Neuro Flashcards
vision loss described as a dark curtain falling down over eye
amaurosis fugax
- causes transient vision loss due to ischemia from hypoperfusion of the optic nerve, retina, or both
what produces CSF?
choroid plexus
- choroid plexus papilloma may result in increased CSF production and/or obstruction of CSF outflow, either of which can lead to hydrocephalus
where is the amygdala located?
medial temporal lobe anterior to the hippocampus and near the lateral ventricle
where is the lesion?
- Kluver-Bucy syndrome: characterized by a loss of fear, hyperorality, and hypersexuality
amygdala
where is the lesion?
- involuntary movements including resting tremor, sudden jerking motions called chorea, and purposeless writhing movements known as athetosis
basal nuclei
where is the lesion?
- truncal ataxia, gait ataxia, or appendicular ataxia. The latter is often associated with intention tremor
cerebellum
what brain lesion results in retrograde amnesia?
hippocampus
medial temporal lobe posterior to the amygdala and near the lateral ventricle
hippocampus
Lateral strabismus (eye rotated down and out), ptosis (drooping eyelid), and pupillary dilation
ocular nerve palsy
what is the most common site of an aneurysm causing oculomotor nerve palsy?
posterior communicating A
scanning speech, intention tremor, and nystagmus
Charcot triad
- can be the initial presentation of multiple sclerosis
look out for waxing/waning sx
young women, in 20-30’s with recurrent episodes of limb weakness, vision changes, and loss of bladder control
- MRI lesions appear as “white” plaques, mostly near the ventricles (aka multiple ovoid, periventricular white matter lesions)
- optic neuritis is common
MS
- central demyelinating autoimmune disease that targets oligodendrocytes (CNS myelin)
how is CSF is returned to the vascular system?
through arachnoid granulations at the interface of the subarachnoid space and dural venous sinuses
what do schwan cells produce?
myelin for peripheral nerves
microglia
macrophages of CNS
sensations of light touch, vibration, and proprioception
posterior column
pain, temperature, crude touch
spinothalamic tract
what does the lateral horn contain?
preganglionic sympathetic neurons lying deep to the more superficial white matter
roots of long thoracic nerve?
C5-7
roots of phrenic nerve?
C3-5
roots of dorsal scapular nerve?
C5
seizures, neuro-regression, decreased motor skills, neuroimaging, and cherry red retinal spots?
- hyporeflexia
Tay-Sachs
- deficiency in β-hexosaminidase A
- ultimately, patients develop seizures, blindness, and spasticity
- less severe than Niemann-Pick
what is the only cranial nerve that emerges posteriorly from the brainstem and the only one to innervate structures contralateral to its exit from the brainstem?
CN IV: trochlear
- emerges from the midbrain just inferior to the inferior colliculus
eye that is abducted and depressed
lateral strabismus
what causes intention tremors?
damage to cerebellum
- MCC of intention tremors are stroke, multiple sclerosis of the cerebellum, or midbrain trauma that affects cerebellar outflow
weakness/paralysis, hyperreflexia, spasticity
UMN signs
when would you see a resting tremor?
Parkinsons
- damage to substantia nigra
buildup of amyloid plaques and neurofibrillary tangles in neurons of the cerebral cortex, thus decreasing acetylcholine transmission
Alzheimers
cerebral cortex and the epidermis are derived from what layer of the embryo?
ectoderm
what embryonic layer forms gastrointestinal tract, pancreas, liver, parathyroid, lungs, thymus, and thyroid follicular cells
endoderm
wht embryonic layer forms bone, connective tissue, muscle, and lymphatics
- organs include spleen, bladder, kidneys, vagina, adrenal cortex, testes/ovaries, urethra, and blood
mesoderm
Temporal lobe necrosis, often unilateral, in the setting of seizures and fevers is consistent with what?
HSV encephalitis
what is the MCC of septic arthritis in US?
N. gonorrhea
- migratory polyarthritis, tenosynovitis, dermatitis
ptosis (drooping eyelid), miosis (constricted pupil), and anhidrosis (loss of facial sweating)
Horner syndrome
- PAM is NOT sympathetic!! (loss of SNS stimulation)
what does ocular motor nerve damage cause?
ptosis, mydriasis, lateral strabismus
cotton swab on skin tests what?
