Neurology Flashcards
What are serum prolactin levels used for?
Differentiate seizure from pseudoseizure (psychogenic nonepileptic seizure)
Multiple pigments on iris suggests…
Lisch nodules - raised hyperpigmented hamartomas
Neurofibromatosis type I
Neurofibromatosis type I findings
Cafe-au-lait spots
Skinfold freckling (age 5)
Lisch nodules (age 6)
Neurofibromatosis type I cancer risks
Peripheral nerve sheath tumor malignant transformation
Optic pathway glioma
CNS tumors
Pheochromocytoma
Neurofibromatosis type II findings
Vestibular schwannoma (acoustic neuroma)
Some cafe-au-lait macules
Retinal hemangioblastomas are associated with…
von Hippel Landau (–> clear cell carcinoma)
Renal angiomyolipoma is associated with…
Tuberous sclerosis (benign hamartomas in many organs + various skin findings)
Treatment for idiopathic intracranial hypertension
Weight loss (including bariatric surgery)
Carbonic anhydrase inhibitor (acetazolamide), topiramate
Triptan MOA
Serotonin receptor agonist (5-HT 1B/1D) –> decreases neurogenic inflammation and calcitonin gene-related peptide (CGRP) release
Persistent migraine medications
Triptan
Antiemetics (e.g. promethazine)
Dihydroergotamine
Cluster headache treatment
100% oxygen via nonrebreathing mask
Triptan
Ophthalmic findings in glaucoma
Atrophy of optic nerve head: optic disc rim thinning, increased cup/rim ratio (“cupping”)
Increased IOP
Gradual loss of peripheral vision
Glaucoma medications from first-line downward
- Topical prostaglandin (latanoprost, carboprost) - increased drainage through uveroscleral pathway
- Topical beta-blocker (Timolol) - decrease aqueous humor inflow; use with caution in comorbid asthma
- Surgical (laser trabeculoplasty)
Less effective: Alpha agonists and carbonic anhydrase inhibitors (decrease aqueous humor inflow); cholinergic agonists (increase trabecular outflow)
Carbonic anhydrase inhibitors - difference between open and closed-angle glaucoma
Open: Topical dorzolamide
Closed: Systemic/oral acetazolamide
Open globe laceration - signs
Peaked/teardrop pupil
Anterior chamber depth increased/decreased
Reduced IOP
Absent afferent pupillary response
Acuity decreased
What is signified by acute corneal opacification?
Angle closure glaucoma
What is are hypopyon and perilimbic injection?
Hypopyon: layering of inflammatory cells in the anterior chamber
Perilimbic injection/ciliary flush: dilation of vasculature at junction of sclera and cornea
Seen in inflammatory and infectious conditions
Orbital compartment syndrome - treatment
Orbital decompression by cutting eyelid from lateral canthus to orbital rim (lateral canthotomy) and then dividing inferior limb of lateral canthal tendon (inferior cantholysis)
What causes paradoxical improvement in hearing speech in noisy environments?
Conductive hearing loss (e.g. otosclerosis - may also have reddish hue behind tympanic membrane)
Sensorineural hearing loss would result in worse speech understanding with increased background noise
Decreased vision, floaters, and fluffy yellow-white chorioretinal lesions
Candida endophthalmitis
Candida endophthalmitis - risk factors
Hospitalized patients with central venous catheters
TPN
Immunocompromise
How could cancer metastases to the brain affect vision?
Space occupying lesion –> increased intracranial pressure (e.g. bilateral papilledema)
Common drug-induced glaucoma causes
- Glucocorticoids
- Systemic sympathomimetics (e.g. ephedrine)
- Systemic anticholinergics
What is xerophthalmia?
Excessive dryness of conjunctiva/cornea that causes ridges - seen in vitamin A deficiency
Who has paraneoplastic optic neuritis?
Small cell lung cancer
Acute unilateral vision loss, painful
Papillitis on exam
Pain medications for post-traumatic neuroma
- Local anesthetic (diagnoses and treats)
- TCA
- Antiepileptic
How do glucocorticoids cause open-angle glaucoma?
Decrease aqueous humor drainage –> increased IOP
Rapid increase in IOP leads to:
1. Halos around lights
2. Decreased visual acuity
3. Eye pain
4. Headache
5. Corneal edema
Advanced disease –> peripheral vision loss
Meningioma characteristics on MRI imaging; epidemiology; dx; treatment
Extra-axial
Well-circumscribed
Round homogeneously enhancing dural-based mass
Calcification
Hyperdense on non-contrast head CT
These are considered benign - commonly found in middle-age to elderly women
Dx intraoperatively
Tx complete resection
Brain metastasis appearance on imaging
Multiple ring-enhancing lesions at grey-white junction (intra-axial)
What can cerebral amyloid angiopathy lead to?
