When Things Go Wrong (55b, 66b - 77b, 79b) Flashcards
Which genetic mutation is implicated in familial ALS?
C9orf7
- Causes hexanucleotide repeat in chromosome 9
- Autosomal dominant inheritance
What are the EMG findings of small-fiber neuropathy?
None!
- EMG is normal
- Only detects abnormalities in large (A-alpha, A-beta) fibers
- Need to do skin biopsy
This can be super frustrating for patients if they are in pain, and the doctor says its in their head!
Describe the classic pattern of diabetic neuropathy
Is this characteristic of axonal or demyelinating neuropathy?
Glove and stocking pattern: characteristic pattern of numbness is one in which the distal portions of the nerves are first affected, the so-called “stocking-glove” pattern.
Axonal neuropathy
Which area of the cerebellum is damaged?
- Ataxia of the arm and leg
- Disorders of motor planning
Intermediate cerebellar hemispheres
Which area of the brain relays the major output pathway from the basal ganglia?
Ventral thalamus
Also releays major output from the cerebellum
Remember, the output nuclei of the basal ganglia are the substantia nigra pars compacta and the internal segment of globus pallidus
What are the goals of management for hemorrhagic stroke?
How is this accomplished?
- Prevent expansion of the hematoma
- Prevent compression of vital brain structures
Accomplished by:
- Lower blood pressure
- Secure ruptured vessel
- Give platelets + anticoagulants
How do you differentiate between benign essential tremor and Parkinsonism?
- Benign essential tremor
- Faster than Parkinsonism tremor
- Worse with anxiety, fatigue, temperature extremes
- Better with alcohol, sleep
- May be symmetric or asymmetric
- Parkinsonism
- Rest/pill-rolling tremor (4-6 Hz)
Typical acute CNS demyelinating symptoms include all of the following except?
- Optic neuritis
- Partial myelitis
- Abrupt onset of hemiparesis
- Double vision
- Balance impairment
c. Abrupt onset of hemiparesis
* Attacks take >1 day to develop in MS
What is the managment of primary CNS lymphoma?
- Chemotherapy (methotrexate)
- Radiation (whole brain)
- Corticosteroids can decrease edema initially, but disease will recur if other treatments are not used
Basal ganglia, direct pathway
- Receptor:
- Signals to:
- Promotes or inhibits movement?
Basal ganglia, direct pathway
- Receptor: D1 dopamine receptor
- Signals to: Globus pallidus internal segment, substantia nigra reticulata
- Promotes or inhibits movement: promotes movement
On a SPECT scan, what would you expect to see in a patient with Parkinson’s disease?
- Parkinson’s Disease = period-shaped substantia nigra
- Not normal; image B
- Not Parkinson’s Disease = comma shaped
- Normal; image A
- Patient may still have parkinsonism, but look for different etiology
A large cyst with an “enhancing mural nodule” on MRI is most likely which kind of brain tumor?
Pliocytic astrocytoma
- Usually cerebellar
- Histology will show rosenthal fibers
-
pilocytic astrocytoma (Grade 1) occurs in both children and adults most commonly in the cerebellum
- can be seen in association w/ Neurofibromatosis Type 1 (NF1)
- Macroscopic Findings: well circumscribed, often cystic
- Microscopic Findings: biphasic appearance w/ both compact and loose areas, has pink/red accumulations called Rosenthal fibers (which are only seen in slow growing lesions)
Which tracts are involved in ALS?
Corticospinal and corticobulbar
How do we test for small fiber neuropathy?
- Skin biopsy
- QSART (a fancy sweat test)
- If sweating is reduced or it takes too long, indicates autonomic dysfunction
HSV-1 is associated with [meningitis/encephalitis]
HSV-2 is associated with [meningitis/encephalitis]
HSV-1 is associated with encephalitis (frontotemporal)
HSV-2 is associated with meningitis
HSV-1 generally causes worse outcomes; causes acute necrosis
How will agenesis of the corpus callosum affect intelligence, if there are no other structural brain abnormalities?
Intelligence is likely to be normal
What is myoclonus?
