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Questions and Answers
Which area of the brain is primarily associated with the retrieval of episodic memory?
Which area of the brain is primarily associated with the retrieval of episodic memory?
Long-term memory storage is associated with the neocortex.
Long-term memory storage is associated with the neocortex.
True
What is the term for the process of transforming information into a form that can be stored in memory?
What is the term for the process of transforming information into a form that can be stored in memory?
Encoding
The retrieval of memories from the recent past might engage the _______ cortex.
The retrieval of memories from the recent past might engage the _______ cortex.
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Match the types of memory with their descriptions:
Match the types of memory with their descriptions:
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Which part of the brain is known as the gateway of memory?
Which part of the brain is known as the gateway of memory?
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The Mammillary body is part of the Papez circuit and is associated with Wernicke Korsakoff syndromes.
The Mammillary body is part of the Papez circuit and is associated with Wernicke Korsakoff syndromes.
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What is the primary function of the Papez circuit?
What is the primary function of the Papez circuit?
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The ------- gyrus is involved in emotional regulation and is a component of the Papez circuit.
The ------- gyrus is involved in emotional regulation and is a component of the Papez circuit.
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Match the following parts of the Papez circuit with their roles:
Match the following parts of the Papez circuit with their roles:
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Which type of aphasia is characterized by impaired comprehension, repetition, and fluency?
Which type of aphasia is characterized by impaired comprehension, repetition, and fluency?
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Motor aphasia is associated with fluent speech.
Motor aphasia is associated with fluent speech.
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What defines jargon speech in sensory aphasia?
What defines jargon speech in sensory aphasia?
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Pure alexia is caused by a lesion in the __________ gyrus.
Pure alexia is caused by a lesion in the __________ gyrus.
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Match the type of aphasia with its characteristic:
Match the type of aphasia with its characteristic:
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Which type of aphasia is characterized by preserved comprehension but difficulty in finding the right words?
Which type of aphasia is characterized by preserved comprehension but difficulty in finding the right words?
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Patients with conduction aphasia have intact repetition skills.
Patients with conduction aphasia have intact repetition skills.
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Which area of the brain is primarily associated with procedural memory?
Which area of the brain is primarily associated with procedural memory?
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What type of dysarthria results from damage to lower motor neurons in the brainstem nuclei?
What type of dysarthria results from damage to lower motor neurons in the brainstem nuclei?
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Priming is associated with the amygdala.
Priming is associated with the amygdala.
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What type of memory is primarily involved when animals associate fear with their environment?
What type of memory is primarily involved when animals associate fear with their environment?
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In patients with Wernicke's aphasia, comprehension is usually ________ and reading/writing may contain errors.
In patients with Wernicke's aphasia, comprehension is usually ________ and reading/writing may contain errors.
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The gateway of long-term memory is the _______ cortex.
The gateway of long-term memory is the _______ cortex.
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Match the type of aphasia with its characteristic:
Match the type of aphasia with its characteristic:
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Match the areas of the brain with their associated types of memory:
Match the areas of the brain with their associated types of memory:
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What is the most common cause of young onset dementia?
What is the most common cause of young onset dementia?
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Vitamin B₁₂ deficiency can be a reversible cause of dementia.
Vitamin B₁₂ deficiency can be a reversible cause of dementia.
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What is the most important risk factor for Alzheimer's disease?
What is the most important risk factor for Alzheimer's disease?
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The __________ of entorhinal cortex is specific to Alzheimer's Disease.
The __________ of entorhinal cortex is specific to Alzheimer's Disease.
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Match the following conditions with their classification:
Match the following conditions with their classification:
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What abnormal accumulation is associated with amyloid plaques in Alzheimer's disease?
What abnormal accumulation is associated with amyloid plaques in Alzheimer's disease?
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The deposition of Aβ in blood vessels is associated with cerebral amyloid angiopathy.
The deposition of Aβ in blood vessels is associated with cerebral amyloid angiopathy.
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What enzyme is responsible for breaking down insulin in the context of hyperinsulinemia?
What enzyme is responsible for breaking down insulin in the context of hyperinsulinemia?
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Accumulation of _______ proteins leads to neurofibrillary tangles inside neurons.
Accumulation of _______ proteins leads to neurofibrillary tangles inside neurons.
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Match the diseases with their associated features:
Match the diseases with their associated features:
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Which of the following is considered the most common cause of dementia?
Which of the following is considered the most common cause of dementia?
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Cortical dementia is primarily associated with subcortical brain areas.
Cortical dementia is primarily associated with subcortical brain areas.
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Name one cognitive domain affected by dementia.
Name one cognitive domain affected by dementia.
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The area involved in language processing in dementia is the _______ frontal gyrus.
The area involved in language processing in dementia is the _______ frontal gyrus.
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Match the following types of dementia with their characteristics:
Match the following types of dementia with their characteristics:
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Which of the following is the most important risk factor for sporadic Alzheimer's Disease in the elderly?
Which of the following is the most important risk factor for sporadic Alzheimer's Disease in the elderly?
