Summaries Chapter 23: Central Nervous System Flashcards
What is cerebral edema?
Cerebral edema is the accumulation of excess fluid within the brain parenchyma. Hydrocephalus is defined as an increase in CSF volume within all or part of the ventricular system.
Increases in brain volume raise the pressure inside the fixed capacity of the skull. What can this increase be a result of?
Ss a result of increased CSF volume, edema, hemorrhage, or tumor
True/false: Malformations of the brain can occur because of genetic factors or external insults.
True
Various malformations stem from …
failure of neural tube closure, improper formation of neural structures, and altered neuronal migration.
Perinatal brain injury mostly takes one of two forms. Which two?
(1) hem- orrhage, often in the region of the germinal matrix with the risk for extension into the ventricular system; and (2) ischemic infarcts, leading to periventricular leukomalacia.
Certain infections may affect the brain during development with …
subsequent tissue destruction and neurologic consequences.
True/false: Only viruses can infect the brain
False, pathogens from viruses through parasites can infect the brain
What is prion disease?
a protein-induced transmissible disease that is unique to the nervous system
True/false: regardless of the pathogen, all infections cause similar patterns of disease in the brain
False, different pathogens use distinct routes to reach the brain, and they cause different patterns of disease.
What may bacterial infections cause in the brain?
Meningitis, cerebral abscesses, or a chronic meningoencephalitis
What may viral infections cause in the brain?
Meningitis or meningoencephalitis
HIV can directly and indirectly affect the brain. Explain the two mechanisms
HIV can directly cause meningoencephalitis, or indirectly affect the brain by increasing the risk for opportunistic infections
(toxoplasmosis, CMV) or CNS lymphoma.
True/false: Prion diseases are transmitted by an altered form of a
normal cellular protein. They can be sporadic, transmitted, or inherited.
True
Why can diseases of myelin lead to widespread and severe neurologic deficits?
Because of the critical role of myelin in nerve conduction
What is Multiple Sclerosis (MS)?
Multiple sclerosis, an autoimmune demyelinating disease, is the most common disorder of myelin, affecting young adults. It often pursues a relapsing-remitting course, with eventual progressive accumulation of neurologic deficits.
What do other, less common forms of immune-mediated demyelination often lead to?
Infections, and are more acute illnesses (than MS)
What are leukodystrophies?
Leukodystrophies are genetic disorders in which myelin production or turnover is abnormal.
Neurodegenerative diseases cause symptoms that depend on the pattern of brain involvement. What do cortical diseases usually manifest as?
Cognitive change, alterations in personality, and memory disturbances
Neurodegenerative diseases cause symptoms that depend on the pattern of brain involvement. What do basal ganglia disorders usually manifest as?
Movement disorders
What is the pathological hallmark of many neurodegenerative diseases?
Protein aggregates
How is the ‘theory’ of protein aggregation proven in familial forms?
The diseases are often associated with a mutation in the genes encoding these proteins or controlling their metabolism
True/false: all neurodegenerative diseases progress slowly
False (Some of these protein aggregates can show prion like properties, facilitating spread from one cell to the next)
Which dementia is most common?
Alzheimer’s Disease (AD)
What proteins aggregate in AD / what are the hallmarks of AD?
plaques of Aß and tangles of tau
What are other predominantly dementing diseases?
various forms of FTLDs (both forms with tau-containing lesions and with other types of inclusions) and dementia with Lewy bodies (with α-synuclein containing lesions).
Which disease is the most common among the hypo kinetic movement disorders? And which protein aggregates?
Parkinsons Disease (PD) with α-synuclein containing inclusions
Which is the most common form of motor neuron disease?
Amyotrophic lateral sclerosis (ALS)
True/false: ALS can be either genetic or sporadic
True
Tumors of the CNS may arise from the cells of the coverings (i), the brain (ii, ii, ii), or other CNS cell populations (iii, iii), or they may originate elsewhere in the body (iiii).
i: meningiomas
ii: gliomas, neuronal tumors, choroid plexus tumors
iii: primary CNS lymphoma, germ cell tumors
iiii: metastases
True/false: Low-grade or benign tumors can have poor clinical outcomes
True, depending on where they occur in the brain
Distinct types of tumors affect specific brain regions and specific age populations. What are examples of specific brain regions?
e.g. cerebellum for medulloblastoma, an intraventricular location for central neurocytoma
Distinct types of tumors affect specific brain regions and specific age populations. What are examples of specific age populations?
medulloblastoma and pilocytic astrocytomas in pediatric age groups, and glioblastoma and lymphoma in older patients
In which groups are glial tumors broadly classified?
astrocytomas, oligodendrogliomas, and ependymomas
Increasing tumor malignancy is associated with ..
more cytologic anaplasia, increased cell density, necrosis, and mitotic activity
True/false: Metastatic spread of brain tumors to other regions of the body is common
False, it is rare
Which tumors are the dominant type that metastasize to the nervous system?
Carcinomas
