Anterior white commissures (what crosses here?)
Pain and temperature tracts (Commonly compressed in a syringomyelia --- loss of pain and temp in upper extremities due to syrinx at C8-T1)
What do the lateral hypothalamic tracts contain?
Sympathetics to the face (lesion= Horner's syndrome)
Signs of a LMN lesion?
Muscle weakness, atrophy, fasciculations, decrs tone & hyporeflexia
Signs of an UMN lesion?
Increased tone, hyperreflexia (spasticity),clonus, Babinski sign, posturing
Autosomal recessive, triplet repeats in the Frataxin gene Progressive damage to the nervous system Spinal nervous tissue degenerates over time causing ataxia, speech problems, muscle weakness, vision, hearing impairment Also assoc with development of diabetes and heart disease
Secondary structures of proteins (alpha helices and beta sheets) are held in tact by what type of bond?
Melanocytes are derived from what?
Neural crest cells
a monocular scotoma is caused by a lesion ______
at the retina, optic disk or optic nerve (possible causes include Macular degeneration or optic neuritis)
Right anopia is caused by a lesion at the _____
right optic nerve (retinal artery or central vein occlusion)
Bitemporal hemianopia is caused by a lesion at the ______
Optic chiasm (pituitary tumor, craniopharyngioma or aneurysm of anterior communicating artery)
Right nasal hemianopia is caused by a lesion at the ________
right peri-chiasm (caused by a calcification or aneurysm of the internal carotid artery pressing on uncrossed lateral retinal fibers)
Left homonymous hemianopia (with a Marcu Gunn pupil) is caused by a lesion __________
Right optic tract or optic radiation (occlusion of anterior choroidal artery or MCA branch)
Left homonymous superior quadrantanopia is caused by __________
a lesion in the right temporal lobe (Meyer's loop) -- caused by a lesion / stroke in temporal lobe
Left homonymous inferior quadrantanopia is caused by __________
right parietal lobe lesion or stroke
left homonymous hemianopia w/ macular sparing caused by _________
right primary visual cortex (occipital lobe) -- caused by a PCA occlusion, macula is spared b/c of collateral blood flow
What are the afferent & efferent nerves for the corneal reflex?
CN V (sensation of eye) , CN VII (reflex blink)
pt with hearing loss, tinnitus, asymmetric smile and loss of corneal reflex on same side---> a mass is most likely located ___________
at the cerebellopontine angle (the location of CN VIII...... CN V and VII are also nearby & could be affected)
Demyelination decreases the _________ constant
space (aka 'length') constant ---> the distance along the axon the AP can propogate
Which muscle close the jaw?
masseter, medial pterygoid & temporalis muscles (supplied by the 3rd division of the Trigeminal n.--V3)
Which muscle opens the jaw?
Lateral pterygoid muscle (CN V3)
Which nerve roots produce 'saddle anesthesia' if pinched?
low back pain radiating to legs, saddle anesthesia, loss of anocutaneous reflex, bowel & bladder dysfunction, loss of ankle jerk reflex and weak plantarflexion of the foot
Cauda equina syndrome (damage to the lumbar plexus nerve roots)
Man with short term memory loss, nystagmus, ophthalamoplegia & ataxia who's breath smells like alcohol..... which of the structures is most likely damaged in this man's brain?
B- the mammillary bodies --> he is experiencing Wernicke Encephalopathy and could progress to Korsakoff psychosis
CSF flows from the lateral ventricles to the 3rd ventricle via __________________ and then to the 4th ventricle via the _______________ and then out of the 4th and into the subarachnoid space through the __________ & __________
interventricular foramina of Monroe , cerebral aquaduct , lateral foramina of Luschka (2) or the medial foramin of Magendie
a condition that occurs in overweight young females and is related to decreased CSF outflow at the arachnoid villi & increased ICP causing headache/ vision changes
Increased CSF volume occuring when there is brain atrophy
Hydrocephalus ex vacuo
What is the structure with the black arrow? And what disease usually affects it?
the Putamen --> Wilson's dz causes cystic degeneration of the putamen as well as other basal ganglia structures
Name structures A-E
A= Globus pallidus
B = Putamen
C= Internal Capsule
D = part of the Caudate
What supplies sensory innervation to the tongue?
