Schwannomas

 

●        Vestibular >> Trigeminal > 기타

●        현재 추세는 intended subtotal resection + radiosurgery (surgeon마다 policy가 다를 수 있음.)

●        Vestibular schwannoma는 대게 superior vestibular nerve에서 생김 (따라서 facial nerve는 대게 앞쪽으로 밀림)

●        Lateral suboccipital approach (=retrosigmoid approach)를 대게 이용. (크기가 크면 petrosal approach가 필요한 경우도 있음.)

Hearing salvageability

Serviceable and unsalvageable hearing

●        Definition of serviceable hearing: A generous definition of serviceable hearing: PTA < 50 dB and SDS > 50%

○        Unsalvageable hearing

●        Serviceable hearing is unlikely to be preserved post-op when

1. pre-op SDS < 75%
2. or pre-op PTA loss > 25 dB
3. or pre-op BAER has abnormal wave morphology
4. or tumor > 2–2.5 cm diameter

 

 

 

Table 40.3 Clinical grading of facial nerve function (House and Brackmann)
Grade	Function	Description	At rest	Moving
1	normal	normal facial function in all areas
2	mild dysfunction	1. gross: slight weakness noticeable on close inspection; may have very slight synkinesis   2. at rest: normal symmetry and tone 3. motion: a) forehead: slight to moderate movement b) eye: complete closure with effort c) mouth: slight asymmetry
3	moderate dysfunction	1. gross: obvious but not disfiguring asymmetry: noticeable but not severe synkinesis   2. motion: a) forehead: slight to moderate movement b) eye: complete closure with effort c) mouth: slightly weak with maximal effort
4	moderate to severe dysfunction	1. gross: obvious weakness and/or disfiguring asymmetry   2. motion: a) forehead: none b) eye: incomplete closure c) mouth: asymmetry with maximum effort
5	severe dysfunction	1. gross: only barely perceptible motion   2. at rest: asymmetry   3. motion: a) forehead: none b) eye: incomplete closure
6	total paralysis	no movement