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Low IQ is a known risk factor for developing Alzheimer's Disease.
Low IQ is a known risk factor for developing Alzheimer's Disease.
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What clinical stage of dementia involves behavioral abnormalities and personality changes?
What clinical stage of dementia involves behavioral abnormalities and personality changes?
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The gene associated with familial Alzheimer's Disease found on chromosome 14 is known as _____ - 1.
The gene associated with familial Alzheimer's Disease found on chromosome 14 is known as _____ - 1.
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Match the risk factors or characteristics with the associated categories:
Match the risk factors or characteristics with the associated categories:
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Which treatment is considered the first-line option for Alzheimer's disease?
Which treatment is considered the first-line option for Alzheimer's disease?
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Cholinesterase inhibitors include Rivastigmine and Galantamine, but not Memantine.
Cholinesterase inhibitors include Rivastigmine and Galantamine, but not Memantine.
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What imaging technique detects hypometabolism in Alzheimer's disease?
What imaging technique detects hypometabolism in Alzheimer's disease?
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The levels of hyperphosphorylated tau are analyzed in _____ analysis for neurological conditions.
The levels of hyperphosphorylated tau are analyzed in _____ analysis for neurological conditions.
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Match the following treatments with their categories:
Match the following treatments with their categories:
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Study Notes
Papez Circuit
- The Papez circuit, also known as the mammillo-thalamic circuit, is a neural pathway involved in memory and emotion.
- It is crucial for the formation and retrieval of memories.
- The pathway starts at the hippocampus and subiculum, travels through the fornix and mammillary bodies, then continues through the mammillo-thalamic tract to the thalamus.
- From there, it progresses to the internal capsule, cingulate gyrus, parahippocampal gyrus, and finally ends at the entorhinal cortex, known as the "gateway of memory.”
Memory
- Memory encompasses three crucial processes: encoding, consolidation, and retrieval.
- Encoding is the initial stage of memory formation, where information is registered and processed.
- Consolidation involves the strengthening and stabilization of the encoded memories, transforming them from temporary to more permanent forms.
- Retrieval is the process of accessing and recalling stored memories when needed.
Classification of Memory
- Memories can be classified based on their duration or mode of retrieval.
- The traditional classification categorizes memories as immediate, short-term/recent, or long-term, each associated with different brain areas.
Immediate memory
- No permanent storage, usually within 1 minute
- Relies largely on the prefrontal cortex.
Short-term/Recent memory
- Dependent on the hippocampus
- Retained for a few minutes to several hours
- Typically requires the prefrontal cortex for recall.
Long-term memory
- Stored more permanently in the neocortex.
- Retrieving long-term memories also involve the prefrontal cortex.
Mode of Retrieval
- Current classifications focus on the mode of retrieval, dividing memories into explicit (declarative) and implicit (non-declarative) categories.
Explicit memory
- Involves conscious recall of memories.
- Includes episodic and semantic memory.
Episodic Memory
- Encoded with time & context
- Autobiographical in nature
- Primarily located in the hippocampus
- Often affected early in Alzheimer's disease
Semantic Memory
- Based on facts and general knowledge
- Primarily located in association areas of the brain.
- Usually remains intact even in later stages of Alzheimer's disease.
Implicit memory
- Non-conscious memories that influence behavior or performance.
- Includes procedural, priming, associative, and non-associative memories.
Procedural Memory
- Involves skills and habits
- Affected in Huntington's disease
Priming Memory
- Refers to the increased likelihood of remembering something due to prior exposure
- Occurs when exposed to specific information.
Associative Memory
- Forms connections between events or stimuli
- Leads to conditioned learning
- Rarely seen in humans, but common in animals.
Non-associative Memory
- Involves basic forms of learning such as habituation and sensitization
- Relates to changes in reflexes.
Anatomy of Memory
Cortex
- Different regions of the cortex are associated with specific memory types.
- The prefrontal cortex plays a role in all types of memory, including working memory.
- The parietal association area (Parieto-occipital) is involved in semantic memory.
- The temporal lobe, especially the hippocampus, is central to episodic memory and semantic memory.
- The occipital lobe also contributes to semantic memory.
Subcortex
- Specific subcortical structures are also implicated in memory functions.
- The amygdala is associated with associative memory and emotional responses attached to memories.
- The cerebellum is involved in procedural memory, particularly motor skills.
- The entorhinal cortex acts as a "gateway" to long-term memory.
- The basal ganglia, part of the subcortical structures, influences procedural memory, impacting motor learning and habits.
Dementia
- A major cognitive impairment characterized by a significant decline in at least two cognitive domains.
- The decline impacts everyday activities and independence.
