Neuro Flashcards
How does a visual defect present if there’s a lesion in the Right PCA/occiput?
Left Homonymous Hemianopia
How does a visual defect present if there’s a lesion in the Left Temporal region /MCA
Right upper quadrantanopia
How does a visual defect present if there’s a lesion in the Right Parietal region /MCA
Left lower quadrantanopia
What is the afferent limb of the cough reflex?
the internal laryngeal n. (travels through the piriform recess)
the internal laryngeal n. is a branch of the superior laryngeal n. which is a part of the vagus nerve
What and where are Ruffini corpuscles
location: finger tips, joints
used for stretch and joint angle changes
alpha-synuclein production in Parkinsons drive what kind of problems?
NON-MOTOR problems (autonomic dysfunction- constipation, vascular sympathetic nerves- orthostatic hypotension)
because the motor problems (bradykinesia, cogweel rigidity, shuffling gate etc.) is driven by the loss of dopamine
What are the two main substances that get stuck in the brain in Alzheimer’s
beta-amyloid plaques (excess beta amyloid from insoluble fibrils that accumulate into extracellular amyloid plaques)
AND
neurofibrillary tangles (aggregates of hyperphosphorylated tau protein form intracellular tangled clumps)
How will “Dementia from Lewy Bodies” patients presetn
Lewy bodies (alpha-synuclein protein aggregation) are present. Pt will have fluctuating cognitive impairment, dysautonomia, parkinsonism, and visual hallucinations.
Pathogenesis of MS
autoimmune dz of oligodendrocytes, CD4 cells are activated by myelin basic protein!
Pathogenesis of MS
autoimmune dz of oligodendrocytes, CD4 cells are activated by myelin basic protein!
MCC of subarachnoid hemorrhage?
MCC of subdural hematoma?
MCC of epidural hematoma?
anterior communicating artery aneurysm that bursts
hemorrhage of bridging veins
tearing of the middle meningeal artery
What is the problem in Open angle glaucoma?
decreased outflow of aqueous humor or increased production
(from uveitis ,RBCs, retinal detachment) all can cause blockages
Which artery services Wernickes and Brocas area
MCA
1st pharyngeal arch derivatives:
nerves
muscles
cartilage
nerves-> CNV3, chewing
muscles-> mastication (temporalis, masseter, lateral and medial pterygoids), mylohyoid, tensor tympani, anterior 2/3 of tongue, tensor veli palatini, anterior belly of digastric
cartilage-> maxillary process (maxilla, zygomatic bone) mandibular process (meckel cartilage, mandible, malleus and incus, sphenomandibular ligament)
2nd pharyngeal arch derivatives:
nerves
muscles
cartilage
nerves-> CNVII, facial expression
muscles-> muscles of facial expression, stapedius, stylohyoid, platysma, posterior belly of digastric
catilage-> Reichert cartilage (stapes, styloid process, lesser horn of hyoid, stylohyoid ligament)
3rd pharyngeal arch derivatives:
nerves
muscles
cartilage
nerves-> CNIX, swallow stylishly
muscles->
stylopharyngeus
cartilage->
greater horn of hyoid
Alzheimer disease: altered proteins: Change in neurotransmitters: What does brain look like? What type of plaques and tangles? What bodies do we see?
ApoE-2 Dec. risk of sporadic form
ApoE-4 Inc. risk of sporadic form
App, presenilin 1 and 2.
Dec. ACh
Widespread cortical atrophy especially hippocampus. , narrowing of gyri and widening of sulci.
Senile plaques w/ B amyloid core.
Neurofibrillary tangles (intracellular hyperphosphorylted tau proteins.) # of tangles correlates with severity
Hirano bodies in hippocampus (intracellular eosinophilic proteinaceous rods)
What are tangles and which diseases have them
Neurofibrillary tangles are hyperphosphorylated Tau proteins. Found in Alzheimers and Pick’s
Symptoms of central retinal artery occlusion
unilateral painless acute vision loss in patients >40 with thromboembolic risk factors (ex. HTN). Retinal whitening and cherry red macula.
Meniere disease triad
- recurrent vertigo
- ear fullness/pain
- unilateral hearing loss and tinnitus
caused by increase pressure and volume of endolymph in the inner ear
BPPV features
brief episodes brought on by head movement
no auditory symptoms
caused by otoliths in semicircular canals
Vestibular neuritis (labyrinthitis) features
single episode of severe vertigo that can last for days,
termed labyrinthitis when associated with unilateral hearing loss
caused by inflammation of vestibular nerve (viral or postviral)
Acoustic neuroma (schwannoma of CN VIII) features
sensorineural hearing loss, vertigo, and tinnitus
symptoms will be persistent and progressive rather than episodic
caused by a mass lesion (schwannoma) at the cerebellopontine angle
Otosclerosis features
conductive hearing loss, no vertigo, mainly in middle aged people
caused by sclerosis of ossicles particularly bony overgrowths of the footplate of the stapes
What is the most common cause of a transtentorial herniation of the uncus?