meissner’s corpuscles
deep tactile mechanoreceptors located in the dermis of the integument. They have large receptive fields and respond best to skin stretch for as long as the stimulus is present. They are important for detecting changes in finger position, movement allowing alterations in grip, and deformations within the joint capsule
ruffini corpuscles
headaches, seizures, confusion, cognitive dysfunction, focal weakness, sensory abnormalities, or aphasia
- tumors arise in the white matter of the cerebral hemispheres, predominantly in the frontal lobes
- fried egg appearance on bx (rounded cells with clear cytoplasm that surround a dense central nucleus)
- vast vasculature of finely branching capillaries that give it the appearance of chicken wire
oligodendroglioma
5-10 y/o with symptoms of increased intracranial pressure, such as headaches, projectile vomiting, papilledema, a decrease in visual acuity, blurred vision, or bitemporal hemianopsia
- both a solid and cystic component
- microscopic examination will reveal abundant cholesterol crystals in the fluid
craniopharyngioma
- arise from Rathke’s pouch
CNS tumors that arise contiguously to the meninges
- focal weakness, dysphasia, apathy, somnolence, and new onset seizures due to irritation and compression of the underlying cortex
- found at the surface of the brain, either over the convexity or at the skull base
meningioma
pt in first two decades of life w/headache, nausea, vomiting, irritability, ataxia, and visual complaints
- CT or MRI will reveal a unilocular or multilocular cyst with an associated tumor nodule
- Rosenthal fibers which are elongated corkscrew shaped eosinophilic fibers that stain positively for GFAP
pilocytic astrocytoma
- benign CNS neoplasm usually in cerebellum
receives auditory information from the inferior colliculus and the superior olivary complex and projects to the primary auditory cortex of the temporal lobe
medial geniculate nucleus
receives input from the basal nuclei and cerebellum and projects to the primary motor cortex and the association motor cortices. It is involved in controlling and coordinating movement
ventral lateral nucleus
receives somatosensory information from the body (medial lemniscus for light touch, vibration, and position sense; spinothalamic tract for pain and temperature sensation) and projects to the primary somatosensory cortex of the parietal lobe
ventral posterolateral nucleus
receives somatosensory information from the face and projects to the primary somatosensory cortex of the parietal lobe
ventral posteromedial nucleus
receives visual information from the retina and projects to the primary visual cortex of the occipital lobe
lateral geniculate nucleus of the thalamus
- Loss of ipsilateral upper motor neuron function below the level of the lesion
- Loss of ipsilateral tactile discrimination, vibration, and proprioception below the level of the lesion
- Loss of contralateral pain and temperature sensation beginning 2 to 3 levels below the level of the lesion
Brown-Sequard syndrome
pramiprexole, ropinirole
patients with parkinsonism who are taking levodopa and are experiencing end-of-dose akinesia or on-off phenomenon
- can also be used in patients becoming resistant to treatment with levodopa
what major complication is associated with Ehlers-Danlos syndrome?
berry aneurysm in the Circle of Wilis
autoantibody attacks the myelin in the sensory roots and causes often-severe weakness for days to months
Guillian-Barre
what sleep stage has sleep spindles and K complexes on EEG?
stage 2
what sleep stage has dropout of alpha waves and slow rolling eye movements
stage 1
cognitive decline, gait instability, and loss of bladder function
normal pressure hydrocephalus
- wet, wacky, and wobbly
connection linking the Wernicke and Broca areas of the dominant cerebral hemisphere
- Patients are able to speak fluently and with comprehension, but have some difficulty finding specific words. Repetition ability is lost
arcuate fasciculus
lesion affecting Brodmann areas 44 and 45
- located in the inferior frontal gyrus of the dominant cerebral hemisphere
Broca (expressive) aphasia
- lesion in left MCA
lesion affecting Brodmann area 22
- posterior aspect of the superior temporal gyrus of the dominant cerebral hemisphere
Wernicke aphasia
- lesion in left MCA
lesion affecting the mammillary bodies of the hypothalamus
- triad of eye movement abnormalities, ataxia, and confusion, accompanied by profound memory loss
Wernicke-Korsakoff syndrome
- thiamine deficiency
compression of what nerve can cause weakness in elbow flexion and decreased sensation for the lateral forearm
musculocutaneous N
- pierces coracobrachialis m
when would you see CSF with an elevated protein level with a normal white blood cell count?
Guillian-Barre
- elevation of CSF protein is thought to be due to the presence of myelin breakdown products entering the CSF
when would you see red blood cells in the CSF?
herpes simplex virus (HSV) meningoencephalitis and subarachnoid hemorrhage (SAH)
young, obese female (20-40’s)
- idiopathic elevation in CSF pressure that causes papilledema and chronic, diffuse headaches
- elevated opening pressure with normal cell counts, protein, and glucose levels
pseudotumor cerebri
- Progressive decline with eventual Parkinson
- Vivid visual hallucinations
- Rapid eye movement sleep disturbances (acting out dreams)
- Fluctuating attention and alertness
Lewy body dementia
EEG shows triphasic spikes?
