BEHAVIORAL NEUROLOGY Flashcards
Initial cortical processing of afferent sensory input or
source of primary motor efferents.
Directly connected with association cortices and subcortical modulating nuclei
Idiotypic primary cortex (sensory or motor, e.g., primary
visual cortex)
Usually anatomically close to respective primary cortex;
modulates the function of primary cortex
Homotypic unimodal association cortex
Directly connected with each other and unimodal association cortices (including the limbic and paralimbic
regions)
Homotypic heteromodal (multimodal) association cortex
Two major areas OF Homotypic heteromodal (multimodal) association cortex
1) _________concerned with planning of movements and
executive functions
2) ________________: visuospatial perception and language
Anterior heteromodal association area (prefrontal cortex):
Posterior heteromodal association area
What cell type
“Projection neurons” involved in transmitting signals
to other cortical, subcortical, or spinal areas
Located mainly in layers III, V, and VI
The neurotransmitter is glutamate (excitatory
Pyramidal cells
What cell type
Star-shaped neurons with dendritic extensions in all
directions
Found in all layers, but most common in layer IV
Are local inhibitory interneurons; use γ-aminobutyric
acid (GABA)
Stellate cells
Neocortex (primary, unimodal, and heteromodal areas)
is organized in six layers
1) Layers_______ receive afferents
2) Layer __________projects to spinal cord, brainstem, and basal
ganglia
3) Layer _____ projects to thalamus
I to IV
V
VI
Layer I—molecular (plexiform) layer: consists mainly of
local _____ and ______ of pyramidal cells
in deeper layer
interneurons and apical dendrites
Layer II—external granular layer
1) _________: axons project to deeper cortical layers
2) ___________: axons project to contralateral cortex
as commissural fibers
Stellate cells
Pyramidal cells
Layer III—_________layer: pyramidal cells
with projections to ipsilateral cortices (association fibers)
or contralateral hemisphere (commissural fibers
external pyramidal
Layer IV—internal granular layer
1) Consists mainly of ______ cells
2) Receives afferent glutaminergic input from ____
3) Prominent layer in _____
stellate
thalamus
primary sensory cortices
__________ layer
1) Pyramidal cells: axons project to basal ganglia, brainstem,
spinal cord, and contralateral cortex (commissural
fibers)
2) Prominent layer in primary motor cortex, which contains
giant pyramidal cells of Betz
Layer V—internal pyramidal layer
Layer VI—multiform layer: pyramidal cells with projections
to ____ and _____
thalamus and layer IV
Each column is a functional unit of cortex
Vertical (columnar) cortical organization
__________connection between different cortices
in same hemisphere
Association fibers:
Examples of Association fibers
1) U-fibers (short association fibers)
2) Superior longitudinal fasciculus
3) Cingulum (part of the Papez circuit)
4) Inferior longitudinal fasciculus
5) Uncinate fasciculus
__________ connection between the two
cerebral hemispheres
Commissural fibers:
Examples of Commisural fibers
1) Corpus callosum
2) Anterior commissure
3) Posterior commissure
4) Hippocampal commissure
_______ corticosubcortical fibers
Projection fibers:
Premotor areas. What type of cortex?
homotypic unimodal cortex
parietopremotor pathways are important in ______
goal-directed
movements (reaching and grasping)
Responsible for initiating motor plans in response
to sensory stimuli (e.g., stopping at a red light)
Involved in learning to associate a particular
sensory stimulus with a particular motor movement
(associative learning)
Ventral and dorsolateral premotor cortex
Input from ipsilateral parietal lobe and prefrontal
“presupplementary area
Blood flow increases when one is thinking about or planning a movement
SMA
Projects to premotor areas involved in motor programs
required for speech production
Broca’s area
Important for executive functions, planning, judgment,
problem-solving
Dorsolateral prefrontal cortex
Responsible for emotional and visceral activities,
social behavior, and inhibition of inappropriate
behavior in a particular social context as well as
judgment
Orbitofrontal cortex
Connections of the orbitofrontal cortex
Widespread interconnection with limbic system and
basal ganglia
Where is the lesion?
