Brain Anatomy/Function Flashcards
Hippocampal Memory System
Semantic and autobiographical memory.
Periventricular White Matter Lesion
Leads to: magnetic gait (shuffling feet), urinary incontinence
Caused by: subcortical microvascular disease, NPH.
Cerebellum Lesion
Leads to: wide-based (ataxic) gait
Caused by: alcoholism, wenicke’s encephaloopathy
Cortical Lesion Presentation
Loss of cognitive function, 4 A’s (amnesia, aphasia, agnosia, apraxia)
Caused by: Alzheimer’s , Cerebrovascular disease
Subcortical Lesion Presentation
Leads to: losso fcoordination of cognitive function. 4 D’s (dysmnesia, delay, depletion, dysexecutive).
Caused by: Binswanger’s Parkinson’s, Huntington’s Wilson’s , NPH
Dorsal Raphe, Locus Ceruleus, Dorsal Motor Nucleus
Can lead to autonomic instability. Lewy bodies can be deposited here.
Pseudobulbar Affect
Happens when prefrontal circuits are damaged.
Etiology: stroke, multiple sclerosis, TBI, ALS
Supranuclear Palsy syndrome
Atypical parkinsonism seen in FTD. Gaze deficits, early falls, rigidity, bradykinessia, dysarthria.
Corticobasal syndrome
Atypical parkinsonism also seen in FTD. Tremor ,disturbed gait, rigidity, alien limb syndrome, limb apraxia
Key reward structure?
Nuccleus Accumbens
Where in the brain is stuff seen on autopsy of chronic alcoholics?
Mammillary bodies
Nigrostriatal pathway
involved in EPS
Mesocortical pathway
Involved in negative/cognitive symptoms of schizophrenia.
Tuberoinfundibular pathway
A dysfunction of this is involved in hyperprolactinemia
stiatopallidothalamic pathway
involved cognition and emotional processing.
Mesolimbic pathway
A dysfunction of this results in positive psychotic symptoms.
4 Pathways for dopamine
Mesolimbic nigrostiatal (substantia nigra to basal ganglia), mesocortical (VTA to prefrontal cortex), and tuberoinfundibular tracts (hypothalamus)
4 pathways for serotonin
Dorsal raphe to substantia nigra
Dorsal raphe to cerebral cortex (neg sx, cognitiion),
Regulation of the dopamine system.
PCP and Ketamine antagonize what?
glutamate antagonists
What parts of the brain are involved in anxiety?
Amygdala **, locus ceruleus , raphe nucleus, prefrontal cortex, cingulate gyrus.
What part of the brain is impacted in OCD?
Anterior cingulate gyrus ***** (also orbitofrontal cortex, caudate, and thalamus) . Cingulotomies ameliorate OCD
What does Deep Brain Stimulation target?
Anterior cingulate gyrus and ventral striatum.
What does TMS target?
Orbitofrontal cortex and pre-supplementory motor cortex
Neuroimaging findings in ADHD
Smaller total cerebral volumes , cerebellar volumes, corpus callosal volumes, frontal lobe volumes, caudate volumes, and lower levels of dopamine transporter in the nucleus accumbens.
Neuroimaging findings in Tourettes?
Larger rt dorsolateral prefrontal cortex . Multi-focal brain activation during tics.
In CD kids, what area gets activated on fMRI when they watch pain inflicted on others?
Amygdala and ventral striatum (reward area)
In IED, what area might get activated on fMRI?
Amygdala.
Paratonia is a sign of what part of the brain dysfunction?
Frontal lobe. This is gegenhalten.
Where is the olfactory cortex?
Medial temporal lobe which overlies the amygdala. When you have that seizure, discharges from there will cause rage.
EEG Finding: Triphasic Waves
Metabolic/toxic delirium
EEG Finding: Diffuse Slowing
hepatic encephalopathy
EEG Finding: Increased fast wave activity
Alcohol/sedative withdrawal
EEG Finding: Localized delta activity
focal lesions
EEG Finding: Continuous discharges
nonconvulsive status epilepticus
In what context would you use diffusion tensor MRI (“DTI”)?
When patient gets shaken or TBI . Shaken baby syndrome. DTI measures the tracts of the white matter.
In general, when is it good to use CT?
Early hemorrhagic lesions of the brain, bone and calcifications.
Subdural bleed vs Epidural bleed
Epi bleed is small and confined to a lens shape, subdural spreads out.
When do you order TI MRI?
For anatomy, white matter will be white.
When do you order T2 FLAIR MRI? Pathology
For pathology. White matter is dark. CSF is suppressed.
When do you order T1 with contrast (gd)?
For tumors
When do you order diffusion imaging?
For acute strokes.
When do you order PET (FDG or Amyloid)?
For Dementia
What is a gradient recalled echo MRI?
New technology, good for strokes. May eventually replace ct.
What is a DAT scan looking for?
Dopamine receptors , used in parinsons.
Amyloid-B or Tau protein with imaging
Functional Neuroimaging can now assess for these things. Bindint to disease related substrates.
What is a benefit of SPECT?
Good resolution for cerebral blood flow. Fast (lower resolution) and Slow (high resolution).
Can help differentiate between toxoplasmosis and lymphoma.
How do you distinguish between parkinsonism and Parkinson’s dz?
I-ioflupane SPECT = DaTscan , only FDA indicated to support diagnosis of parkinsonism. Spect that labels dopamine.
PET
Glucose gets labeled. Absolute measures of metabolism and blood flow. PET is more expensive than SPECT.
Why doesn’t alzheimer’s light up in the back of the brain?
The dz process starts at the back (visuospatial problems), then memory (parietal/middle), then executive functioning difficulties.
In Pick’s dz, the front won’t light up.
Which artery supplies the amygdala and hippocampus?
Posterior cerebral
Structure: Anterior Cingulate
Artery?
Syndrome?
1) Bilateral anterior cerebral
2) Akinetic mutism
Structure: Inferolateral frontal
Artery?
Syndrome?
1) Bilateral MCA
2) Broca’s aphasia/aprosodia (L/R)
Structure: Lateral
Artery?
Syndrome?
1) Bilateral MCA
2) Global aphasia/aprosodia (L/R)
Structure: Arcuate fasciculus
Artery?
Syndrome?
1) bilateral mca
2) conduction aphasia
Structure: L Angular Gyrus
Artery?
Syndrome?
1) bilateral mca
2) alexia with agraphia
Structure: Posterior sup. temporal
Artery?
Syndrome?
1) bilateral MCA
2) wernicke’s aphasia/receptive agraphia (L/R)
Structure: R parietal
Artery?
Syndrome?
1) Bilateral MCA
2) Unilateral neglect, anosognosia