Simultaneous cerebral and spinal fluid pressure recordings in surgical indications of the Chiari malformation without myelodysplasia

Patients with Chiari's malformation without myelodysplasia often suffer fro m another associated spinal cord lesion - syringomyelia. A condition entire ly overriding the clinical picture, affecting adversely the results of surg ery as well as the prognosis of this congenital developmental defect. Proce eding from the results of their surgical treatment of 40 patients with hind brain malformation, the authors recommend, in accordance with the literatur e, a different approach to and classification of patients depending on the presence of syringomyelia (A/B classification; A: syringomyelia on MR - pre sent, B: absent). The pathological development of the syrinx is caused by obstruction to the natural CSF circulation in the subarachnoid spaces of the craniocervical ju nction (Williams' dissociation theory). The authors are convinced that rout ine (static) imaging methods (CT, MR) cannot prove the presence or behaviou r of a CSF block, and that they cannot help choose reliably the optimum typ e of treatment. In contrast, direct measurement (and monitoring) of CSF pre ssure in different compartments of the CSF pathways (intracranial/intraspin al compartment, i.e., in front of and beyond the suspected block) are a met hod which can help ascertain with precision the presence and behaviour of a CSF circulatory block, and which also provides dynamic information on such a block during the diurnal rhythm for a period of several days. The authors present the results of a prospective study of 25 patients with hindbrain malformation and describe a technique of parallel monitoring of t he two CSF compartments using an adaptation of the Williams method, as well as two different types of dissociation tests designed to prove the presenc e of a CSF block. CSF flow obstruction was found in 11 patients, in 14 pati ents it could not be proved. In 8 out of 9 patients with a fully developed syrinx (group A) the block was found as expected. It was, however, diagnose d also in 3 patients until then whitout any graphic proof of a syrinx (grou p B). The authors also report on short-term (3-year) results of surgical tr eatment in patients with rhombencephalic malformation, who had 2 different modes of treatment indicated on the basis of dissociation test results. The advantages and disadvantages are discussed of direct measurement and paral lel monitoring of CSF in comparison with radiological methods; emphasis is laid on inevitable radicality in the recanalization of CSF passages in pati ents with well established CSF blocks.