atrophy of caudate nucleus
huntington’s disease
depigmentation within the substantia nigra pars compacta
parkinson’s
symmetric lesions in the paraventricular regions of the thalamus and hypothalamus, mammillary bodies, and periaqueductal region of the midbrain
wernicke’s and korsakoff’s
neurofibrillary tangles
think:
think alzheimer’s
places in the brain not protected by the BBB
OVLT (organum vasculosum of the lamina terminalis; senses change in
osmolarity), area postrema - in the floor of the fourth ventricle (responds to emetics)
which area of the brain makes:
ADH
oxytocin
ADH: supraoptic nucleus
oxytocin: paraventricular nucleus
part of the hypothalamus responsible for:
hunger satiety cooling off/parasympathetic heating up/sympathetic circadian rhythm
hunger - lateral - zap the lateral and you shrink laterally
satiety - ventromedial - zap the ventromedial and you grow medially and ventrally
cooling - anterior hypothalamus - A/C = anterior cooling
heating - posterior - heated seats heat your posterior
circadian rhythm - suprachiasmatic nucleus - you need sleep to be charismatic (SCN –> NE release –> pineal gland –> melatonin)
part of the brain responsible for REM eye movement
PPRF paramedian pontine reticular formation
if you have a lesion here, your eyes look away from the side of the lesion
desmopressin acetate
mimics ADH, used to treat betwetting
preferred over imipramine because of the SE
mneumonic for stages of sleep
BATS Drink Blood
awake - beta awake (eyes closed) - alpha N1 - theta N2 - sleep spindles and K complexes N3 - Delta
REM - beta
thalamus nuclei
input from what nerve?
what sense is it?
VPL
VPM
LGN
MGN
The role of the thalamus is the major relay for all ascending sensory information except olfaction
VPL - ventral posteriolateral - input is spinothalamic and dorsal columns/medial lemniscus - pain and temp, pressure, touch, vibration, and proprioception - goes to the primary somatosensory cortex
VPM - ventral posteriomedial - trigeminal and gustatory pathway - face sensation and taste - goes to primary somatosensory cortex (put Makeup on your face)
LGN - Lateral geniculate nucleus - from CN II - does vision - goes to the calcarine sulcus - Lateral = Light
MGN - medial geniculate nucleus - from the superior olive and inferior colliculus of tectum - does hearing - goes to auditory cortex of temporal lobe - Medial = Music
VL - ventrolateral - from basal ganglia, cerebellum, does motor stuff
what do you get form lateral lesions in the cerebellum
medial lesions?
lateral lesions - voluntary movement of the extremities; when injured, get a propensity to fall toward injured (ipsilateral) side
levels of what change in the brain of someone with huntingtons
Caudate loses ACh and GABA
CAG repeat disease
sudden, wild failing of 1 arm
what is it called
where is the lesion
hemiballismus (“half of body ballistic”)
lesion is contralateral subthalamic nucleus (lacunar stroke - often from uncontrolled hypertension)
athetosis
slow, writhing movements; especially seen in fingers
lesion in basal ganglia (huntingtons)
primidone
used to treat essential tremor
when do you get a slow, zigzag motion when pointing/extending toward a target
cerebellar dysfunction (intention tremor)
patient has agraphia, acalculia, finger agnosia, and left-right disorientation
what happened
left parietal-temporal cortex (visual association cortex aka the angular gyrus)
Gerstmann syndrome
someone is in a coma
what part of their brain lesion specifically is responsible for reduced levels of arousal and wakefulness
reticular activating system (midbrain)
confusion, ophthalmoplegia, ataxia, memory loss,
wernicke-korsakoff syndrome
B1 (thiamine) deficiency and excessive EtOH
can be precipitated with sugar in the absence of B1
inability to make new memories
where in the brain is lesioned
anteriograde amnesia - hippocampus
an elepheant never forgets
but
a hippo makes new memories
where are your lesions if the eyes look
towards the lesion?
away from it?
