neuro based on kaplan q bank Flashcards
40 yo man with progressive weakness culminating in paralysis of all voluntary muscles —> death by respiratory failure. Both upper and lower motor neurons degenerated. Which area of the CNS would show the most neuronal loss?
the spinal cord
- it’s ALS (Amytrophic lateral sclerosis)
- pt may experience uppper motor symp (CNS symp): babinski sign, hyperreflexia, spasticity
- OR pt may experience lower motor symp: weakness, muscular atrophy, fasiculations
damage to the caudeate nucleus is associated with which disease?
huntingtons– choreiform movements
damage to the cerebellum is associated with which diseases?
spinocerebral degenerative diseases (Freidrich ataxia and olivopontocerebellar atrophy– both of which have ataxia as a major symp)
damage to the glubus pallidus is assoc. with which disease?
striatonigral degen (looks like parkinsons)
damage to teh substantia nigra is assoc. with which disease?
parkinsons (tremor + difficulty initiating movements)
Berry aneurisms commonly occur where in the circle of willis? What do they lead to if they rupture?
ACA (ant. cerebral art) close to the branch point with the ant comm. art. If they rupture, they usually lead to a sub arachnoid hemorrhage
what is a berry aneurism?
a variant of aneurism that occurs in the intracranial cavity and most commonly affects the anterior portion of the circle of willis (ACA) close to where the and. comm art. are taking off
alzheimer’s primarily affects what type of memory?
short term
22 yo man with bilateral loss of pain and temperature in upper extremities but normal touch sensation and no motor abnormalities. What disorder does he have and what is it most commonly associated with (1) Also assoc. with (3)?
He has syringomyelia– a fluid filled cyst that obstructs the anterior white commissure (usually on the level of c8-T1) resulting in Pain and Temp loss from damage to the spinothalamic tract.
Commonly assoc. with 1) Chiari Malformation (congenital protrusion of cerebellum and medulla thru the foramen magnum) Most common with Chiari 1, sometimes seen with Chiari II. Also seen with 2) trauma (whiplash), 3) prior meningitis, and 4) CSF obstruction
syrengomyelia- what is it and how does it present?
cavitation of the spinal cord (usually C8-t1) at the anterior commissure– blocks the spinal thalamic tract (pain and temp) at that level
Presentation: bilateral pain and temperature loss at the level of the lesion (usually upper extremities). As the disease progresses (lesion gets bigger) —> muscle weakness/atrophy, flacid paralysis due to destruction of anterior horn. Eventually there can be loss of sympathetic func because of lesion expanding to lateral horn
where is the broca’s area located? what does damage to broca’s area do?
inferior frontal gyrus
- it controls the motor aspects of speech so a lesion in the area causes nonfluent aphasia: slow, effortful, telographic speech with good comprehension
What is horner syndrome?
knock out of sympathetic innervation of the face: ptosis (drooping eyelid), miosis (pupil constriction), and anhidrosis (no sweating). You might see homer syndrome as a late manifestation of syringomyelia if the lesion grows to affect the hypothalamic fibers in the lateral column of the spinal cord. (syringomyelia is more commonly associated with chiari than horner syndrome)
what is tabes dorsalis? Presentation?
degeneration of the dorsal column and dorsal roots of the spinal cord due to tertiary syphilis.
Presentation: paresthesias, impaired proprioception, and vibration sense, and ataxia. They have a “high step” stride because they can’t tell where the ground is.
wernicke encephalopathy- who is it seen in? how does it present?
who: alcoholics with Vit. B1 (thiamine) deficiency
presentation: ophthalmoplegia, confusion and ataxia.
