A patient with a history of alcohol use disorder is explaining to you that they are late for their appointment because there was a bank robbery that they were stuck in on their way to the doctor. You know that this is unlikely, so you order a brain MRI. Imaging shows increased signal intensity in the area of the mamillary bodies How would you treat this patient? | Give thiamine Confabulation, spurious answers to questions, damage to mamillary bodies all support thiamine deficiency Thiamine deficiency is common in people with alcohol use disorder
Recall: Wernicke portion (acute)
Korsakoff portion
Anterograde and retrograde amnesia Poor judgement, initiative, impulse controle Confabulation, spurious answers to questions
Technically, you give thiamine to prevent the Korsakoff portion, but it makes sense that even if that is there you should probably still supplement with thiamine? |
What are the 4 main functions of the limbic system? | HOME Homeostasis (Hypothalamus) Olfaction (Olfactory cortex) Memory (Hippocampal formation) Emotions and Drives (Amygdala)
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Stimulation of the amygdala will result in which behaviors/moods? | Fear Anxiety Rage Aggression |
Describe the structure of the hippocampus Which sectors are most susceptible to ischemia? | Divided into sectors CA1, CA2, CA3, CA4 CA1 and CA2 are the Sommer Sector: most susceptible to ischemia
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List the sructures in the hippocampal formation |
Dentate gyrus
Hippocampus Subiculum
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Which receptors are targeted by limbic encephalitis? What is the result? | NMDA receptors Cognitive impairment Disordered perception Mood changes Sleep distrubances Seizures
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Which vitamin deficiency causes Wernicke-Korsakoff syndrome? Which brain structures are damaged? What are the symptoms? | Thiamine deficiency Mamillary bodies (bilateral necrosis) Wernicke portion (acute)
Korsakoff portion
Anterograde and retrograde amnesia Poor judgement, initiative, impulse controle Confabulation, spurious answers to questions
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What is the result of a bilateral hippocampal legion? | Anterograde amnesia (No new memories can be formed) This is what happened to patient HM |
Which part of the brain is damaged in Alzheimer’s disease? What is the result? | Parts of the Papez circuit |
What is the function of the Papez Circuit? | Connects the cortex to the hypothalamus It is the “anatomic substrate” for the convergence of cognitive activities, emotional experiences, and expression |
List the steps in the pathway thorugh the paralymbic cortex | Cingulate gyrus Paraolfactory gyrus Orbital-Frontal cortex Insula Uncus Parahippocampal gyrus Back to cingulate
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What is the function of the hippocampus?
| Converts short term (up to 60 min) into long-term memory Bilateral hippocampal lesion -> anterograde amnesia |
Which area of the brain is most likely to be affected by HSV1 encephalitis? | |
If the limbic system is damaged, what functions might be lost? | HOME Homeostasis (Hypothalamus) Olfaction (Olfactory cortex) Memory (Hippocampal formation) Emotions and Drives (Amygdala)
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List the steps in the Papez circuit | Function: connect cortex to hypothalamus; the cortex sends inputs at each step |
List the 5 components of the limbic system |
Limbic lobe
Parahippocampal gyrus Cingulate gyrus Subcallosal gyrus
Amygdala Hippocampal formation Olfactory cortex Hypothalamus
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Lesions in which areas can result in anterograde amnesia? | |
A lesion in the medial amygdala will result in which behaviors? | |
What is the most common symptom of damage to the limbic system? | Anterograde amnesia May be caused by trauma, vitamin deficiency, HSV1, autoimmune Takeaway: there are many things that can damage the limbic system, resulting in anterograde memory deficits
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What is the function of the paralimbic cortex? | Connects the assoication cortex and the limbic system
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A lesion in the lateral amygdala will result in what behavior? | Bulimia (unrestrained eating) |
What is the function of the hippocampal formation | Short term and long term memory |
Which structure serves as the input for the hippocampal formation?
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