towards a frontal eye field lesion
away from a paramedian pontine reticular formation lesion (abducens nerve)
from hi to low and low to hi correcting sodium mneumonic
“From low to high, your pons will die”
(Central pontine myelinolysis)
“From high to low, your brain will blow”
(cerebral edema/herniation)
Lewy bodies composed of alpha-synuclein - intracellular eosinophilic inclusion
parkinsons
damage in the brain in severe hypotension - Sx
upper leg/arm wea
MCA (Middle cerebral artery) stroke Sx
(effects temporal areas and posterior frontal area)
Sx: contralateral paralysis - upper limb and face
Contralateral loss of sensation - upper and lower limbs and face
Aphasia if in dominant (left) hemisphere
Hemineglect if lesion affects non dominant (usually right) side
ACA (anterior cerebral artery) stroke Sx
contralateral paralysis of lower limb
contralateral loss of sensation of lower limb
lenticulostriate artery stroke Sx, cause, area of damage
contralateral hemiparesis
caused by unmanaged hypertension (lacunar infarct)
lesion in the striatum, internal capsule
Deviation of the tounge to the right
limb weakness on the on the left
loss of discriminative tough, proprioception, and vibration sense on the left
where is the infarct
right anterior spinal artery
this is called medial medullary syndrome
(hypoglossal nerves don’t cross over)
medullary pyramid and corticospinal fibers of the pyramidal tract damage causes weakness
medial lemniscus is responsible for loss of discriminative touch, proprioception, and vibration sense
Vomiting, vertigo, nystagmus, decreased pain and temp sensation from ipsilateral face and contralateral body; dysphagia, hoarsness, decresed gag reflex, ipsilateral horner syndrome, ataxia, dysmetria
where is the stroke/lesion
PICA
lateral medullary syndrome (wallenberg)
Nucleus ambiguus effects are specific to PICA lesions “don’t PICA horse (hoarse) that can’t eat (dysphagia)”
vomiting, vertigo, nystagmus, paralysis of face, decreased lacrimation, salivation, decreased taste from anterior 2/3, decreased corneal reflex. decreased pain and temp sensation, decreased ipsilateral hearing, ipsilateral horners
lateral pontine syndrome
facial nucleus effects are specific to AICA lesions “facial droop means the AICA’s pooped)
locked in syndrome
stroke locations
basilar artery
pons, medulla, lower midbrain, corticospinal and corticobulbar tracts, ocular cranial nerve nuclei, paramedian pontine reticular formation.
eye is down and out, with ptosis and pupil dilation
what artery
posterior communicating artery
lesions are typically aneurysms, not strokes.`
“worst headache of life”
rupture of a berry aneurysm leads to subarachnoid hemorrhage
epidural hematoma rupture of what artery
rupture of middle meningeal artery (branch of maxillary artery) often secondary to fracture of temporal bone
lucid period
LMN neuron lesion with flaccid paralysis
what part of the spinal cord was damaged
destruction of the anterior horns
get poliomyelitis and spinal muscular atrophy (werdnig-hoffmann disease)
enzyme deficit you might see in ALS
defect in superoxide dismutase 1
cause of tabes dorsalis. Sx?