Creutzfield-Jacobs
what does the paramedian pontine reticular formation help with?
it coordinates adduction movement of contralateral eye
- to look L, L eye activates LR muscle, and the PPRF sends a signal to contralateral MR to adduct (so R eye also looks L)
- if neither eye can look one direction, most likely a lesion in PPRF
MC complication of solder dystocia?
Erb-Duchenne palsy (damage to upper trunk C5-6)
- weakness of the deltoid, biceps, and infraspinatus muscles
MC site for Berry aneurysm?
junction of anterior communicating and anterior cerebral A
- look out for bitemporal hemianopsia
microgial cells are stained with what?
- silver* stain
- difficult to visualize on H&E
what cells have several important functions in the CNS, including physical support, repair, potassium metabolism, removal of excess neurotransmitters, stimulation of glial scar formation in response to injury, and maintenance of the blood-brain barrier.
astrocytes
what is the first manifestation of symptomatic hypermagnesemia?
loss of DTRs
- look out for in preeclampsia or HELLP, where you are giving them magnesium sulfate
stroke of the MCA
- involves upper motor neurons with upper extremity muscles and muscles of the face
Damage to the lateral precentral gyrus
pt can hear, but responds inappropriately?
Wernicke’s aphasia (word salad)
good comprehension, good fluency, but repetition is poor?
conduction aphasia (arcuate fasciculus)
history of blunt-force trauma to the head, transient period of regained consciousness, and subsequent oculomotor nerve palsy
- lens shaped hematoma (bubbles out)
epidural hematoma
- rupture of MMA
minor bridging veins, inside the cranium and perforating the dura mater, are disrupted
- slow bleed, delayed neuro sx
- crescent shaped hematoma (thin, follows curve of skull)
subdural hematoma
thunderclap headache?
- hyperdensity (white area) in the suprasellar cistern
subarachnoid hemorrhage
loss of sensation from the right medial arm?
medial cutaneous nerve
- musculocutaneous supplies lateral forarm
- normal/mild high CSF opening pressure
- mildly elevated protein
- normal glucose
- predominant lymphocytic infiltrates
viral encephalitis
- high CSF opening pressure
- low glucose
- high WBC
- high protein
bacterial meningitis
peripheral dopa decarboxylase inhibitor, reduces peripheral conversion of levodopa to dopamine
- so more levodopa can cross BBB
carbidopa
- levodopa + carbidopa are first line tx for Parkinsons
what hypothalamic nuclei monitors thermoregulation?
anterior
what hypothalamic nuclei produces oxytocin and antidiuretic hormone for transport to the circulatory system. Stimulation causes increased blood volume, blood pressure, and metabolism. Lesion causes diabetes insipidus
supraoptic
middle-aged female, complains of vision disturbances, muscle weakness that progressively gets worse throughout the day or after use, and difficulty chewing
myasthenia gravis
- ptosis, muscular weakness with sustained activity (usually chewing muscles), and normal pupillary responses
- thymus abnormalities common (thymomas)
drugs of choice for MG?
neostigmine or pyridostigmine
- prevent the actions of AChE from degrading ACh in the neuromuscular junction
lesion in the medial longitudinal fasciculus (MLF)?
internuclear opthalmoplegia -> MS
scissoring gait? hyperreflexia?
UMN lesion
what nerve traverses through the spiral groove on the posterior side of the humerus?
radial N
looping of single-stranded DNA that triggers the mismatch repair mechanism -> CAG repeats
HD (AD)
hepatosplenomegaly, bone disease, anemia, thrombocytopenia
- abnormal macrophages
Gaucher dz
- lipid laden macrophages d/t a deficiency of lysosomal β-glucocerebrosidase
accumulation of necrotic cell debris and foamy macrophages after cerebral infarction?
liquefactive necrosis
Weakness in elbow extension and decreased sensation for the posterior arm and forearm
radial nerve injury
what causes trendelenburg gait?
gluteus medius injury
- superior gluteal n supplied glut med, glut min, TFL
what hypothalamic nucleus mediates circadian rhythm?
suprachiasmatic
alternating constriction and dilation of both pupils with the swinging flashlight test is characteristic of what?
Marcus Gunn pupil
- When the penlight is directed into the eye on the affected side, the pupils appear to dilate
what is the most common site of spontaneous hypertensive hemorrhage in patients with long-standing hypertension?
