Neuroscience Flashcards
what are the different type of apraxia
limbic kientic
ideomotor
Oculomotor apraxia
Constructional apraxia
ideation apraxia
what is Ideomotor apraxia
ideomotor apraxia: This condition is characterised by a patient’s inability to perform a task on command but may be able to do so automatically. In the scenario described, the patient’s attempt to brush their teeth with a pencil, despite understanding the task, suggests a disconnect between the concept and the performance of the motor action. This is indicative of ideomotor apraxia, where the patient cannot use an object correctly on command due to a disruption in the ability to plan or execute motor functions, despite understanding the use of the object and having the physical ability to perform the action.
define limbic kinetic apraxia
Limb kinetic apraxia: This type of apraxia affects fine motor movements and is not typically related to the use of objects inappropriately. It is characterised by clumsiness or loss of dexterity in the limbs, which is not what is described in the scenario.
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define oculomotor apraxia
Oculomotor apraxia: This affects the control of eye movements and would not explain the misuse of an object in a task. It is not relevant to the action described in the scenario
define constructional apraxia
Constructional apraxia: This involves difficulty in constructing or drawing objects and is not related to the misuse of objects for a task, as seen in the patient’s behaviour.
define ideational apraxial
Ideational apraxia: This form of apraxia involves a breakdown in the knowledge of what is to be done or how to perform a sequence of actions, which is not the case here, as the patient appears to understand the concept of brushing teeth but uses the wrong object.
what is the fissure of rolando
the fissure of Rolando, also known as the central sulcus, divides the frontal and parietal lobes
what is the metabolite of serotonin
5 hydroxyindolacetic acid
5-HIAA
what IS 5HIAA associated with
1/3 of depressed patients had low
also low levels are associated with
poor response to antidepressants aggression and more likely to commit suicide
where do the majority of acoustic neuromas take place
90% at the cerebellarpontine angle
5% intracranial tumour
also known as vestibular schwanomma
what is bilateral acoustic neuroma associated with
neurofibromatosis 2
what is the investigation choice for acoustic neuroma
MRI of cerebellar pontine angle
what is seen with each nerve affected
V (5)
VII (7)
vIII (8)
v - Absent corneal reflex
VII facial palsy
VIII– vertigo, hearing difficulities
how does alpha secretase work?
it cleaves APP to break it down into non toxic fragnments
beta and gamma secretase break APP into fragments which clump into amyloid plaques which accumulate
new drugs to increase alpha secretase and decrease the beta/gamma are being developeed
what is prosopagnosia
inability to recognise faces
which part of brain does propsoagnosia affect
fusiform gyri
what is anosognosia
inability to recognise own condition
which area does anosognosia affect
R hemisphere of brain
what is autopagnosia
what does it affect
inability to recognise ones own parts of the body
it affects L parietal region
what is phonagnosia
inability to recognise familiar voices
affects R temporal lobe
what is simulatenognosia
the inability to recognise two objects in the same visual field
affects bilateral damage to occipital pareital lobe
what is asterognosia
aster- touch
affecting somatosensory cortex in Parietal lobe
what is the resting potential
-70mV
-55mV influx of Na
+40mV at which depolarisation takes place
what are macroscopic changes seen in alzehimers
cerebral atrophy especially of hippocampus
amyloid plaque with tangles
formation
enlarged ventricles
what is a core and corona in dementia plaques
Senile (or neuritic) plaques consist of a core and a corona (see below). The core is an extracellular deposit of Aβ, while the corona is made of degenerating neurites, mainly axons.
