CNS Flashcards
(143 cards)
Describe cervical myelopathy signs
Myelopathy (UMN signs below the level of lesion) - due to cord compression
Radiculopathy (LMN signs at level of lesion) - due to nerve root compression
Elevated 14-3-3 protein
Creutzfeldt-Jakob disease
Nonspecific marker of neuronal cell death
Anti-Hu antibody
Paraneoplastic syndrome (SCLC, patients who smoke)
Anti-NMDA receptor antibody
Anti-NMDA receptor encephalitis - associated with ovarian teratomas
Median age 21, 4x greater in women
Low alpha-synuclein; round, eosinophilic inclusions of it
Parkinson dementia if in basal ganglia/midbrain, dementia with Lewy bodies if in cerebral cortex
Low hypocretin/orexin
Narcolepsy type 1
Creutzfeldt-Jakob disease - signs
- Rapidly progressive dementia
- Myoclonus provoked by startle
- Mood symptoms (e.g. depression)
- Hypersomnia
CSF noninflammatory, contains elevated 14-3-3 protein (marker of neuronal cell death), elevated tau
Test for abnormally folded proteins using real-time quaking induced conversion (RT-QuIC) assay - mix abnormally folded proteins with normally folded proteins and watch for increased fluorescence following conformational changes in normal proteins
Most common sites of hypertensive hemorrhage in descending order
- Basal ganglia (putamen)
- Cerebellar nuclei
- Thalamus
- Pons
- Cerebral cortex
Cerebellar hemorrhage - signs
- Occipital headache (may radiate to neck/shoulders
- Neck stiffness (extension of blood into 4th ventricle)
- Nausea/vomiting
- Nystagmus
- Ipsilateral hemiataxia of trunk (vermis) and/or limbs (hemispheres) as corticopontocerebellar fibers decussate twice
What hemorrhage and damage would cause pinpoint pupils?
Large pontine hemorrhage - damage to descending sympathetic fibers
What is a useful screening test for hemineglect?
Drawing a clock - requires both sensory and motor components
Malignant hemispheric infarction
When an ischemic stroke causes:
1. Massive cerebral edema - from enthothelial dysfunction and breakdown of BBB –> mass effect, ICP, brain herniation
2. And/or hemorrhagic transformation - from blood extravasation from injured cerebral vessels into brain parenchyma (larger infarcts –> greater risk)
What is the difference between viral and fungal (Cryptococcus)/tuberculous meningitis on CSF?
Both have slightly elevated protein and lymphocytic predominance, but viral has normal glucose
Diagnostic confirmation of Cryptococcus
After CSF, India ink stain or polysaccharide antigen testing
How does Botulinum toxin work?
Cleaves SNARE proteins, preventing ACh release from neuron at neuromuscular junction
Botulinum vs myasthenia gravis
Myasthenia gravis spares pupillary function, autonomic dysfunction is less prominent, and symptom progression typically less rapid
Both are descending weakness
Cauda equina vertebral levels and corresponding effect
L2-sacrum + coccygeal nerve:
S1-S2: absence ankle reflex
S2-S4: saddle anesthesia
S3-S5: bowel, bladder, or sexual dysfunction (e.g. urinary straining)
Can have asymmetric lower extremity weakness/sensory loss
Conus medullaris vs cauda equina
- Conus medullaris is L1-L2
- Severe pain limited to lower back (vs radiating into leg)
- Numbness symmetric and limited to perianal area
- Weakness symmetric
- UMN findings such as hyperreflexia (vs absent ankle reflex)
Who is at increased risk of internal carotid artery dissection?
- Connective tissue disease (Ehlers-Danlos)
- Smoker
- Uncontrolled HTN
- Oral contraceptives
Why does internal carotid artery dissection only present with partial Horner syndrome?
Ptosis and miosis but not anhidrosis - sympathetic fibers for facial diaphoresis travel along the external carotid artery
Dementia with Lewy bodies
Dementia plus >=2 of the following:
1. Visual hallucinations
2. Parkinsonism
3. Fluctuating cognition
4. REM sleep behavior disorder
Blurred optic disc margins
Papilledema
Jervell and Lange-Nielsen syndrome - presentation
Congenital long QT syndrome
Inheritable sensorineural hearing loss due to mutations affecting endolymph production
Presents in childhood with profound bilateral deafness and episodes of arrhythmia-induced syncope during stress
What causes relative afferent pupillary defect?
Optic nerve injury - most often caused by indirect high-intensity force to orbit and transmission of shearing forces
Vision improves with conservative management in half of patient
Surgical decompression may be required
Loss of light perception is associated with worse prognosis