- lacunar infarcts
- hispanics and african americans
- HTN or uncontrolled diabetes
lenticulostriate arteries
- supply the internal capsule and basal nuclei
impaired vertical gaze, normal to large pupils, light-near dissociation, convergence-retraction nystagmus, and eyelid retraction
Perinaud syndrome
- can be caused by a pineal gland tumor (especially in the young), hydrocephalus (due to dilation of suprapineal recess), multiple sclerosis, and brainstem infarction
congenital malformation characterized by aplasia or hypoplasia of the cerebellar vermis, cystic dilation of the fourth ventricle, and enlargement of the posterior fossa
Dandy Walker malformation
Downward displacement of the cerebellar tonsils through the foramen magnum
Chiari malformation type I
rapidly progressive primary brain malignancy, presenting with a single lesion. Characteristically, it is described as a butterfly-appearing lesion that crosses the midline
Glioblastoma multiforme
Klumpke palsy what nerve roots?
C8-T1
- falling from a tree branch
- hyperextension of the metacarpophalangeal joints and hyperflexion of the interphalangeal joints
Marcus Gunn pupil is typically associated with diseases of what?
the retina or optic nerve
what is the one antiseizure med that inhibits CYP450?
valproic acid
- Carbamazepine, oxcarbazepine, and phenytoin INDUCE
spastic paralysis or paresis, hyperreflexia, and a positive Babinski sign?
UMN lesion
fasciculations, hyporeflexia?
LMN
- Guillian-Bare, ALS
40-60 y/o
- periodic episodes of vertigo, sensorineural hearing loss, and tinnitus
Meniers disease
- due to hydropic dilation due to excess endolymphatic fluid in the cochlea
- look for ear fullness or pressure
PREcentral gyrus contains upper motor neurons, while POSTcentral gyus contains what?
somatosensory input
what foramen does MMA enter the skull through?
foramen spinosum
- is terminal branch of maxillary A (from external carotid)
- ipsilateral loss of pain and temperature sensation in the face
- contralateral loss of pain and temperature sensation in the body
- dysarthria
- dysphagia
- ataxia
Wallenburg syndrome (lateral medullary syndrome) - occlusion of posterior inferior cerebellar A (PICA)
- Ipsilateral face analgesia
- Contralateral body analgesia
- Ipsilateral face hemiparesis
- Ipsilateral deafness
lateral pontine syndrome
- occlusion of anterior inferior cerebellar A (AICA)
multisystem disorder from defective DNA repair
- abnormal blood vessel formation commonly seen in the eyes and skin
- frequent infections of the sinuses and lungs occur
- increased risk of leukemia or lymphoma
ataxia telangiectasia
- usually presents before 4 years old
- ATM gene mutation
5-25 year old
- progressive ataxia, dysarthria, and abnormal eye movements
- proprioception, vibration, and deep tendon reflexes are lost
- hypertrophic cardiomyopathy and diabetes mellitus
- pes cavus or scoliosis
freidrich ataxia (AR) - MC ataxia
epistaxis, gastrointestinal bleeding, iron deficiency anemia, and telangiectasia
Osler-Weber Rendu syndrome
MCA -> inferior trunk vs superior trunk
superior = broca inferior = wernicke
bilateral loss of pain and temperature sensation in the upper extremities
syringomyelia
- associated with Chiari malformation Type I
- look for hydrocephalus as well
somatosensory pathways for the face run through which thalamic nucleus?
ventral posteriomedial
- ventral posteriolateral is somatosensory for the body
lateral geniculate nucleus vs medial geniculate nucleus?
medial: primary auditory cortex
lateral geniculate nucleus: primary visual cortex
tumor most often in the cerebellum
- common in von Hippel-Lindau syndrome
- can produce erythropoietin -> secondary polycythemia.
- histo will reveal foamy cells with a high vascularity
hemangioblastoma
tumors that arise within the ependymal lining of the ventricles
- in kids: MC near 4th ventricle
- in adults: MC in lining of central spinal canal
- new onset seizures, insidious onset of lethargy, headache, nausea, and vomiting
- “toothpaste tumor” that squeezes into the ventricle
ependymoma
- associated w/ neurofibromatosis type II
medial strabismus (adduction) at rest and an abduction deficit when attempting to gaze laterally
abducens nerve palsy
- vs internuclear opthalmoplegia (seen in MS), which is adduction weakness for one eye, with normal abduction for the other eye, while attempting lateral gaze
weakness in the contralateral lower limb with relative sparing of the upper limb and face
- bowel/bladder incontinence
ACA stroke
weakness, hemineglect in contralateral upper extremity
MCA stroke
- if on left side, may also see expressive aphasia
upper extremity weakness contralateral to the lesion, and dysarthria due to damage to upper motor neurons that innervate speech muscles
MCA stroke affecting the primary motor cortex
what CN provides taste sensation to the anterior tongue?
