Neuro week 8 info
encephalitis lethargica
-Inflammation and damage to midbrain, basal ganglia and substantia nigra. -Display parkinsonian features. -Difficulty initiating/controlling volitional movement, inhibiting nonvolitional movement. statue like appearance no 24 hour rhythms
if you have 2 copies of e4 gene, how at risk are you for alz
16x
what caused encephalitis lethargica
1918 spanish flu (virus) Got in through olfactory nerve, made connections to substantia nigra and migrated to other brain areas
if you have 1 copy of e4 gene, how at risk are you for alz
2.5x
how long do you have to have sleep difficulties to be diagnosed with insomnia
3 times a week for at least 3 months
what was the back to sleep campaign
A campaign in 1994 to make sure parents made their infants sleep on their backs. It substantially reduced but did not eliminate crib death.
wisconsin card sorting test
A neuropsychological test that evaluates a patient's ability to remember that previously learned rules of behavior are no longer effective and to learn to respond to new rules. measures executive function (attention, learning, memory, problem solving, set shifting)
narcolepsy
A sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times. happens at least 3 times a week
iowa gambling task
A task in which participants must learn to avoid risky choices (generating a net loss) in favor of less risky (and more rewarding) choices tests the executive function by risk testing Task involves getting play money ($2000). After selecting a deck, participant may win or lose $. They must figure out the most optimal strategy of selecting decks with moderate payoff (advantageous decks). Disadvantageous decks have big payoffs but also big loss. Big gamblers do worse on this than others that are good with long term gratification (like med students)
Mini-Mental State Examination (MMSE)
A test that is used to measure cognitive ability, especially in late adulthood. where are we? count backwards by 7 from 100 copy a drawing remember 3 words
what is the leading cause of dementia
Alzheimer's disease
amyloid beta peptide
Breakdown product of beta amyloid precursor protein that builds up in the brain
As a function of age, the total number of hours spent sleeping decreases. why?
Could be from physiological functions or comorbidible reasons that interfere with sleep
in a healthy brain, what happens to beta amyloid? what happens during alz?
In a healthy brain, these protein fragments are broken down and eliminated. In Alzheimer's disease, the fragments accumulate to form hard, insoluble plaques.
inion
Most prominent point of external occipital protuberance
If our sleep is disturbed, would it be worse to have it happen at the beginning of the night or the last 3rd of the night?
Waking up during rem or at the latter end of the night is much more disruptive to our functioning of the next day relative to a same disruption to the earlier part of the night due to rem being responsible for restorative functions
Kluver-Bucy syndrome
a condition, brought about by bilateral amygdala damage, that is characterized by dramatic emotional changes including reduction in fear and anxiety
fatal familial insomnia
a fatal inherited disorder characterized by progressive insomnia Person will have difficulty sleeping, then hallucinations, then cognitive decline (like alz disease), and then a quick death after liek a year a half of symptoms insomnia --> hallucination --> dementia --> death
beta amyloid
a protein fragment snipped from an amyloid precursor protein (APP)
wada test
a test in which a short-lasting anesthetic is delivered into one carotid artery to determine which cerebral hemisphere principally mediates language
what nt is important for sleep
adenosine
advantage and disadvantge of eegs
adv: high temporal resolution (ms) dis: poor spatial resolution (Cm) as its limited to the number of electrodes on head
when fearful eyes are subliminally presented to subjects, mri scans revealed higher levels of activity in what region
amygdala
what area is important for anxiety and also aggression?
amygdala hippocampus is also involved (and for motivated behavior)
the connection between pathophysiology and behavioral levels in still being studied for alz, but what do we think is NOT involved?
amyloid beta
One of the hallmarks of Alzheimer's disease is the accumulation of
amyloid plaques between nerve cells (neurons) in the brain.
causes of early alz
amyloid precursor protein (APP) presenilin 1 and 2
how much time do we spend in rem sleep throughout our lives?
babies spent alot of time and premature babies spend even more of time askeep in rem adults do 20% each night in rem
do the brain changes from alz happen before or after functional impairments?
before
what does benadryl and antihistamines do to tuberomammillary nucleus
blocks the histaminergic receptors and increases sleep if used for short times spans but decreases sleep if used long term
nasion
bridge of nose
what area is affected when you can understand but not produce language (expressive aphasia)
brocas
Most common psychoactive drug in the world is
caffeine
main structures of sleep
cerebral cortex thalamus brainstem
when are we the coldest? the warmest?
coldest at 3-4 am warmer later in the evening
suprachiasmiatic nucleus controls what
controls sleep and wake rhythms
damage to the wernickes area causes what deficits
deficits in language comprehension and production
EEGs (electroencephalograms)
depict via freauency and ampltidues cortical electrical activity as non-invasively recorded from electrodes on the scalp expresses alpha and beta rhythms
septum
divides a cavity or structure into smaller one
what area of the brain can be injured and cause perseveration errors
dorsolateral prefrontal cortex
highest risk genes of alz in order
e3,e2,e4
narcolepsy occurs from the presence of at least one of three things
episodes of cataplexy (loss of muscle tone) hypocretin deficiency a polysomnography showing REM in people that fall asleep in 15 minutes or less
the hippocampus is important for what type of memory? what is it NOT important for?