68 yo man with progressive difficulty walking and headaches over the past month. 2 pack/day cigs for 30 yrs, no etoh, but now walks as if he was drunk, staggering/loses balance. wide based, unsteady gait, falls to the right. no abnormalities on finger to nose exam, or heel to shin, and rapidly altering movements are normal. Where is the lesion?
cerebellum- planning and fine tuning of movements/balance
a wide-based “drunken sailor” gait (called truncal ataxia)- implies a lesion of the vermis (middle part of the cerebellum).
headache- suggests lesion is intracranial
HO smoking: differential of lung cancer metastatic to the cerebellar vermis
16 yo boy, multiple episodes sudden onset fainting. no abnormal movements or loss of bowel func. physical exam is normal. ECG is normal. EEG shows abnormal spiking. What type of seizure is he having?
atonic or “drop” seizure most closely resembles fainting. The patient suddenly loses muscle tone and falls to the floor.
which seizure most closely resembles fainting?
an atonic seizure- The patient suddenly loses muscle tone and falls to the floor.
an atonic seizure is characterized as…
drop” seizure most closely resembles fainting. The patient suddenly loses muscle tone and falls to the floor.
absence seizures (aka petit mal seizures) are characterized by
blank stares and absence of any position change. They are more commonly seen in childhood
myoclonic seizures- characterized by
quick, repetetive jerks
tonic seizures- characterized by
stiffening of the muscles
tonic-clonic seizures (aka grand mal seizures)
tonic contractions of muscles throughout the body, followed by intermittent relaxation of muscle groups (clonic phase)
20 yo with HO depression and binging/purging for 5 mo. Txt with antidepressant —> dose is gradually increased —> pt develops seizures. Which antidepressant used?
bupropion: NE and dopamine reuptake inhib antidepressant indicated for the txt of major depressive disorder and smoking cessation. BUPROPRION IS CONTRAINDICATED FOR PEOPLE WITH EATING DISORDERS BC INCREASED LIKELIHOOD OF SEIZURES SECONDARY TO METABOLIC DISTURBANCES.
busiprone
antianxiety agent mostly used in conjunction with antidepressants for txt of comorbid depression and anxiety. not used for bulimia. relatively well tolerated, with mild cns and gi side effects
fluoxetine
only antidepressant currently approved for bulimia nervosa. Assoc. with serotonin syndrome, CNS stim, and sexual dysfunction
Mirtazapine
antidepressant for the txt of depression. Not approved for bulimia. side effects: somnolence, weight gain, dry mouth
Sertraline
SSRI for depression, not approved for txt with bulimia. Assoc. with serotonin syndrome, CNS stim, and sexual dysfunction
40 yo man w/progressive memory loss, confusion, incontinence, CD4 count of 25/mm^3, moderate atrophy on MRI, who dies of disseminated aspergillosis. Autopsy: cerebrl atrophy, multifocal lymphohistocytic infiltrates with numerous microglial nodules and scattered mutinucleated giant cells. What is likely responsible for neuro conditions?
HIV encephalitis: HIV gains access thru imcoming macrophages and may cause subacute inflammation of the brain parenchyma known as HIV encephalitis. Presence of multinucleated giant cells = typical of HIV encephalitis
Aspergillosis
opportunistic ifxn caused by aspergillus, ubiquitous fungus in envt. Aspergillosis is frequent in pt with AIDS/immuno comp. Specific tropism for blood vessels —> hemorrhagic infarcts in brain/other organs
CMV encephalitis- what is it?
diagnostic?
opportunistic ifxn affecting HIV pt. tropism for epithelial and ependymal cells (so virus is found in ependymal and periventricular locations).
diagnostic: typical cytomegalic cells, which contain large purple inranuclear inclusions and granular cytoplasmic inclusions
- lymphocytic infiltration (perivascular cuffing), microglial nodules, and neuronophagia (degenerating neurons surrounding by lymphocytes
mycobacterial ifxns
chronic meningoencephalitis involving the basal surface of the brain or tuberculoma (circumscribed lesion consisting of confluent caseating granulomas). Acid-fast bacilli can be demonstrated in these lesions
vacuolar myelopathy
noninfectious complication of obscure pathogenesis involving the spinal cord
- very similar to subacute combined degen Vacuolar myelopathy, like subacute combined degen, may be related to vitamin B12 deficiency
- ascending (sensory) tracts in the posterior columns and descending (pyramidal-motor) tracts in the lateral columns degen leading to sensory loss, ataxia and spastic paraplegia
Where is wernicke’s region in the brain? what is the blood supply? a lesion there causes…
posterior part of the superior temporal gyrus of language dominant hemisphere.