facial nerve
- exits skull at internal auditory meatus
what CN causes secretion of the parotid by providing parasympathetic innervation?
hypoglossal nerve
ipsilateral third nerve palsy causing “down and out” eye deviation, ptosis, mydriasis, and contralateral limb weakness/hemiparesis
Weber syndrome
what CN lesion causes
- decreased sensation/taste of the posterior third of the tongue
- diminished sensation of the soft palate/tragus/mastoid region
- mild dysphagia
CN IX palsy - glossopharyngeal
what controls the gag reflex?
glossopharyngeal (CN IX) and vagus (CN X) nerves
- also innervate the posterior pharynx, posterior 1/3 of the tongue, soft palate, and stylopharyngeus muscle
sharp, stabbing pain in the lower jaw, teeth, and cheek
- episodes occur during chewing or brushing teeth and last for a few seconds at a time
trigeminal neuralgia
- tx is carbemazepine (anticonvulsant that blocks sodium channels to inhibit action potential propagation)
cherry red fovea (center of macula) and hypotonia
- hepatosplenomegaly , feeding difficulties, and loss of early motor skills in the first few months of life
- areflexia
Niemann-Pick
- deficiency in acid sphingomyelinase
- NO hepatosplenomegaly in Tay-Sachs
- hyperreflexia in Tay-Sachs
unilateral facial weakness, facial droop, hyperacusis, and a featureless brow
Bell’s palsy (facial N)
facial N exits the skull through which foramen?
stylomastoid foramen
valley fever, SW US, earthquakes?
- large spherules with endospores
Coccidioides immitis
involuntary hyperkinesia continuous during consciousness and diminished upon sleep
hemibalismus
- lesion in contralateral subthalamic nucleus (w/in basal ganglia)
postviral symptoms of nausea, vomiting, dizziness, and vertigo with preserved hearing and ambulation
vestibular neuritis
- sx should start to improve in 48 hrs
paresis or paralysis of the contralateral upper extremity and lower face due to an upper motor neuron (UMN) lesion
MCA stroke, superior trunk
- uvula deviates toward the strong side and the tongue toward the weak side
what nucleus is located in the caudal pons?
facial motor nucleus
bilateral weakness and loss of pain and temperature sensations below the lesion, with sparing of light touch sensation
occlusion of anterior spinal artery
- supplies all of the spinal cord except the posterior columns (which is why light touch is spared)
caudate nucleus degeneration?
huntington (AD)
- xsome 4
- chorea, depression, dementia
- confused
- ataxic gait
- vision problems
- anterograde amnesia
Wernicke-Korsakoff syndrome (thiamine def)
- areas most affected include the mammillary bodies, the thalamus, and the periaqueductal gray matter
right superior quadrantanopsia, the lesion where?
left temporal radiation
periventricular plaques and oligoclonal bands?
MS
neurofibrillary tangles in the cerebral cortex of the brain.
- the result of β-amyloid protein deposition leading to tau protein aggregation
AD
- proteins cause the destruction of cerebral neurons, and over many years, result in atrophy of the entire cortex
- linked to Down syndrome!
atrophy of the caudate nuclei
- enlargement of lateral ventricles
Huntington’s (AD)
- cognitive decline, chorea, family hx
what cells produce aqueous humor, and are target of glaucoma meds?
epithelial cells of the ciliary body
ventromedial hypothalamic nuclei?
mediates satiety
- destruction -> hyperphagia
ventrolateral hypothalamic nuclei?
mediates hunger
- destruction -> anorexia
anterior hypothalamic nuclei?
mediates heat dissipation
- destruction -> hyperthermia
posterior hypothalamic nuclei?
mediates heat conservation
- destruction -> hypothermia
arcuate hypothalamic nuclei?
secretion of dopamine (inhibits prolactin)
- GHRH
medial preoptic hypothalamic nuclei?
secretion of GnRH
- mediates sexual behavior
paraventricular hypothalamic nuclei?
secretion of oxytocin, CRH, TRH, small amounts of ADH
supraoptic hypothalamic nuclei?
secretion of ADH and small amount of oxytocin
suprachiasmatic hypothalamic nuclei?
regulation of circadian rhythm and pineal gland function
