CSF Findings
Xanthochromia
Subarachnoid hemorrhage
Most sensitive and specific test for Multiple Sclerosis
MRI of brain and spinal cord w/ gadolinium (reveals plaque formation)
Gold standard for diagnosis of Atrioventricular malformations
Angiography
T/F: Empiric antibiotics for bacterial meningitis can be given before lumbar puncture
True (it takes ~2 hours for abx to affect CSF)
On CT w/ contrast: hypointense ring-enhancing lesions in deep white matter (Hint: diagnosis highly likely if tumor found in conjunction w/ uveitis)
CNS lymphoma
Oligoclonal bands
Multiple sclerosis
Gold standard for dx of Myasthenia Gravis
Single Fiber Electromyography (shows decremental response to repetitive stimulation of motor nerves)
What do you see on CT of epidural hematoma?
Biconvex/football-shaped bleed that does NOT cross suture lines
Definitive diagnosis of viral meningitis
PCR testing (Not necessary in all patients)
Gold standard for brain tumor evaluation
MRI with and w/o contrast
Increased CSF pressure (otherwise normal)
How is Guillain Barre Syndrome diagnosed?
Lumbar puncture shows elevated CSF protein with normal CSF WBC
What do you see on CT for subdural hematomas?
Concave/crescent-shaped bleed that can cross the suture lines
How is diagnosis of ischemic stroke confirmed?
MRI
Which type of brain tumor frequently becomes calcified (unique amongst tumors) and is visible on CT?
Meningioma
High protein w/ increased WBS (Primarily PMNs), decreased glucose
Bacterial Meningitis
Initial test for Myasthenia Gravis
CT chest (to r/o thymoma)
What should be performed if you're suspicious for SAH and CT is negative?
Lumbar puncture
Initial test performed in the setting of ischemic stroke
Non-contrast CT (to rule out hemorrhage)
On MRI w/ contrast: heterogenous lesions w/ variable ring of enhancements; serpiginous margins; may cross corpus callosum
Glioblastoma multiforme
Normal glucose, increased WBCs (lymphocytes)
Viral meningitis
What are the McDonald Criteria?
Used to Dx Multiple Sclerosis
Dissemination in space and dissemination in time
Initial test for all hemorrhages
CT w/o contrast
In the setting of bacterial meningitis, CT/MRI does NOT need to be performed first if all of these are true (5)
Patient has classic symptoms, GCS of 15, no clinical suspicion for elevated ICP, no focal neuro deficit, no risk factors for space occupying lesion
On MRI w/ contrast: homogenously enhancing, well-circumscribed, characteristic "dural tail" is classic
Meningioma