what are neurofibrillary tangles made of
hyperphosphorylated tau
what are the tauopthies
Frontotemporal dementia
Progressive supranuclear palsy
Corticobasal syndrome
Chronic traumatic encephalopathy (e.g. dementia pugilistica)
alzehimers
what is glossis
is marked by increased activated microglia and reactive astrocytes at the site of amyloid plaques
what is the nucleus basalts of meynert
he nucleus basalis, also known as the nucleus basalis of Meynert
in substantia innominata in basal forebrain
somewhat diffuse collection of large cholinergic (produce acetylcholine) neurons
what happens to basalis of meynert in Alzheimer’s
degenerates in Alzheimer’s resulting decrease in acetylcholine in the brain. For this reason, most currently available pharmacological treatments for Alzheimer’s focus on compensating for faltering function of the nucleus basalis through artificially increasing acetylcholine levels.
what are hirano bodies
hirano bodies are actin-rich, eosinophilic (they stain with the bright pink dye eosin) intracytoplasmic inclusions which have a highly characteristic crystalloid fine structure.
what is the difference between hirano bodies and lewy bodies
Lewy bodies are made of ubiqiuin
where are hirano bodies predominantly found
in the hippocampi of the elderly
are especially numerous in patients with various dementias or degenerative diseases (amyotrophic lateral sclerosis, Alzheimer’s disease, Pick’s disease, and some forms of Creutzfeldt-Jacob disease) and alcoholism
what is found on neuroimaging in azlehimers
hypoperfusion of pastoral and temporal lobes
especially on SPECT imaging
how do u differentiate between LB dementia and Alzheimers on SPECT
DLB shows lower perfusion in occipital cortex (long arrows). In contrast, AD showed lower perfusion in medial temporal areas (short arrowheads).
where is the amygdala
in the anterior temporal lobe of the limbic system
how many nuclei are there
6
name the six nuclei
lateral
basolateral
central
media
corticomedial
basomedial
what does the lateral nuclei of amygdala
receive sensory information
involved in learning /fear conditioning
basolateral nuclei of amygdala does
role in the processing and interpretation of emotional valence from the sensory input.
cognition and attention, particularly regarding the emotional significance of events.
what does the central nuclei or amygdala do?
main output
fight or flight
expression of emotional responses and initiation of the fight-or-flight response via connections with various brainstem areas.
what about the
medial, corticomedial and basomedial nuclei of amygdala
coritcomedial -> olfactory system,
corticomedial - projects into ventromedial nucleus to hypothalamus re: - hunger and eating
basomedial autonomic -response and memory
where are Broca and wernike situated
by the sylvian fissure in the perisylvian language area’.
which is non fluent and fluent language
broca
non fluent
comprehension not impaired
wernike
fluent
but comphrension impaired
two main aphasia classifications
are the Boston Group classification
and Luria’s aphasia interpretation
which is the most severe form of aphasia
global is most severe
non fluent and no comprehension
MCA, ICA and SCA affected usually
what is agraphia
what is it seen in
inability to write
with Broca aphasia
what supplies the Broca region and wernikes
superior part of MCA
wernike -inferior part of MCA
what is conductive aphasia
arcuate fasciculus which connects Wernicke’s to Broca’s area.
there are four perisylvan aphasia what are they
broca
wernike
conductive
global
what are extrasylvian aphasias
share the clinical characteristic of preserved repetition and the sparing of the core perisylvian language zone. T
less common than perisylvian aphasias.
Many arise from infarcts, but they may also appear in conjunction with tumors, abscesses, hemorrhages, and other lesions.
what is seen in anomic aphasia
Naming or word finding problems
Transcortical motor aphasia
transcortical sensory aphasia
TSA
like wernikes but with repetition
TMA
Spontaneous output is severely disrupted, non-fluent, and halting. In contrast, the ability to repeat sentences verbatim is preserved, as is reading aloud. Comprehension is undisturbed. Naming may be mildly impaired.
Alexia
Alexia without agraphia (pure alexia):
Presents as an acquired loss of reading ability in a literate person, with preserved ability to write spontaneously.
impacts left occipital lobe and the splenium of the corpus callosum
Alexia with agraphia:
Patients exhibit loss of literacy (inability to read or write) but relatively well-preserved oral language function. Speech is fluent, although anomia is often present, and auditory comprehension and repetition are intact.
