Neuro Flashcards
Holoprosencephaly develops from a defect in the ____encephalon via ____ gene patterning.
Prosencephalon
SHH signaling
How can maternal Type I diabetes affect the baby’s brain?
Can cause anencephaly
What is an Arnold-Chiari malformation?
Cerebellar herniation through the foramen magnum
I = just the tonsils II = tonsils + vermis
What is a Dandy Walker malformation?
Agenesis of cerebellar vermis
How is Neuroleptic Malignant Syndrome (NMS) treated?
- Discontinue causative agent (anti-psychotic)
2. Dantrolene (a direct-acting skeletal muscle relaxant that works by inhibiting Ca release in the SR)
Alanine and glutamine are important for transporting _________ throughout the body. Specifically alanine is used in the glucose-alanine cycle to remove excess amounts of this substance in the liver.
Alanine then goes on the be used as a carbon skeleton for gluconeogenesis.
Nitrogen
Alanine -> transaminated to form pyruvate -> alpha-KG then takes amino group in TCA cycle -> glutamate formed
Acute dystonic reactions (spasmofic torticollis) is an extrapyramidal symptom due to recent initiation of what medication?
Antipsychotics
Work via D2 dopaminergic inhibitions
The most common cause of retinitis in HIV-positive patients is ____ infection. How is it treated?
CMV
Treat with ganciclovir
Occurs when the CD4 count is <50
Flow of CSF:
Generated by the pia matter capillaries/ependymal cells ->
Lateral ventricles -> interventricular foramina of Monro ->
Third ventricle -> cerebral aqueduct ->
Fourth ventricle -> 2 lateral foramina of Luschka OR midline foramen of Magendie -> end in subarachnoid space where CSF enters the venous circulation via the arachnoid villi/granulations.
Trochlear nerve damage causes what functional difficulties?
Difficulty going down stairs and reading
due to vertical diplopia most obvious when the affected eye looks down and toward the nose
Impairment of downgaze when the eye is adducted.
What direction does the eye move with a CN III oculomotor nerve damage/palsy?
Down and out
What are the clinical findings of Von Hippel-Lindau disease?
Capillary hemangioblastomas in the retina and/or cerebellum
Congenital cysts and/or neoplasms in the kidney, liver, or pancreas.
At increased risk for (bilateral) renal cell carcinoma
Inheritance = autosomal dominant
Damage to the brainstem _______ the level of red nucleus (midbrain tegmentum, pons) causes DECEREBRATE (EXTENSOR) posturing.
At or below
Most of the nervous system is derived from neuroectoderm, which important thing in the brain is derived from mesoderm?
Microglia
Immune destruction of schwann cells in Guillain Bare is caused by molecular ______.
Mimicry
Acoustic neuroma aka _______ Schwannoma
Vestibular
Merkel disc vs. Ruffini endings?
Merkel = static touch and position Ruffini = sustained pressure and stretch (slow adapting)
Which nerve coating is the hardest to penetrate?
Perineurium
What is the major neurotransmitter associated with REM sleep?
Acetylcholine
What is the root/origin of the phrenic nerve?
C3-C5
What brain structure is particularly sensitive to hypoxia?
Hippocampus
What is the treatment for subarachnoid hemorrhage?
Calcium channel blocker
In addition to worst headache of my life, what other symptoms might you see in a subarachnoid hemorrhage?
Photophobia and nuchal rigidity
Hoarseness is a pretty specific clue that you are dealing with ?
Wallenberg/lateral medullary syndrome - lesion in PICA
Other sx:
Contralateral nystagmus
No gag reflex
Ipsilateral Horner
Ipsilateral loss of pain and temp on face
Ipsilateral paralysis of tongue
Contralateral hemiparesis
and contralateral loss of proprioception/sensation
Medial medullary syndrome - lesion in anterior spinal artery
Ipsilateral facial paralysis Reduced lacrimation and salivation Absent corneal reflex Contralateral loss of pain and temperature in body IPSILATERAL loss of pain and temperature in face Ipsilateral ataxia
AICA
Loss of vision
Hemianopsia with macular sparing
PCA
Locked in syndrome vessel?
