To Finish up Flashcards
What side of the body does the primary sensory cortex receive projections from?
contralateral
Proprioceptive information from muscles and joints arrive where? To relay what information?
In the primary somatosensory cortex to relay info about the position of the body parts in relation to one another
role of S1 vs S2
primary processor of sensory input vs higher-order integration and interpretation
location of S1 vs S2
postcentral gyrus vs parietal operculum
input of S1 vs S2
thalamus vs S1 and other brain regions
function of S1 vs S2
localization, discrimination, proprioception
integration, learning, complex tactile recognition, pain perception
What happens if a lesion were to occur in the primary somatosensory cortex?
Varied degrees of focal impairment in sensation the contralateral side of body
acute stage: loss of all sensory modalities on contralateral body or face
chronic stage: recovery of sensation and pain and temperature and crude touch sensation (due to sensory cortices compensating + thalamic and S2 means recovery of pain and temp
What would happen if the lateral left parietal lobe was lesioned?
Apraxia– patient loses sense of what particular movement is for
How are Broca’s and Wernicke’s areas cnnected?
acuate fasciculus in parietal lobe
Why is Wernicke’s area mostly in the left hemispshere?
Bc language is mostly lateralized in the left hemisphere
language is different from speech → speech is supported by the entire motor system for vocalization
What would happen if the dominant (left) hemisphere of the association sensory cortex were lesioned?
at inferior parietal lobe at the level of the angular gyrus– alexia (inability to read written language)
at the inferior parietal lobe at the supramarginal gyrus – conduction aphasia (understand what is said, but unable to repeat)
Alexia vs. Dyslexia?
Acquired (e.g. stroke) vs Developed
Damage to the superior parietal lobule results in?
Optic ataxia (inability to accurately point or reach for objects under visual guidance in contralateral right hand
What would happen if the non dominant (right) hemisphere of the association sensory cortex were lesioned?
Would result in damage to other areas involving inferior parietal lobule
ex: Anosagnosia (lack of awareness or denial of one’s neurological deficit
ex: left visual field neglect (person has difficulty paying attention to or processing information on the left side of their visual field due to right hemisphere damage (hemineglect)
What are the key functions of the temporal lobe?
- Olfaction
- Audition
- Emotion
- Memory: the medial temporal lobe; most significant
- areas overlapping with inferior occipital cortex (visual perception, or the “what” pathway)
What are mitral cells?
Complex sets of olfactory receptors on different olfactory neurons that distinguish new odor from background environmental odors and determine the concentration of that odor
What are glomeruli?
clusters in the olfactory bulb that are formed by axons from the convergence olfactory sensory neurons
Where do Mitral cells send their axons to?
Anterior olfactory nucleus, piriform cortex, medial amygdala, entorhinal cortex, olfactory tubule
Piriform cortex purpose
area most closely associated with identifying odor
Medial amygdala purpose
social functions and associating an odor w/ an emotional reaction
Entornhinal cortex purpose
associated with memory
Early signs of Anosmia, or loss of smell, is indicative of what?
serious neuropsychological problems
What does the primary audition cortex come to represent?
acoustic frequencies and intensities of large range of pitched and unpitched sounds so as to permit recognition and spatial localization
Can unilateral damage cause deafness?
NO! Each auditory cortex receives information from both ears
What is the purpose of the auditory association cortex?
memory and classification of sounds (like langauge comprehension)
A unilateral lesion in dominant left hemisphere of auditory association cortex leads to?
pure word deafness (verbal auditory agnosia). This agnosia is restricted to words – patient does NOT recognize speech sounds
if lesion in auditory association cortex is in the posterior area, you’ll get what type of aphasia?
Wernicke’s
Unilateral lesion in the right non dominant hemisphere of the auditory association cortex will lead to?
non-verbal auditory agnosia-amusia (inability to recognize non-verbal sounds)
What is the purpose of the amygdala?
Attaching emotional significance to events.
What happens when there’s damage to the amygdala?
There is a marked decrease in the ability to express emotions
What cortical and subcortical structures of the limbic system are associated with memory?