poor executive functions, planning,
judgment, and problem solving
Dorsolateral:
Where is the lesion?
disinhibition, impulsive behavior,
poor judgment and insight
Orbitofrontal:
Interconnections with limbic system (especially
amygdala)
Important role in initiation, motivation, and goaloriented
behavior
Mesial frontal cortex and anterior cingulate cortex
severe impairment of the Mesial frontal cortex and anterior cingulate cortex leads to:
akinetic mutism (no spontaneous behavior)
Stimulation/epileptic activity of mesial frontal
complex motor and gestural automatisms
Sensitive measure of function of prefrontal cortex
The subject is asked to sort the cards according to a
certain perceptual attribute of a visual stimulus
Wisconsin Card Sorting Test
occipitoparietal visuospatial pathway responsible for visuomotor tasks
Dorsal M pathway:
___________ pseudothalamic syndrome
Syndrome of delayed pain and paresthesias, as may
occur sometimes with thalamic infarcts
Lesion of S II at parietal operculum:
anomia, alexia, constructional difficulties, acalculia, dysgraphia, finger anomia, right-left disorientation
Angular gyrus syndrome (lesion of angular gyrus,
heteromodal cortex)
___________optic ataxia, ocular apraxia,
simultanagnosia (bilateral lesions)
Balint’s syndrome:
amnesia for nonverbal, visuospatial information. Where is the lesion
Nondominant hemisphere
amnesia for verbal information. Where is the lesion?
Dominant hemisphere
Difficulty with recognition of songs, primarily
because of disturbance of recognition of different
characteristics of music composition
Amusia
Left temporal lobe lesions:
not true amusia,
patient has difficulty understanding lyrics
Ageusia (lack of taste): Where is the lesion?
bilateral
lesions of insular cortex
lesion for semantic dementia
dominant anterior temporal lobe
lesion for Prosopagnosia
Lesion in posteroinferior temporo-occipital region
sensation of familiarity with a previously
unfamiliar experience, place, or event
Déjà vu:
sensation of familiarity with a
previously unfamiliar auditory experience (e.g.,
sound, music, speech, or narrative)
Déjà entendu
sensation of unfamiliarity with a
previously familiar experience, place, or event
Jamais vu:
Recurrence of an image no longer present in visual
field. May occur with posterior temporo-occipital
epileptic focus
Palinopsia
What layer of the occipital cortex Receives the majority of input from lateral geniculate nucleus
Layer IV
Projections of the occipital cortex to_____ and ______: responsible for production of saccades
and rapid shifting of gaze to another point in the
visual field in response to a novel stimulus
superficial layer of superior colliculus and pulvinar
Anomia, alexia, constructional difficulties, acalculia,
dysgraphia, finger anomia, right-left disorientation
± aphasia
Angular gyrus syndrome
Bilateral medial occipital lobe lesion
Cortical blindness associated with denial of the
deficit, for which the patient is unaware, and
confabulation
Anton’s syndrome
Lesion involves occipitotemporal pathways
bilaterally, often seen with Alzheimer’s disease
Optic ataxia, ocular apraxia, simultanagnosia
Balint’s syndrome
Bilateral anterior temporal lobe lesion
Hyperorality and oral exploratory behavior,
altered eating habits, weight gain, emotional
blunting, blunting of response to fear and
aggression, and altered sexual activity (hyposexuality
> hypersexuality
Klüver-Bucy syndrome
Belief that the strangers are identified by the
patient as familiar
Usually seen in context of dementia
Fregoli syndrome
Belief that a family member is an imposter
Usually associated with paranoid delusions in
the context of dementia
Capgras’ syndrome
“Syndrome of approximate answers”; answers
are consistently nearly correct but not correct
Usually seen in context of psychiatric disease
and malingering but may also be seen in
degenerative dementias
Ganser syndrome
Impaired ability to produce an internal image of
a named object
Charcot-Wilbrand syndrome
Location of the Visual association areas (peristriate cortices)
Located in the peristriate occipital areas (areas 18 and
19) and middle and inferior temporal gyri (areas 20,
21, 37)
Dorsal M pathway location