Brief, lightning-like muscle jerks
- Not rhythmic
- Parkinsonism tremor is rhythmic/predictable
- Most common = asterixis
- Quick flap of the hand
Which of the mechanisms is not considered to be a pathologic feature of multiple sclerosis ?
- Innate immune activation
- Axon damage due to metabolic stress
- Loss of Schwann cells
- Elaboration of increased sodium channels in demyelinated axons
c. Loss of Schwann cells
- Demyelination in MS is due to autoreactive lymphocytes and inflammation
- Will affect white AND grey matter
Which tumors are associated with “chicken wire vasculature” and “fried egg appearance”
Oligodendroglioma
A patient presents with headache is worst in the morning but diappears during the day, recurring the next day
The headache is worse with head shaking and the valsalva maneuver
They have been increasing in frequency and severity
What are you most concerned for?
Brain tumor
- Classic brain tumor headache = signs of increased intracranial pressure
Will Parkinson’s disease be symmetric or asymmetric at onset?
Asymmetric
Which tumor is associated with pseudo-rosettes and true rosettes?
Ependymoma
An infant is admitted to the NICU after imaging reveals bilaterally hypoplastic optic nerves, absent septum pellucidum, and thin corpus callosum.
What is the most likely diagnosis?
What screening tests should be ordered?
Septo-optic dysplasia
Order glucose monitoring screen and endocrine function tests
- Failure of midline prosencephalic structures
- 2/3 of the following confirm diagnosis:
- Optic nerve hypoplasia
- Pituitary defects
- Midline brain defects
A-alpha fibers are [motor/sensory]
A-beta fibers are [motor/sensory]
A-alpha fibers are motor
A-beta fibers are sensory
What is the treatment for acute-onset Guillain-Barre Syndrome?
- Plasmapharesis + IVIG
Steroids do not work!!
What is the acute treatment for cluster headache?
100% oxygen face mask at 7 L/min, in a seated position
What are the “big 3” migraine triggers?
Hormones
Fasting
Alcohol
Where are oligodendrogliomas usually located?
Supratentorial
Frontal lobe
Usually white matter
A patient presents with sudden onset of:
- Left eye painless vision loss (aka amaurosis fugax)
Which artery is occluded?
Which areas of the brain are affected?
Left retinal aretery occluded
May be caused by plaque breaking off of the internal carotid
(ICA -> Ophthalmic artery -> central retinal artery)
- None of the brain is affected!
- Complete vision loss in one eye = retinal problem
Weakness, spasticity, clonus, and hyperreflexia are [UMN/LMN] signs of ALS
Weakness, spasticity, clonus, and hyperreflexia are UMN signs of ALS
Basal ganglia, indirect pathway
- Receptor:
- Signals to:
- Promotes or inhibits movement?
Basal ganglia, indirect pathway
- Receptor: D2 dopamine receptor
- Signals to: Globus pallidus external segment -> subthalamic nucleus -> GPi, SNr
- Promotes or inhibits movement: inhibits movement
What is dystonia?
Sustained but not fixed muscle contraction that can cause twisting or repetitive movements
- Caused by abnormal contraction of muscles
- May be generalized or focal
What are the symptoms of ciguatera fish poisoning?
Diarrhea, vomiting, numbness, itchiness, sensitivity to hot or cold, dizziness, weakness
Prevalence increasing with increased algal blooms associated with climate change :’(((((
Which area of the cerebellum is damaged?
- General balance problems
- Vestibulo-ocular reflexes
Flocculus, nodulus
What is chorea?
Excessive, spontaneous movements from a flow of muscle contractions
- Dance-like
- Irregularly timed (not rhythmic)
- Parkinsonism is rhythmic/predictable
- Randomly distributed/not predictable
List some of the characteristics of a cluster headache
- Unilateral, supraorbital and/or temporal
- VERY severe
- Occurs during sleep
- Wakes patients form sleep
- More common in males
- Weird facial stuff (at least one) on the side of the headache
- Conjunctival injection
- Facial sweating
- Lacrimation
- Miosis
- Nasal congestion
- Ptosis
- Rhinorrhea
- Eyelid edema
What is the go-to treatment for Parkinson’s Disease in older patients?
