[Operative approach for hydrocephalus associated with cerebellar tonsillar hernia].

OBJECTIVE

To assess the pre-operative examination and operative approach for hydrocephalus associated with cerebellar tonsillar hernia.

METHODS

A retrospective analysis was conducted for 24 patients of hydrocephalus associated with cerebellar tonsillar hernia. All subjects received both pre-operative and post-operative Cine MRI examinations to detect the velocity and quantity of cerebrospinal fluid (CSF) at the important sites in ventricular system. A majority of cases had endoscopic third ventriculostomy (ETV) while others underwent both ETV and endoscopic posterior cranial fossa decompression.

RESULTS

The pre-operative CSF hydrodynamics of all cases were abnormal at foramen magnum. A post-operative CSF flow through stoma might be detected by Cine MRI in all cases. The clinical symptoms improved to different extents in 21 cases while another two cases showed no improvement. Later these two patients underwent endoscopic posterior cranial fossa decompression. Cerebellar tonsillar hernia improved in 14 cases.

CONCLUSION

Cine MRI can detect the CSF hydrodynamics at craniocervical junction so as to help a surgeon determine the time and the plan of operation. Most cases of hydrocephalus associated with cerebral tonsillar hernia are of obstructive hydrocephalus. The efficacy of ETV for hydrocephalus has been confirmed. Also ETV has a therapeutic effect for cerebellar tonsillar hernia and syringomyelia.