Blood supply: Posterior branch of MCA
presentation: impaired comprehension/don’t respond approp. to commands/questions
- mt be able to close their eyes on command or stick out their tongue. Spontaneous speech is meaningless/nonsensical. inability to repeat words and unaware of their deficits. May be angry/paranoid—> can be misdiag for schizophrenia. contralateral visual field cut is commonly associated (particularly right upper quadrant) bc of interruption of visual radiations in temporal lobe (Meyer’s loop)
arcuate fasciculus- what is it? what does a lesion there produce?
arises in wernicke’s area and travels to broca’s area
lesion: produces conduction aphasia, characterized by a striking inability to repeat while language comprehension and output are largely preserved.
Crus cerebri- where is it?
located in the midbrain, anterior to the substantia nigra and contains the corticospinal and corticobulbar fibers of the descending pyramidal system.
inferior frontal gyrus- what’s there? Presentation of lesion there…
location of the broca’s area– lesions there lead to language output disorder– slow, effortful speech that is agrammatic and telegraphic. Comprehension is largely preserved. Repetion is affected
Precentral gyrus- where is it? what’s in it? lesion there results in…
the motor strip, located in the frontal lobe. Lesion would result in motor difficulties
Prefrontal cortex lesions exhibit…
variety of symptoms depending on the location, including inappropriate social behavior, loss of the ability to problem solve, loss of initiative, abstracting ability, concentration and judgement
3 types of aphasias and the location of each one
- broca’s aphasia- inferior frontal gyrus
- conduction aphasia- arcuate fasciculus
- wernicke aphasia- superior temporal gyrus
fluency is maintained in what type(s) of aphasia?
conduction and wernicke (NOT Broca’s)
comprehension is maintained in what type(s) of aphasia?
Wernicke (not broka and conduction)
ability to repeat is maintained in what type(s) of aphasia?
none! (not wernicke’s. broca’s or conduction)
generalized anxiety disorder is associated with:
excessive worry and can lead to insomnia, muscle tension, impaired conc., autonomic arousal and restlessness
lorazepam, alprazolam, and diazepam are what type of drugs? how do they work?
Benzodiazepines- they potentiate the effects of gamma-aminobutyrate (GABA) at the GABA _A receptor by increasing freq. of GABA-A channel opening —> antianxiety effect
sedative/anticonvulsant actions of benzodiazapine (lorazepam, alprazolam, and diazepam) mostly involve GABA receptors located…
in the limbic system, cortex, and mesencephalic reticular sys.
how do barbituates work?
they increase their duration of GABA-A channel opening
what types of meds are propranolol and metoprolol?
beta blockers- block beta-adrenergic receptors (HTN, angina pectoris, and various CV conditions)
Amphetamines- how do they work? what are they indicated for?
increase release of NE from central noradrenergic neurons. Indicated for txt of narcolepsy, ADD with hyperactivity and exogenous obesity
amitriptyline, nortriptyline, and doxepin- what type of meds are they? how do they work?
tricyclic anti-depressants (TCAs)- indicated for txt of clinical depression w/or w/out anxiety or sleep disturbances
- inhib biogenic amine (norepinephrine and serotonin) reuptake at presynaptic neuron (antidepressant effects)
- induce sedation
- central and periph anticholinergic
36 yo man with HIV ifxn dvps rt-sided weakness, involving rt leg but not rt arm. mRI shows mass lesions within white matter of left frontal lobe w/a bright signal peripherally and dark core. most likely source of ifxn in US?
Poorly cooked Pork
- HIV predisposes to opportunisic ifxns
- “ring enhancing lesionn = mass that contains a rim of contrast (bright sig) and dark center (necrosis). Often due to cerebral toxoplasmosis. Tpxoplasma gondii is a protozoan that infects humans who ingest oocysts from cat feces or undercooked pork/lamb. (in europe it’s poorly cooked cow)
toxoplasmosis ifxn is only severe in what two pops?
fetuses and immunosuppressed pt
toxoplasmosis in fetuses causes
extensive brain damage to parenchyma and retina
toxoplasmosis in AIDS pt causes
necrotizing lesions surrounded by chronic inflammation
Most frequent causes of ring-enhancing lesions in AIDS pts
lymphoma and toxoplasmosis
anopheles mosquitos transmit…
malaria parsites.
