CNS Flashcards
(20 cards)
What is cerebral edema?
Cerebral edema is the accumulation of fluid within the brain parenchyma.
How is cerebral edema different from hydrocephalus?
Cerebral edema involves fluid accumulation within the brain parenchyma, while hydrocephalus is an increase in CSF volume within the ventricular system.
What are the causes of cerebral edema?
Causes include inflammation, tumors, and ischemia.
What are the morphological changes in generalized cerebral edema?
The edematous brain is softer than normal, with flattened gyri and narrowed sulci.
What happens to brain tissue 48 hours after irreversible injury?
The tissue becomes pale, swollen, and the corticomedullary junction becomes indistinct.
What are the routes of entry for CNS infections?
Hematogenous, direct implantation, and local extension.
What is the most common causative organism of acute pyogenic meningitis in neonates?
Escherichia coli and group B streptococci.
What is the most common causative organism of acute pyogenic meningitis in adolescence?
Neisseria meningitides.
What is viral meningitis mainly caused by?
Enteroviruses.
What is a common complication of tuberculous meningitis?
Arachnoid fibrosis and hydrocephalus.
What is the most common predisposing factor for brain abscess?
Infective endocarditis.
What are the main causes of viral encephalitis?
Arboviruses and herpes simplex viruses.
What are gliomas?
Brain tumors that arise from glial cells.
What are the characteristics of high-grade astrocytomas?
High-grade astrocytomas, such as glioblastoma multiforme, show nuclear atypia, necrosis, and vascular endothelial proliferation.
What is the prognosis for oligodendroglioma?
Oligodendroglioma has a better prognosis compared to other gliomas.
Where are ependymomas usually located?
Near the ventricular system.
What is medulloblastoma, and where is it located?
Medulloblastoma is a highly undifferentiated tumor that occurs in children and is located in the cerebellum.
What are meningiomas?
Benign tumors of the meningothelial cells found along the external surface of the brain.
What are the most common primary sources of metastatic brain tumors?
Lung, breast, skin melanoma, and kidneys.
What percentage of intracranial tumors are metastatic tumors?
Metastatic tumors account for 1/4 of intracranial tumors.
