Neuro 1 Flashcards
Which arteries feed the pons?
Basilar artery (also midbrain) Anterior Inferior Cerebellar Artery (also parts of cerebellum)
What artery feeds the medulla?
Posterior Inferior Cerebellar Artery
What do the first-order neurons of the dorsal columns do? What do the second-order neurons do?
Enter at ipsilateral dorsal horn…ascend in fasciculus gracilis (lower body) and cuneatus (upper body)…synapse at nucleus gracilis and nucleus cuneatus…respectively
Decussate at medulla…ascend as medial lemniscus
What information do the nerves in the medial lemniscus carry?
Two-point discrimination*
Vibration
Proprioception*
What do the first-order neurons of the spinothalamic tract do? Second-order?
Originate in DRG, synapse in dorsolateral tract of Lissauer
Decussate in ventral white commissure…ascend in lateral spinothalamic tract
What information do the nerves in the lateral spinothalamic tract carry?
Pain
Temperature
What do the first-order neurons of the corticospinal tract do? Second-order?
Descend from internal capsule and midbrain…decussate in medullary pyramids…descend in corticospinal tract…synapse in ventral horn through interneurons
Exit through ventral horn
What information do nerves in the corticospinal tract carry?
Voluntary movement of striated muscle
A patient comes in presenting both lower motor involvement (weakness, cramps, fasciculations) and upper motor involvement (difficulty walking due to spasticity). What does this person likely have? What is affected?
Amyotrophic Lateral Sclerosis (ALS…AKA Lou Gehrig’s)
Cerebral cortex, brain stem, spinal cord (corticospinal tract, ventral horn)
A patient comes in after 2-5 days of flu-like symptoms with asymmetric weakness and flaccid paralysis. What is likely going on? What is affected?
Poliomyelitis (poliovirus is a picornavirus)…can still happen after ORAL vaccine
Ventral horn
A patient comes in with lightening-pain shooting down thigh or abdomen and has had difficulty walking. On exam, his eyes don’t react to light, but they do react to near test. What is the likely diagnosis? What is affected? What else could be going on with this patient?
Tabes dorsalis (tertiary syphilis)
Dorsal columns
Cardiac problems and/or gummatous syphilis (granulomatous infiltration of any organ [liver, skin])
A patient is brought in with bilateral flaccid paralysis and bilateral spastic paresis. On exam, it is determined that sense of pain and temp are also lost. What is likely diagnosis? What is affected?
Spinal artery syndrome
Corticospinal tract (at level of lesion) Spinothalamic tract (one level below lesion) Ventral horn (at level of lesion) Lateral gray matter (at level of lesion)
A patient comes in with bilateral spastic paresis affecting her legs. On exam, she is found to have decreased since of vibration and two-point discrimination. What would you likely see on labs? What is affected?
Megaloblastic anemia…because this is B12 deficiency
Dorsal columns
Corticospinal tracts
A patient is brought in with bilateral flaccid paralysis. On exam, he is found to have lost send of pain and temp bilaterally almost as high as he feels weak. What is the likely diagnosis? What is affected?
Syringomyelia
Ventral horn
Ventral white commissure…where spinothalamic tract decussates
A patient is found to have loss of vibration and discriminatory sense, spastic paresis, and flaccid paralysis on one side; and loss of sense of pain and temp on the other side. What is the likely diagnosis? What is affected?
Brown Sequard syndrome (I think this is like a stabbing victim)
ALL tracts on one side
A patient has a headache, neck pain, AMS, positive Brudzinski and Kernig signs, and petechiae. What is the likely bug?
Neisseria meningitidis
What should always be done before doing an LP? Why?
Neuro exam
Increased intracranial pressure + LP = increased risk of uncal herniation
Increased intracranial pressure: papilledema, focal neurologic deficits, pupil asymmetry)
How is meningitis initially treated?
Third gen cephalosporin (ceftriaxone)
What should be given to close contacts of patient’s with bacterial meningitis?
Rifampin or ciprofloxacin for Neisseria
Rifampin for H. influ in nonvaccinated kids
What viruses can cause meningitis?
Enterovirus Echovirus HSV Lymphocytic choriomeningitis virus Mumps virus
What is the most common cause of meningitis in newborns? What else can cause it?
GBS
E. coli, listeria, H. influ
What is the most common cause of meningitis in 1m-2yo? What else can cause it?
Strep pneumo and N meningitidis
GBS, Listeria, H. influ
What is the most common cause of meningitis in 2-18yo? What else can cause it?
N. meningitidis
Strep pneumo, Listeria
What is the most common cause of meningitis in 18-60yo? What else can cause it?
Strep pneumo
N. meningitidis, Listeria
What is the most common cause of meningitis in 60+yo? What else can cause it?
Strep pneumo
Listeria, gram- rods
An LP is done of a patient with expected meningitis, and results are: elevated WBC (lymphocytes), significantly elevated pressure, decreased glucose, and increased protein. What kind of meningitis is it? What should be given?
Fungal infection or TB
Fungal: Amphotericin B
TB: RIPE
What can cause encephalitis?
It is a viral infection
VZV, HSV, mumps virus, poliovirus, rhabdovirus (rabies), coxsackie virus, arbovirus (St. Louis and Cali strains), flavivirus (West Nile), and measles
A patient presents with severe pain kinda over cheeks and along the jaw. What should be considered? What is the treatment?
Trigeminal neuralgia
Carbamazepine, baclofen, phenytoin, gabapentin, valproate, clonazepam, or other anticonvulsants…surgical decompression of nerve may help