tertiary syphilis. Results from degeneration (demyelination) of dorsal columns and roots
impaired sensation and proprioception and progressive sensory ataxia (inability to sense or feel the legs –> poor coordination)
syringomyelia - lesion region
anterior white commissure of the spinothalamic tract (second order neurons)
get bilateral loss of pain and temperature sensation, seen with Chiari I malformation; can expand and affect other tracts
what causes subacute combined degeneration of the spinal cord
vitamin B12 or vitamin E deficiency
get demyelination of dorsal column, lateral corticospinal tracts, and spinocerebellar tracts; ataxic gait, parasthesia, impaired position and vibration sense
blown pupil
what arteries could the stroke have occurred in
posterior cerebral
superior cerebellar
(cranial nerve III exists the midbrain between these two arteries)
patient has “lateral gaze palsy” or “nystagmus on lateral gaze” where is the lesion (nucleus and artery)
in CNVI (abducens) in the middle of the pons pontine branches of the basilar artery
mneumonic for reflex origins in the spinal cord
S1, 2—“buckle my shoe” (Achilles reflex)
L3, 4—“kick the door” (patellar reflex)
C5, 6—“pick up sticks” (biceps reflex)
C7, 8—“lay them straight” (triceps reflex)
inability to look up
where is the lesion
parinaud syndrome
paralysis of conjugate vertical gaze due to lesion in the superior colliculi of the brain stem (your eyes are above your ears, and the superior colliculus (visual) is above the inferior colliculus (auditory) (can be caused by a pinealoma)
nerve that innervates the superior oblique
trochlear (CN IV)
function of nucleus solitarius
Visceral sensory information (taste, baroreceptors, gut distention)
its a vagal nucleus
gets inputs from facial, hypoglossal, and well as the vagus
function of the nucleus ambiguus
motor innervation of pharynx, larynx, and upper esophagus (swallowing, palate elevation)
it is a vagal nuclei, but also gets inputs from IX, XI
dorsal motor nucleus
on of the vagal nuclei along with solitarius and ambiguus
sends autonomic (parasympathetic) fibers to the heart, lungs, upper GI
brain abnormality of autopsy of patau baby?
holoprosencephaly
what areas of the brain are effected during paralysis in a patient with central pontine myelinolysis
Corticobulbar - muscles of the face, head, neck
Corticospinal - torso, upper and lower limbs
lesions in medial longitudinal fasciculus cause what
often seen in what disease
The lesion causes Internuclear ophthalmoplegia
the MLF coordinates both eyes to move in the same horizontal direction. they are highly myelinated because then must communicate quickly so eyes can move at the same time.
lesions seen in people with demyelinating disease like MS
(MILFs (MLFs) get MS, and you gotta watch them walk by)
mech of succinyl choline
binds to ACh receptors irreversible for the first moments, but can be dissociated later.
used to paralyze people in surgery
reverse it with neostigmine later
CD count is like 24
demyelination of CNS due to destruction of oligodendrocytes, rapidly progressive and usually fatal
what organism
increased risk assc with what drug
JC virus causing progressive multifocal leukoencephalopathy (PML)
JC virus reactivation causes demyelination
JC virus is a polyomavirus (DS and circular DNA) along with BK virus (JC: junky cerebellum, BK: Bad Kidney)
increased risk with natalizumab
Tx for absence (petit mal) seizures
mech
SE
Ethosuximide (Sux to have Silent Seizures)
blocks T-type calcium channels.
EFGHIJ—Ethosuximide causes
Fatigue, GI distress, Headache,
Itching, and Stevens-Johnson
syndrome
new onset seizures in an HIV-positive patient with CD count less than 100
what do you see in brain
tx?
toxoplasmosis
ring enhancing lesions
sulfadiazine and pyrimethamine (dihydrofolate reductase inhibitor) (martin shkreli made pyrimethamine really expensive)
subdural hematoma in an old person
what veins
rupture of the bridging veins
beta interferon is used to treat what
MS
alpha interferon is used to treat what
chronic hepatitis B and C, kaposi sarcoma, hairy cell leukemia, condyloma acuminatum, renal cell carcinoma, malignant melanoma
interferon gamma is used to treat what
Chronic granulomatous disease (NADPH oxidase deficiency)
human leukocyte antigen associated with MS
HLA-DR2
this one is also associated with hay fever, SLE, and goodpasture
blind as a bat, red as a beet… fill in the rest
what is it
Tx?