Entorhinal cortex and hippocampal formation
What happens if there is a lesion in the structures of the limbic system?
Anterograde memory impairment (cannot form new memories)
What is hyposmia?
reduced ability to detect odors
What is anosmia?
complete loss of sell
What is dysosmia?
distorted or altered sense of smell; includes parosmia and phantosmia
What is phantosmia?
Perception of a smell that isn’t actually there (olfactory hallucination)
What is parosmia?
distorted perception of a real odor
What is the uncus?
an anterior extremity of the parahippocampal gyrus (the part of th olfactory cortex that resides in the temporal lobe covers the uncus
lesions or seizures of the uncus can result in what?
olfacory hallucinations
What is retinal detachment?
separation of retinal cells from the layer of blood vessels that provide oxygen and nourishment to the eye
What are warning signs of retinal detachment?
reduced vision, sudden appearance of floaters and flashes of lights
What is trochlear nerve palsy
Diplopia– when walking downstairs, complaining of double vision
What CN does Bell’s Palsy deal with?
CN VII, or the facial nerve
Mnemonic for CNs?
Oh, Oh, Oh, to touch and feel very green veggies, AH!
Mnemonic for sensory, motor, or both?
Some say marry money, but my brother says big brains matter more
UMN of Bell’s Palsy means that?
forehead is spared
LMN of Bell’s Palsy means that?
forehead is weak
Grading muscle strength scale
0-5
0 is no movement
5 is normal strength
Issues with balance when eyes are OPEN means there are issues in what?
Cerebellum and vestibulocochlear CN
By closing patient’s eyes and having them do a Romberg test, swaying means there’s issues with?
proprioception
Cerebellum and feedback control: What do these stand for?
A
H
A
N
D
T
Ataxia
Hyptonia
Asynergia
Nystagmus
Dysmetria
Tremor
Coordination and Gait testing
finter to nose/heel to shin testing + Romberg test
If a person has NO caudate, this is a sign of what?
Huntington’s Chorea
What is the cause of Parkinson’s Disease?
Degeneration of Substantia nigra & dopamine (less than 25% = Parkinson’s). Lack of dopamine leads to inhibition of basal ganglia (putamen and globus pllidus)
What are symptoms of Parkinson’s?
Bradykenisia
Retropulsion
Masked facies
Stopped Posture
Resting tremor vs intention tremor
led pipe rigidity
What are the causes of Huntington’s disease?
Genetic: autosomal dominant (short arm fo chromosome 4). Overabundance of dopamine, and parts of basal ganglia specifically degenerating are caudate and nucleus
Symptom’s of Huntington’s disease include:
Quick jerks, rapid movements
loose muscle tone
patient will have trouble swallowing in chronic stage due to twitching
Symptoms of atrophy of the vermis of the cerebellum
Broad based gait
Can’t tandem
Speech slurring
Rapid alternating movements off
intention tremor
limb control off
What does a coma require?
Damage to reticular activating system and both hemisphere’s impaired
What manifestation of brain injury is decorticate posturing?
Rostral of midbrain
What manifestation of brain injury is decerebrate posturing?
Caudal of midbrain (pons)
Mental Status Exam includes tests of what?
Attention
Language
Memory
Visuospatial
Executive function
What are the immediate effects of a stroke?
sudden difficulty speaking, blindness in one eye, numbness and/or weakness usually on one side of the body
What are the risk factors of a stroke?
Hypertension, Cigarette smoking, Diabetes, Hypercholesterolemia, overweight/ no exercise
Atherosclerosis means?
“Hardened vessels”
What are plaques made of and what do they do?
fatty deposits of cholesterol accumulating inside arteries and blocking the lumen, reducing blood flow
What are clots and what causes them?
immune cells traffic to area to remove cholesterol deposits that lead to plaques, and release substances that inevitably aids in forming the clot
What is a thrombus?
clot attached to artery wall
What is an embolism?
clot floating in a bloodstream
How does an aneurysm occur?
when an artery wall balloons under pressure, and the weakened wall cans subsequently burst (burst aneurysms are usually fatal)
What is a stroke?
an injury to the brain caused by interruption of blood flow to a focal area of brain or bleeding into or around the brain
What is a Transient Ischemic Attack (TIA)
a temporary stroke; caused by a brief interruption of blood flow to the part of the brain “mini-stroke” or “warning-stroke”
2 main types of strokes include?
