Neurobehavioral disorders Flashcards
R/L hemisphere emotional valence
R hemisphere = places negative valence on stimuli
Lesion -> associated with euphoria
L hemisphere = places positive valence on stimuli
Lesion -> associated with dysphoria
The right hemisphere places negative valence on stimuli whereas the left hemisphere places positive valence: Right-sided lesions are often associated with euphoria and focal left lesions with dysphoria, in a sense inhibiting, disabling the natural hemispheric emotional valence tendencies.
Aprosodias
Disorders of prosody indicate that the nondominant hemisphere does contribute some important input to language in the form of paraverbal communication.
- Expressive aprosodia, characterized by an inability to properly convey the inflection and tonal quality of emotion, such that speech often has a
robotic quality.
–The pathology here typically involves the area contralateral to Broca’s area. - Receptive aprosodia, characterized by difficulty interpreting emotional prosody, rhythm, pitch, stress, intonation, and so on and manifested in an inability to recognize sarcasm, cynicism, jokes, and other idiomatic forms of speech.
–The pathology is often due to dysfunction in regions contralateral to Wernicke’s area.
Dorsolateral Prefrontal Syndrome
(dysexecutive syndrome)
Characterized by poor problem solving, word-list generation, organization, sequencing, abulia/amotivation (“pseudo depression”), and sometimes perseveration.
Orbitofrontal Syndrome
(inferior/ventral frontal syndrome)
Characterized by emotional lability, impulsivity, disinhibition, childishness, personality change, and distractibility.
Dorso Medial/anterior Cingulate cortex Syndrome
Characterized by decreased initiation and indifference, but can also have amnesia, incontinence, and leg weakness.
Capgras syndrome
Feeling that a person has been duplicated or is an imposter
Damage to:
Right temporal
Bilateral frontal
Finger agnosia
loss of the ability to name or identify the fingers of one’s own hand(s) or the fingers of the hand(s) of another person
part of Gerstmann’s syndrome
result from a lesion in the left inferior parietal lobe, in particular, the angular gyrus
Right–Left Disorientation
involves an inability or loss of the ability to identify the right and left sides of one’s own body and the right and left sides of the body of another person.
result from a lesion in the left inferior parietal lobe, in particular, the angular gyrus
Apraxia of Speech
involves impairment in planning the movements necessary for speech production
disorder of the planning and organization of articulatory movement,
-in contrast to dysarthria, which is a disorder of motor coordination.
In the childhood version, a defining characteristic is often the child’s ability to pronounce single words or words in series (e.g., ABCs, numbers) but in conversation speech dysprosodic rhythm and poor articulation are apparent.
Ideational Apraxia
loss of the ability to plan and execute complex gestures, as though one has lost the “idea” behind the gesture or use of a tool even though knowledge about the use of the tool is unaffected.
involves problems in motor planning and is manifest in errors in sequencing the necessary actions for a task (e.g., lighting a pipe before putting in the tobacco). Assessment of serial acts is important in identifying this disorder.
Has been associated with bilateral, nonfocal lesions and with left hemisphere lesions, especially the posterior temporal-parietal junction
Ideomotor Apraxia
a.k.a. “body-part-for-object substitution”
refers to loss of the ability to perform or pantomime gestures on command and to imitate, although spontaneous production of the gesture may remain intact.
It involves difficulty making believe one is using a tool and is manifest in tool use and gestures. During pantomime, patients with ideomotor apraxia will often use a body part as if it were an object (e.g., their hand as a “comb”).
Usually involves lesions in the left inferior parietal lobe or supplementary motor area
Disorders of Apraxia associated with lesions in/near…
language zone of the left hemisphere, but can be the result of bilateral lesions. Localizes generally to the left inferior parietal/sensory area, and frontal lobe systems,
Limb-Kinetic Apraxia
inability to precisely move one’s hands or legs, but not related to skilled movement because there is no apparent inability to select or sequence motor movements
Unlike other apraxic disorders, appears to be the result of lesions in the pyramidal motor system
Alexithymia
An inability to understand, process, or describe one’s own emotions
Right hemisphere, particularly amygdala
Pseudobulbar Affect
Type of emotional lability; extreme involuntary emotional responses (i.e., tearful crying, excessive laughing) to mild stimulation
Due to pseudobulbar palsy, or damage/lesions to the *upper motor neuron *corticobulbar tract and connections to the cerebellum
May be due to brainstem stroke, ALS, TBI, dementia, etc.