Basilar artery
Only blinking is spared
Impaired verbal repetition = damage to?
Arcuate fasciculus
What -seemingly unrelated- diseases predisposes to berry aneurysms?
APCKD - adult polycystic kidney disease
Ehlers Danlos
Marfan
What drugs are used to PROPHYLACTICALLY treat migraines?
Propranolol
Tricyclic antidepressants
Calcium channel blockers
Which headache can be associated with Horner syndrome?
Cluster headaches
Parkinson’s = ______ tremor
Resting
MS = ________ tremor
Intention
What are Lewy bodies composed?
Alpha-synuclein inclusions
Huntington’s = defect in the _____ (part of the _____)
Caudate nucleus
Part of the striatum
Huntington = Chromosome ___
4
Friedrich’s Ataxia = Chromosome ___
9
What is the route of transmission of polio?
Fecal-oral
What is the difference between use of atropine and pralidoxime for the treatment of organophosphate poisoning?
Atropine acts centrally and reverses cholinergic effects on MUSCARINIC receptors only (i.e. DUMBELS mnemonic)
Atropine therefore does not treat muscle paralysis…Pralidoxime reactivates cholinesterase and thus degrades excess ACh affecting both musarinic AND nicotinic effects.
Uncal herniation most often affects the ____lateral CN ____.
Ipsilateral
CN III -> oculomotor nerve palsy and fixed DILATED pupil
Baclofen, a GABA-B agonist is an effective monotherapy used to treat ______ which is seen in _____ and ____.
Spasticity seen both brain and spinal cord disease (e.g. MS)
In Wilson disease, ceruloplasmin levels will be ___.
LOW!
Urinary copper excretion will be high and copper content in liver will be high
How do you detect Wilson Disease other than frank copper levels?
Slit-lamp testing to view Kayser-Fleischer rings
Serotonin = _____ nucleus
Raphe
Corneal reflex = ____ branch of CN ____. and motor = ________
Sensory: Nasociliary branch of V1
Motor: Temporal branch of VII
Both enter through the superior orbital fissure
What drug is given to treat Wilson Disease?
D-Penicillamine
What drug is given to treat Hereditary Hemochromatosis?
Deferoxamine
Explain Conversion disorder vs Somatic symptom disorder
Conversion disorder is a type of somatic symptom disorder neurologic symptom incompatible with any known neurologic disease; often acute onset/associated with stress.
Pure somatic symptom disorder is characterized more by excessive and persistent health anxiety and preoccupation with multiple somatic symptoms but they do not have the loss of function incompatible with recognized neurological illness.
What is the mechanism of action of phenytoin?
Inhibits neuronal high-frequency firing in the cortex by reducing the ability of sodium channels to recover from inactivation.
Pie in the sky = _______ region tumor.
Temporal
What effect do fluorinated anesthetics have on the brain?
CNS depression
Increased cerebral blood flow/ICP due to decreased vascular resistance in the brain
Narcolepsy is associated with low levels of what neuropeptides int eh CSF?
Hypocretin-1 (orexin A) and Hypocretin-2 (orexin B)
The decrease in acetylcholine levels in Alzheimers is caused by a deficiency of what?
Choline acetyltransferase most notably in the basal nucleus of Meynert (which participates in memory and cognition)
Months to years after brain infarction, the necrotic area appears as a cystic cavity surrounded by:
A wall composed of dense fibers formed by astrocytic processes (glial scar)
Ewing sarcoma is associated with what translocation?
t(11;22)
Tetanus toxin blocks release of inhibitory neurons _____ and _____ to cause muscle spasm and tetany.
Glycine and GABA
Locus ceruleus = _____ synthesis
Norepinephrine
The etiology of lacunar infarcts is most often: ____ and ____ rather than embolism from carotid atherosclerosis or valvular disease because those are typically larger and often thus cortical infarcts.
Lipohyalinosis and microatheroma formation
Vertical axis nystagmus = _______ vertigo
Central
You can also have horizontal nystagmus
Peripheral vertigo is only horizontal
Despite what the name implies, cholestatomas are composed of ______.
