Exam IV Flashcards
what is the general function of the cerebellum? how does it work?
(1) detect erroneous movements and correct them
(2) receives sensory information and relays it’s influence on the motor system of the cortex and brain stem
what are the three major functions of the cerebellum?
(1) synergy of movement
(2) maintenance of upright posture
(3) maintenance of tone
what movement do the lateral and intermediate hemispheres of the cerebellum control?
limb movement
what movement do the vermis and floculonodular lobes control?
trunk movement
what do cerebellar lesions result in?
ataxia (irregular, uncoordinated movement)
what motor pathways are influenced by the lateral hemispheres of the cerebellum?
(1) lateral corticospinal tracts
what motor pathways are influenced by the intermediate hemispheres of the cerebellum?
(1) lateral corticospinal tracts
(2) rubrospinal tract
what motor pathways are influenced by the vermis and flocculonodular lobes of the cerebellum?
-Trunk Coordination
(1) anterior corticospinal tract
(2) reticulospinal tract
(3) vestibulospinal tract
(4) tectospinal tract
Balance & -Vestibuloocular reflexes
(1) medial longitudinal fasciculus
what is the order of cerebellar nuclei from lateral to medial?
Don’t Eat Greasy Foods
(1) Dentate
(2) Emboliform
(3) Globase
(4) Fastigial
where do each of the cerebellar nuclei receive input from?
(1) Dentate: lateral hemisphere
(2) Emboliform: intermediate hemisphere
(3) Globase: intermediate hemisphere
(4) Fastigial: vermis
where do climbing fibers of the cerebellum receive input from?
inferior olivary nucleus
where do mossy fibers of the cerebellum receive input from?
pontine nuclei
are mossy and climbing fibers excitatory or inhibitory on the cerebellar cortex?
excitatory
does ataxia due to a cerebellar lesion present ipsilaterally or contralaterally?
ipsilaterally
what does a lesion to the midline of the cerebellum cause?
(1) unsteady gait (truncal ataxia)
(2) eye movement abnormalities
what does a lesion lateral to the vermis cause?
limb ataxia (appendicular ataxia)
what do lesions to the cerebellum cause ipsilateral ataxia as opposed to contralateral ataxia?
the pathways are double crossed
what are the major cerebellar input pathways?
(1) pontocerebellar fibers
2) Spinocerebellar pathways (4 tracts
what information do the Dorsal spinocerebellar and Cuneocerebellar tracts carry?
unconscious proprioception of limb movements
what information does the Ventral spinocerebellar tract and Rostral spinocerebellar tract carry?
activity of interneurons within the spinal cord;
the Dorsal spinocerebellar tract relays information from what part of the body?
lower extremity
the Cuneocerebellar tract relays information from what part of the body?
upper extremity
what part of the spinal cord does the Ventral spinocerebellar tract relay information from?
lower region of the spinal cord
what part of the spinal cord does the Rostral spinocerebellar tract relay information from?
upper region of the spinal cord
is the dorsal spinal cerebellar tract ipsilateral or double crossed? where does it run and where does it synapse?
Ipsilateral
(1) 1st synapse: in nucleus dorsalis of Clark
(2) 2nd synapse: ipsilateral lateral region of cerebellum
is the Cuneocerebellar tract ipsilateral or double crossed? where does it run and where does it synapse?
Ipsilateral
(1) 1st synapse: external cuneate nucleus
(2) 2nd synapse: ipsilateral lateral region of cerebellum
is the Ventral spinocerebellar tract ipsilateral or double crossed? where does it run and where does it synapse?
Double Crossed
(1) decussates: ventral commisure
(2) decussates: superior cerebellar peduncle
where does the superior cerebellar artery branch off of? what does it supply blood to?
(1) branches off the basilar artery
(2) superior region of the cerebellum
where does the anterior inferior cerebellar artery (AICA) branch off of? what does it supply blood to?
(1) branches off the basilar artery
(2) anterior inferior region of the cerebellum
where does the posterior inferior cerebellar artery (PICA) branch off of? what does it supply blood to?
(1) vertebral artery
(2) posterior inferior region of the cerebellum AND lateral medulla
what are some signs and symptoms associated with cerebellar artery infarcts?
(1) vertigo
(2) horizontal nystagmus
(3) limb ataxia
(4) unsteady gait
(5) HA
what impairments might an infarct of the AICA cause?
unilateral hearing loss (AICA supplies internal auditory artery)
what impairments might an infarct of the superior cerebellar artery cause?
ipsilateral ataxia (little to no brainstem involvement)
what are the signs of a cerebellar hemorrhage?
HA, ataxia, nystagmus, GI problems, CN IV palsy
what is the difference between dysrhythmia, DDD, and dysmetria?