Cognitive Domains Affected by Dementia
- Episodic memory: impairment in the ability to remember past events
- Language: difficulty with speech, comprehension, and naming
- Complex attention: challenges with focusing, shifting attention, and multitasking
- Executive function: problems with planning, decision-making, and problem-solving
- Social cognition: difficulties with understanding social cues and interacting appropriately
- Visuospatial function: challenges with navigating, drawing, or copying
Causes of Dementia
- Alzheimer's disease accounts for the majority of cases
- Diffuse Lewy body (DLB) dementia is another common cause
- Vascular dementia, including post-stroke dementia and white matter dementia (Binswanger disease), is a significant cause
- Normal pressure hydrocephalus (NPH) is relatively uncommon but can be a reversible cause of dementia.
Location of Brain Damage
- Dementia can be classified based on the affected brain areas into cortical dementia and subcortical dementia:
Cortical Dementia
- Diffuse Lewy body (DLB) dementia
- Progressive supranuclear palsy
- Binswanger disease
Subcortical Dementia
- NPH
Genetic Basis of Dementia
- Strong correlation with a family history of dementia.
- Genes linked to dementia include:
- Presenilin-1 (chromosome 14): The most common defect in familial Alzheimer's disease
- Presenilin-2 (chromosome 1):
- ApoE4 (chromosome 19): A significant risk factor for sporadic Alzheimer's disease, especially in late-onset cases.
Risk Factors for Dementia
- Age: The most critical risk factor, with the risk significantly increasing after 85 years.
- Family history of dementia
- Head trauma or concussions
- Stroke
- Metabolic syndrome
- Hypertension
- Diabetes
Factors NOT associated with increased dementia risk
- Low IQ
- Smoking
- NSAIDS
Clinical Stages of Dementia
- Dementia progresses through distinct stages, impacting different cognitive areas:
Stage I: Korsakoff Amnestic Stage
- Characterized by episodic memory loss, particularly difficulty consolidating new memories.
- Key brain area affected: hippocampus.
Stage II: Stage of Anomia
- Involves naming and comprehension difficulties
- Associated with challenges in language processing.
Stage III: Visuospatial Disorientation
- Marked by difficulties with orientation in space and problems with visual perception tasks
- Linked to damage in the angular gyrus.
Stage IV: Behavioral Abnormalities and Personality Changes
- Significant impact on personality and behavior
- Often involves emotional changes, agitation, and behavioral disturbances
- Primarily related to prefrontal cortex dysfunction.
Neurological Assessment of Aphasia and Dysarthria
Aphasia
Types of Aphasia
- Conduction aphasia: Lesion in the arcuate fasciculus, resulting in difficulty repeating words and sentences.
- Transcortical Sensory Aphasia: D/t infarct, causing issues with comprehension and repetition.
- Wernicke's aphasia: D/t infarct, leading to impaired comprehension. Reading and writing are also impacted.
Categories of Aphasia Based on Language Function
-
Preserved Comprehension:
- Anomic aphasia: Lesion in the angular gyrus, causing difficulty finding the right word.
-
Impaired Comprehension:
- Conduction aphasia: Lesion in the arcuate fasciculus, resulting in inability to repeat accurately.
- Transcortical sensory aphasia: D/t infarct, causes impaired comprehension and repetition.
- Wernicke's aphasia: D/t infarct, leads to impaired comprehension, reading and writing issues.
Dysarthria
Types of Dysarthria
-
Cortical Dysarthria: Related to Broca's aphasia, affecting motor speech control.
- Pseudo bulbar (Spastic dysarthria): D/t damage to corticobulbar fibres impacting the anterior horn cells.
-
Bulbar Dysarthria: Occurs due to damage to lower motor neurons in the brainstem nuclei.
- Flaccid Dysarthria: Damage to lower motor neurons, resulting in weak speech muscles.
Investigations for Dementia
- The diagnosis of dementia relies on clinical assessment, neuropsychological testing, and imaging techniques.
EEG
- Can show general slowing of brain activity, but usually not specific to dementia.
CSF Analysis
- May reveal elevated levels of amyloid beta (Aβ42) or hyperphosphorylated tau proteins, suggesting Alzheimer's disease.
PET Scan
- Utilizes radioactive tracers to visualize brain activity and metabolic function.
- In dementia, PET scans can show hypometabolism in affected brain regions.
- Specialized amyloid PET scans can detect amyloid plaques.
MRI
- Can show structural changes in the brain, such as atrophy, particularly in the hippocampus and temporal lobe.
Treatment of Dementia
- Currently, no cure exists for dementia, but medications can help manage symptoms and slow the progression of the disease.
Medications
-
Cholinesterase inhibitors (DOC):
- Donepezil
- Rivastigmine
- Galantamine
- NMDA antagonist: memantine
- Monoclonal antibody against Aβ42: Aducanumab
Obsolete Medications
- Tacrine (due to hepatotoxicity)
PIB PET Scans
- Can be used to detect amyloid plaques, providing further evidence for Alzheimer's disease.
- Images of PIB PET scans show higher amyloid deposition in individuals with Alzheimer's disease, indicating increased plaque formation.
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Description
Explore the Papez circuit, a neural pathway critical for memory and emotion. This quiz covers the components of memory, including encoding, consolidation, and retrieval processes. Test your knowledge on how these elements work together in the brain.