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
Structure: hippocampus
Artery?
Syndrome?
1) Bilateral PCA
2) Global amnesia
Structure: Occipital cortex
Artery?
Syndrome?
1) Bilateral PCA
2) Cortical blindness, Anton’s Syndrome (claim they can see)
Structure: Cerebral Peduncle
Artery?
Syndrome?
1) PCA
2) Peduncular hallucinations (often described as vivid, colorful visions of people and animals)
Structure: Midbrain
Artery?
Syndrome?
1) Basilar artery
2) Top of basilar syndrome (can only move eyes), visual hallucinations
Structure: Base of the pons
Artery?
Syndrome?
1) Basilar artery penetrating branches
2) Locked in syndrome
Structure: Anterior thalamic
Artery?
Syndrome?
1) Basilar artery penetrating branches
2) Memory , perseveration, executive dysfunction , disinhibition
This one is tricky bc the anterior thalamus can mimic a frontal lobe lesion.
On neuroimaging, where is the lesion in Huntington’s?
Caudate Atrophy
On neuroimaging, where is the lesion in Wilson’s?
T2 signal diffuse basal ganglia and brain stem
On neuroimaging, where is the lesion in limbic enceophalitis?
Increased T2 signal mesial temproal regions , mostly bilateral.
On neuroimaging, where is the lesion in Wernicke-Korsakoff?
Decreased size in increased T2 signal of mamillary bodies
On neuroimaging, where is the lesion in Creutzfeldt-Jacob?
T2 or DWI signal bilatearl putamen and head of caudate and deep cortical structures.
Schizophrenia neurology correlations
1) enlarged ventricles on MRI
2) reduced gray matter in prefrontal, cingulate, temporal cortices.
3) increased subcortical dopamine synthesis capacity
Autism neuro correlation
Larger brain volume at birth or abnormal increase in size in first year of life (found with MRI and by head circumference)
ADHD neuro correlation
1) Hypoactivity in premotor and prefrontal areas
2) smaller brain volume (3-5%)
Reading disorder neuro correlation
Normal size asymmetry in the planum temporale (it’s part of wernicke’s language area ) is LESS in reading disorder.
Depression neuro correlate
Smaller hippocampus (10% shrinkage)
PTSD neuro correlate
Reduced hippocampus (5-25%)
Exaggerated amygdalar response
Decreased hippocampal activation
OCD neuro correlate
Overactivity in orbitofrontal cortex
Tourettes neuro correlate
Overactivity in prefrontal cortex and ventral striatum (nucleus accumbens, olfactory tubercle = part of reward system)
Tics: additional overactivity in motor and premotor cortex nd anterior cingulate gyrus
coprolalia: additional overactivity in broca’s and wernicke’s language areas.
What gets targeted in DBS for parkinsons?
Subthalamic nucleus
MRI findings in carbon monoxide or manganese
Bilateral hyperintensities of globus pallidus and nonspecific white matter changes.
Locked In syndrome, where is the lesion?
Basis Pontis cuased y basilar artery occlusion or central pontine myelinolysis.
People with TBI and PTSD have what on diffusion tensor imaging?
White matter changes
Symptom of apathy, where is the lesion?
frontal lobe
Deficit in cingulate gyrus
akinetic mutism and control of motivation
Deficit in amygdala
anxiety
Deficit in hippocampus . Left hippocamus? Right?
declarative memory (recollect facts and events) or long term explicit memory .
Left: verbal memories
Right: nonverbal memories
Deficit in hypothalamus
Autonomic and endocrine system instability
Deficit in basal ganglia
Control of voluntary motor movements, procedural learning memory, eye movements, cognition, and emotions.
Deficit in planum temporale?
Dyslexia
Role of the thalamus
All sensory except olfactory goes through the thalamus.
- Pain, crude touch.
- Relays info from basal ganglia and cerebellum, RAS, and limbic relay.
What parts make up the basal ganglia?
Caudate nucleus, putamen (together form straitum), globus pallidus (+ putamen make lenticular nuclei), subthalamic nucleus, and substantia nigra.
Role of the insula?
Emotional connection to pain. Basic connections. Helps person have a concept of the self.
Role of anterior limb of internal capsule
Separates the thalamus from the putamen/globus pallidus.
Associated with the processing of emotion, cognition, decision making, and motivation. Abnormalities in the white matter of the anterior limb are seen to be abnormal in psychiatric illnesses such as schizophrenia, bipolar disorder, and obsessive-compulsive disorder.
Role of hypothalamus
Homeostsis and controls basic drives such as thirst, hunger, sex, temperature, circadian rhythm (SCN). Controls homestasis via neuroendocrine or neurologic (connected to the limbic system).
Unilateral reduced smell could be defect of what?
Cranial Nerve I which could be damaged by trauma, tumor of frontal lobe, or trauma.
What field of vision will be lost with a pituitary tumor?
Bitemporal hemianopsia (Left side of left and right side of right)
What field of vision will be lost with a pituitary tumor?
Bitemporal hemianopsia (Left side of left and right side of right) due to compression of the optic nerve.
“Third nerve palsy leaves you “
“big, down and out” (big pupil, droopy eyelid, lateral gaze)
“My neck is sore from”
“cranial nerve 4” (pt will intentionally rotate neck to not have diplopia. )
“Pons Zimmer wanted to have 6 batman movies”
Pons stroke may disrupt cranial nerve 6 , leading to medial gaze in the bad eye.
Orbitofrontal Syndrome
Looks like a manic episode in an elderly man with no other findings. Could have a palmar grasp reflex present. Happens from stroke, neoplasm.
Bilaterla lesions to the amygdala cause what?