(1) dysrhythmia: abnormal timing
(2) DDD: rapid alternating movements
(3) dysmetria: abnormal trajectories
what is false localization ataxia?
(1) ataxia caused by lesion outside of the cerebellum that involve cerebellar input or output pathways
what are a couple tests for appendicular ataxia?
(1) finger to nose
(2) heel-shin test
what is a test for truncal ataxia?
tandem gait
where does the basal ganglia send and receive information from?
the cortex
what is the primary function of the basal ganglia?
(1) planning, initiating, and executing movements
(2) helps maintain muscle control and postural control
what structure does the caudate nucleus and putamen make up?
striatum
what two structures make up the lenticular nucleus?
globius pallidus and putamen
how does the thalamus tell the body to move?
excitatory signals to the motor areas
how does the direct pathway of the basal ganglia work?
DIRECT PATHWAY
(1) cortex releases glutamate
(2) causes excitation of the striatum
(3) striatum releases GABA
(4) GABA is inhibitive
(5) globus pallidus (internal) and SN Pars reticularis become inhibited
(6) this inhbition prevents the release of more GABA to the thalamus
(7) if GABA isn’t released to the thalamus, thamalus WILL NOT be inhibited
(8) THIS CAUSES MORE MOVEMENT
how does the indirect pathway of the basal ganglia work?articularis
(1) Cortex releases glutamate and SN pars compacta releases dopamine (Inhibitory)
(2) striatum sends inhibitory GABA to globus pallidus (external)
(3) when GP (external) is inhibited, it doesn’t inhibit subthalmic nucleus
(4) subthalmic nucleus releases Glutamate
(5) Glutamate excites GP (internal) and SN pars articularis
(6) GP (internal) and SN pars reticularis then releases GABA to Thalamus
(7) Thalamus becomes inhibited
(8) THIS STOPS MOVEMENT
what is the function of the oculomotor channel of the basal ganglia?
regulation of eye movements
what is the function of the prefrontal channel of the basal ganglia?
cognitive processes
what is the function of the limbic channel of the basal ganglia?
(1) regulation of emotions
(2) thought to play a key role in neurobehavioral and psychiatric disorders
what demographics does Parkinson’s disease most commonly affect?
(1) men
(2) 40-70 y/o
what hertz is a pill rolling tremor? what hertz is a postural or resting tremor?
pill rolling: 4Hz
postural: 8Hz
what is Froment’s manuever?
voluntary movement and resistance against gravity increase rigidity in Parkinson’s patients
what are some chracteristics of PD other than the classic signs and symptoms (TRAP)?
(1) anosmia
(2) dystonia
(3) micrographia
(4) orthostatic hypotension
(5) dementia
what are signs and symptoms that are NOT seen in Parkinson’s and help differential diagnosis (such as Parkinsonism)?
(1) significant weakness
(2) spasticity
(3) hyper or hyporeflexia
(4) Babinski signs
(5) sensory loss
does PD present with symmetrical or asymmetrical signs and symptoms?
asymmetrically
what is the cause of PD?
degeneration of the substantia nigra (replaced with Lewy bodies)
what percentage of the substantia nigra is degenerated in PD patients before s/s are present?
70-80%
when dopamine can’t be released, which pathway takes over in PD patients? what does this result in?
indirect pathway; loss of movement
what is the cause of Huntington’s disease?
(1) genetic
2) progressive atrophy of the striatum (mainly caudate nucleus
which pathway takes over in Huntington’s patients?
direct pathway; causes lots of excessive movement
what are the 4 functions of the limbic cortex?
HOME
(1) Homeostasis
(2) Olfaction
(3) Memory
(4) Emotion
what structure of the limbic system is responsible for olfaction?
olfactory complex
what structure of the limbic system is responsible for memory?
hippocampal formation
what structure of the limbic system is responsible for emotions and drives?
amygdala
what structure of the limbic system is responsible for homeostasis?
hypothalamus
what parts of the telencephalon are components of the limbic system?
(1) cingulate gyrus
(2) parahippocampal gyrus
(3) temporal pole
(4) orbital frontal gyri
how may a patient with damage to the orbitofrontal lobe of the limbic cortex present?
(1) non-emotional state
(2) minimal emotional stimuli to pain
(3) decreased motivational drive
(4) cognitive deficits (cognitive perseveration)
how may a patient with damage to the inferior temporal lobe of the limbic cortex present?
(1) impossible to learn a visual tasks
(2) cannot learn or process new information
what functions is the septal nuclei responsible for within the limbic system?
(1) pleasure center
(2) modulates memory
what is the thalamus responsible for within the limbic system?
emotional response to sensations
what is the hypothalamus responsible for within the limbic system?
mediates autonomic response to emotion (ex. blushing when you’re embarrassed)
where is the rhinencephalon found? what is the main function of this area?