Levodopa + Carpidopa
- Levodopa = L-Dopa, converted to dopamine by endogenous L-dopa decarboxylase
- Carbidopa inhibits L-dopa decarboxylase peripherally, so more L-dopa can get into the CNS and be converted to dopamine there
Note: in younger patinets who may be more tolerant to side effects, give dopamine reuptake antagonist (amontidine) - prolonged (5+ year) levodopa can lead to dyskinesias
A migraine headache is caused by activation of a mechanism that results in the release of ____________ around the nerves and blood vesels of the head
A migraine headache is caused by activation of a mechanism that results in the release of pain-producing inflamatory substances around the nerves and blood vesels of the head
What exposures might precede Guillain Barre Syndrome?
- Illness
- Vaccination
- Dental procedure
- Surgery
-> Autoimmune response that leads to acute demyelination
Which kind of brain tumors are associated with Homer-Wright Rosettes?
Medulloblastoma (IV)
Weakness, atrophy, fasciculations, and cramps are [UMN/LMN] signs of ALS
Weakness, atrophy, fasciculations, and cramps are LMN signs of ALS
What are the two most common bacterial causes of encephalitis?
- Borrelia burgdorferi (lyme disease)
- Treponema pallidium (syphillis)
List some of the classic features of migraine
- Headache
- Unilateral
- Pulsatile
- Nausea
- Photosensitivity
- Aggravated by routine physical activity
- Lasts hours-days
- May be preceded by aura (usually visual)
IV tPA must be administered within ___ of the infarct
IV tPA must be administered within 4.5 hours of the infarct
-
ischemic penumbra = salvageable brain tissue that is supplied by the blocked artery and other arteries; damage is not immediate and may be reversible; it will infarct if not treated on time
- treatment to save the penumbra:
- IV tissue plasminogen activator (tPA), which is thrombolytic agent (up to 4 hrs from onset)
- intra-arterial catheter based methods for large vessel occlusions (up to 6 hrs from onset)
- Opening up a blocked artery has a decreasing effect as time increases ® core expands as penumbra is dying
- treatment to save the penumbra:
Describe the eye movements associated with benign positional paroxysmal vertigo (BPPV)
Ipsilateral beating and torsional nystagmus
A lesion in the right posterior canal will result in right beating and right torsional nystagmus
(drift to the left and snap back to the right)
Note: in BPPV, the snap back is toward the lesion side, whereas in vestibular neuritis the drift is toward the lesion side and the snap back is away
(idk if this is the right description)
[vestibular neuritis/benign paroxysmal vertigo] is caued by otoconia breaking off and lodging in the cristae ampullaris, resulting in overstimulation of the vestibular system
Benign paroxysmal vertigo is caued by otoconia breaking off and lodging in the cristae ampullaris, resulting in overstimulation of the vestibular system
Is Guillan Barre Syndrome axonal or demyelinating neuropathy?
Demyelinating
- Diffuse ascending weakness/paresis
- Vs. axonal, which is localized to a single dermatome or in a length-dependent glove and stocking pattern*
A patient presents with the “worst headache of their life (WHOL)”
This is _______ until proven otherwise
Subarachnoid hemorrhage
What are the major output nuclei of the basal ganglia?
- Substantia nigra pars compacta
- Internal segment of globus pallidus
Which area of the cerebellum is damaged?
- Overall decreased coordination
- Disorders of posture
- Disorders of eye/head movements
Vermis
What is the most severe, recurrent, primary headache?
Cluster headache
Glascow Coma Score for eye opening
(Which actions correspond with which scores?)
- 1 - No opening
- 2 - Opening to pain
- 3 - Opening to speech
- 4 - Spontaneous opening
Agents that cause [vasoconstriction/vasodilation] may be useful to treat migraine
Agents that cause vasoconstriction may be useful to treat migraine
Vasodilation and the release of inflammatory, pain-inducing substances are parts of the pathogenesis of migraine
What is the fundamental organizing principle of the central vestibular system?
The central vestibular system is built upon sensory integration of multiple inputs
- Somatic sensory
- Visual
- Vestibular
If one is damged, others will compensate
What is the most common modifiable risk factor for stroke?