Anterior 2/3 = mandibular div of trigeminal (V3)
Posterior 1/3 = CN IX
Tongue root = CN X
What supplies TASTE to the anterior 2/3 pf the tongue?
Corda tympani (from CN VII - facial nerve)
65 y.o. man with vision problems, exam shows small yellow lesions clustered around the macula and scotomas
Occlusion of the ACA (anterior cerebral artery) would lead to problems with what parts of the body?
What arteries make up the circle of willis?
What feature of the capillaries in the brain prevents drugs from freely crossing the BBB?
Tight junctions btw the capillary endothelial cells
the CNS originates from _______________ & the PNS originates from _________________
CNS --> from neuroectoderm
PNS --> from Neural crest cells
What is the Nissl substance?
the RER in neurons
when an axon is injured and degenerates distally
Hypothalamus structures and functions
Supraoptic nucleus --> makes ADH
Paraventricular nucleus --> makes Oxytocin
Lateral hypothalamus --> hunger (Leptin inhibits)
Ventromedial hypothalamus --> satiety (Leptin increases)
Anterior hypothalamus --> cooling, parAsympathetic
Posterior hypothalamus --> heating, sympathetic
Suprechiasmiatic nucleus --> circadian rhythm (sleep)
Occlusion of which artery would cause Broca's or Wernicke's aphasia?
MCA (probably the LEFT MCA since most people are Left dominant)
Speech that is fluent and words that are well articulated but it is meaningless "word salad", patient cannot understand you
neuromuscular disease (ataxia, myopathy, decrs sensation) & hemolytic anemia indicate a deficiency of ___________
can happen in pts with Cystic Fibrosis due to malabsorption of fat soluble vitamins
a common feature of temporal arteritis (in > 50% of people with the dz)
Polymyalgia rheumatica (fever, neck, torso, pelvic & shoulder girdle pain and weight loss)
an old ischemic infarct of the brain will appear like a cystic space and will be lined by what kind of cells?
Astrocytes --> ischemic neurons undergo irreversible damage (become "red neurons") and die, then macrophages move in and eventually the necrotic material is resorbed and a cystic cavity forms --> around the cavity Astrocytes proliferate (GLIOSIS)
What is usually the 1st symptom of alcohol withdrawal?
Tremulousness ("the shakes")
a boy with significant kyphoscoliosis and high plantar arches, his brother had a neurologic disorder and dies of heart failure at a young age, what does the boy have?
-autosomal recessive, Frataxin gene mutation, trinucleotide repeat expansion
- gait ataxia
- dorsal column degeneration
- kyphoscoliosis & foot abnormalities
- Hypertrophic Cardiomyopathy
- Diabetes (in 10%)
Most common complication of a subarachnoid hemorrhage (happens in > 50%)
secondary vasospasm around the ruptured aneurysm (leads to ischemia )
- can prevent with Nimodipine
triad of tinnitus, vertigo and sensorineural hearing loss in the affected ear
- increased volume of endolymph in the inner ear
What is the most common site of a Subarachnoid hemorrhage (saccular berry aneurysm rupture)?
Circle of Willis -- Anterior Communicating Artery
- associted with ADPKD and Ehlers Danlos
- artery doesn't develop a media layer --> is weakend
man with lung cancer develops weakness getting up from a chair and fixing his hair--> he most likley has antibodies to __________________ __________
presynaptic calcium channels
- ha has Lambert Eaton syndrome (like Myastenia gravis but assoc with cancer and gets better with activity)
what patients have a increased chance of developing Alzheimer's by age 40?