The underlying lesion classically involves the dominant inferior parietal lobule (angular gyrus).
Pure word deafness (auditory verbal agnosia):
Patients resemble Wernicke’s aphasics. Comprehension and repetition of spoken language are impaired, whereas speech is fluent
can recognise sounds like car horn
what produced neuropeptide Y
hypothalamus to increase appetite
what produced ghrelin
gut to increase appetite
what produced leptin
adipose issues to indicate saitety
and reduced appetite
what produces CCK
gut to decrease appetite
who is autoimmune encephalitis usually seen in
young people
sudden onset
what are the four conditions affecting the basal ganglia
which parts do they affect
Huntington’s chorea (caudate nucleus)
Wilson’s disease (copper deposition in basal ganglia)
Parkinson’s disease (substantia nigra)
Hemiballism (subthalamic nucleus)
what is seen in bipolar on neuroimaging
increased bilateral ventricular volume
lower hippocampal volime
lower amygdala volume
lower thalamic volume
widespread pattern of thinner cortex
reduced white matter
what specficially seen in bipolar compared to healthy controls
difference seen in ventrolateral prefrontal coretex
the region involved in emotions and controlling responses
what can pass the BBB and what can increase permeability
lipid molecules
water molecules not so much
inflammation
what are the regions for tumours in adults and children
adult;~ supratentorial
childhood : infratentorial
what aere gliostoma
most common tumour
pleomorphic
tumour cell necrotic area
meningoma are what
2nd most common primary brain tumour in adults
spindle cells
how do meningoma present on CT
dura tail
what are schwanomma associated with
cereballipontine angle
acoustic neuroma
verocay bodies
who are pilocystic astrocytoma seen in
most common primar in children
presents with rosenthal fibre corkscrew bundle
most common type of tumour
metastases
what are carinopharygoma formed from
ratkhke pouch
which tumour is made of fourth ventricle
ependymoma
which tumour is made with foam cells
haemganioblastoma
vascular tumour of cerebellum
associated with VHL von hippel lindau
what do pituary adenoma produce
prolactinoma
significant brodmann areas
45/45 broca
wernike 22
what are catecholamines
bezene ring with 2 hydroxyl groups + amine
neuromodulators most common examples are norephierine and dopamine adrenaline
which AA make catechoalmines
The amino acids phenylalanine and tyrosine are precursors for catecholamines.
list the cells of the CNS
oliogdendrocytes
schwann cells
astrocytes
microglia
ependymal cells
list the cerebellar dysfunction signs
ataxia
intentional tremor
disdyskinesia
nystagsmus
intetentional tremor
broad based giat
dysmetiia
list the function of each cell
oliogdendrocytes = produces myelin in CNS
schwann cells = form myelin sheath and produce myelin in PNS
astrocytes = remove K cells ,bbb, metabolic proceeses
microglia = immune cells by phagocytosis
ependymal cells- lining to ventriclesd
what divides the cerellebum into two
the medial sulcus
what lobes is the cerebellum divided into
flucculonodular
anterior posterior
functionally : vestibulo, spino and cerebro
what is another name for the atnterior tranverse temporal gyrus
heschl gyrus
part of temporal lobe
where is heschl situated compared to planium temporal
the planum temporale is the cortical area just posterior to the auditory cortex (Heschl’s gyrus) within the Sylvian fissure
what is heschl gyrus important for
primary auditory cortex for auditory processing
broadman 41
sounds first proceeded here
where is planum temporal in relation to heschl gyrus
within sylvian fissues
posterior to hesch gyrus
cortical area of superior temporal gyrus
what is the function of the planum temporal region