Hypertension
Is there a direct output from the cerebellum to the spinal cord?
NO!
Output from the cerebellum loops back to the (ventral) thalamus, which is where it influences the motor tracts (corticospinal, rubrospinal, vestibulospinal, reticulospinal)
Which branches of the immune system are involved in the pathogenesis of MS?
- Adaptive
- Th1, Th17 cells
- B cells are involved, nobody really knows how, but treatments that target B cells work
- Antigen-presenting cells
- Innate
- Microglial activation
TBH I rembember very little about the immune system (sorry Dr. Wolniak) the point here is that both the innate and adaptive immune systems have a role
Which agents can be used to treat migraine prophylactically?
In general, select an agent that will treat the underlying cause (if one can be found) and won’t exacerbate underlying conditions
- Beta blockers
- Ca2+ channel blockers
- Antidepressantes
- Serotonin antagonist
- Serotonin plasma levels are high preceding a migraine
A brain tumor that has cells with eccentric, prominent nuclei and pink cytoplasm in a 3 month old is most likely…
What genetic mutation is it associated with?
Atypica Teratoid/Rhabdoid tumor
Loss of hSN5/InI1 on chromosome 22
Which virus is most likely to cause meningitis via neuronal transmission?
HSV 2
Describe the “ideal candidate” for intra-arterial catheter-based method for removing an occulsion in a brain vessel
- Small infarct core + large penumbra
- Lots of tissue can be saved!
- >4.5 hours from onset
- IV tPA will be less effective at this point
Reponses of primary motor cortex neurons are related to [muscle force/movement of objects]
Responses of neurons in premotor areas are related to [muscle force/movement of objects]
Reponses of primary motor cortex neurons are related to muscle force
Responses of neurons in premotor areas are related to movement of objects
List 3 common signs of cerebellar disease
Which clinical exam test is used to identify these signs?
Finger-nose-finger test
- Decomposition
- Movement is broken down into parts
- Intention tremor
- Tremor as patient’s finger gets closer to target
- Dysmetria
- Patient misses your finger
What environmental exposures increase risk of MS?
- EBV
- Tobacco smoke
- Low vitamin D
- MS is associated with higher latitudes
- Obesity in youth
- Born in the spring
Describe the presentation of vestibular schwannoma.
How is it managed?
- Unilateral hearing loss
- Vague dizziness
- Hemifacial spasm if tumor is large
- Compressing CN VII
Surgery is curative, but high morbidity (hearing loss, headache, facial paralysis)
Which area of the cerebellum is damaged?
- Postural issues
- Trunk ataxia
- Abnormal VOR eye movement
Middle cerebellar hemispheres
In vestibular neuritis, the head will tilt [toward/away from] the lesion and the eyes will look [toward/away from] the lesion
In vestibular neuritis, the head will tilt away from the lesion and the eyes will look toward the lesion
However, nystagmus will cause the eyes to snap back away from the lesion
The lesion = the side with damaged vestibular nerve
The medial motor pathways coordinate ________
The lateral motor pathways coordinate ________
The medial motor pathways coordinate posture, locomotion
(Vestibulospinal, reticulospinal)
The lateral motor pathways coordinate limb and extremity movement
(Cortiospinal, rubrospinal)
What is required to diagnose parkinsonism?
Bradykinesia
+ at least one of:
- Rigidity
- Postural instability
- Tremor
A baby presents with tachypnea alternating with apnea and less eye movement than expected for developmental age.
What syndrome is most likely?
What sign on brain imaging would confirm your suspicion?
Joubert syndrome
Molar tooth sign is pathognomonic
- Joubert Syndrome:
- Cerebellar vermian hypoplasia
- Abnormal cerebellar peducncles
- Deep interpeduncular fossa
- -> Abnormal breathing pattern
- -> Oculomotor apraxia
- -> Intellectual disability
Which of the following factors is not associated with an increased risk of developing multiple Sclerosis
- Low vitamin D levels
- Alcohol use
- Tobacco smoking
- Residence in temperate (milder) latitudes
b. Alcohol use
List some of the possible presenting symptoms of MS
- Sensory
- Numbness, tingling, burning, tightness
- => NOT ALS
- Visual
- Diplopia, pain on eye movement, vision changes
- Motor disturbance
- Impaired coordination
- Imparired urninary bladder
- Cerebellar symptoms
What kind of hydrocephalus is commonly associated with myelomeningocele and Chiari II malformation?