Down Syndrome patients
- gene for APP is on chromosome 21
Histologic & Gross findings in Alzheimer's dz
- extracellular senile plaques of AB Amyloid
- intracellular neurofibrillary tangles of phosphorylated tau protein
- grossly --> widespread cortical atrophy , narrow gyri & wide sulci, dilation of the ventricles (hydorcephalus ex vacuo)
- decreased Ach levels in the hippocampus & nucleua basalis (b/c choline acetyltransferase decreased)
-slow- onset dementia
-no focal neurologic deficits
-APOE 4 allele is assoc with incrs risk
- AB amyloid plaques and tau tangles
2nd most common cause of dementia
- due to HTN, atherosclerosis, vasculitis
-degeneration of the frontal and temporal cortex
- round aggregates of TAU protein (Pick bodies) in the neurons
- behavior and language changes early on
Pick disease (frontotemporal dementia)
- loss of dopaminergic neurons in the substantia nigra pars compacta
- loss of dopamine --> can't initiate movement --> shuffling gait, frozen face, tremor, bradykinesia
-Tremor at rest
-Postural instability / shuffling gait
--the dementia should set in LATE in the dz ((if early on --> it's Lewy Body dementia)
Histologic findings of Parkinson's
- round, eosinophilis inclusions ("Lewy bodies") in the affected neurons
- made of alpha- synuclein
- loss of GABA neurons in the caudate nucleus
- autosomal dominant , trinucleotide repeats of _______?
- further expansion of repeats during _______leads to Anticipation
- CAG repeats
- further expansion during spermatogenesis causes anticipation
-urinary incontinence, gait instability, dementia
-increased CSF causes dilated ventricles and streches the corona radiata causing the symptoms
"wet, wobbly, & wacky"
-Normal Pressure Hydrocephalus
-LP can relieve symptoms
-PrPc (alpha helix) is converted to PrPsc (Beta sheet)
- becomes resistant to proteases
- rapidly progressive dementia , ataxia, startle myoclonus
Spongiform encephalopathy (ie: Creutzfeldt Jakob)
- prion disease
what are the 3 most common sources of brain metastases?
--mets are usually multiple and at the gray/white junction **
primary brain tumors are usually SUPRAtentorial in __________ and INFRAtentorial in _________
Adults , kids
most common malig brain tumor in adults
- crosses the corpus callosum ('butterfly pattern")
- GFAP +
- poor prognosis
most common BENIGN CNS tumor of adults
- more in females
- tumor of the arachnoid cells
- psammona bodies may be present
benign tumor at the cerebellopontine angle that presents w/ hearing loss, tinnitus, tumor cells will be S-100 +
((if bilateral --> think NF-2))
-malignant tumor , presents w/ seizures
- calcified tumor in white matter of frontal lobe
- fried egg appearace
most common BENIGN CNS tumor in kids
- usually in cerebellum
-cystic lesion w/ nodular mass
- Rosenthal fibers
- GFAP +
-malignant CNS tumor in children
- derived from neuroectoderm
- small, round blue cells & Homer-Wright rosetts
- always in cerebellum
incomplete closure of the neural tube at week ______ will result in neural tube defects
increased ________________ in maternal bld and amniotic fluid indicates a neural tube defect
AFP (alpha fetoprotein)
most common cause of hydorcephalus in newborns
Congenital aqueduct stenosis
What is shown in the photo?
