Workup/staging Flashcards
1
Q
What tests are performed on physical exam for pts with CPA lesions?
Tightening anterior neck muscles is what CN?
What does marching in place with eyes closed do?
A
- Rinne test (mastoid bone air > bone condution)
- Weber test (Occiput, vibratory sound louder on good side these confirm sensory neural hearing loss
- Cn deficits- CN VII, hypesthesia, corneal twitching
- Platysma is inervated by CN VII and is affected by large AN lesions
- Marching in place veer to side of lesion
2
Q
Best screening test for ANs?
A
Audiometry (asymmetric sensorineural loss more at higher frequencies) best tool for ANs
3
Q
- Average growth rate for ANs?
- Which % of ANs are stable (shrink or don’t grow)
- Is the size of tumor at presntation predictive of tumor’s growth rate?
- Does tumor size correlate with hearing loss
A
- 1mm/yr growth rates from 0.5-2.5mm/yr to >2.5mm a year for fast growing lesions
- 20-40% are stable
- No
- Usually not, location of tumor is more predictive (intracanicular vs. not intracanalicular) tumor growth < 2.5mm/yr have higher hearing preservation thant those with higher tumor growth
4
Q
what do brainstem auditory evoked potentials typically show for patients with ANs?
A
- delay of conduction time on the affected side is seen in auditory evoked potentials
5
Q
What imaging study for ANs? what if contraindicated
What is the ice cream cone?
A
- thin slice (1-1.5mm MRI with GAD can detect tumors as small as 1-2mm in diameters
- T1
- slightly hypointense cf. adjacent brain (63%) 2
- isointense cf. adjacent brain (37%) 2
- may contain hypointense cystic areas
- T2
- heterogeneously hyperintense cf. to adjacent brain 5
- cystic areas fluid intensity
- may have associated peritumoural arachnoid cysts 3
- T1 C+ (Gd)
- contrast enhancement is vivid
- but heterogeneous in larger tumours
- T1
- if NF suspected neuraxis MRI is performed
- if contraindicated CT +/- contrast
- Icecream cone- enhancing lesions in canal (Cone) and cpea