blind as a bat, red as a beet, mad as a hatter, hot as a hare, dry as a bone
sx of atropine overdose (cholinergic antagonist) (can be from eating the black shiny berries of the belladona plant)
treat with an acetylcholinesterase inhibitor like physostigmine (ups the amount of ACh available to the body) if they are super acutely poisoned and unstable
carbamazepine mech
SE
increases Na channel inactivation
can cause agranulocytosis
can induce P-450 (greasy carbs)
can cause SIADH, stevens-johnson syndrome
flashback: how do thiazides cause hyperglycemia
opens the ATP sensitive potassium channels of pancreatic beta cells, which STOPS depolarization, which stops insulin secretion
where is ACh made in the brain
basal nucleus of Meynert
patient is fluent in speech, has intact comprehension, but impaired repetition
what type of aphasia
where is the lesion
conduction aphasia, damage to the arcuate fasciculus
patient has vertigo, hearing loss, and tinnitis
meniere disease
increased or decreased excretion of endolymph
kid is sick with rash and then develops dementia, myoclonus, personality changes years later
what was the initial rash
measles rash (rubeola), starts at the neck and head and spreads downward (also get koplik spots)
mutation in people with neurofibromatosis type 1
mutated NF1 tumor suppressor gene (normally suppresses RAS) on chromosome 17
mech of damage in lambert-eaton myasthenic syndrome
assc with what cancer
what happens when you administer AChE inhibitor
autoantibodies to presynaptic Ca channel leading to decreased ACh release
small cell lung cancer
minimal effect with AChE inhibitor (where it would reverse symptoms in myasthenia gravis)
embryonic origin of microglia cells
mesoderm, like all macrophages they are derivative of blood monocytes
alpha-synuclein is in what disease
parkinsons
what area of the brain may be ablated in treatment of parkinsons disease
globus pallidus internus
what drug do you use to diagnose myasthenia gravis
edrophonium
mech of sumatriptan
5HT1B/1D AGONIST!
drugs that exhibit zero order elimination kinetics
phenytoin (calcium channel blocker that is first line for prophylaxis against status epilepticus) - can also cause megaloblastic anemia, hirsutism, SJS, induction of CYP, and gingival hyperplasia
ethanol
aspirin
physostigmine vs neostigmine
neo = no CNS penetration
physo = “phyxes” atropine overdose and penetrates the CNS
damage to what structure in the brain causes internuclear ophthalmoplegia
medial longitudinal fasciculus (MLFs in MS)
on gaze to the left, the primary movement is started in the left cranial nerve (CN VI (trochlear)), and cannot be transmitted to the right CN III nucleus via the right medial longitudinal fasciculus because of demyelination in MS. As a consequence, the right eye cannot adduct.
convergence in usually intact as this maneuver does not utilize the MLF pathway
most common causes of meningitis in newborn (0-6mo)
empiric Tx?
group B strep (agalactiae) - most common
E coli
listeria - tumbling motility, gram + rod with LPS - give ampicillin
ceftriaxone, vanco, and add ampicillin if listeria is suspected
intracellular eosinophillic inclusions in the brain
parkinsons - these are called lewy bodies and they are made of alpha-synuclein
labs in someone with viral meningitis/encephalitis
high WBC with lymphocytic or monocytic predominance
normal protein, glucose, and opening pressure
bloody CSF on lumbar puncture in aids patient who had a seizure
what is it
Tx?
where in the brain?
HSV causing viral encephalitis
treat with acyclovir
in the temporal and deep frontal lobes
tumor in the brain
small dark nuclei and a light clearing around the nuceli
fried egg appearance
oligodendroglioma - rare, slow-growing tumor commonly seen in the frontal lobes.
drug that ends in -azine
one of the typical antipsychotics along with haloperidol
in alzheimer’s, what protein is found in the cytoplasmic inclusions of neurons?
what protein is found outside the neurons as plaques?
cytoplasmic inclusions: tau (composes the neurofibrillary tangles)
outside the neurons as plaques: beta-amyloid
organophosphate-based pesticides can do what to humans
tx?
cause excess cholinergic activity (SLUDGE)
treat with atropine (muscarinic antagonist)
bells palsy - UMN lesion or LMN lesion?