Lesions in the temporal lobe!
Symptoms: ipsilateral oculomotor nerve palsy with a fixed dilated pupil due to preganglionic parasympathetic nerve fiber damage
What are the symptoms of an uncal herniation?
This kind of herniation will compress the cerebral peduncles, resulting in corticospinal tract injury with contralateral hemiparesis.
Patients will have hyporeflexia and flaccid paralysis
When is nystagmus present?
lesions to the pons, medulla, or cerebellum due to disruption of vestibular pathways
When does an upward gaze palsy occur?
Anything that causes compression of the dorsal midbrain (superior colliculus, pretectal area); usually occurs due to hydrocephalus and dilation of the third ventricle
What is the most common cause of a transtentorial herniation of the uncus?
Lesions in the temporal lobe!
Symptoms: ipsilateral oculomotor nerve palsy with a fixed dilated pupil due to preganglionic parasympathetic nerve fiber damage
What are the symptoms of an uncal herniation?
This kind of herniation will compress the cerebral peduncles, resulting in corticospinal tract injury with contralateral hemiparesis.
Patients will have hyporeflexia and flaccid paralysis
When is nystagmus present?
lesions to the pons, medulla, or cerebellum due to disruption of vestibular pathways
When does an upward gaze palsy occur?
Anything that causes compression of the dorsal midbrain (superior colliculus, pretectal area); usually occurs due to hydrocephalus and dilation of the third ventricle
What does equilibrium potential mean?
Equilibrium potentials of cellular ions reflect how they affect the membrane potential if the membrane were permeable solely for that ion.
Non-REM stage 1 (N1) Features
EEG- theta waves (4-7.9 Hz)
characteristics- easy to wake; wakefulness-sleep transition
Non-REM stage 2 (N2) Features
EEG- theta waves (4-7.9 Hz) and K complexes and sleep spindles
characteristics- largest percentage of sleep
Non-REM stage 3 (N3) Features
EEG- delta waves (<4 Hz)
characteristics- prominent 1st half of night, difficult to wake, sleepwalking and night terrors
REM Features
EEG- resembles wakefulness, occasional sawtooth waves
characteristics- prominent 2nd half of night, dreams, REMs, muscle atonia, REM sleep behavior disorder and nightmare disorder
Difference between premotor cortex and primary motor cortex
premotor cortex- selection of motor plans for voluntary movements
motor cortex- actually executes the voluntary movements
Why would someone have decreased perception of flavors after a traumatic brain injury?
The perception of flavor is dependent on both smell and taste, with SMELL being more important. Patients with anosmia often describe difficulties with taste, even if taste sensation is intact.
What is semantic memory? What part of the brain is impaired if there is a loss in semantic memory
Semantic memory refers to memory made from general knowledge (words, pictures, objects). This information is stored in the anterior temporal lobe.
What provides taste to the tongue?
What provides sensation to the tongue?
Taste-
anterior 2/3rd is from facial nerve via chorda tympani
posterior 1/3rd is from glossopharyngeal nerve
Sensation-
anterior 2/3rd is from lingual nerve (branch of V3)
posterior 1/3rd is from glossopharyngeal nerve
what does a Myasthenic crisis look like
Patient will be in hypoxic respiratory failure and will be hypercapnic, indicating global hypoventilation. Patient will also have ptosis, bulbar weakness and low forced vital capacity.
Features of Myasthenia Gravis
Characterizd by autoantibodies against the nicotinic acetylcholine receptors on the postsynaptic membrane of the neuromuscular junction, resulting in receptor degradation.
Muscle weakness worsens with repetition as Ach stores within the presynaptic nerve terminal get progressively depleted.
Tx: Acetylcholinesterase inhibitors (pyridostigimine, neostigmine)
Draw out direct/indirect basal ganglia pathway
hehe!
pg 516
Draw out circle of willis
pg 519
Epidural hematoma
what vessel affected
classic presentation
middle meningeal artery
Lucid interval after traumatic event then rapid deterioration
presentation for congenital toxoplasmosis
chorioretinitis
hydrocephalus
diffuse intracrainial calcifications
What occurs as a complication of subarachnoid hemorrhage and how do you treat it
Vasospasm occurs due to blood breakdown or rebleed 3-10 days after event - nimodipide (ca) prevents vasospasm
What gets demyelinated in Guillan barre
Endoneurium (innermost layer of connective tissue around nerve)
which toxins bind to Na channels inhibiting influx and preventing action potential conduction
Tetrodotoxin (puffer fish)
Saxitoxin (dinoflagellates in “red tide”)
which toxins bind to Na channels, keeping it open and causing persistent depolarization
Ciguatoxin (exotic fish, Moray eel)
Batrachotoxin (South American frogs)