Intracerebral hemorrhage
When is urgent surgical decompression and clot evacuation indicated for intracerebral hemorrhage?
Cerebellar hemorrhage with area >3 cm, brainstem compression (stupor, coma, death), or obstructive hydrocephalus
Signs of neurologic deterioration (lethargy, obtundation, coma)
Pterion region
Junction of frontal, parietal, temporal, and sphenoid bones
Fracture here often occurs with epidural hematoma and tearing of middle meningeal artery
What artery is most associated with epidural hematoma?
Middle meningeal artery
Acute epidural hematoma - signs, imaging
Loss of consciousness followed by lucid interval (however, some may initially remain alert)
Elevated ICP - headache, n/v, altered mental status - within minutes to hours
CT - hyperdense biconvex lesion
Intracerebral hemorrhage etiologies
Usually older patients:
1. Severe HTN
2. Cerebral amyloid angiopathy
3. Anticoagulant/antiplatelet use
Subarachnoid hemorrhage - signs, etiology
Sudden, severe “thunderclap” headache
Loss of consciousness
Meningismus
Usually due to rupture of intracranial aneurysm
Subdural hematoma - etiology
Trauma –> tearing of bridging veins –> venous bleeding
Typically older adults, those on antithrombotic agents
Acute –> coma
Chronic –> insidious onset of confusion, headache, somnolence over days/weeks
When does paroxysmal sympathetic hyperactivity occur?
10-20% of those with severe traumatic brain injury
Thought to be due to loss of cortical inhibition of lower sympathetic centers (e.g. hypothalamus, brainstem, spinal cord)
Opioids, GABA-agonists, and a2-agonists may help
What is the most common cause of focal epilepsy?
Mesial temporal (hippocampal) lobe sclerosis
Gerstmann syndrome
Lesions in dominant (left) parietal lobe - difficulties with:
1. Writing
2. Calculations
3. Distinguishing fingers
4. Left-right disorientation
Lesions in dominant (right) hemisphere affect?
Nonverbal spatial mapping and orientation:
1. Neglect
2. Distortions in position sense (e.g. feeling of floating)
3. Visual interpretation (e.g. object size)
Myopia causes focal point to move in which direction relative to retina?
Anterior to retina
Anterior-posterior diameter of eye is increased in myopia
Use diverging (concave) lens
What is considered high myopia? What bad things can happen? Treatment?
> =6 diopters of correction required
Stretching/thinning of sclera, choroid, retina –> retinal detachment, macular degeneration
Treatment:
1. Antimuscarinic drops (e.g. atropine)
2. Orthokeratology (i.e. rigid contact lens)
Who has cotton-wool spots (yellow-white retinal lesions)?
Hypertension, diabetes - retinal microinfarctions caused by arteriolar obstruction and ischemia
Spinal epidural abscess - treatment
Antibiotics + emergency surgical decompression
How may antipsychotics contribute to orthostatic syncope?
Alpha-1 blocking properties (e.g. haloperidol, risperidone, quetiapine)
Brown-Sequard syndrome
Hemisection (disruption of half) of spinal cord:
1. Ipsilateral hemiparesis
2. Ipsilateral loss of proprioception, vibration, light touch
3. Contralateral loss of pain and temperature (spinothalamic tract) 1-2 levels distal to cord injury and below - axons move up 1-2 levels before crossing over, saving those at the level of the injury
- Ipsilateral Horner syndrome (if cervical)
- Spinal shock –> ipsilateral reflexes initially absent –> ipsilateral hyperreflexia and positive Babinski
Anterior cord syndrome affects which tracts?
Distal paralysis (LCT) and decreased pain/temperature (LST)
Cyclopentolate
Anticholinergic eye drops
Traumatic iritis (e.g. left perilimbal conjunctival injection)
Treat with physostigmine (cholinesterase inhibitor)
Where do brain mets tend to localize on MRI?
Multiple well-circumscribed lesions with vasogenic edema at gray-white matter junction
Primary CNS lymphoma on MRI
Periventricular lesion, irregular and nonhomogeneous
Most common intracranial tumor of NF1?
