Neuroanatomy
Name 3 regions of the PFC, and their functions.
dl_PFC: goal directed behavior (r-behavior plan, l-motor plan)
OFC: adaptive learning, site for identity, fear extinction
vlPFC: social/contextual behavior
mPFC: reasoning and working memory
What is a transience?
The progressive and natural deterioration of episodic, semantic, and spatial memory over time
Which NT acts as a precursor of MEL? When is MEL released?
SE; MEL is released upon activation of the pineal portion of the EPI, by the HPT, responding to the exposure of the SCN to wavelengths of light of about 700nm.
Which symptoms can be expected from an MCA stroke (LBD), that happened 8 weeks ago?
- UMNS, hypoesthesia, paresthesia, and/or anesthesia of the contralateral side, mostly affecting the UL and face.
- Abstraction and spatial orientation deficits.
- Aphasia (understanding and/or production).
- Difficulties consolidating procedural memory.
Compare PD and PSP in a differential diagnostic context.
- Tremor: rare in PSP, cardinal symptom in PD
- Development: symmetry in PSP, asymmetry in PD
- Falls: early in PSP, late (HY3) in PD
- Dysarthrophonia: linked to spasticity in PSP, bradykinesia in PD.
- DAergic medication: no effect in PSP, effective in PD
Name 5 regions that supply the pINS with information.
piPC, psPC
PRECUN, CUN
S1, A1, EC/AM/HPC
TP
What is a memory sin of commission?
A memory flaw where the construction of memory is influenced by facts that are unrelated to the event, but influenced by other sources (internal or external)
What is the role of NE during wakefulness and sleep?
During wakefulness: triggers the AM, activating the HPT axis in response to perceived threats, maintaining stability of the system through a positive feedback loop between the AM and LC.
During sleep: acts on the consolidation of memories, mostly during REM, but also in SWS, and to a minor extent in N2. It can also interrupt glymphatic activity in excess, and lead to wakefulness.
What are the differences between a post-contusion depressive and non-depressive fracture, in terms of prognostic?
A non-depressive fracture would contribute to a higher ICP at the moment of the accident, decreasing the time for rescue, while a depressive fracture would increase the risk of encephalopathies, delaying recovery.
Which structures experience degeneration in PD, PSP, HD, and ALS, that would be used for diagnostic purposes?
PD: SN
PSP: STN
HD: CAU
ALS: aTHA
What is the role of the aCC in an AM-centric system?
1) maintain the focus of attention on perceived threat
2) modulate mPFC activity and regulate AM activity
What is the role of MAO and COMT in the reuptake process of NE, SE and DA?
They destroy the reabsorbed molecule that was reuptaken by the presynaptic neuron
What is the difference between vicariation and equipotentiality?
Vicariation will occur in an area deprived of its primary inputs, making use of these clusters for other forms of processing, while in equipotenciality, cluster with a similar neuroarchitecture will be recruited on the contralateral hemisphere to assist or substitute the overloaded or damaged ipsilateral region.
How do the symptoms of an UMNS evolve from an acute to a subacute phase in ABI?
- Hypotonia to pyramidal hypertonia
- Hyporreflexia to hyperreflexia
- Plegia to paresis
- Increased to decreased occurrence of pathological "reflexes".
- Progressive increase in the occurrence and intensity of myoclonia
What are the characteristics of a patient experiencing dementia at level 7 in the GDS?
- Loss of linguistic abilities
- Apathy
- Depression
- Presence of repetitive movement
- Loss of facial expression
What kind of information is mostly transmitted by the posterior nuclei of the THA?
visual information to V1
Which presynaptic receptors are involved in the reuptake of DA, SE, NE?
DA: DRD2 and NET
SE: SERT
NE: NET
What kind of projections does GPe receive from the other basal nuclei?
SN - DAergic
CAU/PUT/Acc - GABAergic
Which gait characteristics can be expected after an ACA stroke, during the chronic phase? Justify by linking each to its origins.
- Circumduction and pelvic elevation on the affected side, and trunk oscillation to the contralateral side, due to spasticity/lack of motor control in knee and hip flexion, and plantarflexion.
- decreased spatial navigation, due to damage to SMA, decreased somatosensation leading to issues with spatial orientation and attention/WM deficit leading to decreased spatial reasoning and planning.
- balance deficit, due to attention, planning and navigation deficits, and issues with fear extinction that can lead to fear of falling.
Which signs are used to recognize the occurrence of a traumatic brain injury? Identify the ones that indicate a severe injury.
Common: nausea, dizziness, irritability, fatigue, amnesia.
Severe indicators: worsening headache, photo- and sound hypersensitivity, diplopia, LOC, poor cognitive performance, convulsion, altered pupil reflex
What is the function of the PRECUN in planning a voluntary motor action?
Creating a mental picture of the action itself, in the intended environment contributing to orientation, facilitating spatial reasoning and navigation.
Which functions are attributed to BDNF and GDNF respectively?
BDNF: development and maintenance of neuronal structures and cytoarchitectonic adaptations to learning.
GDNF: migration of neurons and maintenance, preventing apoptosis.
Which behaviors are to be expected of an unbalanced state of NE and DA?
Impulsivity, risk-taking behavior, reward/satisfaction deficiency
Which gait characteristics can be expected from a patient experiencing primary PD at H&Y 3?
- decreased trunk and pelvic mobility
- decreased reciprocation
- increased risk of falling and avoidance behavior
- reduced step length
- increased trunk flexion
- decreased speed
What are the symptoms of parkinsonism linked to each DA pathway/circuit?
Nigrostriatal: motor symptoms: resting tremor, rigidity, and bradykinesia.
Mesolimbic: cognitive and behavioral symptoms: attention deficit, reasoning and working memory deficit, planning deficit.
Mesolimbic: behavioral and emotional symptoms: memory deficit, anxiety, depression, attention deficit, social and contextual behavior planning deficit, decreased fear extinction.