E5 Flashcards
How does Rett differ from autism?
Rett: universal regression
What is required for autism diagnosis?
Persistent deficits in social interaction across multiple contexts
- -Social-emotional reciprocity
- -Nonverbal communication
- -Developing, maintaining, and understanding relationships
Restricted, repetitive patterns of behavior/interests/activities
What are the four core features of Rett syndrome?
Psychomotor REGRESSION --Language --Hand use Stereotypic movements (hand washing, wringing, squeezing, clapping, tapping, etc) Gait dysfunction
What is the genetic mechanism of Angelman syndrome?
Loss of UBE3A, normally maternally inherited
What is the genetic inheritance of Fragile X?
X-linked dominant
What causes exophthalmos in Graves’ disease?
Accumulation of extracellular matrix proteins, inflammation, and fibrosis
What is caused by tears in bridging veins?
Subdural hematoma
What is the most common intraocular malignancy in adults?
Metastatic carcinoma
What is the most common primary intraocular malignancy in adults?
Uveal melanoma
Where does uveal melanoma typically metastasize to?
Liver
Where does uveal melanoma typically metastasize to?
Liver
Diffuse acute focal suppurative CNS infections can lead to…
Cerebral abscess
How is viral meningo-encephalitis diagnosed?
Increased protein
Normal glucose
Lymphocytes and macrophages in perivascular Virchow-Robbins spaces
Bitemporal encephalitis is ____ until proven otherwise
Herpes simplex
PML is caused by…
JC virus
PML affects what type of patient and what type of cell?
Immunocompromised / oligodendrocytes
What is the main feature of PML?
Demyelination
Histological appearance of HIV encephalitis
Perivascular giant cells in white matter
Protein conformation change in prion diseases
PrP-C to PrP-SC
What are the four ways in which guidance cues can direct connectivity?
- Graded axon guidance cues
- Homophilic adhesion cues
- Axon-axon recognition cues
- Sub-cellular adhesion cues
How are axons guided in the eye?
- Axons are directed to the optic disc (repulsed from periphery of retina, attraction to optic disc)
- Axons are then guided to the optic chiasm, where temporal axons are sent ipsilaterally, and nasal axons are sent contralaterally
- These axons reach the tectum, where a gradient exists to send axons to the proper location
What is a critical period?
Specific time in development in which activity/physiology influences responsiveness
In what order to critical periods open during development?
Vision/sensory –> language/higher function
T/F: Critical periods for language and higher cognition diminish, but don’t ever close
True
What is amblyopia?
Reduced vision in absence of overt ocular pathology
What is the primary cause of amblyopia?
Strabismus (misaligned or crossed eyes)
What is anisometropia and how is it treated?
Unequal focus due to refractive error. Use glasses to correct.
How does anisometropia cause amblyopia?
One eye is out of focus, so other one over-compensates
What causes the most severe form of amblyopia?
Cloudiness in the normal clear eye tissue or lid droop
How do you treat amblyopia?
- Patches
- Eye drops (atropine) –> temporarily blur vision in stronger eye, so patient is forced to use weaker eye
- Glasses –> correct refractive errors
- Surgery (cataracts, extraocular muscles to realign eyes in strabismus)
Which visual functions have relatively short periods of development?
Basic spectral sensitivity functions of rods and cones
3-6 months
Which visual functions have relatively long periods of development?
More complex functions such as monocular spatial vision or resolution
25 months
How long is the period of development for binocular vision?
Long, over 25 months
How does increasing GABA function affect critical periods?
Leads to premature maturation of period (early end of plasticity)
How does decreasing GABA function affect critical periods?
Leads to delayed critical period (extends period of plasticity)
Increased/decreased GABA leads to premature development.
Increased
What is neuroplasticity?
Ability of the brain to reorganize by creating new neural pathways to adapt, as it needs
What is the difference between explicit and implicit memory?
Implicit (Nondeclarative) – nonconscious – skills/behaviors
Explicit (Declarative) – conscious – facts/events
What type of memory does Korsakoff’s syndrome affect?
Explicit memory (and in some cases implicit)
How does chronic alcohol abuse affect memory?
Causes thiamine deficiency, which leads to cell death in medial thalamus and mammillary bodies
Damage to what structures causes complete loss of ability to form new memories?
Mesial Temporal System –> entorhinal and perirhinal cortices, hippo, parahippo, amygdala
What are two types of plasticity?
Functional: brain can move a function from a damaged area to an undamaged one
Structural: brain can change structure as a result of experience or learning
What structures of the brain are associated with implicit memory?
