EBS Microvascular Decompression for Hemi Facial Spasm After Excision of Acoustic Neuroma Macquarie Neurosurgery Evidence Based Surgery presentation Date: 25/2/16 By Dr Chris Davidoff
EBS
Microvascular Decompression for Hemi Facial Spasm After Excision of Acoustic Neuroma
Macquarie Neurosurgery
Evidence Based Surgery presentationDate: 25/2/16
By Dr Chris Davidoff
Clinical case
58yr old enrolled nurse presents with right sided facial spasms
• removal of right sided acoustic neuroma in 2005
• started having right sided facial spasms and tinnitus in 2012
• progress scans showed no recurrence of tumour
• reviewed by neurologist and multiple medical therapies trialled
• trialled botox therapy twice without relief
• ongoing severe spasm and tinnitus, starting to affect her ability to work
• desperate to undergo microvascular decompression
Searchable question (PICO format)
P – Patients who have hemifacial spasm after resection of a cerebellopontine angle lesion
I – microvascular decompression or surgical management
C – none
O – surgical success rate and/or complication rate
Question: “What is the role of surgery for hemi facial spasm after excision of a cerebellopontine angle lesion?”
Prisma Flow Diagram
Medline 18 articles Embase 48 articles Scopus 111 articles Cochrane 1 article
143 Abstracts reviewed
5 Articles retrieved
138 Excluded- 137 irrelevant- 1 inaccessible
0 Papers reviewed
5 excluded
Summary of papers
• retrieved as it was a case series of HFS caused by CP angle tumours• aimed to investigate the possibility that one of the cases had received an
operation prior to GK
Summary of papers
• single case report study• retrieved to see if there was a relevant cross over between HFS and
hemimasticatory spasm• reviewed to ascertain how the spasm was managed in the post-
operative period
Summary of papers
• case series of 9 patients with HFS as the result of CP angle tumours • retrieved to ascertain if any of the patients’ HFS did not resolve as the
result of surgery• 2 cases had HFS recur – 1 as a result of subtotal resction of AN, 1 due
to thickened arachnoid due to “inflammatory changes”• no comment made as to whether re-operation was attemped
Summary of papers
• retrospective cohort study of 652 patients undergoing surgical resection of AN
• 61 patients had HFS at 3 months post-op – this improved in 45 patients at 24 months and persisted in 16 patients
• 17 patients developed HFS between 3-24 months post-op• showed a 13% chance of developing HFS in the post-op period, with a
42% chance it would resolved in 24 months
Summary of papers
• single case study on HFS and AN being treated by a single GK exposure
• retrieved to investigate the possibility that HFS was treated after AN received GK therapy
• reported that the HFS was likely secondary to AN and that GK therapy resolved the HFS
Difficulties of search
• Difficult to construct a search delineating MVD for HFS after AN resection
• Re-operation search strategies focused on failure of MVD surgery, not for MVD after previous surgery
• Relative paucity of papers on HFS
• Broadening search to include CP angle tumours netted multiple papers focusing on gamma knife surgery
• Looking for individual case results resulted in having to read throughmany abstracts and papers