Week 4.4: Limbic System Disorders Flashcards
(21 cards)
What virus has a tropism for the limbic cortex and can cause encephalitis?
Herpes simplex virus (HSV).
What is a common symptom of herpes simplex encephalitis?
Bizarre psychotic behavior, headache and confusion.
What is a classic MRI finding in herpes simplex encephalitis?
Unilateral or bilateral temporal and frontal necrosis (highlighted as a darker area).
What is Kluver-Bucy syndrome?
A disorder caused by bilateral lesions of the amygdala and temporal lobe characterized by a lack of fear, hypersexuality, and compulsive attentiveness.
What symptoms are seen in Kluver-Bucy syndrome?
Fearlessness, hypersexuality, compulsive hyperorality, and excessive attention to sensory stimuli.
What is autism?
A behavioral disorder characterized by impairments in social communication, and attentional abilities, with repetitive behaviors and obsessive interests.
What brain areas are often affected in autism?
Limbic system, frontal cortex, and cerebellum.
What are the neuropathological findings in autism? Abnormally small and densely packed neurons in the entorhinal area
hippocampus
What is Alzheimer’s disease (AD)? The most common form of dementia that affects thinking
behavior
What percentage of dementia cases are due to Alzheimer’s disease? About 70% of dementia cases are Alzheimer’s disease.
What is the typical onset age for sporadic Alzheimer’s disease? After age 65.
What causes familial Alzheimer’s disease? A rare genetic condition that leads to symptoms usually appearing in the 40s and 50s.
What brain areas are primarily affected in Alzheimer’s disease? Hippocampus
entorhinal cortex
What is the main cause of memory loss in Alzheimer’s disease? Loss of neurons in the hippocampus and adjacent entorhinal cortex.
What are early symptoms of Alzheimer’s disease? Memory loss (especially short-term)
visuospatial problems
What is the hallmark pathological feature of Alzheimer’s disease? Amyloid beta plaques and tau protein neurofibrillary tangles.
What is the progression of Alzheimer’s disease? The pathology spreads from the entorhinal cortex and hippocampus to the limbic lobe
amygdala
What macroscopic findings are seen in Alzheimer’s disease? Reduced brain weight
brain atrophy
What microscopic features are seen in Alzheimer’s disease? Amyloid plaques and tau neurofibrillary tangles.
What are the risk factors for Alzheimer’s disease? Advancing age
genetic factors (APOE4 allele)
What are some protective factors against Alzheimer’s disease? Hormone-replacement therapy (in post-menopausal women)
moderate alcohol consumption