Cerebellum, basal ganglia
What structures of the brain are associated with Sensory memory?
Where (spatial) - dorsolateral prefrontal cortex
What - orbito-prefrontal cortex
When does consolidation of long term memory occur?
During sleep when serotinergic raphe nucleus neurons are active in their projection to the hippocampus
Where is much of the work associated with memory done in the hippocampus?
CA1/CA3 regions
Which drug blocks NMDA receptors, thereby preventing new LTP and blocking entry of Ca2+?
AP5
What are three mechanisms of synaptic plasticity?
- LTP results in insertion of new AMPA receptors into dendrites
- Increase in GLUT receptors = stronger potentials in active synapse
- Synaptic growth: dendritic spines split after LTP –> new synapses
Stimulation of the Schaffer collaterals generates EPSP in postsynaptic CA1 cells. What is this ideal for?
Facilitating memory formation
Which enzyme in dendrites is activated by Ca2+?
CaM-KII
Ca2+ binds with CaM-KII, linking proteins attached to NMDA receptor
AMPA receptors are linked to NMDA receptor by protein
LTP results in the insertion of new AMPA/NMDA receptors into the dendrite.
AMPA
Which receptors are ionotropic glutamate receptors, thereby creating stronger potentials in an active synapse?
AMPA
AMPA receptors are located inside the _____, but move to _______ after LTP.
dendrite / tips of spines
Additional synthesis of what molecules is required for long term memory?
Proteins
Protein synthesis inhibitors lead to deficits in ____ and _____.
learning / memory
What is GAP43? What is it involved in?
Protein involved in synaptic maintenance and neuritic regeneration.
Which protein is significantly reduced in the frontal cortex and hippocampus of Alzheimer’s patients?
GAP-43
There is a significant positive correlation between GAP-43 and the number of senile plaques in which structure?
Hippocampus (but not frontal cortex)
What is LTP?
Stimulation of excitatory fibers that make connections with hippocampal pyramidal cells?
What causes increased efficiency of CA1 pyramidal cell response?
Short, high-frequency stimulation of entorhinal afferents or Schaffer collaterals to hippocampal pyramidal cells over time
Where is alpha-synuclein predominantly expressed?
Hippocampus, neocortex, thalamus, substantia nigra
Epidermal growth factor favors differentiation into ____, whereas fibroblast growth factors promote _____.
glial cells / neuronal production
What type of gene therapy can induce neurite outgrowth from mammalian auditory neurons?
BDNF
What type of gene therapy can increase sprouting of dopaminergic axons in the striatum?
Glial cell line-derived neurotrophic factor (GDNF)
List the return to play parameters
In order:
- -No activity
- -Light aerobic exercise
- -Sport specific exercise
- -Non contact training drills
- -Full contact practice
- -Return to play
- -Symptomatic for more than 10 days, see doctor
What anti-inflammatory drugs can be used after a concussion?
Cox inhibitors: aspirin, ibuprofen, naproxen
Cytokine blockers/microglia suppressors: minocycline, progesterone
Which neurotrophic drugs are used after concussion?
BDNF agonists: SSRI, TCA, progesterone
Which immune-boosting drugs are used after concussion?
Probiotics, vitamin D, B-glucan
What are the components of the SCAT3?
- GCS
- Maddocks score
- Symptoms
- Cognitive assessment
- Neck examination
- Balance examination
- Coordination examination
- SAC delayed examination
When is tau protein found in athletes?
In chronic traumatic encephalopathy
When do simple concussions resolve?
7-10 days
After concussions, children should return to ____ before return to _____.
learn / sport
When can SCAT3 be used?
When the patient is 13 years or older
Symptoms immediately following concussion
Blurred/double vision Sensitivity to light or noise Headache Dizziness/balance problems N/V Fatigue Confusion Trouble sleeping
What are post-concussion syndrome symptoms?
Chronic headaches Fatigue Sleep problems Personality changes Dizziness Short-term memory loss Nausea
In most people, when do post-concussion syndrome symptoms begin?
Symptoms occur within first 7-10 days and go away within 3 months, though they an persist for a year or more.
What is the most long-term sequella of a concussion?
Depression
What is CTE?
Accumulation of tau protein in neurons
What does CTE cause?
Dementia pugilistica
Brain atrophy
Most common symptoms of CTE
Aggression Depression Loss of memory Loss of impulse control Impaired judgement Balance difficulties
What are the three components of concussion pathogenesis?
Metabolic, excitotoxic, immunologic
What is resveritrol?
Reduces brain inflammation by calming microglia and macrophages