neuro Flashcards
Mode of pathogen progression of Listeria for immunosuppressed and pregnant women
ingestion of unpasteurized milk, soft cheeses, coleslaw, and ready to eat turkey and pork
bacteria causing neonatal meningitis
Group B Strep, Listeria, E. Coli
Listeria monocytogenes
G+, beta hemolytic, catalase +, bacillus, causes meningitis in neonates
can be contracted by passage through birth canal, inhalation of infected amniotic fluid, or nosocomial infection: in immunosuppressed most common route is ingestion of unpasteurized milk
ACA supplies what area of the brain, and when damaged causes
medial surface of the brain, motor and sensory cortices of the contralateral leg and foot
layers of the head from superficial to deep
skin, periosteum, bone, dura mater, arachnoid, pia, and brain parenchyma
Meningeal layers of the brain
dura, arachnoid, pia
subarachnoid hemorrhage sx
worst HA ever, nuchal rigidity
Most common causes of subarachnoid hemorrhages
berry aneurysms, less commonly from arteriovenous malformations
CSF in subarachnoid hemorrhages
appear yellow - bilirubin in CSF, sign of hemorrhage and blood cell breakdown because the subarachnoid space is continuous with the spinal space
Intraparenchymal hemorrhage
caused by chronic hypertension, commonly affect the basal ganglia and thalamus - grossly appears more like a bruise and less like a pool of blood like a subarachnoid hemorrhage
subdural hemorrhage
caused by damage to bridging veins, potential space between dura and arachnoid mater
epirdural hemorrhage
temperoparietal bone fx, damage to the middle meningeal artery
Huntington Disease
chorea, dystonia, altered behavior, and dementia
AD
CAG triplet repeats on 4p
Genetic Anticipation
Caudate and Putamen are mainly affected, altering indirect pathway of basal ganglia - loss of motor inhibition
Gliosis - proliferation of astrocytes in areas of CNS damage
imaging - lateral ventricles may appear dilated due to caudate atrophy
Reserpine - minimizes motor abnormalities
Alzheimer’s Disease
Most common cause of dementia in elderly
deposition of neuritic plaques - abnormally cleaved amyloid protein
Neurofibrillary tangles - phosphorylated tau protein in cerebral cortex
Doneprezil/Vitamin E therapy - slows down progression
Wilson Disease
AR
failure of copper to enter the circulation bound to ceruloplasmin due to problem with excretion of copper from the liver
copper accumulation in the liver, corneas, and basal ganglia
Sx - asterixis, parkinsonian symptoms, cirrhosis, Kayser-Fleischer rings (corneal deposits of copper)
Parkinson Disease
Loss of dopaminergic neurons in the substantia nigra leading to depigmentation
Alter direct pathway of basal ganglia, decreasing excitation
Difficulty initiating movement, cogwheel rigidity, shuffling gait, pill-rolling tremor
Tx - Levodopa/Carbidopa combo
MS
scattered plaques of demyelination anywhere in the CNS
periventricular areas and the optic nerve are commonly affected due to high levels of myelination
Oligodendricytes (responsible for CNS myelination) are autoimmune targets
recurrent multifocal lesions separated in time and space
optic neuritis, internuclear ophthalmoplegia (diff. with horizontal eye movements), sensory and motor changes, Lhermitte sign (electric shock felt down the spine with neck flexion
meningohydroencephalocele
protrusion of the meninges, brain, and portion of the ventricle through a defect in the skull
spina bifida with meningomyelocele
protrusion of the meninges and spinal cord through a vertebral defect to form a sac
meningoencephalocele
protrusion of the meninges and brain through a defect in the skull
protrusion of the meninges through a defect in the skull
meningocele
Spina Bifida with meningocele
protrusion of the meninges through a vertebral defect to form a sac, spinal cord remains in its normal position
Foramina of the Trigeminal Nerve
Standing Room Only
Superior Orbital Fissure - V1
Foramen Rotundum - V2
Foramen Ovale - V3
Compression of the CN V3
mandibular division - numbness of the ipsilateral jaw and lower face
Compression of CN V2
maxillary division - decreased sensation over the cheek and middle face
leaves skull through foramen rotundum
What foramen transmits IX, X, XI
Jugular Foramen
Glossopharyngeal
motor inervation of stylopharyngeus muscle, parasympathetic innervation of the parotid gland, nd sensory innervation of the pharynx, middle ear, and posterior third of the tongue
Also innervates chemoreceptors and baroreceptors of the carotid body
Vagus Nerve
motor innervation of the pharyngeal and laryngeal muscles, parasympathetic innervation to visceral organs, sensory innervation to the pharynx and meninges
Also innervates chemoreceptors and baroreceptors of the aortic arch
Spinal Accessory Nerve
XI
innervates the sternocleidomastoid and upper part of the trapezius muscle
What passes through the superior orbital fissure
III, IV, V1, VI, superior ophthalmic vein
oculomotor, trochlear, ophthalmic, abducens
lesions of these nerves lead to ipsilateral extraocular muscle paralysis - III, IV, VI
