Jerônimo Buzetti Milano1, Alécio Cristino Evangelista Santos Barcelos2, Franz Jooji Onishi3, Jefferson Walter Daniel4, Ricardo Vieira Botelho5, Fernando Rolemberg Dantas6, Eloy Rusafa Neto7, Eduardo de Freitas Bertolini8, Marcelo Luís Mudo9, Roger S Brock7, Ricardo Santos de Oliveira10, Andrei Fernandes Joaquim11. 1. Neurological Institute of Curitiba, Curitiba, PR, Brazil. 2. Federal University of Paraíba (UFPB), João Pessoa, PB, Brazil. 3. Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil. 4. Santa Casa de São Paulo, São Paulo, SP, Brazil. 5. Hospital do Servidor Público Estadual, São Paulo, SP, Brazil. bitbot@uol.com.br. 6. Hospital Biocor - Belo Horizonte-MG, and Post-Graduation Program, Hospital do Servidor Público Estadual, São Paulo, SP, Brazil. 7. University of São Paulo (USP), São Paulo, SP, Brazil. 8. Hospital do Servidor Público Estadual, São Paulo, SP, Brazil. 9. Hospital São Camilo de Itu-SP, Itu, SP, Brazil. 10. University of São Paulo (USP), Ribeirão Preto, SP, Brazil. 11. Department of Neurology, State University of Campinas (UNICAMP), Campinas, SP, Brazil. andjoaquim@yahoo.com.
Abstract
PURPOSE: Symptomatic Chiari type I malformation (CM) is treated with posterior fossa decompression with/ without duroplasty. Few authors suggested cerebellar tonsil caudal migration due to a supposed "caudal traction" of cranial nerve structures in a so-called occult tethered cord syndrome. For these authors, filum terminale (FT) sectioning may improve CM symptoms. The objective of this review is to evaluate the effect of FT sectioning on the treatment of CM. METHODS: Using the PRISMA guidelines for systematic reviews, we reviewed studies to evaluate patient's outcomes with CM who underwent FT sectioning. The MINORS instrument was used for methodological quality assessment. The included studies' levels of evidence (LOE) were classified according to the Oxford Centre of Evidence-Based Medicine. RESULTS: Two studies from the same group of authors were included. We cannot assure if the cited cases in the first study were also included in their latter published study. The described results suggest that outcomes were not collected in a standardized fashion. Outcomes are described vaguely as a percentage of improvement. Case series samples were small and included not only patients with CM but also patients with scoliosis and syringomyelia. The MINORS score reported that both studies had low methodological quality. Both included studies were classified as level 4 of evidence. CONCLUSION: There is no scientific support for filum terminale sectioning in patients with CM without evidence of tethered cord. This procedure may be considered experimental and should be validated in a strict criterion of inclusion clinical trial comparing outcomes in posterior fossa decompression.
PURPOSE: Symptomatic Chiari type I malformation (CM) is treated with posterior fossa decompression with/ without duroplasty. Few authors suggested cerebellar tonsil caudal migration due to a supposed "caudal traction" of cranial nerve structures in a so-called occult tethered cord syndrome. For these authors, filum terminale (FT) sectioning may improve CM symptoms. The objective of this review is to evaluate the effect of FT sectioning on the treatment of CM. METHODS: Using the PRISMA guidelines for systematic reviews, we reviewed studies to evaluate patient's outcomes with CM who underwent FT sectioning. The MINORS instrument was used for methodological quality assessment. The included studies' levels of evidence (LOE) were classified according to the Oxford Centre of Evidence-Based Medicine. RESULTS: Two studies from the same group of authors were included. We cannot assure if the cited cases in the first study were also included in their latter published study. The described results suggest that outcomes were not collected in a standardized fashion. Outcomes are described vaguely as a percentage of improvement. Case series samples were small and included not only patients with CM but also patients with scoliosis and syringomyelia. The MINORS score reported that both studies had low methodological quality. Both included studies were classified as level 4 of evidence. CONCLUSION: There is no scientific support for filum terminale sectioning in patients with CM without evidence of tethered cord. This procedure may be considered experimental and should be validated in a strict criterion of inclusion clinical trial comparing outcomes in posterior fossa decompression.