LMN lesion
if the ipsilateral forehead is moving normally, it is an UMN lesion (cerebrovascular event) (the forehead is bilaterally supplied by UMNs
what inhaled anesthetic can cause seizures?
which causes nephrotox?
which causes hepatotox?
seizures - enflurane
nephrotox - methoxyflurane
hepatotox - halothane
polio causes damage to what part of the spinal cord
anterior horn cells
degeneration of the posterior columns and corticospinal tracts in a lady with tingling fingers
vitamin b12 deficiency
treatments for huntingtons
tetrabenazine and reserpine - inhibit vesicular monoamine transporter (VMAT), limit dopamine vesicle packaging and release
haloperidol - dopamine receptor antagonist
left side weakness
right side tounge deviation
left side loss of sensation and proprioception from the body, sparing face
where is the damage in the CNS
medial medullary syndrome
weakness and loss of sensation - damage to lateral corticospinal tract at the level of the medullary pyramid
tounge deviation - damage to cranial nuclei XII
epilepsy drug that can cause neural tube defects
valproic acid
mech of tetanospasmin
protease that cleaves SNARE proteins (proteins required for vesicle release)
toxin prevents release of inhibitory (GABA and Glycine) neurotransmitters from Renshaw cells in spinal cord
common causes of meningitis in children (6mo-6yr)
most common - S. pneumo - gram pos diplococci, alpha hemolytic
N meningitidis - gram neg diplococci, maltose fermenter (gonorrhoeae doesn’t ferment)
H flu type B (esp if not vacced) - gram neg coccobacilus, requires factors V and X
HSV - going to find blood in the CSF probs
number one cause of meningitis in teens
N meningitidis - gram neg diplococci
hypopigmentation, eczema, and hyperreflexia with a strange odor in a kid
what AA becomes essential
kid has PKU
tyrosine becomes essential (cannot convert phenylalanine to tyrosine)
hypopigmentation is from impaired melanin synthesis
decreased alpha fetoprotein in pregnant woman: ?
increased?
decreased: down syndrome (but elevated beta-hCG), edwards syndrome (also has decreased beta-hCG)
increased: neural tube defects
trinucleotide repeat expansion diseases
Tri HUNTING for MY FRIED EGGS (X)
huntington - CAG (Caudate loses ACh and GABA)
myoTonic dystrophy - CTG (muscle Tone)
friedreich ataxia - CAA (AA - Ataxia)
fragile X - CGG
two types of drugs used to treat alzheimers
memantine (NMDA receptor antagonist; helps prevent excitotoxicity (mediated by Ca)
AChE inhibitors - donepezil, galantamine, rivastigmine, tacrine
baby with generalized muscle atrophy, fasciculations, and diminished deep tendon reflexes
werdnig-hoffmann
autosomal recessive destruction of the anterior horn cells, only affects the lower motor neurons system.
bezos vs barbs - what channels do they act on and how do they do it
benzos increase the frequency of chloride channel opening
barbs increase the duration they are open
lack of this nutrient can give you hypersegmented neutrophils
folate
a patient with normal pressure hydrocephalus may have defects in which site of venous drainage in the brain
superior sagittal sinus - this is the main sinus that collects CSF from the subarachnoid space into the bloodstream
what meningitis can cause refractory hypotension and widespread purpura (sepsis with adrenocortical insufficiency)
N meningitis - waterhouse-friedrich syndrome
what happens when the globus pallidus internus is “on”
inhibits the thalamus and stops movement
what happens when the sub thalamic nucleus is “on”
it makes the globus pallidus do it’s job, which is to inhibit the thalamus and stop movement
injury to this (lacunar stroke) can cause hemiballismus (uncontrolled movement
where do the divisions of the trigeminal nerve leave the skill
“standing room only”
Superior orbital fissure (CN III, IV, V1, VI, ophthalmic vein, sympathetic fibers)
Foramen Rotundum (V2)
Foramen Ovale (V3)
what goes through the foramen spinosum
middle meningeal artery
what nerves go through the internal auditory meatus
VII - facial
VIII - vestibulocochlear
What nerves go through the jugular foramen
9,10,11
what nerves go through the hypoglossal canal
XII
where are the main dopamine RECEPTORS in the brain
striatum (caudate and putamen)
mneumonic for drugs that cause seizures
I BITE My tounge
INH, Buproprion, Imipenem, Tramadol, Enflurane, Metoclopramide (D2 antagonist used to treat nausea in chemotherapy)
common ruptured aneurism in the brain that causes blown pupils
posterior communicating artery (runs by CN III)
fasciculations - lesion in UMN, LMN or both
LMN
40 yo
progressive hearing loss
impaired balance
multiple, soft tissue nodules on her back
brain MRI shows bilateral masses at the cerebellopontine angle
what syndrome
what types of cells are effected
genetics?
