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)