Cognitive Dysfunction and Dementia Flashcards
Define: Agnosia, Agraphia, Alexia.
Agnosia - failure to recognize or comprehend perceived stimuli (i.e. prosopagnosia)
Agraphia - inability to write (implies you’ve been able to before)
Alexia - inability to read (implies you’ve been able to before)
Define anomia, anosognosia, neglect
Anomia - difficulty finding words
Anosognosia - difficulty to recognize illness / lack of awareness of one’s disability
Neglect - Inattention to stimuli from one side of the visuospatial environment
Define aphasia, apraxia, dysarthria
Aphasia - inability to understand and use language (higher order language deficit)
Dysarthria - motor inability to speak (movement deficit) / inability to articulate
Apraxia - impairment of skilled movement upon command or attempted mimicry despite comprehension and normal motor function
How is repetition affected in Broca’s, Wernicke’s, conduction, and global aphasia?
All impaired
In conduction aphasia -> loss of arcuate fasciculus = this is the primary defect. Can formulate thoughts and say things, but bad at repeating things -> requires Wernicke and Broca strong communication
Global aphasia is just total knockout
How do transcortical motor / transcortical sensory aphasia differ from other aphasias?
Transcortical motor - affects frontal lobe around Broca’s area. Similar symptoms except repetition is intact (Broca’s area not affected)
Transcortical sensory - affects temporal lobe around Wernicke’s area. Similar symptoms except repetition is intact (Wernicke’s area not affected)
What is transcortical mixed aphasia also called and what characterizes it?
Also called pure echolalia
- > patient has intact Wernicke’s, Broca’s, and arcuate fasciculus but frontal and temporal lobes are damaged
- > can only repeat, nonfluent speech production and comprehension
- > analogous to transcortical version of global aphasia.
When is anomia typically seen?
It is common with all aphasia and often the only sign of mild or resolving aphasia.
What is aprosodia and what causes it?
A-prosody - inability to see intonation and emphasis in speaking
-> cannot detect affective or emotional content of speech
Prosody perception occurs in the superior temporal gyrus of the nondominant hemisphere (analogous to Wernicke)
Prosody expression occursin the inferior frontal gyrus in the nondominant hemisphere (analogous to Broca)
What does a dominant parietal lobe lesion cause?
Gerstmann’s syndrome
- think of someone trying to count their fingers
Tetrad:
-Finger agnosia - cannot identify finger named by examiner or recognize which finger has been touched / moved
-Left-right disorientation
-Acalculia
-Agraphia - writing impairment
How is left-right disorientation tested?
Best via crossed pointing
-> have patient point to right foot with left hand. Makes it more difficult when you have to think of two directions at once
Why does acalculia occur in Gerstmann’s syndrome?
Usually due to aphasia -> inability to perceive and hold numbers in recent memory for calculation
However, true anarithmetria can happen
What will lesion of the nondominant parietal lobule cause?
Contralateral neglect, often with anosognosia of the issue.
If it affects more superior portion can cause constructional apraxia (difficulty drawing objects like clockface) or dressing apraxia (poor processing of spatial information so cannot put clothing on well)
What is cortical blindness vs Anton’s syndrome?
Cortical blindness - no visual perception due to cortical deficit in occipital lobes
Anton’s syndrome - cortical blindness + visual anosognosia -> patient maintains that they can see. Probably due to disconnection syndrome between visual cortex and visual integration cortices
What is Balint’s syndrome? What is notably preserved?
Triad:
1. Oculomotor apraxia - cannot gaze effectively via saccadic eye movements
- Optic ataxia - can’t reach out to a visual target accurately (i.e. finger to nose on someone else, but could do on themselves easily since proprioception is intact)
- Simultanagnosia - visual inattention, can’tt ell whole from the parts. Often associated with prosopagnosia.
Basically similar in reasoning to Anton syndrome, and Anton may recover thru Balint’s.
Color vision is notably preserved.
What is achromatopsia and what causes it?
Loss of color vision in all or part of the visual field, due to inferior occipital lobe lesions (where color vision is sent thru from visual cortex)
What is prosopagnosia and what is it caused by?
Inability to recognize faces, but generally difficulty recognizing specific members of a general class of objects on basis of minor variations (i.e. a farmer and his cows, a bird watcher and species of birds)
Disorder of visual cueing of memories -> they can tell you what goes with what, but can’t name that person or thing
-> fusiform gyrus normally implicated
What is visual agnosia?
Ability to see and describe an object’s features without being able to recognize / name it, as well as associate it with its function
Patient does not have anomia - i.e. they can tell you what a glove is
They can even draw the object and match it to a drawing or picture
i.e. man who took his wife for a hat
What are the four types of memory?
- Registration / working memory - your attention span (can only remember it as long as you are thinkin about it)
- Short-term memory - recall within minutes
- Long-term memory - requires consolidation
- Motor skills and conditioned reflexes
What are the portions of the brain responsible for each type of memory?
Working memory - frontal cortex
Short-term memory and longterm memory - hippocampus and neocortex
Motor skills / conditioned reflexes - cerebellum / neocortex
What is Ribot’s law?
More recent memories are more affected by retrograde amnesia than are more distant memories
What areas of the brain are typically affected in an amnestic syndrome?
Medial temporal lobes (hippocampus), anterior thalamic nucleus, or mammillary bodies
Remember, papez circuit goes hippocampus->fornix->mamillary bodies-> mammillothalamic tract-> anterior nucleus of the thalaus
What are the symptoms of amnestic syndrome?
Mixture of anterograde and retrograde amnesia which will improve as the lesio resolves
-> patient will be left with a memory gap
What is transient global amnesia?
An acute onset transient anterograde amnesia which is usually benign, but leaves a permanent memory gap during that period
There will be a full recovery of anterograde memory
What is psychogenic amnesia also called and what psychiatric problem often accompanies it?
Dissociative amnesia
-> often accompanied by dissociative fugue - abrupt travel or wandering during period of dissociative amnesia