cerebral malaria is caused by…
Plasmodium falciparum- causes sludging of RBCs in small cerebral caps —> Vascular occlusion —> numerous small infarcts
Bird Droppings cause what two common opportunistic ifxns
cryptococcosis and histoplasmosis
- cryptococcus neoformans causes meningoecephalitis, not intracerebral necrotic lesions
- histoplasma capsulatum rarely affects the brain
legionella pneumophila- what is it? how is it spread?
gram neg bact. that causes legionnaire disease (fatal pneumonia)
air conditioning sys —> aerosolized forms
rodent droppings carry what virus?
hantavirus– causes fatal resp illness and is endemic to SW desert in US
meningoencephalitis localized to the base of the brain post scuba diving can be caused by orgnisms entering the skull where?
cribiform plate–naegleria fowleri enters thru nasal mucosa —> crosses cribiform plate —> olefactory nerves.
- changes in pressure created during diving predisposes to ifxn
cavernous sinus is the site of entry for what microorg? in what population?
zygomycophyta (rhizopus, mucor, or absidia) in diabetic ketoacidotic pt or adults with cancer. The
primary amebic meningoencephalitis what org causes it? where/how do you get it? how does it enter the brain? txt?
what org causes it: Naegleria fowleri
where/how do you get it: diving into warm, freshwater lakes
how does it enter the brain: cribiform plate during forceful diving
txt: amphotericin B (rarely successful)
what is the only antidepressant currently approved for bulimia nervosa?
fluoxetine (Assoc. with serotonin syndrome, CNS stim, and sexual dysfunction)
A lumbar puncture is generally done at what level of the spine?
L4-L5
when doing an LP (lumbar puncture) you must go through what layers of the spine? (10)
- skin
- superficial fascia
- deep fascia
- supraspinous ligament
- interspinous ligament
- ligamentum flavum
- epidural space
- dura
- arachnoid
- subarachnoid space– where you get CSF
When giving an epidural, what are the layers of the spine you must cross to get there (7)
- skin
- superficial fascia
- deep fascia
- supraspinous ligament
- interspinous ligament
- ligamentum flavum
- epidural space
When giving spinal anesthesia, you must go through what layers? (10)
spinal anesthesia is done at the subarach. level (like an LP) so the levels are the same:
- skin
- superficial fascia
- deep fascia
- supraspinous ligament
- interspinous ligament
- ligamentum flavum
- epidural space
- dura
- arachnoid
- subarachnoid space– where you get CSF
60 yo man w/difficulty walking down stairs, double vision when reading books in his lap. PE shows limitation of extraocular eye mvmt and dysarthic (poor articulation due to speech motor probs). Rigidity of proximal muscles/poverty of mvmt. Looks around by moving his head, not his eyes/has axial rigidity. MMSE shows normal intelligence. What is the disease? Underlying cause of pt condition?
Disease: progressive supranuclear palsy (degen disorder characterized by ophthalmoplegia, psudobulbar palsy, axonial dystonia and bradykinesia)
CAUSE By: widespread neuronal loss and gliosis in subcortical sites with sparing of the cerebral/cerebellar cortices
-
in Parkinsons, which neurons degenerate where?
pigmented neurons in the substantia nigra (pars compacta) and locus ceruleus
In alzheimer’s disease, there’s diffuse atrophy of what part of the brain?
diffuse cortical atrophy, especally over the cortex of frontal, temporal and parietal lobes with relative sparing of primary sensory and motor areas
selective frontal and temporal lobe atrophy is characteristic of which disease
Pick disease
Pick Disease is characterized by…
selective frontal and temporal lobe atrophy
In huntington disease, what two areas of the brain undergo severe atrophy?
caudate nucleus and putamen (cortical atrophy occurs to a lesser extent)
MRI of 47 yo woman w/progressive neuro condition shows massive expansion of the lateral ventricles. What disease does she probably have? what are the symptoms?
Huntington’s disease (caudate degen and putamen/nucleus accumbens degen —> lateral ventricles appear very large when imaged)
symp: choreoathetosis and dementia
bradykinesia, resting tremor and difficulty initiating movements = typical of what disease?
parkinsons
intention tremor and akinesia are signs of…
cerebellar dysfunc
moon facies, amenorrhea, HTN, truncal obesity, increased facial hair, acne, irritability, dpression, decreased energy = typical of what syndrome?