Obstructive/noncommunicating hydrocephalus
- Failure of primary neurulation
- -> Decreased posterior fossa volume
- -> Obstructed flow through posterior fossa
- -> Hydrocephalus
- noncommunicating (obstructive) hydrocephalus: CSF in ventricles are blocked from reaching subarachnoid space ® enlargement of ventricles proximal to the blockage
Which cancers are most likely to metastasize to the brain?
- Lung
- Melanoma (skin)
- Breast
What are the indications for imaging when a patinet presents with headache?
- Decreased metal status
- Exertional headache
- Nuchal rigidity (neck stiffness)
- Focal neurologic signs
- Onset age >50
- “First or worst” headache of this type
Which neurodegenerative disease pathogenesis involves acitvation of Th1 and Th17 cells and elaboration of new Na+ channels in neuronal axons?
Multiple Sclerosis
- Th1 and Th17 cells are activated in the periphery by APCs
- Reactivated in the CNS
- -> Inflammation
- -> Damage to axons and myelin
- White AND grey matter
- -> New Na+ channels mobilized to try to maintain transmission
- -> Metabolic stress :(
NMO-AQP4 IgG antibodies are characteristic of which disorder?
Neuromyelitis Optica Spectrum Disorder (Devic’s Disease)
What causes Myasthenia Gravis?
Autoantibodies to the ACh receptor
= a post-synaptic issue
- characterized by fluctuating and fatigable weakness w/ repeated activity, ptosis, diplopia
- > Early fatigue, ptosis with upward gaze
- associated w/ thymoma
A _________ headache is caused by activation of a mechanism that results in the release of pain-producing inflammatory substances around the nerves and blood vesels of the head
A migraine headache is caused by activation of a mechanism that results in the release of pain-producing inflammatory substances around the nerves and blood vesels of the head
Which area of the cerebellum is damaged?
- Disorders of fine hand movements
- Disorders of motor planning
Lateral cerebellar hemisphere
What is the mechanism of action of a Triptan drug?
What is it used for?
-
Agonist at the 5HT-1B and 5HT-1D receptors
- -> Vasoconstriction
- -> Prevents release of inflammatory peptides (substance P and CGRP)
- -> Also activates a negative feedback loop to inhibit the further release of 5HT (serotonin)
Triptans are the cornerstone of migraine therapy - must be taken very early during the migraine
What pathological changes occur in CTE?
- Tau deposition/NFT
- Beta-amyloid deposition
- Frontal/temporal atrophy
A patient presents with sudden onset of:
- Right leg weakness and numbness
- Difficulty initiating verbal responses
Which artery is occluded?
Which areas of the brain are affected?
Left ACA
- Motor cortex: leg = medial homunculus
- Sensory cortex: leg = medial homunculus
- Initiating verbal response = Prefrontal cortex, supplemental motor area
What glascow coma scores would be cause for intubation?
GCS ≤8
What disease modifying treatments are available for ALS?
Riluzole (something to do with glutamate)
Edravone (neuroprotective)
What CSF finding is pathognomonic for Guillain-Barre syndrome?
Albuminocytologic dissociation
Output from the [part of the cerebellum] influences the medial descending system
Which tracts?
Output from the vermis influences the lateral descending system
Vestibulospinal, reticulospinal
-> posture/trunk issues
How do you differentiate Parkinson’s disease from Progressive Supranuclear Palsy?
Progressive Supranuclear Palsy will have…
- Falls early in the course
- Impaired upward gaze
- Tao neurofibrillary tangles
- Hummingbird or mickey mouse sign on imaging due to loss of tegmentum and cerebellar peduncles
Whereas PD is unlikely to present with falls, upward gaze not impaired, none of these imaging findings
Which genes are associated with increased MS risk?