- failure of cerebellar vermis to develop
- huge, dilated 4th ventricle and no cerebellum
cystic degeneration at C8-T1
- loss of P&T in upper extremeties , spares dorsal columns
- due to involvement of ant white commisures & spinothalamic tract
congental herniation of the cerebellar tonsils thru the formamen magnum
Arnold- Chiari Malformation Type 2
- viral destruction of the anterior motor horns
- fecal-oral spread
- LMN signs
autosomal recessive degeneration of the anterior motor horns
- "floppy baby" at birth
atrophy and weakness of the hands is an early sign of __________
- will get both UMN & LMN signs eventually
-tract that carries Pain & Temp from the body
- cell body in DRG --> immed crosses in Ant white commisure --> ascends to thalamus
tract that carries fine touch, vibration, pressure, & proprioception
- cell body in DRG --> crosses in medulla , ascends via medial lemniscus to thalamus
tract that carries voluntary movement from cortex to body
- pryamidal neurons in cortex descend, cross over in medullary pyramids --> synapse on anterior motor horn cells (UMN) --> then travels to LMN on muscle cells
Lateral Corticospinal tract (Pryamidal)
inflammation of the leptomeninges (pia & arachnoid) , can be due to bacterial, viral or fungal infection
- most common causes in neonates: Listeria, E.coli & GBS ("LEG")
do diagnose Meningitis, do an LP by placing the needle between ____ & ____
L4 & L5 (level of the Iliac crests)
-spinal cord ends at L2 in adults
viral meningitis in children
- CSF will have lymphocytes with normal glucose
CSF findings inbacterial meningitis
neutrophils w/ decreased glucose
CSF findings in Fungal meningitis
lymphocytes and decreased glucose
most strokes are ____________________
ischemic (85%) --> ischemia that lasts longer than 24 hours is a stroke
can be caused by:
-Thrombus --- pale infarct
-Emboli -- hemorrhagic infarct
- Lacunar strokes -- 2nd to hyaline arteriolosclerosis
ischemic stroke results in ___________ necrosis
the earliest change after an ischemic stroke is the presence of ______________
RED NEURONS (12 hrs after infarct)
rupture of a Charcot- Bouchard microaneurysm will cause a ____________________ hemorrhage
Intracerebral hemorrhage --> bleeding into the parenchyma
- these are a result of HTN
-lenticulostriate arteries in the basal ganglia are the most common sites
LP shows xanthochromia
- yellow due to the breakdown of bilirubin
blood btw dura and skull, lens shaped clot, lucid interval then LOC
-due to rupture of the Middle meningeal artery
blood btw dura & arachnoid , due to tearing of bridging veins, crescent shaped lesion on CT
uncal herniation (displacemnet of the temporal lobe uncus under the tentorium cerebelli) causes compression of CN ______
- eye moves down & out
- dilated pupil
Name the types of herniations
1= Uncal herniation
2= Central (transtentorial)
3= Cingulate (subfalcine)
5= Upward (upward cerebellar or upward transtentorial)
6= Tonsillar (downward cerebellar)
galactocerebroside accumulates in macrophages in this autosomal recessive dz
- deficicency of galactocerebroside beta-galactosidase
impaired addition of Coenzyme A to long chain FA's
Diagnosis of MS is made by:
-LP and a T2 weighted MRI
- LP will show lymphocytes, immunoglobulins w/ oligoclonal IgG bands
Subacute sclerosing panencephalitis is due to persistant _________ infection
Central pontine myelinolysis is due to
rapid IV correction of hyponatremia
-clinically presents as "locked in syndrome"
-focal demyelination of the pons
an ACA infarct will affect what part of the body? and an MCA occlusion will affect what parts?
ACA --- legs
MCA -- upper extremeties, face (including Broca's and Wernicke's areas)
spatial neglect syndrome (agnosia of the entire left side)
lesion of the right parietal lobe
affects 1 area of brain, preceded by aura, can be simple or complex
- Simple Partial = no LOC
-Complex Partial = impaired consciousness
nucleus of the thalamus that gets sensory from the body
nucleus of the thalamus that gets sensory from the face
Lateral geniculate nucleus gets input from CN _____ to relay ______
CN II to relay vision input
Medial geniculate nucleus gathers input from olives & inferior colliculus to relay _______ info
lesion at the cerebellar vermis causes ______
truncal ataxia & dysarthria
damage to PPRF causes________
damage to frontal eye fields causes __________
PPRF ---- eyes look away from lesion side
FEF --- eyes to toward lesion side
PICA infarct causes .....
Lateral Medullary (Wallenberg) syndrome
- vertigo, nystagmus, voimiting
-decrs P&T to limbs and face
- IPSI Horner's syndrome
PCA infarct at the occipital lobe causes _______
contralateral hemianopsia w/ macular sparing
Hemisection of the spinal cord (ie: after getting stabbed in the back) will cause __________
Brown -Sequard Syndrome
-IPSI UMN signs below the lesion
-IPSI loss of fine touch, vib, prop.. below lesion
- CONTRA P&T loss below lesion
-IPSI loss of ALL sensation at the level of the lesion
-LMN signs at the level of lesion
** and if above T1 -- will also have Horner's syndrome
CN V exits the skul via what foramen??