Cushing syndrome
cushing syndrome can be caused by what?
too much ACTH (adrenocorticotropic hormone)– ACTH secreting pituitary adenoma
motor and vocal tics are indicative of what syndrome?
Tourette syndrome
slowly progressive memory impairment and irritability are indicative of which disease?
Alzheimers
In alzheimers, what is seen in the brain?
cortical atrophy, neuronal loss, plaques and tangles particularly in the medial temporal lobes
violent flinging of the proximal limb muscles occurs with which disease?
hemiballismus– - unilateral flinging movements occur contralateral to the lesion, which is typically in the subthalamic nucleus
where is the lesion typically located in hemiballismus (causes violent flinging of the proximal limb muscles on the cotralateral side)
subthalamic nucleus
chorioid plexus papillomas are usually found where? What other structure might be affected by the papilloma?
lateral ventricles.
caudate nucleus might also be affected because it’s right next to the lateral ventricles
newborn with: cleft lip, celft palate, small eyes, fissures of the iris, shallow supraorbital ridges, slanted palpebral fissures. Ears are low set/malformed. Each hand has six fingers and a simian crease. which neuro complication is associated with the congenital disorder?
holoprosencephaly–
trisomy 13 (aka patau syndrome). usually die before 1 yo - usually microphthalmia, microcephaly, cleft lip/palate, polydactyl, congenital heart disease, severe mental retardation
anencephaly
no brain develops- grossly deformed head with no cranial vault
encephalocele
protrusion of brain and meninges through developmental defect in skull
hydrancencephaly
extreme form of porencephaly in which cerebral hemispheres are destroyed, but the external head forms normally (unlike anencephaly)
porencephaly
cyst or cavity in the brain that communicates with the ventricles (dvpmtal anomoly or secondary to inflamm. disease/vascular accident)
what is trisomy 13 associated with
holoprosencephaly, severe mental retardation, micrpthalmia, microcephaly, cleft lip/palate, polydactyly, congenital heart disease
- not compatable with life– dead by 1
the floor of the eye orbit is also the roof of what sinus?
maxillary
people with alzheimer’s are particularly susceptible to what type of hemorrhages? why?
large lobar hemorrhages centered in parietal lobe due to amyloid deposition into the walls of cerebral bv (amyloid angiopathy) that makes bv weak/prone to rupture (ie the same amyloid plaques that increase with disease build up in bv)
what is amyloid angiopathy?
amyloid deposition into the walls of cerebral bv- happens in pt with alzheimers- makes bv weak/prone to rupture —> and can lead to large lobar hemorrhages centered in parietal lobe that can destroy an entire hemisphere/kill someone
rupture of charcot-bouchard aneurysm might cause…
sudden hemorrhage within the brainstem causing coma and death
charcot-bouchard aneurysms are particularly associated with…
severe HTN
familial alzheimers is passed on in what manner?
autosomal dominant trait
failure of absorption of CSF by the arachnoid villi leads to…
normal pressure hydrochephalus (ventricles are enlarged due to lack of the final absorption step in CSF circ, but there’s no obstruction present)
oversecretion of CSF leads to
communication hydrocephalus without obstruction (ie a choroid plexus papilloma)
Rathke’s pouch
an outgrowth of oral ectoderm in which the anterior pituitary dvps
persistence of remnants of rathke’s ouch (an outgrowth of oral ectoderm in which the anterior pituitary dvps) may produce…
a craniopharyngioma, an often-calcified tumor in the sella turcica that frequently exhibits some symptoms through compression of the optic chiasm
progressive cavitation of the spinal cord causes…
syringomyelia– destruction of spinothalamic fibers that cross in the anterior commissure- bilateral loss of pain and temp in the hands and forearms. (with progession, LMN in ventral horn are compressed —> flacid paralysis of upper limb muscles)
middle meningeal artery is a branch of what artery?
maxillary
the middle meningeal artery enters the intracranial cavity through the… and is located…
foramen spinosum and is located in the floor of the middle cranial fossa
aniscoria
when one pupil is bigger than the other