explicit memory (events) and spatial memory NOT procedural (motor)
what aphasia does brocas cause
expressive aphasia
what is tau a component of
forms part of microtubules
beta activity
frontal 14-69 hz (low low amplitude) person is awake and attentive
amyloid
general term for protein fragments that the body produces normally.
what chemical is responsible for the eeg signal
glutamate
prevalence of alz
higher chance as you age global prevalance is 24 million predicted to double every 20 years until 2040
10/20 system of electrode placement
i. An objective system for placing electrodes on the human scalp ii. Think of the 10-20 system as an operational definition of electrode placement
where is the tuberomammillary nucleus
in hypothalamus
Neurofibrillary tangles
insoluble twisted fibers found inside the brain's cells.
what did dr saxx give to patients with encephalitis lethargica
l dopa to increase dopamine and patients responded well but only for a short period of time
There can be pronounced tissue loss in alz. As a result, the sulci and ventricles get larger/smaller
larger
lefties usually have the language area of the brain in which hemisphere?
left hemisphere
Where is Wernicke's area located?
left temporal lobe
lefties/righties are more prone to atypical language organization
lefties
diagnostic of insomnia
less quality and quantity of sleep trouble falling and staying asleep early morning awakening sleep disturbance causes significant distress
serotonin levels in sudden infant death syndrome cases
levels are diminished in raphe nucleus in sids kids 1a receptors diminished reducting in the RL enzyme for synthesis of 5ht
Hippocampus is believed to be a key are in the transfer of information from working memory to _________ memory.
long-term
an increase in serotonin in rostral medulla neurons points to what physiology in sids
may be due to crosstalk between ach and 5ht system since ach plays a big role in kid development
SCN controls 24 hour rhythms in what 3 things
melatonin other hormones (testosterone) temperature
possible cause of insomnia
melatonin rhythm amplitude and duration of signal is decreased
usual timeline of alz symptoms
memory impairment progressing to language and visuospatial deficits followed by executive dysfunction
what is the only known dsm disorder discussed with a known biochemical abnormality
naroclepsy one of only 2 in the dsm
symptoms and pathology of dementia
neuronal loss plaques (beta amyloid) tangles (tau)
did the alzheimer's vaccine work well?
no
do sleep stages get affected if you transect at the lower medulla
no only affects when you transect at upper brain stem and thalamus (between pons and midbrain) - makes us believe the upper medulla is an important component of sleep stages and consciousness
alpha rhythm
occipital 8-13 hz / low amplitude awake but eyes closed and relaxed
how common is early onset of alz
only 5% of cases (seen in 50s)
iowa gambling task tests what cortex
orbital frontal cortex
hypocretin is aka
orexin
orexin binds to
ox 1 and ox 2
oxB binds most
ox2 receptors
when can you actually diagnosis true alz?
post mortem, cant do it while alive and its just considered presumptive alz
early onset of alz is considered to be what age
pre age 60
anatomical changes precede/proceed functional changes in alz
precede
schizophrenics have underactivity in which cortex
prefrontal cortex
predation aggression
quiet attack
what aphasia does wernickes cause
receptive aphasia
perservation
state of repeatedly performing the same segment of a task or repeatedly saying the same word/phrase without purpose
anatomical changes during alz
sulci and ventricles get bigger as tissue is lost csf areas get larger ventricles get bigger loss of tissue (Atropy) in hippocampus and temporal cortex
what do neurofibrillary tangles consist of
tau
stroop test of attention
tests neurocognitive functions say the color of the font, not the text use MRI to see ACC light up
what causes fatal familial insomnia
thalamic underactivity
amyloid plaque
the clusters of beta amyoid
The microtubule helps transport nutrients and other important substances from one part of the nerve cell to another. In Alzheimer's disease, however, the tau protein is abnormal and what happens to the microtubule structure.
the microtubule structures collapse
what is a brain region affected early in alz? why is this problematic
the nucleas basilis involves somas for the ach system which projects to important areas of coognitiion like hpp, prefrontal cortex, and frontal cortex
sudden infant death syndrome
the unexplained death of a seemingly healthy baby #1 cause of death during 1 month-1 year of life
defensive aggression
threatening hissing
what nucleus is the sole source of histamine pathways in the brain and promotes wakefulness
tuberomammillary nucleus
causes of late alz
unknown
cause of sudden infant death syndrome
unknown but seems to be a trifecta of age and vulnurabilty to neurochemical abnormalities, genetic risks, and environmental factors (sleeping on belly)
where is the brocas area
usually inferior frontal cortex (left)
nucleus accumbens recieves dopaminergic axons from what area
ventral tegmental area (Tva)
orexin promotes wakefulness/sleepiness
wakefulness