music memory
language processing
detection of sound location
what is found about R handed people
70% have 10x larger Left hemisphere
seen even in gestation
which conditions is reduced planum temporal assyemtry seen in
dyslexia
schizophrenia
what are the layers of the outerlayer of ceberal hemispjere
neocortex
paelocortex
archicortex
which one makes most of the cerebral hemisphere
95% neocortex
how many layers is each layer
neocortex - 6
paelocortex -3
archicortex -2 to 4 layers
name layers of the neocortex
where is it located
Molecular (plexiform) layer *
External granular layer
External pyramidal layer
Internal granular layer
Internal pyramidal layer
Multiform (fusiform) layer
under pia mater*
what cells are in the neocortex
pyramidal and non pyramidal
what does the non pyramidal make up of stellate and granular
what are archicortex
and plaeocortex involved in
archi -learning and memory limbic system
palecortex - olfactory system broadman 34
what do stellate cells do
excitatory -glutmate production
gaba inhibitory
normal intracranial pressure
5-15 mmhg
which cells makes CSF
ependymal cells in chorid plexus
of lateral /3/4th ventricle
how does csf pass through brain
lateral ventricle –> foramen munro –> 3rd ventricle —> aqudaduct to fourth ventricle –> formen magendie and luskha foramen –> subachrdoid space –> spinal cord
what does raised ICP do to CSF
increase absorption but not production
what is the difference between CSF and aplasma
same sodium content
raised mag and chloride
reduced ph, calcium, ph, cholesterol, glucose and protein
what are the meninges
lympahtic vessels
what is the cingulate gyrus
fold in the cortex of medial cerebral hemisphere next to corpus callosum
function on cingulate gyrus
process emotion
connects action, sensation and emotion
reward
what is seen oN PET imaging in depression
elevated amygdala activity
increased amygdala activity with negative stimuli
increased activity with subgunseal anterior cingulate cortex
reduced activity in dorsolateral prefontal cortex
layers of mater in brain
DURA
ARAChnoid
pia
which one is folded and where
dura is folded at:
The tentorium cerebelli - cerebellum and brainstem from the occipital lobes of the cerebrum.
The falx cerebri, which separates the two hemispheres of the brain, is located in the longitudinal cerebral fissure
The cerebellar falx (falx cerebelli) is a vertical dural infolding that lies inferior to the cerebellar tentorium in the posterior part of the posterior cranial fossa. It partially separates the cerebellar hemispheres.
sellar diaphragm covers pituary gland
what is dysarthria
defect in production of speech
affecting volume, rate, pitch, quantity, tone
commonly seen as first sign in stroke
name the types of dysarthria
spastic
flaccid
hypokinetic
hyperkinetic
ataxia
where does spastic affect and how does it present
forceful slow rate UMN
pseudobublar palsy
drooling
hyperreflex
what is flaccid dysarthria
LMN bulbary palsy
nasally breathy voice
mono pitch
short phrases
no gag reflex
e.g. myanethis gravis
ataxia dyarthria
cerebellum damage
slow speech
prolonged vowels/letters
drunk speech
alcoholic
fdererichs
hypokinetic dysartharia
basal ganglia- parkinson
e.g. slow quiet with tremor
inappropriate silences
low pitch
how does it differ from hyperinetic dysarthria
excess doapmine
also basal ganglia
e.g. huntingdons , Tardive dyskinesia
strained and variable
what is inheritance patternof ssential tremors
bengin or autosomal dominant
when are essential tremors worse
with hands out spread
improved with alcohol or rest
mx with propanolol
what are difference between fissure and sulci
The surface is folded to increase surface area. Grooves are called sulci and ridges are called gyri.
what is the role of glycine
binds to receptor on post synamic membrane
makes it more perameable to chloride ions
what is an antagonist of glycine
strychnine
what is a trigger for gullian barre syndrome
camyplobacter jejuni
which inflammatory cytokines are increased in depression
IL6
INF alpha
CRP
What is a intracranial venous thrombosis
cerebral infaraction
50% are isolated from sigital sinus
how does an Intracranial venous thrombosis present
hyeadache
nausea vomiting
sagitial sinus thormbosis - seizure, hemiplegia
cushing triad
regular, decreased respirations (caused by impaired brainstem function) · Bradycardia · Systolic hypertension (widening pulse pressure
which head injury shows with a cresent
subdural
What is kluver bucy syndrome
bilateral damage to medial temporal lobe
how does kluver bucy syndrome present
docility
dietary changes -eating inedible objects
hyperorality - puttings things in mouth licking chewing
visual agnosia unable to recognise objects- can see but not register
what are the causes of kluver bucy syndrome
herpes (children)
FTD
late alzheimers
trauma /stroke
infarct
another name for lateral medullary syndrome
wallenberg syndrome
what is LMS
due to ischemia in the lateral part of the medulla oblongata in the brainstem. The ischemia is a result of a blockage most commonly in the vertebral artery or the posterior inferior cerebellar artery.[1
LOCKED in syndrome affects which part of brain
pons or medulla
basilar artery emboli
what secretes melatonin
pineal gland
which part of brain is involved in lying
dorsolateral frontalcortex
what is motor neuron disease
fasciculations
wasting of muscles
Motor Upper and lower neuron signs
no cerebellum signs
it is a clinical diagnosis
progressive
exclusion
what is seen in amytrophic lateral sclerosis
U/L neuron
limb weakness
progressive bulbar palsy
U+L Neuron
swallowing
speech
progressive bulbar palsy
LMN
primary lateral sclerosis
UMN
when does myelin production start
week 14 gestation
frontal lobes last to myelinate
what are autonomic disturbances
atonic bladder
postural hypotension
shy drager syndrome
revised name, multiple system atrophy
T half of the people with this condition become wheelchair-bound due to a progressive lack of motor skills within 5 to 6 years of diagnosis.
parkinsonism cerebaellar signs
Some of the symptoms reported with MSA include:
fatigue
weakness
blurred vision
problems with bowel or bladder control
incontinence
erectile dysfunction
constipation
dry skin
what causes the signs in shy drager syndrome
striangiral degeneration parkinsonism
oliopontocerebellar atrophy - cerebellum feature
macroscopic features - pallor of s.nigra, greenish putamen, cerebral atrophy
microscopy - Papp lantos bodies, alpha inclusions in SN, cerebellum, basal ganglia
UMN
increase reflex
weakness
increase tone
mild atrophy
bakinski reflex
pronator drift
clonus
LMN
reduced reflex
reduced tone
atrophy
weakness
What neuroimaging techniques are there classified by
structural and functional
what do structural neuroimaging techniques look at
size structure shape location
whereas functional is more neural firing and metabolic profile
summarise CT
uses radiational XR
2d picture
dense tissue appears as as white 9bone)
air black
how does MRI work
capitalises on magnetic properities of tissue
specifically hydrogen nuclei (proteins in water molecular)
and align based on their magnetic moment
what is DTI
a type of MRI
anisotropic diffusion to estimate the axonal (white matter) organisation of the brain.
Diffusion tensor imaging (DTI)
in cerebral white matter, water molecules tend to diffuse more freely along the direction of axonal fascicles
assessment of the deformation of white matter by tumours - deviation, infiltration, destruction of white matter
delineation of the anatomy of immature brains
presurgical planning
Alzheimer disease - detection of early disease
schizophrenia
focal cortical dysplasia
multiple sclerosis - plaque assessment
what are functional MRis
PET and SPECT
looks at blood flow and o2 consumption
injection of radioactive substance required
an example of a dye used in PET scan
raclopride d2/d3 antagonist
what does spect use
SPECT gamma ray as substance decays, poorer quality but longer half life
PET
collision of positions and electrons
higher resolution but limited half life
Magnetic resonance spectroscopy (MRS)
Magnetic resonance spectroscopy (MRS) and the related technique of magnetic resonance
looks at metabolites from chemical breakdown