Ischemic (83%) and Hemorrhagic (17%)
What is an ischemic stroke?
obstruction of blood vessel supplying brain by a blood clot that deprives brain of essential nutrients. If blood flow is not stored, it will lead to irreversible damage. Can lead to thrombus or embolism
Hemorrhagic Stroke is?
Bleeding into the brain substance or around the brain
What are the four subtypes of ischemic strokes?
Atherothrombic (most common)
Cardioembolic (second most common)
Lacunar stroke (small vessel disease/ 15% of ischemic strokes)
and other causes
What causes an atherothrombic stroke?
Atherosclerosis of major extra cranial and intracranial vessels
extracranial – internal carodid, vertebral arteries
intracranial– basilar, carotid siphon, orgin of middle and posterior cerebral arteries
Balloon angioplasty is what?
when a balloon is inflated in the coronary artery to “squash” the plaque and widen the lumen
What is a stent?
roll of wire used to hold open the coronary artery
What is acute Ischemia?
Sudden onset and short duration (minutes to hours)
Causes of acute ischemia?
thrombis, embolism, trauma
What is chronic ischemia?
Gradual onset, long duration (months to years)
Causes of chronic ischemia?
Atherosclerosis and inflammatio of blood vessels
Causes of cardioembolic?
thrombus arising from heart
Lacunar stroke (aka small vessel disease) can lead to?
Can lead to vascular dementia
Cellular mechanisms of stroke
loss of blood supply –> leads to failure of ionic pumps and mitochondrial injury
Cellular effects lead to production of free radicals and activation of leukocytes/ influx of sodium, calcium, and chloride ions, release of excitatory neurotransmitters like glutamate
What is the main symptom of the intracerebral hemorrhage?
“worst headache of patients life” + vomiting or nausea, focal neurological deficit (can be caused by AVM)
What are microtubules?
Microtubule associated proteins (MAPs) regulate microtuble assembly and function . . . changes in MAPs are called tau
Cytosleketon gives a neuron it’s shape, and the bones are made of:
Microtubules
Tau proteins are supposed to guide ____ to where it needs to go in your brain
nutrients
What gene increases the risk of late onset AD?
ApoE4
What are mutations on Tau linked to?
Fronto-Temporal Dementia
What is the role that microglia play in alzheimer’s disease?
release inflammatory proteins and attempts to clean up damage caused by beta-amyloid plaques but actually seem to contribute to spread
What are treatment options of AD?
Cholinergic replacement and anti-amyloid agents
What are picks bodies?
abnormal clumps of tau protein inside neurons
Is Pick’s disease early or late onset?
Early (40’s-60’s)
FTD symptoms include?
changes in personality, behavior, language, motor skill. behavioral variant is most common and can cause disinhibition, apathy, loss of empathy
After AD what is the most common type of dementia?
Vascular dementia
What is vascular dementia caused by?
strokes or damage to blood vessels
What are the causes of acute dementia?
Delirium (intoxications)
Metabolitic abnormalities (renal failure, substrate deficiencies like B12, hypthyroidism)
Depression (pseudodementia)
Infection agents (fungal meningitis/ HIV/ Neurosyphilis
Difference between focal and obtuse TBI
focal is confined to one area of the brain and diffuse happens in more than one area
location of brain tumors in adults vs children
cerebral hemispheres vs brainstem and cerebellum
Amygdala is the trigger structure for emotion from ______ inducers
primary
OFC/VM prefrontal cortex is the trigger structure for emotion from _______ inducers
secondary
emotion vs feeling
emotion: what an outside observer can see or measure
feeling: what the individual senses or subjectively reports