“Pseudo” = the presence of bulbar signs like dysarthria and dysphasia in the absence of bulbar (pons, medulla, cerebellum) lesions
Phonemic Paraphasias
The substitution or the rearrangement of sounds or syllables in otherwise correct words (e.g., fig instead of pig).
Semantic Paraphasias
The substitution of a correct word or phrase for another semantically related word or phrase (e.g., dog instead of cat).
Semantic paraphasias in the form of multi-word paraphasic errors or “paragrammatism” is one feature that differentiates the syndrome of Wernicke’s aphasia from other fluent aphasic syndromes.
Angular gyrus syndrome
Transcortical sensory aphasia
Alexia with agraphia
Gerstman’s syndrome (acalculia, L/R confusion, agraphia, finger agnosia)
can be caused by posterior MCA
provides an interface between Wernicke’s area and polymodal cortical areas that process meaning/semantics (hence aphasia and Alexia)
Not associated with confabulation
Parkinson’s disease
results from loss of dopamine neurons in substantia nigra (basal ganglia)
Treatment: levodopa a.k.a. L-dopa
Can selective mutism be diagnosed in adulthood?
Yes
The difference between narcolepsy Type I and II:
Type I occurs with cataplexy (loss of muscle tone), whereas type II narcolepsy occurs without it.
Strong emotions, such as laughing, can trigger a narcoleptic episode.
What is reduplicative paramnesia?
The feeling that a place has been duplicated. Capgras syndrome and Fregoli’s syndrome are imposter syndromes (person).
Alexia without agraphia is associated with damage to the:
Left visual cortex and splenium of the corpus callosum (which is posterior).
Alexia without agraphia relies on disconnecting (via white matter tracts) visual input to the left parietal regions that are critical for the processes of reading. In contrast, writing is not so dependent on visual input; patient with alexia without agraphia can write but cannot read what they have written.
Can be cause by PCAs that spare angular gyrus
classic triad of symptoms seen in acute Wernicke-Korsakoff Syndrome
“ACE”
Ataxia
Confusion
Eye movement abnormalities
Lesions resulting in prosopagnosia
Lesions are typically bilateral in the occipitotemporal cortex and underlying white matter
If unilateral, it results from right hemisphere lesions
Affects following exposure to pesticides
Acute exposure: headaches, blurred vision, restlessness, mental slowing, anxiety/depression, slurred speech, and ataxia
Chronically exposed: irritability, confusion, depression, attention/memory, response speed
Astereognosis
used to describe both the inability to discriminate shape and size by touch and the inability to recognize objects by touch.
Anton’s Syndrome
manifestation of bilateral occipital lobe damage in cortically blind patients.
These patients lack insight into their disease, deny their blindness, and confabulate visions.
Is confabulation common in Gerstmann’s syndrome?
No
Is confabulation common in anosognosia?
Yes - often accompanied by denial and confabulation
Optic aphasia vs. optic ataxia vs ocular apraxia
Optic aphasia - impaired naming of visual objects with the patient still Abel to identify the object by other means and able to explain characteristics
Ocular apraxia - difficulty voluntarily directing one’s gaze toward objects in the peripheral vision through eye gaze
- can result in difficulty scanning a visual scene
Optic ataxia - impaired ability to reach for or point to objects in space under visual guidance
- Once an object has been touched, can perform smooth movements back and forth to it (not the case in cerebellar ataxia) poor hand eye coordination
How does diencephalic amnesia differ from bilateral temporal lobe amnesia?
Diencephalic amnesia results in temporal ordering impairment
Locked in syndrome
Results from lesion to * ventral pons* that affect bilateral corticospinal and corticobulbar tracts
complete paralysis of all voluntary muscles except for the ones that control the movements of the eyes.
Kluver-Bucy syndrome (KBS)
rare neuropsychiatric disorder due to lesions affecting bilateral temporal lobes, especially the hippocampus and amygdala.
It is characterized by hyperorality, hypermetamorphosis (excessive attentiveness to visual stimuli with a tendency to touch every such stimulus regardless of its history or reward value), hypersexuality/changes in sexual orientation, bulimia, placidity, visual agnosia, and amnesia
not associated with aggressive behaviors
Describe relationship between subjective memory complaints and objective memory performance
Correlations between the two are LOW and generally mediated by the patient’s mood and anxiety symptoms.
In split-brain subjects, when a word was flashed into the left visual field of the patient, they could…
Because information presented in left visual field is processed in the right hemisphere, no verbal processing was was done. Therefore the patient could not name it but could draw it or choose by feeling with left hand an appropriate object that matched the word
