      • Caused by bacteria, fungi, or mixed infections
      • Direct spread from adjacent infections (sinusitis, osteomyelitis)

    • Acute Pyogenic Meningitis

      • Neonates: Group B Streptococcus, E. coli
      • Adolescents/Adults: Neisseria meningitidis
      • Elderly: Streptococcus pneumoniae, Listeria monocytogenes

    • Clinical Picture

      • Fever, headache, vomiting, photophobia, neck rigidity
      • Septicemic shock/Waterhouse-Friderichsen syndrome as complications

    • Aseptic Viral Meningitis

      • Often hematogenous spread
      • Mild self-limiting disease, frequent in seasonal patterns
      • CSF shows slight protein elevation, normal sugar, lymphocytes elevated

    • Chronic Meningitis/Meningoencephalitis (e.g., TB, Syphilis, Lyme Disease)

      • Characterized by chronic inflammatory process
      • Often involves a variety of CNS sites
      • Syphilis, specifically, causes meningitis and vasculitis
      • TB meningitis usually involves a primary site in lung spreading hematogenously to brain, causes inflammation of the meninges

    • Tuberculous Meningitis

      • Hematogenous spread from lung, direct from vertebral infection
      • Thick cheesy exudate and thick meninges
      • Basal cisterns and sulci most affected
      • Caseating granulomas

    • Neurosyphilis

      • Meningovascular: meninges infection and obliterative endarteritis in brain vessels
      • Paretic: invasion of frontal lobe; plasma cells characteristic of lesions

    • Parenchymal Infections

      • Localized (abscesses, tuberculomas, toxoplasmosis, parasites)
      • Diffuse (encephalitis, viruses)

    • Brain Abscess

      • Direct implantation, local extension (mastoiditis, sinusitis, middle ear infection), hematogenous (e.g. predisposing conditions)
      • Focal suppuration and liquefactive necrosis surrounded by granulation tissue, reactive astrocytes
      • CSF shows increased protein, cells, and normal sugar

    • Fungal Encephalitis

      • Candida, Cryptococcus, Aspergillus, Mucor (especially in diabetics)
      • Hematogenous or direct spread

    • Viral Encephalitis

      • HSV, VZV, Rabies

    • Antenatal Infections (e.g. CMV, Rubella)

      • Systemic infection that may produce some CNS effects

    • Immune Deficiency Infections (e.g., HIV, PML)

      • Progressive multifocal leukoencephalopathy (PML) caused by JC virus
      • Infect oligodendrocytes and astrocytes

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Pathology of the CNS PDF

    Description

    This quiz covers various aspects of neuronal reactions to injury in the central nervous system. Topics include acute injury necrosis, apoptosis, chronic injury due to degenerative diseases, and axonal injury. Test your understanding of these crucial concepts and the pathology behind neurological conditions.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser