Week 1 & 2 Flashcards
agnosia
impaired ability to recognize/perceive objects
Associative – cannot access memory or meaning
Apperceptive – cannot perceive objects
apraxia
cannot perform skilled, purposeful tasks
Constructional – cannot build or draw
Ideation – cannot conceive how to do sequential actions
Ideomotor – cannot convert idea to task (mimic)
aphasia
language disability
Alexia – impaired reading
Agraphia – impaired writing
orbitofrontal syndrome
disinhibition (incontinence, hugging, touching, laughing) due to prefrontal cortex lesion
hemispatial neglect
parietal lobe lesion causing hemiparesis and hemisensory deficit
denial of contralateral side
4 things that Gerstmann’s syndrome results in
finger agnosia, left-right confusion, agraphia and acalculia
auditory association complex
comprehension of spoken word
• Wernicke’s area on dominant side
arcuate fasciculus
tract that connects PAC and AAC
• Corrects error during speech repetition
Sensory (Wernicke’s, receptive) aphasia
- Difficulty understanding spoken words, but understand motion
- Have fluent speech (full words and sentences) even if jargon
Motor (Broca’s, expressive) aphasia
- Normal comprehension of speech but cannot articulate
* Halted speech pattern, lack of full sentences and linking words
conduction aphasia
fluent speech and good comprehension with poor repetition
Kluver Bucy syndrome
bilateral amygdala lesion causing inappropriate sexual behaviors and mouthing of objects along with emotion instability (docility, anger)
grey matter feature
neuron cell bodies
white matter feature
myelinated axons
spinal cord sensory area develops from ____
Alar plate in posterior half
spinal cord motor area develops from ____
Basal plate in anterior half
cells derived from neural crest (4)
- Sensory neurons in peripheral nerves
- Schwann cells
- Postganglionic autonomic nerves
- Enteric nerves
cells derived from neural tube (4)
- CNS glia – astrocytes, oligodendrocytes, microglia, ependymal cells
- Upper and lower motor neurons
- Preganglionic autonomic neurons
- Interneurons
anencephaly
absence of a major portion of the brain, skull, and scalp due to failure of rostral neuropore to close
encephalocele
sac-like protrusions of the brain and membranes through openings in the skull due to failure of rostral neuropore to close
spina bifida occulta
no herniation of intraspinal contents; often small hair tuft at defect site due to failure of caudal neuropore to close
meningocele
herniated sac contains CSF, meninges due to failure of caudal neuropore to close
myelomeningocele
herniated sac contains CSF, meninges, and cord due to failure of caudal neuropore to close
what is elevated in neural tube defects
α-fetoproteins
oculomotor palsy
affected eye will look down and out
trochlear palsy
head tilt away from lesioned side to minimize misalignment and double vision (diplopia)
lower motor neuron lesion of facial nerve
paralysis of entire face on lesioned side
upper motor neuron lesion of facial nerve
paralysis of lower face only because UMN projects bilaterally
vagus nerve lesion
palate will not rise and uvula will deviate away from lesioned side when saying “ah”
hypoglossal nerve lesion
tongue will deviate towards side of injury
anterior cerebral artery supplies which homunculus regions
genitals, feet, legs and trunk
middle cerebral artery supplies which homunculus regions
arms, hands, face and tongue
also Wernicke’s and Broca’s
what supplies the spinal arteries
segmental arteries
anterior spinal artery is motor or sensory
motor
posterior spinal artery is motor or sensory
sensory
what integrates input and output, and has many voltage gated Na channels?
axon initial segment
dendritic spines
sites of excitatory synapses going into the cell
actin based
shapes controls the transmission strength
purkinje cells of the cerebellum send _____ signals
inhibitory
astrocytes are stained with _____
GFAP
microglia are stained with _____
Iba-1
glitter cells
microglia that acts as post infection marker
normal CSF when compared to serum
low protein
low glucose
minimal cells
more acidic
flow of CSF from ventricles to cord
Lateral ventricles -> foramen of Monroe -> third ventricle -> mesencephalic aqueduct -> fourth ventricle -> spinal cord
normal intracranial pressure
7-15 mmHg
laying down
communicating hydrocephalus
no obstruction
- without normal pressure = obstructed reabsorption i.e. subarachnoid hemorrhage
- with normal pressure = meningitis
non-communicating hydrocephalus
obstructed flow due to malformations or tumor
bacterial meningitis CSF signs
neutrophils, high protein, low glucose
viral meningitis CSF signs
lymphocytes, slightly increase protein, normal glucose
sensory ascend or descend anterior or posterior lobe gyrus
ascending
posterior
parietal lobe
postcentral gyrus
motor ascend or descend anterior or posterior lobe gyrus
descending
anterior
frontal lobe
precentral gyrus
2 sensory tracts
posterior column/medial lemniscus system
spinothalamic tract/anterolateral system
where does the medial lemniscus system decussate
2nd order neurons in the medulla
means spinal cord lesion will have ipsilateral sx
brain lesion will have contralateral sx
where does the spinothalamic tract decussate
2nd order neurons in the ANTERIOR white commissure in spinal cord
will cause contralateral analgesia
what does the medial lemniscus system sense
discriminative touch, vibration, proprioception
what does the spinothalamic tract sense
pain, temperature, non-discriminative touch
2 motor tracts
corticospinal tract
corticonuclear tract
what does the corticospinal tract do
fine movements of body, trunk and limbs
what does the corticonuclear tract do
movements of face
where does the corticospinal tract decussate
pyramids of medulla
where does the corticonuclear tract synapse
cranial nerve nuclei in brainstem
upper motor nerve lesion will cause
impairs inhibitory control
- Spasticity, hyperreflexia, spastic paralysis
• Brain lesion –> contralateral
• Spinal lesion –> ipsilateral
lower motor nerve lesion will cause
no triggering of contraction
- Hyporeflexia, hypotonicity, flaccid paralysis
• Ipsilateral deficits and atrophy
excitatory pathway of the motor loop
direct pathway
thalamus via D1 receptors
inhibitory pathway of the motor loop
indirect pathway
basal nuclei via D2 receptors
dopamine is released by
substantia nigra pars compacta
vestibulospinal tract
brainstem-spinal tract that corrects postural instability based on sensory input from the vestibular system
reticulospinal tract
brainstem-spinal tract that anticipates imbalance and makes postural changes that precede ongoing limb movements
tectospinal tract
brainstem-spinal tract that orients auditory and visual stimuli
paramedian brainstem lesions cause _____
MOTOR due to basilar or anterior spinal artery lesions 1. corticospinal tract 2. motor cranial nerves (3, 4, 6, 7, 12) “paresis is paramedian” “median is motor” “ocular palsy is paramedian”
lateral brainstem lesions cause ______
SENSORY due to circumferential artery lesions 1. anterolateral system 2. vestibulocochlear nuclei “lateral lesion analgesia” “lateral lesion affects listening”
ipsilateral brainstem lesions cause _____
trochlear nuclei damage, CONTRALATERAL defect
“controchlateral”
weber syndrome aka medial midbrain lesion
Posterior cerebral artery
Contralateral motor
CN 3 palsy
locked in syndrome aka medial midbrain lesion
Basilar artery
• Quadriplegia but awake (reticular formation spared bc circumferential artery ok)
foville syndrome aka medial pons lesion
Basilar artery
Contra lateral motor
CN6 palsy
dejerine syndrome aka medial medulla lesion
anterior spinal artery (from vertebral artery)
contralateral spastic hemiplegia
Contralateral sensory loss (only medial sensory issues)
CN12 palsy
Lateral midbrain syndrome
lateral midbrain lesion
Posterior cerebral artery
Medial lemniscus, spinothalamic tract: contralateral sensory loss
lateral pontine syndrome
AICA
contralateral hemianalgesia of the body
ipsilateral CN5 and CN7 palsy
wallenburg syndrome aka lateral medulla lesion
very infamous boards stroke syndrome
PICA
Spinothalamic contralateral loss of pain and temp sensation on body
Spinal trigeminal, CN 5: ipsilateral loss of pain and temp sensation on face
Vagus nucleus: uvula, hoarse voice, dysphagia
Spinocerebellar: ipsilateral vertigo, stumble or fall to side of injury
3 functional modules of the cerebellum
pontocerebellar
vestibulocerebellar
spinocerebellar
pontocerebellar module
aids planning, initiating, timing of dexterous movements; posterior lobe of cerebellum
vestibulocerebellar module
posture, balance, coordinated eye movements; flocculonodular lobe of cerebellum
spinocerebellar module
adapts motor coordination to changing circumstances; anterior lobe of cerebellum
form of stroke characterized by ipsilateral oculomotor nerve palsy and contralateral hemiparesis or hemiplegia
superior alternating hemiplegia
awake quadriplegia
locked in syndrome from bilateral crus cerebri ischemia
form of stroke characterized by ipsilateral abducens nerve palsy and contralateral spastic hemiplegia
middle alternating hemiplegia
form of stroke characterized by contralateral spastic hemiplegia, contralateral sensory loss and ipsilateral CN12 palsy
dejerine syndrome (inferior alternating hemiplegia, medial medullary syndrome)
form of stroke characterized by contralateral sensory loss
lateral midbrain syndrome
form of stroke characterized by contralateral loss of pain and temp on body, ipsilateral loss of pain and temp on face, hoarseness and stumbling
wallenburg syndrome (lateral medullary syndrome)
ipsilateral motor deficit including oscillating intention tremor, dysmetria, hypotonia, and rebound phenomenon
posterior lobe syndrome
bilateral motor deficit including truncal ataxia, loss of tandem gait, positive romberg sign, nystagmus and trmeor
flocculonodular lobe syndrome
ipsilateral motor deficit including clumsy gait, side-to-side motion, and positive shin to heel test
anterior lobe syndrome
Gerstmann’s syndrome is a lesion to _________
left parietal lobe
Suprachiasmatic nucleus of hypothalamus
circadian rhythms
Supraoptic nucleus of hypothalamus
vasopression
Paraventicular nucleus of hypothalamus
CRF and ANS
Oxytocin
Anterior nucleus of hypothalamus
reproductive, sexual development, sexual drive
Pre-optic nucleus of hypothalamus
thermoregulation, sexual activity, cooling off
Lateral nucleus of hypothalamus
feeding
promotes eating behavior via ghrelin
• Damage here – anorexia and failure to thrive
• Certain drugs can do this too via ↓DA i.e. methamphetamine
Medial nucleus of hypothalamus
satiety (leptin)
leptin, CART/POMC and +MC4R and -AgRP/NPY
• Damage to leptin receptors can result in obesity and hyperphagia
• If tumor disrupts medial nuclei = overeating
Posterior nucleus of hypothalamus
heat generation, shivering
What creates fever?
SNS is stimulated to increase set point via PGE2 from organum vasculosum lamina terminalis to hypothalamus
General role of thalamus
relay station
sensory, memory, arousal, visual, motor
Ventral anterior/ventral lateral (VA/VL) of thalamus
motor circuit
anterior = action
Ventral posterolateral (VPL)
somatosensory (postcentral gyrus) of body
• Receives from medial lemniscus, spinothalamic spinal tract
• VPL= Vibration, Pain, Proprioception, Light touch
Ventral posteromedial (VPM)
somatosensory (postcentral gyrus) of face
• Receives from medial lemniscus, spinothalamic trigeminal tract
• VPM = make up on face
Medial geniculate (MGN)
auditory cortex (superior temporal gyri) • Receives from inferior colliculus • MGN = listen to music
Lateral geniculate (LGN)
visual cortex (occipital lobe) • Receives from optic tract • LGN = see the light
posterior to the cranial nerve, everything is ______
opposite
• Midline lesion = lateral VFD
• Left lesion = right VFD
• Superior lesion = inferior VFD
lesion in optic chiasm causes
bitemporal hemianopia
Saccade eye movement
a quick, simultaneous movement of both eyes between two or more phases of fixation in the same direction
smooth pursuit eye movement
eyes move smoothly instead of in jumps
track moving target
mediated by cerebellum
vestibulo-ocular reflex
eye movements that oppose head movements to stabilize image on retina
Doll Sign
how does one gaze to the left
- Right frontal eye field (FEF) signals the left paramedian pontine reticular formation (PPRF) to make the left eye look left
- The left PPRF signals the medial longitudinal fasciculus (MLF) to make the right eye look left
afferent action and nerve of pupillary light reflex
CN 2 projects bilaterally = direct and consensual activation
efferent action and nerve of pupillary light reflex
CN 3 projects ipsilaterally = R and L pupillary sphincter can constrict independently
Marcus Gunn defect
relative afferent pupillary defect (RAPD) - problem sensing
Lesioned eye will constrict when light is shown in healthy eye (because efferent CN3 is intact
When light is shown in lesioned eye, neither will constrict, because light cannot be sensed (afferent CN 2)
angular acceleration organ
cristae ampullares in semicircular duct
linear acceleration organ
maculae in vestibule
afferent nerves of balance
- Cochlear branch of CN8
* Vestibular nuclei
efferent nerves of balance for head stabilization
- Medial vestibulospinal tract
- Bilateral spinal cord
efferent nerves of balance for posture
- Lateral vestibulospinal tract
- Ipsilateral spinal cord
efferent nerves of balance for conjugate eye movements
- Contralateral PPRF
- Abducens nuclei
- Medial longitudinal fasciculus
- Oculomotor nucleus
direction of vestibular nystagmus is always ______ the orientation of the affected semicircular duct
OPPOSITE
direction of vestibular nystagmus is always opposite the orientation of the affected ________________
semicircular duct
superior canal injury causes ___________ directed nystagmus
inferiorly
stumbling in vertigo occurs towards or away from affected side
towards
____ orients eyes, head and body to sounds
inferior colliculus
_________ relays ipsilateral input to other nuclei
cochlear nucleus
__________ compares right and left ears to localize sounds
superior olivary complex
Central deafness
central pathway defect
- Deafness (bilateral), aphasia, agnosia
- Cortical deafness – perceived deafness, may still react to sounds
Sensorineural deafness
inner ear dysfunction
- Spiral organ or CN 8 lesion
- Begins with high pitch loss
Conductive deafness
outer ear dysfunction
- Cerumen impaction, otosclerosis, otitis media
- Begins with low pitch loss
weber test what is it and what are the findings in: normal conduction deafness sensorineural deafness
tuning fork pressed on top of skull in midline
- Normal: sound heard equally
- Conduction: sound louder in affected ear
- Sensorineural: sound louder in unaffected ear
rinne test what is it and what are the findings in: normal conduction deafness sensorineural deafness
tuning fork held to mastoid process and in front of meatus
- Normal: air conduction hearing lasts longer than bone conduction
- Conduction: bone lasts longer than air
- Sensorineural: air lasts longer than bone (like normal) but quieter
Blood supply of lateral midbrain
PCA
Blood supply of medial midbrain
PCA
Blood supply of lateral pons
AICA
Blood supply of medial pons
Basilar
Blood supply of lateral medulla
PICA
______ cortex = deliberate retrieval of semantic facts
______ lobe = integrative or spatial memory
_______ = stores tasks and physical skills
_________ = plays role episodic and pattern recognition memory
frontal - semantic
parietal - spatial
cerebellum - skills
hippocampus - pattern
Wernicke-Korsakoff Syndrome
- Most common in alcoholics and/or thiamine deficiency
- Usually occur together – “Korsakoff” occurs later and associated with mammillary body damage and amnesia
- “Confabulation” is common (fill in memory gaps with ‘stories’)
Right sided weakness
Left eye down and out
What is lesion and where is infarct
Weber’s (left medial midbrain)
PCA
Can’t finger to nose on left Loss of pain and temp on face Left eyelid droop Loss of pain and temp right leg Hoarse voice Raised right palate
What is lesion and where is infarct
Left lateral medulla
Wallenburgs
PICA
Right deafness
Loss right finger to nose
No corneal reflex
Right face numbness
What is lesion and where is infarct
Right lateral pons
declarative memory
explicit like episodic (events) and semantic (facts)
4 changes in acute neuronal injury
- Shrinkage of cell body
- Loss of basophilic Nissl substance
- Increasing cytoplasmic acidophilia due to increased density of damaged mitochondria
- Condensation of nuclear chromatin and nuclear pyknosis
an increase in ____ is associated with forgetting
GABA
long term potentiation
consolidates short-term into long-term memory via repeated stimulation, glutamate, Ca and CREB
mammillothalamic tract projects to________ for ________
cingulate gyrus
memory
______ cortex = deliberate retrieval of semantic facts
______ lobe integrative or spatial memory
_______ stores tasks & physical skills
_________ plays role episodic & pattern recognition memory
frontal - semantic
parietal - spatial
cerebellum - skills
hippocampus - pattern
Wernicke-Korsakoff Syndrome
- Most common in alcoholics and/or thiamine deficiency
- Usually occur together – “Korsakoff” occurs later & associated with mammillary body damage & amnesia
- “Confabulation” is common (fill in memory gaps with ‘stories’)
_______________ is the reward center in septal nuclei area
nucleus accumbens
pathway of the mesocorticolimbic dopamine system
ventral tegmental area (VTA) -> nucleus accumbens -> pre-frontal cortex
Basal Nucleus of Meynert is associated with _____ and rich in ____ receptors
memory
Ach
“red neurons” appear in ________
acute neuronal injury
4 changes in acute neuronal injury
- Shrinkage of cell body
- Loss of basophilic Nissl substance
- Increasing cytoplasmic acidophilia due to increased density of damaged mitochondria
- Condensation of nuclear chromatin and nuclear pyknosis
neurons in certain parts of the brain that are especially vulnerable to hypoxic damage are:
- Pyramidal neurons in the CA1 field of the hippocampus
- Pyramidal neurons in layers 3 and 5 of the neocortex
- Purkinje cells in the cerebellum
chromatolysis (4 things and result)
disintegration of Nissl bodies, movement of nucleus to periphery, increase in nucleolus, nucleus and cell body size
Neuron could regenerate or undergo apoptosis
Lewy bodies in substantia nigra (_____) and in cortex (_____)
Parkinson’s
Lewy body dementia
______ in substantia nigra (Parkinson’s)
Lewy bodies
Pick body in ____ and _____ cortex in Pick’s disease
frontal and temporal
HSV brain inclusions
Cowdry bodies
eosinophillic in nuclei
CMV brain inclusions
Owl’s eye
dark pink inclusions in enlarged neurons
Rabies brain inclusions
Negri bodies
______________ is most important indicator of CNS injury
gliosis
Rosenthal fibers
cytoplasmic inclusions in astrocytes and consist of Intermediate filament (GFAP), crystallin and ubiquitin in response to injury
microglial nodules are hallmark of _______
viral infection
foam cells occur in _____ and do _____
tissue damage
phagocytose
hallmark of Alzheimer’s
aggregates of amyloid plaques and tauopathy of neurofibrillary tangles
enzymes in Aβ biosynthesis
γ-secretase and β-secretase
enzymes in Aβ degradation
α-secretase, IDE, Neprilysin, Plasmin
stroke is an example of _____ (type of molecular injury)
excitotoxicity (due to glutamate accumulation)
can nerves regenerate in CNS
not usually because end up being surrounded by glial scar and cannot form through that (also MAG and NOGO)
can nerves regenerate in PNS
yes, Schwann cells proliferate and stretch across damaged area, after a few months, can have complete regeneration (or neuroma if not)
in wallerian degeneration, proximal axons _______ and the distal portion _____
Proximal - retreat to last node of Ranvier
Distal - degeneration of axon and myelin
progressive autoimmune disorder against myelin sheath
multiple sclerosis
autoimmune disease of PNS triggered by infection with antibodies against gangliosides
guillan-barre
transependymal edema in brain
occurs with increased pressure within ventricles
FLAIR is the most sensitive MRI sequence for detection
CSF in the parenchyma around the ventricles, especially laterally
Major functions
dorsal/posterior horn -
ventral/anterior horn -
lateral horn -
dorsal/posterior horn - sensory
ventral/anterior horn - somatic motor
lateral horn - autonomic
in CT scans ___ will appear dark
tissue, edema, necrosis
in CT scans ___ will appear bright
bone, fresh blood
CSF is ___________ in T1 MRI
dark
CSF is ___________ in T2 MRI
bright
subdural hematoma
Bleeding between arachnoid mater and dura Follows the contour of the brain; crescent shape
epidural hematoma
Bleeding between dura mater and skull
Bulges out into the brain space
intracellular edema in brain
cytotoxic, inadequate functioning of Na/K pump
Grey white matter junction is not visible
Brown Sequard syndrome (hemisection)
Ipsilateral motor loss, tactile loss, proprioception loss, anesthesia
contralateral pain and temp loss
transependymal edema in brain
occurs with increased pressure within ventricles
FLAIR is the most sensitive MRI sequence for detection
CSF in the parenchyma around the ventricles, especially laterally
ALS
paresis, spasticity, atrophy, weakness, dysphagia
no sensory symptoms!
syringomyelia
central canal development abnormality
cape like bilateral sensory loss
presents as burns or cuts on hand that were not felt
reticulospinal tract
affects α and γ motor neurons, connect with reticular formation and autonomics
tectospinal tract
reflex movements in response to light, sounds or sudden movements
also pupillary dilation
rubrospinal tract
muscle tone
hydromyelia
canal of fluid in spinal cord that is lined with ependymal cells
anterior cord syndrome
- Bilateral flaccid paralysis (corticospinal), bilateral loss of sensation (spinothalamic; pain, temp and touch), incoordination (spinocerebellar), respiratory paralysis, bilateral Horner’s, incontinence
- Dorsal column (medial lemniscus; vibration and proprioception) undamaged
central cord syndrome
- Bilateral lower motor neuron damage (flaccid paralysis, areflexia), bilateral loss of spinothalamic (pain, temp, light touch)
- Sacral sparing (more in arms than legs)
Brown Sequard syndrome (hemisection)
Ipsilateral motor loss, tactile loss, proprioception loss, anesthesia
contralateral pain and temp loss
poliomyelitis
Acute viral infection Degeneration of anterior horn and cranial nerve
Symmetric flaccid paralysis, atrophy, hypotonia, hyporeflexia
ALS
paresis, spasticity, atrophy, weakness, dysphagia
syringomyelia
central canal development abnormality
cape like bilateral sensory loss
tabes dorsalis
3* syphilis sensory ataxia (+ Romberg’s test), absent deep tendon reflex, Charcot joints, Argyll pupil
cauda equina syndrome
gradual onset, unilateral saddle-shaped sensory area, severe spontaneous radicular pain (along a dermatome), low back pain, incontinence, muscle atrophy, loss of L3 and S1 reflexes
friedreich’s ataxia
trinucleotide repeat disorder (GAA) from AR mutation of FRADA
kyphoscoliosis, ataxia and falling (spinocerebellar), paralysis (corticospinal), vibration and proprioception (medial lemniscus), speech, hearing, vision (CN 8, 10, 12)
COD - hypertrophic cardiomyopathy
hydromyelia
canal of fluid in spinal cord that is lined with ependymal cells
polymicrogyria
too many gyri
grey matter heterotopias
type 2 chiari
caudal herniation of vermis, brainstem and fourth ventricle
- Associated with myelomeningocele (open spina bifida), agenesis of corpus callosum
type 3 chiari
rare; low occipital and high cervical encephalocele with herniation of brainstem, occipital lobe and fourth ventricle
type 4 chiari
aplasia of cerebellum
Diastematomyelia/Diplomyelia
Bifid spinal cord, common in Asians, tuft of hair, tethered spinal cord
Type 1 – separate dural sleeves
Type 2 – same dural sleeve
lipomeningocele
defect in the bone causing fat to be connected to spinal cord, tethering it
holoprosencephaly
3 types
- Alobar – monoventricle/no separation
- Semilobar – partially developed occipital and temporal horns
- Lobar – almost complete separation/interhemispheric fissure and falx present/ fused frontal lobes
septo-optic dysplasia
agenesis of the septum pellucidum, optic nerve or chiasm hypoplasia (vision problems)
dandy walker complex
dilated 4th ventricle/ enlarged posterior fossa/ upward displacement of lateral sinuses, tentorium, vermian aplasia or hypoplasia
lissencephaly
smooth brain
type 1 - layered
type 4 - disorganized
polymicrogyria
too many gyri
grey matter heterotopias
brown sequard syndrome has Horner’s if
injury is above T2 level
Enhancement on gadolinium infusion suggests breakdown of the ________, seen in _______ edema.
blood-brain barrier
vasogenic
red neurons show up ______ hours post injury
12-24
ependymitis
inflammation of columnar cells that line ventricles due to infection like CMV, Varicella or Mumps