NF2
can get schwanomas (bilateral - cause hearing and balance problems) (derivative from neural crest, function to myelinate peripheral nerves)
meningiomas
ependymomas
autosomal dominant, NF2 gene on chromosome 22 (type 2 = chromosome 22)
sturge-weber syndrome
SSTURGE:
Sporadic (not genetic) Stain (port wine) Tram track Ca (opposing gyri) Unilateral Retardation Glaucoma GNAQ gene Epilepsy
tuberous sclerosis mneumonic
HAMARTOMASS
Hamartomas in CNS and skin Angiofibromas Mitral regurg Ash-leaf spots cardiac Rhabdomyoma Tuberous sclerosis autosomal dOminant Mental retardation renal Angiomyolipoma Seizures Shagreen patches
biochemical defect in albinism
you have a normal melanocyte number with decreased melanin production due to decreased tyrosinase activity or defective tyrosine transport. can also be caused by failure of neural crest cell migration during development
boy presents at 12 yo
intellectual disability, osteoporosis, tall stature, kyphosis, lens subluxation (down and in), thrombosis, atherosclerosis
homocystinuria
defective in either cystathionine synthase (give cystine, reduce methionine)
or
defective in homocysteine methyltransferase (aka methionine synthase) (give methionine)
OR
decreased affinity of cystathionine synthase for pyridoxal phosphate (give B6)
things that cause stevens johnson syndrome
Steven Johnson has epileptic allergy to sulfa drugs and penicilin
(anti-epileptics, allopurinol, sulfa drugs, penicillin)
what is the cell responsible for the output signals of the cerebellum
what neurotransmitter is used
purkinje cell is the only output of the cerebellum, all outputs from the cerebellum are inhibitory and use gamma-aminobutyric acid (GABA)
antiviral that is used to treat parkinsons
what is its mechs
amantadine
promotes the synthesis, release, or reuptake of dopamine
dementia that gets hallucinations early on in its course
Lewy body dementia
mech of dantrolene
prevents release of Ca from the sarcoplasmic reticulum of skeletal muscle by binding to the ryanodine receptors
Albuminocytologic dissociation
means elevated protein, normal WBC count in the CSF
characteristic of guillain-barre syndrome
protein 14-3-3
what disease
what do you see on EEG
cruetxfeldt-jacob disease - fatal prion disease characterized by rapidly progressive dementia
EEG may demonstrate periodic sharp-wave complexes
first line treatment for acute status epilepticus
benzos, increase GABAa Action by increasing the frequency in which Cl channels open
Tx for guillain-barre
plasmapheresis and immunoglobulin
locked in syndrome
thrombosis to where?
basilar artery (ventral pons, bilateral corticospinal and corticobulbar tracts)
yeast found in pigeon droppings
what is it
what does it look like
cryptococcus neoformans
5-10um with narrow budding, highly encasulated
highlighted with india ink and mucicarmine
subacute combined degeneration of the spinal cord
where in the spine is affected
what is the underlying pathology
SCD - Spinocerebellar, lateral Corticospinal, Dorsal columns
b12 deficiency