numbness of the ipsilateral forehead and upper face - V1
Tx for ALS
Riluzole - reduces presynaptic release of glutamate
ALS
upper and lower motor neuron signs
affects both anterior horn cells in the spinal cord and upper motor neurons in the spinal cord - corticospinal tract
B12 neuropathy - subacute combined degeneration of the spinal cord
associated with pernicious anemia
demyelination of axons in dorsal columns - loss of vibration and position sense, and spinocerebellar tracts - arm/leg ataxia
Demyelination of axons in the posterior limb of the internal capsule would cause
UMN signs
contralateral spastic paralysis secondary to disruption of the descending fibers of the corticospinal tract
What is affected in Charcot - Marie - Tooth Disease
neuronal loss in the anterior horn cells and posterior columns in the spinal cord
loss of conscious proprioception - posterior columns
LMN signs - ant. horn motor neurons
Neuronal loss in the region of anterior horn cells in the spinal cord
An acute inflammatory viral infection that affects the lower motor neuron and results in flaccid paralysis
Poliomyelitis
Supraoptic hypophyseal tract of hypothalamus controls:
ADH and oxytocin are synthesized in the supraoptic and paraventricular nuclei and transported to the posterior pituitary via the suproaptic hypophyseal tract
ADH facilitates the retention of water and therefore the concentration of urine
Oxytocin stimulates the release of milk not it’s synthesis
Hypothalamic-hypophyseal portal system
connects the hypothalamus with the anterior pituitary
milk synthesis is mediated by
prolactin
secreted by anterior pituitary
ovulation is stimulated by
LH
secreted by anterior pituitary
Salt retention is the primary function of
aldosterone
spermatogenesis is stimulated by
follicle-stimulating hormone
secreted by anterior pituitary gland
function and location of the chemoreceptor trigger zone
area postrema of the medulla, on the floor of the 4th ventricle, outside of the BBB
controls vomitting
Prochlorperazine
anti-psychotic, dopamine blocker at the chemoreceptor trigger zone
used for anti-emetic properties
Pituitary Gland Roles
TAN HATS thirst adenohypophysis neurohypophysis hunger autonomic regulation temperature regulation sexual urges
Internal Carotid Artery supplies blood to what arteries
ACA and MCA
Where is the lesion in Wernicke Korsakoff syndrome
Mamillary bodies
Korsakoff psychosis is characterized by
anterograde amnesia and confabulation
Wernicke’s Encephalopathy
confusion, ataxia, and ophthalmoplegia
assoc. with alcoholism
reversible with thiamine
kluver bucer syndrome
bilateral lesions to the amygdala
hyperorality, hypersexuality, and disinhibition
meningioma
often located in convexities of cerebral hemispheres
Psammoma bodies - laminated mineral deposits formed via calcification of whorled clusters
PSaMMoma Papillary - thyroid Serous - ovary Meningioma Mesothelioma
oligodendrogliomas
cerebral hemispheres in middle aged people
fried egg cells
Internuclear opthalmoplegia
indicative of MS
lesion of medial longitudinal fasciculus - movement started by CN VI and cannot be transmitted to III - diplopia and nystagmus
Arcuate fasciculus connects what two areas
Broca’s and Wernicke’s of left hemisphere
Manifests as impaired repetition
Medial Lemniscus carries what information
sensory information on light touch, conscious proprioception, and vibration in the extremities from the nucleus gracilis and cuneatus to the thalamus
role of the internal segment of the globus pallidus in Parkinson’s Disease
excessive inhibition of the ventral lateral nucleus of the thalamus making it difficult for patients to initiate movements
normally, dopaminergic neurons from the substantia nigra induce striatal neurons to inhibit the globus pallidus, thereby lifting the inhibition of the thalamus
bells palsy affects which nerve
VII
afferent taste from ant 2/3 of ipsilateral tongue
touch and pain sensory fibers from ipsilateral ear
motor fibers to muscles of facial expression, ipsilateral paralysis
ipsilateral stapedius
dryness in ipsilateral eye and mouth - facial nerve carries parasympathetic fibers to ipsilateral lacrimal and submandibular/sublingual glands
+ facial muscle weakness prevents eyelids from closing - exacerbating eye dryness
physostagmine vs neostigmine MOA
both are reversible anticholinesterases
Physostagmine - crosses BBB, better CNS penetration, used as antidote for anticholinergic toxicity
Neostigmine - does not cross BBB, better peripheral action especially on skeletal muscle, used to treat Myasthenia Gravis
PICA supplies blood to
dorsolateral quadrant of the medulla, including the nucleus ambiguous and the inferior surface of the cerebellum - holds V (face and pain), vestibular nuclei, nucleus ambiguous (palate problems and hoarse voice), spinothalamic tract (contra pain and temp), descending sympathetic fibers (Horners Syndrome)
Lateral Medullary Syndrome - Wallenberg Syndrome
PICA stroke
cochlea and vestibular nuclei supplied by what artery
