Microbiology
A 6 yo F presents to the doctor due to new onset chest pain with mild SOB. She recently got over a GI illness. She also has an elevated troponin. If her disease is caused by an enterovirus, what is the specific virus she likely has?
Coxsackie B
an enterovirus that can progress to myocarditis
May be asymptomatic and have sudden death
Myocarditis due to molecular mimicry of ventricular myosin and bystander activation
Other enteroviruses
HFMD, herpangina (know the picture)--> Coxsackie A and enterovirus 71
Aseptic meningitis--> Coxsackie B and echoviruses
After a traumatic accident, you are concerned your patient has brain damage. You use the corner of a paper towel and attempt to touch their cornea. What 2 cranial nerves must be intact for this reflex?
Corneal reflex: sensation is CNV1 and motor is CNVII (orbicularis oculi)
Pupillary reflex: CNII is sensory and CNIII is motor
Gag reflex: CNIX is sensation and CNX is motor
If you had an injury to the septal nuclei of the hypothalamus, what physiologic function would be altered in you?
Difficulty regulating temperature-> can't get rid of heat
Septal nuclei should cause vasodilation when temp increased-> sweating, antidiuresis...
Caudal area in posterior hypothalamus-> hold onto heat with vasoconstriction, shivering, increased tissue metabolism....
Septal nuclei and caudal area go to preoptic area in the anterior hypothalamus
A 56 yo M comes to the ED due to acute weakness. He was standing and suddenly lost sensation in his R leg and is no longer able to lift it. What artery is likely occluded in this patient?
ACA stroke (L sided)
Contralateral paralysis and loss of sensation below the waist
A 56 yo M comes to the doctor due to concerns from his wife. She says over the past 6 months he has become more irritable and has forgotten things he usually wouldn't. He also acts out his dreams. During the exam, he begins to ask about the dogs in the corner and his wife says this is not anything new. What is his likely diagnosis?
Lewy Body Dementia
Hal-LEWY-cinations
Also with personality changes and dementia that develop within 1 year of motor symptoms
REM sleep behavior disorder and sensitivity to antipsychotics
Alpha synuclein inclusions
Give cholinesterase inhibitors for memory and levodopa-carbidopa for movement issues
A 34 yo F comes to the neurologist due to episodes of vision issues and weakness separated by space and time. She is diagnosed with MS and started on rituximab. 6 months later she returns and complains of hemianopia, new weakness, and ataxia. What CSF cell does this virus replicate in?
PML-> reativation of JC virusSeen in those with immunosuppression, caner, immunomodulators
Symptoms: hemianopia, ataxia, weakness, seizures, mental impairment
Multiple non-symmetric lesions of demyelination in the brain and enlarged astrocytes and oligodendrocytes on brain biopsy
Replicates in oligodendrocytes
A 15 yo M comes to the ED after being hit in the head during a basketball game. He immediately lost consciousness, but got back up quickly and continued playing. He now is sleepy and difficult to arouse. CT scan is notable for a convex hyperintensity. What artery is likely damaged in this teen?
Epidural hematoma
From damage to the middle meningeal A, usually as it passes behind the pterion
Period of lucency
Fill in the blanks:
The tectospinal tract allows the _______ to direct head movement to match ________ movement.
Tectospinal tract connects superior colliculus to the neck muscles so that head will move with eyes
Cross ventral to central gray substance and descend ventral to MLF and travel in the ventral column
Lesion in 1 supr colliculus= no saccades in contralateral visual field
A 67 yo F comes to the ED for sudden onset difficulty speaking. She lacks fluency, but her words make sense. She also has weakness and sensory loss in her R arm. Where would you expect a lesion in this patient?
MCA stroke
Supplies Wernicke/Broca if on L
Upper extremity weakness
Contralateral homonymous hemianopsia
A 35 yo M comes to the ED due to HA. He says for the past week he has had sudden attacks of severe R sided HA behind his eye that last for 15-20 minutes and occur multiple times per day. He also endorses tearing, flushing, and sweating on the R side of his face during these episodes. What is the likely diagnosis in this patient?
Cluster HA: unilateral, in M, one sided, comes on in "clusters", have other symptoms like lacrimation, tearing, sweating, congestion, redness
Tension HA: W>M, bilateral "band-like" distribution, occurs during times of stress (tension)
Migraine HA: W>M, unilateral, pulsatile, aura/phonophobia/photophoia
A 13 yo fully vaccinated M from Egypt comes to the ED due to weakness and trouble seeing. On exam he has 2/5 strength in the R leg and 5/5 strength in his L. Fundoscopic exam is notable for optic neuritis. What are the 2 tests of choice to diagnose the most likely pathogen in this boy?
This is West Nile-> looks like polio but occurs in vaccinated people
Symptoms: asymmetric weakness, cranial neuropathies, ataxia, optic neuritis
Diagnose with CSF PCR (days 1-4) or CSF ELISA (days 7-10)
Following an inferior parathyroidectomy a patient has difficulty talking. Her voice is much hoarser than it was before the surgery. What N was likely damaged during this surgery?
Recurrent laryngeal (when in doubt- pick it)
Around subclavian on the L and the common carotid on the R
A branch of CNX that runs with inferior thyroid A
You arrive at your family's house on Thanksgiving to many smells. The pumpkin pie stands ut to you and you begin to have memories of many Thanksgiving's in the past. The olfactory bulb projected to what cortex to allow you to have these memories triggered by the smell?