(1) olfactory complex
2) smell and sensation of taste (and memories associated with them
where does the lateral olfactory stria travel?
uncrossed to primary olfactory complex
where does the medial olfactory stria travel?
crosses to contralateral bulb via anterior commissure
what are the 3 main nuclei of the amygdala?
(1) corticomedial nuclei
(2) basolateral nuclei
(3) central nuclei
how does a person with damage to the amygdala present clinically?
(1) hypersexuality
(2) disinhibited behavior
(3) socially embarrassing
(4) Kluver Bucy Syndrome
what are the two output pathways of the amygdala? where do they run?
(1) stria terminalis: anterior commissure; continues to septal nuclei or hypothalamus
(2) ventral amygdalofugal: travel along base of brain to cortical and sub cortical areas
what are the two main regions for memory formation in the brain?
(1) medial temporal lobe
(2) medial diencephalic areas
what is the function of the circuit of papez (medial limbic circuit)?
memory and emotion
what stucture connects the two hemispheres?
corpus callosum
when someone is right handed, what is the dominant hemisphere?
left hemisphere
what is the dominant hemisphere for language in majority of people?
left hemisphere
what hemisphere is perception typically processed in?
right (non-dominant) hemisphere
the anterior portion of the brain is more responsible for what?
planning, control, and execution of actions
the posterior portion of the brain is more responsible for what?
interpreting perceptual data; assigning meaning to sensory information
the left hemisphere typically deals with what? what does the right hemisphere deal with?
(1) LANGUAGE, math calculation, following set instructions
(2) right: visual-spatial analysis and awareness,
perception, emotion conveyed in language
what is the difference between Broca’s and Wernike’s area?
(1) Broca: motor aspects of speech formulation
(2) Wernike: language comprehension
a lesion to where would most likely cause a Broca’s aphasia? how will this patient present clinically?
(1) LEFT MCA (superior division)
(2) full comprehension; dysarthria, right hemiparesis, frustration
a lesion to where would most likely cause a Wernike’s aphasia? how will this patient present clinically?
(1) LEFT MCA (inferior division)
(2) impaired comprehension, fluent speech, but doesn’t make sense, angry / paranoid, patient is unaware of their deficits
what is cortical deafness? what causes it?
(1) can hear sound but can’t interpret it
(2) lesion to Heschel’s gyrus
what is alexia? what is apgraphia?
(1) alexia: impaired reading
(2) agraphia: impaired writing
what is nonverbal auditory agnoisa?
understands speech but doesn’t understand non-verbal sounds
what is deficits are seen with Gerstmann Syndrome?
agraphia, acalculia, right-left disorientation, finger agnosia
what is the difference between ideamotor and ideational apraxia?
(1) ideamotor: inability to carry out an action in response to a verbal command
(2) ideational: inability to conceptualize, plan, and execute motor actions
what is aphemia?
verbal apraxia
how do lesions to the left or right hemisphere differ with their presentations?
(1) right (non-dominant) lesion: long-lasting deficits of neglect to contralateral side
(2) left (dominant) lesion: mild or undetectable neglect to contralateral side
a lesion to which hemisphere leads to more severe neglect?
right sided (non-dominant) hemisphere
what two gyri are assocaited with spatial processing? (right / non-dominant)
(1) supramarginal gyrus
(2) angular gyrus
does hemineglect syndrome affect sensory or motor?
(1) sensory neglect
(2) motor neglect
(3) combined sensory and motor neglect
what is capgras syndrome?
insist that friends and family have been replaced with identical imposters
what is Fregoli syndrome?
believing different people are somebody they know in disguise (ex. thinking your neighbor is your mother in disguise)
what is Reduplicative paramnesia?
believing a person, place, or thing exists as two identical copies
what are the three main functions of the frontal lobe?
RIO
(1) Restraint (ex. judgement, delaying gratification, concentration)
(2) Initiative (ex. motivation, drive, personality, creativity)
(3) Order (ex. working memory, planning, organization, sequencing)
what is the function of the prefrontal cortex?
(1) executive function
(2) problem solving
(3) motivation
(4) solve complicated problems
(5) plan for the future
what does the dorsolateral prefrontal cortex deal with?
(1) working memory
(2) leanring new material
(3) selective attention
what does the orbitofrontal lobe deal with?
(1) impulse control
(2) judgement
(3) social appropriateness
how do lesions of the dorsolateral part of the frontal lobe present?
apathetic and lifeless
how do lesions of the ventromedial part of the frontal lobe present?
impulsive, disinhibited behavior, and poor judgement
how doe lesions to the LEFT side of the frontal lobe duffer from those of the RIGHT side?
(1) left frontal lobe lesion: depression like symptoms
(2) right frontal lobe lesion: behavior disturbance