Originates in M cells of retina that project to magnocellular portion of lateral geniculate nucleus
M pathway carries information on perception of
____________of a particular visual input
depth, analysis of motion, and spatial orientation
“where”
Ventral P pathway location
Originates in P cells in retina that project to parvocellular
portion of lateral geniculate nucleus
Function of the Ventral P pathway location
Concerned primarily with perception of form and
color; important in recognition of faces and objects
and pattern identification
Results of lesions of the Ventral P pathway
Aperceptive visual agnosia, Achromatopsia, Color agnosia, Prosopagnosia
a. Acquisition of new knowledge and experience and alteration of behavior as a result of the experience
b. In its simplest form, it represents change in response over time to repeated exposure to the same stimulus
Learning
knowledge that
requires conscious recall and acquisition; requires
fast acquisition and conscious recall
Types are:
Semantic memory
Episodic memory
Explicit (declarative) memory
knowledge that
does not require conscious recall; acquisition is generally slow
Types are
Procedural memory
Priming
Implicit (nondeclarative) memory
Knowledge of facts, objects, and abstract concepts
unrelated to events (e.g., geography
requires inferotemporal association areas and other regions outside mesial temporal lobe
Semantic
Knowledge of past events that have been
encoded and stored with certain associations
established in particular time and place
Episodic
long-lasting or permanent, relatively
more resistant to dementing illness and cerebral
insult than short-term memory
Long term:
Knowledge for performing a motor task is
slowly acquired (learned) by repeatedly
performing the same task
Acquisition is slow and incremental, the
knowledge is resistant to forgetfulness by degenerative
conditions
Procedural memory
Parts of the limbic system
Basal forebrain
Septal area
Substantia innominata
Amygdala complex
Connections with hippocampus and hypothalamus
has cholinergic projections to hippocampus
Septal area
Part of Substantia innominata
Cholinergic projections to amygdala and neocortex,
Receives projections from subiculum
Nucleus basalis of Meynert
connections with hippocampal
formation responsible for attachment and association
of an emotion with a particular memory
Amygdala complex
Parts of Hippocampus
Dentate gyrus
Hippocampus proper
Subicular complex
______ is generally resistant to metabolic, vascular
(anoxic), and degenerative insults with few exceptions
(argyrophilic grain disease [Braak’s disease]
selectively affects CA2)
CA2
Focal damage to ____ and ______ is sufficient to
cause anterograde amnesia
CA1 and CA2
Parts of the subicular complex
a) Consists of the subiculum proper, presubiculum,
and parasubiculum
Mediator of acquisition of emotional memory; important
role in emotional responses, particularly ones
involving conditioned
Amygdala
Responsible for judgment and social behavior and
inhibition of inappropriate behavior in a particular
social context
Part of the pFC
Orbitofrontal cortex
involved mainly with motivation
Part of the pFC
Medial frontal (anterior cingulate cortex)
What is “Temporal lobe personality”
observed in patients with
temporal lobe epilepsy: hypergraphia, hyperreligiosity,
altered sexual behavior (hyposexuality >
hypersexuality), circumstantiality of speech (with
excessive detail about minute points), euphoria,
sadness, emotionality, and, sometimes, anger and
aggressive behavior
Acquired impairment of language processes that may
include disturbance in comprehension and/or formulation
of language symbols (across all modalities, not
only verbal
Aphasia
amotivational, akinetic state characterized
by poor effort to initiate speech, lesion usually localized
to mesial frontal lobes
Akinetic mutism:
pure anarthria, no speech output
Usually due to bilateral lesions of the corticobulbar
(upper motor neuron) tract, often from bilateral
capsular infarcts limited to corticobulbar fibers (written
language and verbal comprehension are preserved)
Aphemia:
often considered
part of Broca’s area rather than independent language area)
Writing is usually abnormal (including copying written
material in these lesions
Exner’s area,