Keratin/squamous cell debris
Uncal herniation aka _________ herniation
Transtentorial
In addition to motor output to the face, what other nerve functions run with CN VII?
- Parasympathetic innervation to the lacrimal, submandibular, and sublingual salivary glands
- Special afferent taste to anterior 2/3 tongue
- Somatic afferents from the pinna and external auditory canal
High plantar arch AND foot drop and problems with foot drop = what disease?
Charcot Marie Tooth
May also see kyphoscoliosis
High plantar arch AND hypertrophic cardiomyopathy = what disease?
Friedrich’s Ataxia
Flame-shaped retinal hemorrhages are caused by what common condition? What are other ophtho findings in this condition?
HTN
AV nicking
Arterial wall thickening
Cotton wool spots
Wrist and finger extension = _____ nerve
Radial
Lacunar stroke/hemiballism/subthalamic nucleus damage
.
What is (and what is another name for it) pseudotumor cerebri?
Idiopathic intracranial hypertension
Elevated intracranial hypertension in the absence of ventricular enlargement on imaging. Typically presents in young, obese women with headache, papilledema and possible vision loss due to optic neuropathy.
Sharp stabbing pains in extremities + sensory loss = ?
Tertiary syphilis/tabes dorsalis
Stabbing pains known as “lancinating pains”
May also see Argyll-Roberts pupils
Chronic glaucoma = slow onset loss of ______ vision.
Peripheral
Epinephrine is _____ in acute glaucoma, but the _____ treatment in chronic glaucoma.
Contraindicated in acute glaucoma
Common treatment for chronic glaucoma
Acute onset encephalitis with temporal lobe edema = what infection?
HSV 1
Can be dx with a “viral pattern” on CSF tap:
Lymphocytes
Increased protein
erythrocytes
What is the major cause of spontaneous lobar hemorrhages in adults >60?
Cerebral amyloid angiopathy (beta amyloid deposition similar to the amyloid seen in Alzheimers)
often are recurrent and affect the occipital and parietal lobes
In anesthetic drugs, how can you remember if a drug is an ester or an amide?
Amides have 2 i’s in the name
tx for essential tremor:
beta blocker (propranolol)
Donepezil is a palliative tx for what?
Alzheimer’s
What nerve root is the patellar reflex?
L4
What nerve root is the achilles reflex?
S1
Vertigo AND hearing loss/tinnitus = _______ caused by _______
Meniere’s Disease
Increased volume of endolymph
Internal capsule injury = pure _____ weakness
motor
Homonymous hemianopia with macula sparing = ____ infarct.
PCA
The striate cortex receives information from the ipsilateral LGN (with contralateral visual field information)
Muscle wasting
Frontal balding
Cataracts
Presents between ages 20-40
=??
Myotonic dystrophy
AD, trinucleotide repeat
What is the pathogenesis of HIV-associated dementia?
Inflammatory activation of microglial cells
Parinaud syndrome = damage to the dorsal midbrain causing what classic finding?
Limitation of upward gaze
Often caused by a pineal mass causing compression and thus may present with papilledema, headache, and vomiting cause by hydrocephalus.
What is the #1 side effect of SSRIs (and also the #1 cause for non-adherence)?
Sexual dysfunction
Which anesthetic class is associated with hepatocellular damage and liver toxicity?
Halogenated inhaled anesthetics
e.g. halothane, enflurane, isoflurane, sevoflurane
What is the primary adverse effect of second generation antipsychotics (e.g. olanzapine and clozapine, etc)
Metabolic adverse effects.
Patients should be monitored for weight gain, waist circumference, bp, fasting glucose, and lipid profile.
Why are thiazide diuretics contraindicated in patients receiving lithium?
Thiazide diuretics will cause minor salt wasting/hyponatremia (that’s their job) and to compensate the kidneys will try to take it back/absorb more cations (and thus more lithium -> lithium toxicity)
How do you treat drug-induced Parkinsonism?
Benztropine, a centrally acting antimuscarinic
Left-sided frontal lobe lesions cause ______.
Right-sided frontal lobe lesions cause ______.
Left = apathy and depression Right = disinhibited behavior