HLA DRB1 *1501
Describe the basic physiologic principle of the peripheral vestibular system (the inner ear)
- Hair cells are arranged as “morphologically polarized accelerometers”
- A hair cell in your right ear is paired with one in your left ear with opposite polarity
- Hair cells have a tonic (baseline) rate of firing when you’re not moving
How do you differentiate Parkinson’s disease from Dementia with Lewy Bodies?
Dementia with Lewy Bodies will have…
- Dementia that presents at the same time as parkinsonism, or very early in the course
- Visual hallucinations
- Fluctuations in cognition
Whereas PD might have dementia presenting LATE in the course, will not have visual hallucinations or cognitive changes
List some of the characteristics of tension headache
- Bilateral pressing/tightening
- Photophobia possible
- NOT worsened with routine physical activity
- NO nausea
- Less intense than migraine
What are 3 signs of increased cranial pressure?
Headache
Nausea
Vomiting
What is the most common cause of intracranial hemorrhage?
Hypertension
(followed by aneurysm rupture)
[demyelinating/axonal] neuropathies have a better prognosis
demyelinating neuropathies have a better prognosis
- Ex: Guillain-Barre
What is the typical presentation of oligodendroglioma?
Focal seizures in a young adult
- Patients tend to be younger on presentation with oligodendrogliomas than other patinets
- Remember: histology will show fried egg appearance w/chicken wire vasculature
What is the treatment for vestibular neuritis?
- Manage symptoms
- Vestibular suppressants, anti-emetics
- Start vestibular rehabilitation therapy after a few days
Describe the eye movments associated with vestibular neuritis
Nystagmus in which the eyes drift slowly toward the lesion and snap back to the target
So damage to the right vestibular nerve would result in left beating nystagmus
(Nystagmus is named for the direction of the fast movement)
What are the most common viral causes of encephalitis?
- HSV-1
- West Nile
- Rabies
- HIV
Are anti-MOG antibodies associated with MS?
No
If found, they can rule out MS
Diagnosis is Anti-MOG antibody disease
- Optic neuritis
- Primary demyelinating disease
- vs MS, which is demyelinating 2/2 inflammation
Which tumors are associated with 1p19q deletion?
Oligodendroglioma
(Chicken wire vasculatrue, fried egg appearance)
How do you differentiate Parkinson’s disease from multisystem atrophy?
Multisystem atrophy will have:
- No levodopa response
- Autonomic symptoms
- Urinary incontinence, orthostatic hypotension
- Cerebellar dysfunction
- Hot cross bun sign
Whereas PD responds to levodopa, no autonomic symptoms or cerebellar dysf.
Blockage of the posterior limb of the internal capsuel may be caused by which kind of stroke?
What is the effect?
Lacunar stroke
Pure motor deficit
A patient presents with pure motor or pure sensory symptoms of stroke likely has which kind of stroke?
Lacunar
- These strokes are due to occlusion of a small (lacunar) artery, and affect a single, small area
What are the most common bacterial causes of meningitis?
- Strep. pneumoniae (+)
- Nesseria meningitidis (-)
- Lysteria monocytogenes (+)
- Haemophilus influenzae (-)
Which brain tumor is most likely to present with behavior/personality changes?
Why?
CNS lymphoma
Affects the frontal lobe - changes here = changes in personality/behavior
- No “classic B symptoms” in primary CNS lymphoma
- No night sweats, fever, or weight loss
A brain tumor in an infant with lots of primitive, little blue cells is likely to have what other histopathologic finding?
What kind of tumor is this?
Medulloblastoma (IV)
Likely to have Homer-Wright rosettes
(vs. true rosettes and pseudorosettes are seen in ependymomas)
Parkinsonism affects the [direct/indirect] pathway in the basal ganglia
Huntingtion’s affects the [direct/indirect] pathway in the basal gangila
Parkinsonism affects the direct pathway in the basal ganglia
Huntingtion’s affects the indirect pathway in the basal gangila
Which brain tumors are associated with neurofibromatosis-2?