labyrinthine artery
internal capsule, caudate, putamen and globus pallidus are perfused by
lateral striate arteries of MCA
assoc. with lacunar infarcts
Guillan Barre is most common caused by an infection by
campylobacter jejuni
Guillan Barre is best treated by
plasmapherisis followed by immunoglobulins and supportive care
Acute injury to CNS (cauda equina syndrome, metastatic bone disease, or spinal cord injury) is best treated by
glucocorticoids
Donepezil is used for
initial tx of Alzheimer’s
acetylcholinesterase inhibitor - increases ACh in presynaptic space
Selegilin
MAO B inhibitor
increases dopamine, used in parkinson’s
Diazapam
increases frequency of GABA channel opening
Tx for anxiety, status epilepticus, and alcohol withdrawal
Benzodiazapine
Bromocriptine
dopamine receptor agonist, used in Parkinson’s
Desmopressin
ADH analog
Taken nasally to treat central diabetes insipidus
Central Diabetes Insipidus
Failure of kidneys to concentrate urine due to lack of ADH secretion from the posterior pituitary - without ADH distal tubules remain impermeable to water
caused by head trauma, hypothalamic and pituitary tumors
characterized by low urine specific gravity and high serum osmolality
Nephrogenic Diabetes Insipidus
Principal cells of the kidneys do not respond to ADH because of defective ADH receptors
caused by lithium toxicity and hypercalcemia
characterized by low urine specific gravity and high serum osmolality
Hydrochlorothiazide
diuretic used to treat nephrogenic DI
ADH is futile if receptors are defective
JC virus in AIDS patients is associated with which disease
Progressive multifocal Leukoencephalopathy
multiple areas of demyelination in the CNS white matter
reactivation of dormant virus
initial findings- speech, memory, coordination, vision deficits
rapid
Common fungal cause of meningitis in AIDS pts
Cryptococcus neoformans
Where would a HSV 1 encephalitic lesion most likely present in an AIDS pt
Temporal Lobe
Pneumocystis jiroveci
common cause of pneumonia in HIV pts whose CD4+ cell counts are less than 200
xray would show ground glass appearance
Toxoplasmosis is the most common cause of encephalitis in pts with
HIV
CD4+ count less than 100
seizures and headache
ring enhancing lesions with surrounding edema
A disease described by dementia, increased impulsivity and hyperoral habits (frontotemporal dementia),
confirmed by intracytoplasmic, silver-staining spherical tangles and occasional balloon neurons
Pick Disease
What is affected by a midshaft humerus fracture
The radial groove
Radial nerve and brachial artery
inability to extend the wrist and metacarpophalangeal joints of all digits
What causes a winged scapula
Long thoracic nerve damage - innervated Serratus Anterior
injury to the axilla or lateral thoracic wall
What type of injury can cause damage to the axillary nerve
Surgical neck of the humerus fracture or anterior shoulder dislocation
Axillary nerve innervates deltoid - abduction
Weakness in adduction and abduction of the fingers can be caused
Damage to the ulnar nerve at the medial epicondyle
Supracondylar humerus fracture causes damage to what nerve
Median
What nerve roots are compressed in Erb Palsy
C5 and C6
Axillary nerve
cluster headaches
Always unilateral
repetitive headaches that occur for weeks to months at a time with intervening periods of remission
typically around the eye or temple and are excruciating
not preceded by prodromal symptoms
migraine headaches
preceded by prodromal symptoms
can be bilateral
increase in severity and can last 10-12 hours
A headache that frequently presents with unilateral ear or auricular pain radiating to the jaw is caused by
temporomandibular joint dysfunction syndrome
The most common headache syndrome that typically presents with bifrontal squeezing and constant pain
tension headaches
typically relieved by NSAIDs
Naloxon reverses the effects of
opioid intoxication
opioid receptor antagonist
opioid intoxication can present with miosis due to increased parasympathetic tone
shaking chills of indicative of
bacteremia and sepsis
hypotension, increased WBC, increased temp
a patient has a resected ileum, eats a normal diet, and now presents with weakness in all extremities and + Romberg sign - what is the most likely diagnosis
B12 deficiency - leads to abnormal myelin
macrocytic, megaloblastic anemia withhypersegmented neutrophils on blood smear
B12 combines with intrinsic factor from parietal cells and is reabsorbed in the ileum
Bupropion is an antidepressant contraindicated in which patients for increased risk of seizures
Anorexia nervosa
The anterior pituitary develops from
rathke’s pouch which is composed of surface ectoderm
A functional anterior pituitary adenoma presents with
bitemporal hemianopsia and amenorrhea due to prolactin hypersecretion
gut tube epithelium and its derivatives originate from
endoderm
most of the body’s connective tissue comes from
mesoderm
the parafollicular cells of the thyroid are derived from
neural crest
posterior pituitary is derived from
neuroectoderm