V1 -Superior Orbital Fissure
"Standing Room Only"
abnormal Rinne (BC >AC) and Weber localizes to affected ear
Conductive hearing loss
Sensorineural hearing loss
normal Rinne test and Weber localizes to the normal ear
feared side effect of Buproprion (antidepressant and smoking cessation drug)
Seizures! (esp in pt's with bulimia)
woman with bipolar and new onset seizures, what drug can help both of her conditions?
- anticonvulsant and a mood stabilizer
- increases GABA in the CNS
- Carbamazepine is also both a mood stabilizer and an anticonvulsant **
mechanism of Dantrolene
blocks Ryanodine receptors and prevents Ca+ release into the cyoplasm of skeletal muscle
man working in his yard suddenly develops flushed skin, dry mouth, dilated pupils--> what did he get in to and what can reverse it?
Jimson weed poisoning ("gardener's mydriasis") --belladonna alkaloid that produces strong anticholinergic symptoms
- similar to Atropine overdose (hot as a hare, dry as a bone, mad as a hatter...)
- antagonize by increasing Ach in the synaptic cleft (ex: Physostigmine)
man with long standing diabetes who has recent diplopia, right eye is fixed down and out but PERRLA---> what happened to the nerve?
Diabetic neuropathy causes ISCHEMIC CN III Neuropathy...
- the somatic motor function is lost but the parasympathetics are fine b/c they have different blood supply
-**if the nerve was being compressed, however, the eye would be 'down & out' and the pupils would not be reacting to light
Pramipexole, Ropinerole, Bromocriptine & Pergolide are all ___________
((Bromocriptine also treats Prolactinomas ))
- Pramipexole & Ropinerole are non-ergot cmpds
- Bromocriptine & Pergolide are ergot cmpds
Which part of Wernicke-Korsakoff is permanent?
memory loss and confabulation (Korsakoff's psychosis)
What are the treatment options for Alzheimer's?
1- Cholinesterase inhibitors
2- Antioxidants (vit E)
3- NMDA receptor antagonists (memantine)
endoneural inflammatory infiltrate after a viral illness
Guillain - Barre
- ascending weakness / paraysis
- after vaccination, allergic rxn or illness (campylobacter infection)
What is 1st line treatment for Glaucoma?
Prostaglandins (ie: Latanoprost)
- incrs the outflow of aq. humor
-cause iris to become brown
(Other treatments include Epinephrine, TImolol, Acetazolamide -- to decrs the production of aq humor -- and cholinomimetics like pilocarpine to incrs the outflow)
Morphine, Fentanyl, Heroin, Codeine are all ________
Opioids -- most act at the opiod mu receptor (G-protein receptor)
- decrease synaptic transmission (open K+, close Ca+ channels)
-Toxicity = pinpoint pupils, resp depression*, constipation -- treat overdose with NALOXONE!!
*note: Tramadol is also an opioid agonist (weakly) and also incrs NE & serotonin -- treats Pain
1st line for Tonic Clonic seizures (grand mal)
Phenytoin, Carbamazepine or Valproic acid
- all increase Na+ channel INACTIVAION
-Valproic acid also increases GABA
1st line therapy for a Simple Partial seizure
- incrs Na+ channel INACTIVATION
- also 1st line for Trigeminal neuralgia
1st line therapy for a Partial Complex seizure
What is the mechanism of the drug used to treat Absence seizures?
Ethosuxamide -- blocks thalamic Ca+ channels
What drug is used to PREVENT status epilepticus and what drug is used in the acute setting??
Prophylaxis --> Phenytoin (Na+ channel INactivation)
Acute treatment --> Diazepam or Lorazepam (incrs GABA)
1st line therapy for pregnant women & children with seizures
Phenobarbital (incrs GABA)
Most serious side effects of anti-epileptic drugs
- Bone marrow suppression
Carbamazepine --> agranulocytosis, anemia, SJS, teratogen...
Phenytoin --> gingival hyperplasia, Lupus like syndrome, teratogen
Valproic acid --> liver toxicity , teratogen
Treat overdoses of ________ with Flumazenil
Benzodiazepines (generally end in "-lam , -pam"..)