Olfaction
Receptors->CN1->bulb
From bulb:
Pyriform cortex-> orbitofrontal cortex for perception of smell
Entorhinal cortex-> hippocampal formation for memory
Pyriform cortex, entorhinal cortex, amygdala, olfactory tubercle-> thalamus, hypothalamus and orbitofrontal cortex
Following a stroke a 78 yo M appears to be comatose. On closer exam, he opens his eyes and follows you around the room but is unable to move any other part of his body. What artery would you expect a lesion in this patient.
Basilar A stroke
This is locked in syndrome (Pontine stroke)
May also be quadri/paraplegic, nystagmus, vertigo, diplopia, ataxia, R facial weakness with L hemiplegia
A 90 yo M comes to the ED due to difficulty walking. On further interview, his wife says he has a hard time holding his bladder and has many instances of incontinence. He does not recognize his children in a picture he has in his wallet. When asked to walk, he has a wide based magnetic gait. What would you expect to see on CT in this patient?
Normal Pressure Hydrocephalus
Wet, Wacky, Wobbly
See enlarged ventricles
May also diagnose with large volume LP which may transiently improve symptoms
VP shunt is definitive treatment
A neonate is born and noted to have a rash, PDA, and concern for hearing loss. He appears to be rid of the illness but comes to the hospital around his 10th birthday for new onset anger, decline in school performance, jerking movements. What illness does this patient likely have?
Progressive Rubella Panencephalitis
ONLY in those with congenital rubella and onset around age 8-19
Symptoms similar to SSPE- personality changes, school decline, myoclonus, autonomic dysfunction, coma, death
IgG in CSF elevated for rubella
Match the foramen with the nerve:
CNV2
Cranial N that supplies sensation from forehead to top of nose
Mandibular division of CNV
Foramen rotundum
Foramen spinosum
Foramen ovale
Superior orbital foramen
CNV1 (opthalmic division) thru the superior orbital foramen along with CN3, 4, 6 and opthalmic V
CNV2 (maxillary division) thru the foramen rotundum
CNV3 (mandibular division) thru the foramen ovale along with the lesser petrosal N and accessory meningeal A
If a patient has R sided superior quadrantanopia, where could they have a lesion within the primary visual pathway?
To the picture!
L superior/lateral optic radiations
A 92 yo F comes to the ED for acute onset difficulty seeing. On exam, her L eye is abducted and depressed and her eyelid is drooped. She is only able to see the R field of vision. What artery likely has a lesion in this patient?
PCA stroke
CN3 palsy, homonymous hemianopia
May also have contralateral numbness and weakness or memory impairment
If R sided may have prosopagnosia (can't ID faces)
If L sided may have Gerstmann syndrome (acalculia, agraphia, finger agnosia)
A 46 yo M comes to the physician for worsening HA. He says he has had a HA for months now, and it is progressively getting worse. During the interview he has a seizure and is rushed to the ED. The CT scan demonstrates a ring enhancing lesion with central necrosis surrounded by a ring of vascularity. There is also 1 mm of midline deviation. What 2 cell types would be seen on biopsy in this patient?
GBM- big bad and ugly
A large, rapidly growing tumor that can cause mass effect and has a central area of necrosis because tumor grows faster than blood supply
Multinucleated giant cells and small bipolar cells and express GFAP
A 56 yo M comes to the ED for 3 days of salivation, fevers, agitation and suddenly refused to drink water today. Describe the pathway by which this virus gets to the CNS.
Bite-> replicates in muscle-> goes into PNS-> ascends via sensory fibers-> replicates in DRG-> ascent quickly in spinal cord-> infects brain-> descends to eye, salivary glands, skin...
Moves from post-synaptic to pre-synaptic membrane via receptor mediated endocytosis
One of the motor components of the cervical plexus, the ansa cervicalis, innervates all of the following muscles except the:
Omohyoid
Sternohyoid
Sternothyroid
Stylohyoid
Thyrohyoid
Stylohyoid- innervated by facial N
Ansa cervicalis is a branch of the hypoglossal N
You are walking along a trail and look down on the rough terrain to prevent tripping. What specific part of the reticular formation allows for you to look down? What muscles of the eye are activated to do this?
Vertical eye movement involves CN3 and 4
Horizontal eye movement involves CN 3 and 6
PPRF for horizontal and near abducens nucleus
Rostral midbrain reticular formation near oculomotor and trochlear nuclei--> dorsal for upward gaze, ventral for downward gaze--> rectus and oblique muscles
MLF connects the vertical and horizontal gaze centers
Inferior rectus allows eye to be depressed
A 76 yo M comes to the ED with concern for a stroke. He suddenly developed a posterior HA and vertigo as well as severe nausea. On exam he has L sided horizontal nystagmus. He also has L sided Horner syndrome and R sided body sensory loss. Where would you expect a lesion in this patient?
L sided PICA stroke (Wallenberg syndrome)
Vertigo, N/V, ataxia, hoarse voice, difficulty swallowing, horizontal nystagmus ipsilateral to side of lesion
Ipsilateral Horner syndrome with contralateral sensory loss
A 37 yo F comes to the physician for weakness. She is found to have a hemoglobin of 7.5 and an elevated MCV as well as hypersegmented neutrophils. She has ataxia and loss of vibration sensation in her legs bilaterally up to her thighs. What specific lab values would you expect to also be elevated in this patient?
B12 deficiency- Subacute combined degeneration
Megaloblastic anemia, elevated MMA and VMA
Ataxia, loss of vibration and proprioception and weakness
Damage to DCML and lateral corticospinal tract