Optic pathway glioma in toddlerhood
Then astrocytomas, brainstem gliomas into adulthood
Trochlear nerve innervates which muscle?
Superior oblique - eye downward and intorsion
Palsy leads to hypertropia and extorsion; chin tuck head tilt to compensate
Meningioma appearance
Dural based, calcified, homogeneously enhancing lesion
Arise from meningothelial cells of arachnoid mater
Anti-GQ1b antibodies
GQ1b ganglioside is found in peripheral nerves; antibody can contribute to rapid-onset ophthalmoplegia
Sensitive for Miller Fisher syndrome (MFS) variant of Guillain-Barre but may be present in other variants with predominant ophthalmoplegia
Miller Fisher Syndrome variant of Guillain-Barre
- Ophthalmoplegia
- Ataxia
- Areflexia
Strength often preserved vs classic GBS
Associated with anti-GQ1b antibody
What labs should be obtained in anyone with clinical diagnosis of restless legs syndrome?
Serum iron studies
Those with iron deficiency or even low-normal ferritin (<=75) should take supplemental iron
How does pupillary involvement of CN III palsy help distinguish etiology?
Parasympathetic component (pupil constriction) is on outside of fascicle and less susceptible to ischemia - if non-pupil sparing, consider mass effect and intracranial aneurysm
Motor component runs within nerve and can be damaged by compression or microvascular ischemia - if pupil-sparing, consider microvascular ischemia from diabetes, HTN, HLD, or age
Progressive, painless, symmetric loss of visual acuity and color vision
Toxic optic neuropathy
Complex regional pain syndrome
Pain does not follow specific peripheral nerve
Typically follows trauma or surgery
Associated with edema, vasomotor signs, and trophic changes in skin and hair
Spinal epidural hematoma
Can lead to cauda equina syndrome
Slowly progressive
Management includes MRI and is a surgical emergency, typically requiring urgent decompression (e.g. laminectomy)
What makes essential tremors better?
Alcohol
What is myoclonus status epilepticus?
Symmetric irregular muscle contractions, within 72 hours of hypoxic brain injury
Manage with antiepileptic meds, supportive care
Folate vs B12 deficiency
Folate deficiency does not cause neuro issues
Folate deficiency has normal methylmalonic acid
Opaque conjunctival plaques
Bitot spots - specific for vitamin A deficiency
Would also see xerophthalmia, follicular hyperkeratosis
Small vs large nerve fibers convey…
Small: pain, allodynia, paresthesia
Large: numbness, vibration proprioception, reflexes
CNS hamartomas are associated with…
Tuberous sclerosis
AVM appearance on MRI
Dark flow voids and little surroundong edema
Triptan mechanism
Serotonin receptor agonist
Decrease CGRP release, but also has vasoconstrictive effects
Ergots work similarly, but higher potency and less selectivity
What should be done to prevent falls in elderly with delirium inpatient?
Direct line of sight of nursing staff
Rails, restraints, and bed alarms bad
What diabetes med can cause B12 deficiency despite no changes in CBC?
Metformin - effect on absorption in ileum
Head tremor is associated with…
Cervical dystonia
Tremor is more jerky, less rhythmic than essential tremor
Essential vs intention tremor
Essential can occur with and without intentional movement
Both are action tremors, essential is kinetic whereas intention is a subtype of kinetic that worsens as it approaches
Intention often caused by cerebellar pathology
What causes most cases of mononeuritis multiplex?
Vasculitis, particularly polyarteritis nodosa
Only homocysteine or only MMA elevation is associated with folate deficiency?
Homocysteine elevation only
If both elevated, then B12 deficiency
Salt wasting syndrome
Polyuria, hyponatremia and hypovolemia after brain injury - urinary sodium losses due to BNP secretion
Lambert-Eaton - treatment
Amifampridine or guanidine - decrease K efflux from presynaptic neurons -> prolonged depolarization and ACh release
Pyridostigmine
IVIG followed by oral immunosuppressive agents if persistent disease
Myasthenia gravis - treatment
Plasmapheresis or IVIG +/- steroids
Pyridostigmine +/- glycopyrrolate (antimuscarinic to counter pyridostigmine) for symptoms
Steroids may transition to nonsteroidal immunosuppressants (e.g. azathioprine)
Botulism treatment depending on source
Infant: human botulism Ig - due to ingestion of spores, maybe from honey
Foodborne or wound: equine botulinum antitoxin
Lyme ascending paralysis vs GBS
Lyme doesn’t have autonomic dysfunction