Meningioma
Ependymoma
Visual apraxia/ataxia is associated with damage to the ______ lobe. This is associated with deficits in the [perception/action] pathway
Describe the deficit
Visual apraxia/ataxia is associated with damage to the parietal** lobe. This is associated with deficits in the **action pathway
Patient cannot orient their hand to fit it through a slot; they have problems completing the action
- Parietal lobe
- Ventral stream
- “action”/”where” pathway
- Magnocellular
- Temporal lobe
- Ventral stream
- “perception”/”what” pathway
- Parvocellular
What are the effects of an SOD1 mutation?
Mutations in this gene may have a role in which neuromuscular disease?
SOD1 is involved in clearing ROS from cells
Mutations may be associated with ALS
What virus is associated with recurrent aseptic meningitis?
HSV-2
What hormone is implicated in the pathogenesis of migraine?
Serotonin
Plasma levels are often high preceding a migraine
Several prophylactic therapies are serotonin antagonists
Triptans (used to treat migraine acutely) are agonists at the 5HT-1D and 5HT-1B receptors; activation -> feed back to inhibit further release of 5HT (serotonin)
What is the output neuron of hte cerebellar cortex?
Purkinje cell
- GABAnergic
Movements involving the “where” or “action” pathway (ex: unlocking a door) involve the _____ cortex
Movements involving the “what” or “perception” pathway (ex: getting up and going to class) invovle the _____ cortex
Movments involving the “where” or “action” pathway (ex: unlocking a door) involve the parietal cortex
Movements involving the “what” or “perceptrion” pathway (ex: getting up and going to class) invovle the prefrontal cortex
How can you differentiate between the clinical presentations of viral and bacterial meningitis?
Any neurologic symptoms/behavior change/confusion = bacterial
What are the two clinical phenotypes of MS?
- Relapsing-remitting
- Acute, transient, neurological symptoms during attacks
- Return to baseline between attacks
- Evolves to gradually worsening (secondary progressive
- Progressive onset (primary progressive MS)
- Spinal cord symptoms
- Relapses may occur, but less frequently
A patient presents wiht sudden onset of:
- R face and arm weakness
- R sided sensory neglect
- Global aphasia
Which artery is occluded?
Which areas of the brain are affected?
Left MCA is occluded
- Left Lateral motor homunculus (precentral gyrus)
- Weakness
- Left parietal lobe
- Neglect
- Left Broca’s area (frontal) and Wernicke’s area (temporal)
- Global aphasia
Which neurotransmitter is implicated in ALS?
Glutamate
Which area of the brain relays the major output pathway from the cerebellum?
Ventral thalamus
Also relays the major output pathway from the cerebellum
Rosenthal fibers are associated with which kind of brain tumor?
Pliocytic astrocytoma (I)
What causes LEMS?
Destruction of P/Q Ca2+ channels in the presynaptic membrane
-> no initial response stimulation, then a large response on repeated stim
Which 3 types of brain cells are most at risk during global ischemia?
Why?
- Pyramidal CA1 in the hippocampus
- Purkinje in the cerebellum
- Pyramidal in the cerebral cortex (layers III and V)
These cells are large and have high metabolic requirements
(Watershed areas are also at risk - these are areas at the most distal ends of the MCA, ACA, and PCA; kind of in between blood supplies)
What CSF findings are suggestive of MS?
Oligoclonal bands
[vestibular neuritis/benign paroxysmal vertigo] is caused by damage to vestibular nerve, resulting in decreased input to the vestibular system
vestibular neuritis is caused by damage to vestibular nerve, resulting in decreased input to the vestibular system
Damage to the vestibular nerve (not the inner ear)
Epidural hemorhage is usualy due to [venous/arterial] bleed, and looks ________ on MRI
Subdural hemorrhage is usually due to [venous/arterial] bleed, and looks ________ on MRI
Epidural hemorhage is usualy due to arterial (middle meningeal artery) bleed, and looks lens-shaped on MRI
Subdural hemorrhage is usually due to venous (bridging vein) bleed, and looks crescent-shaped on MRI
What is the current recommendation for folic acid supplementation to prevent neural tube defects, as per the CDC?