-benzo's increase GABA by increasing the frequency of Cl- channel opening
(as opposed to Barbs which incrs GABA by increasing the duration of Cl- channel opening)
which cause LESS respiratory depression, barbiturates or benzodiazepines?
a General anesthetic is faster acting if it is _________
- low solubility in blood (gets 'pushed' into tissues) = fast induction
- low Minimun alveolar concentration (MAC)
- high lipid solubility (high potency)
barbiturates (like Thiopental) have short acting times as IV anesthetics b/c they rapidly shift from the brain to ___________
skeletal muscle & fat
Why do you need to use more local anesthetic in infected tissue compared to healthy tissue??
infected tissue is acidic --> alkaline anesthetics are charged and cannot penetrate easily
What is the order that the local anesthetics (lidocaine, procaine, cocaine...) affect nerve fibers (from 1st to last)?
Small myelinated fibers (beta) > small (a delta) unmyelinated > large myelinated > large unmyelinated
Depolarizing neuromuscular blocker -- can cause hypercalcemia & -kalemia and malignant hyperthermia
(the curare derivatives are non-depolarizing and can be reversed with AchE inhibitors)
fairly new anticonvulsants that are used for treating refractory partial seizures (not responding to other meds)
**BEWARE OF SKIN RASH
1st line treatment for symptoms of alcohol withdrawal?
-Long acting Diazepam or Chlordiazepoxide are the first line
Medications used to abort a migraine headache have what effect at receptors?
stimulate the post-synaptic Serotonin receptor
-Triptans are serotoin 5HT 1B /1D agonists that inhbit the release of vasoactive peptides (like substance P), promote vasoconstriction, & block pain pathways
antidepressant that does NOT have sexual side effects
-good antidepressant, no sexual effects
-also helps treat nicotine dependence
Common drugs that can cause Serotonin Syndrome (clonus, rigidity, hyperthermia, tachycardia, tremor, sweating, agitation, mydriasis, diarrhea...)
-SSRI's, SNRI's, MAOIs, TCA's
-Linezolid (an ABX)
TCA overdose cause of death
-arrythmias, refractory hypotension
- inhibition of the fast Na+ channels in the heart is to blame
What is the antidote / treatment for Serotinin Syndrome?
- antihistamine w/ anti-serotonin properties
Main side effects of Scopolamine (antimuscarinic drug for motion sickness)
Antimuscarinic -- so you will have signs of decrs Ach/ parasympathetic activity
- blurry vision
-urinary retention & constipation
- St John's Wart
-Chronic alcohol use
"Barb Steals Phen-phen and Refuses Greasy CArbs CHronically"
Almost all volitile (inhaled) anesthetics increase blood flow to the __________
- this is NOT a good thing though b/c it increases ICP
- inhalation anesthetics also decrs resp rate and cardiac rate & decrs GFR
Side effects of PHENYTOIN
- generalized lymphadenopathy ("pseudolymphoma")
- hisutism & coarsening of the facial features, acne
Which antidepressants are most likley to cause urinary retention and other antimuscarinic SE's?
- they act at several different receptors and have many side effects
Preferred treatment for people with combined Absence and Tonic-Clonic seizures
Valproic acid (Valproate)
Pt on an antidepressant, ate at an Italian restaurant and developed severe HTN, tachycardia...
-man was on MAOI and ate tyramine containing foods (wine, cheese...)
Thiopental (and other barbiturates) has a short period of action b/c it ___
rapidly redistributes from the brain to muscle and fat
Male with ADPKD has severe headache --> admitted to hospital --> several days later he complains of right sided weakness.... what drug could have been used to prevent the sequalae that occurred?
This pt had a Subarachnoid bleed (predisposed to berry aneurysm's due to ADPKD)
- he then had a secondary VASOSPASM which could have been prevented with a Calcium channel blocker (Nimodipiine**)
Used as chemoprophylaxis for all contacts of a person sick with bacterial meningitis
- must be given to all close contacts within 2 weeks