Kluver Bucy syndrome
Where in the brain is the deficit for OCD?
Hyperactivity in the CAUDATE
What brain changes are seen in those with anorexia nervosa?
Ventricular enlargement
Primary source of histamine?
Tuberomamillary nucleus
What finding on imaging for bipolar patients?
Increased volume of the ventral striatum
What is the caudate AKA?
Corpus Striatum is comprised of the caudate and lentiform nucleus.
Which neurotransmitter is made in the Ventral Tegmental Area?
Dopamine (mesocorticolimbic)
What is seen on imaging of PTSD patients?
Hypoactivity in the hippocampus
Imaging of schizophrenia
Enlargement of third and lateral ventricles. Also atrophy of the thalamus.
Which brain structure is believed to be responsible for EEG rhythms?
thalamus
What area of the brain is involved in depression?
Right prefrontal cortex
What part of the brain for ADHD?
Prefrontal cortex because the pathophysiology of (ADHD) is based on the dysfunction of prefrontal cortex mediated by catecholaminergic neurotransmission abnormalities. Fronto-striatal-cerebellar networks are rich in catecholamine neurotransmitter which is important for inhibition and attention control.
Bulimia on imaging
Increased ventricle to brain ratio is observed in various neuroimaging studies in patients with bulimia nervosa
What part of the brain is involved in auditory hallucinations in schizophrenics?
Arcuate fasciculus is the correct answer as it forms part of an association tract that connects Broca’s area located in the frontal region of left cerebral hemisphere and Wernicke’s areas located in the temporal region of the left cerebral hemisphere. It is associated with producing and understanding language and is associated with auditory hallucinations in patients with schizophrenia.
In what part of the brain do panic attacks come from?
Locus Ceruleus
What part of the brain is associated with kluver bucy?
Amygdala
What part of the brain is targeted for DBS in OCD?
Ventral anterior limb of the internal capsule
What would you see messed up in Wernicke Korsikoff on brain MRI?
lesions of the medial thalamic and periaqueductal areas
Where does the norepineprhine come from in panic attacks?
Locus Ceruleus
Dopamine pathways:
- Nigro-neostriatal
- Mesolimbic
- Mesocortical
- Tuberoinfundibular
The nigro-neostriatal pathway helps control movements. The mesolimbic pathway likely associates with the improvement of positive symptoms, the mesocortical likely explains the cognitive blunting, and the tuberoinfundibular explains hyperprolactinemia. The hypothalamic-pituitary pathway is not associated with dopamine.
What lobe of the brain involved in panic disorder?
Temporal lobes
In what part of the brain does akathisia happen?
Basal ganglia
HIV associated dementia impacts what parts of the brain?
Basal ganglia and hippocampus
Which part of the brain is involved in the regulation of both emotional and behavioral response to fear-inducing stimuli.
Frontal cortex
Where do absence seizures happen in the brain?
Thalamocortical system
What brain changes are happening in conduct disorder?
Reduction of grey matter in the amygdala has been seen in conduct disorder, which might indicate a reduction in fear conditioning. A decreased level of 5-HIAA in CSF, along with a low activity of monoamine oxidase A, has been shown to be present in conduct disorder.
DBS target for parkinsons
Deep-brain stimulation targets for Parkinson’s disease include the subthalamic nucleus and the globus pallidum.
What gets messed up in the brain from MDD?
Atrophy of the caudate nuclei
What part of the brain for hoarding disorder?
Anterior cingulate gyrus.
Right and left orbitofrontal gyrus are both incorrect because patients with the obsessive-compulsive disorder (OCD) which is distinct from hoarding disorder show greater activity in these regions as compared to patients with hoarding disorder.
What part of the brain is responsible for tardive dyskenesia?
Basal ganglia
Nucleus Basalis of Meynert is associated with which neurotransmitter?
Nucleus basalis of Meynert is incorrect as it the principal source of acetylcholine that projects to areas of cortex and amygdala and is implicated in cognitive impairment when there is degeneration
Variable quadreparesis
Central cord syndrome
what brain structure gives rise to the 4th ventricle?
Metencephalon
Why do schizotypal people have trouble with memory?
The understimulation of dopamine 1 (D1) receptors in the dorsolateral prefrontal cortex (DLPFC) leads to working memory impairment. D1 receptor is an important modulator for working memory function in the DLPFC.
Patient unable to recognize faces. What part of the brain is impaired?
Fusiform Gyrus (‘fusiform face’)
What part of the brain is involved in gambling disorder?
Ventral striatum
Paraventricular nuclei make what?
oxytocine
Supraoptic nuclei release what?
vasopressin
What part of the brain do auditory hallucinations come from?
Arcuate Fasciculus
Changes seen in schizophrenia brain
- Decreased whole brain volume
- Increased size of ventricles
- Small frontal lobes
- Small sized thalamus
- Small sized hypothalamus
What is seen on imaging in Huntingtons?
On structural imaging, the basal ganglia are often reduced in size, especially the caudate nuclei
What is going on in the brain of Tourettes?
Children with Tourettes often have significantly larger amygdala volumes There is a decrease in the volume of caudate in individuals with Tourettes and is found to be inversely related to the severity of tics
Metencephalon Diencephalon Mesencephalon Myelencephalon Telencephalon (Give rise to what)
Metencephalon gives rise to the pons and cerebellum. Diencephalon gives rise to the thalamus, hypothalamus, and epithalamus. Mesencephalon gives rise to the midbrain. Myelencephalon gives rise to the medulla oblongata. Telencephalon gives rise to the cerebral hemispheres.
Kluver bucy happens as a result to destruction of what?
amygdala bilaterally