All women of childbearing age should consistently take folic acid (400 mcg), all the time
- To prevent neural tube defects, needs to be taken for at least 1 month prior to conception and throughout the first 2 months of pregnancy
- Most women don’t know if they will become pregnant or if they are pregnant for the first month or so - best to take it all the time
Visual agnosia is associated with damage to the ______ lobe. This is associated with deficits in the [perception/action] pathway
Describe the deficit
Visual agnosia is associated with damage to the temporal** lobe. This is associated with deficits in the **perception pathway
- Temporal lobe = ventral stream = “perception”/”what” pathway = parvocellular
Patinet can move their hand to put it into a slot, but they can’t pick out a line that matches the slot or describe the orientation. They have issues perceiving the orientation in space
- Parietal lobe
- Ventral stream
- “action”/”where” pathway
- Magnocellular
- Temporal lobe
- Ventral stream
- “perception”/”what” pathway
- Parvocellular
How is chorea treated?
Medications that block dopamine signaling
- Neuroleptics
- Dopamine receptor blockers
- Dopamine-depleting agents
A patient presents with acute-onset
- Left hemiparesis
- Right hemiataxia
- Dysarthria
Which artery is occluded?
Which tracts are affected?
Crossed findings => brainstem lesion
Basilar artery is occluded
- Right corticospinal tract -> L hemiparesis
- Right pontine nuclei -> R hemiataxia
- R corticobulbar -> dysarthria
What is required to diagnose MS?
Any of the following apparently?
- Dissemination in Time
- Characteristic lesions at multiple different time points
- Dissemination in Space
- Typical lesions in multiple characteristic locations
- CSF oligoclonal bands + typical lesions
Note: Dawson’s fingers on MRI are usually present in MS, but can also occur in people who do not have MS
A paient presents with sudden onset of
- Left visual field homonymous vision loss
- Left sided numbness
Which artery is occluded?
Which areas of the brain are affected?
Right PCA
- Right visual cortex (occipital lobe)
- Left, homonymous visual field deficit
- Right thalamus
- Left numbness
What is the gold standard imaging method for looking at infarcts?
MRI with IV contrast
(T2 weighted)
A patient presents with acute-onset
- Right dysmetria and ataxia
- Headache
- Nausea/vomiting
- Dizziness
Which artery is occluded?
Which tracts are affected?
Right PICA is occluded
- Right dysmetria and ataxia - cerebellum lesion
- Headache
- Nausea/vomiting - area postrema
- Dizziness - vestibular connections
What is the most common malignant primary brain tumor in adults?
Glioblastoma multiform (IV)
- Contrast-enhancing mass with central necrosis on imaging
What kind of brain tumor has whorls and intranucelar pscudoinclusions on histopath?
Meningioma
Neuromyelitis optica spectrum disorder is not associated with which of the following ?
- Blood test positive for anti-MOG antibody
- Blood test positive for aquaporin 4 antibody
- Gradually progressive neurologic disability
- Presentation with acute attacks resulting from lesions in the brainstem
c. Gradually progressive neurologic disability
- NMOSD is not progressive
- Has acute attacks, but they do not get worse over time
A patient presents with fever, headache, and dysphagia. LP shows 3 RBCs, 48 WBCs (95% lymphocytes), protein 43, glucose 57
What is your diagnosis?
What treatmetn should be initiated?
- CSF suggests aseptic/viral meningitis but dysphagia is a neurologic symptom
- Makes uncomplicated viral meningitis unlikely
- HSV-1 encephalitis is likely - give acyclovir empirically
Cerebral amyloid angiopathy is associated with stroke in which location?
Lobar
What is the treatment for benign positional paroxysmal vertigo?
Vestibular maneuvers to coax the loose otoliths/otoconia out of the semicircular canal
Which kind of brain tumor might appear in the brain or the spinal cord?
Ependymoma
- Spinal cord is usually in older adults
- 4th ventricle more common in kids
What are the two subtypes of Guillain-Barre Syndrome?
How do their treatments differ?
- Acute inflammatory demyelinating polyneuropathy (AIDP)
- Plasmapharesis + IVIG
- NO STEROIDS
- Chronic inflammatory demyelinating polyneuropathy (CIDP)
- Plasmapharesis + IVIG + steroids
