✓ A patient presenting with progressive paraparesis was found to have a dural sacral arteriovenous (AV) fistula. His condition deteriorated abruptly after thoracolumbar angiography. Embolization of the fistula improved the patient's status so that he was able to walk with crutches. One year later his neurological condition worsened. He was treated via an enlarged laminectomy because of uncertainty concerning a lipoma noted on the initial computerized tomography scan. The lesion consisted of an intradural filum terminale lipoma associated with an AV fistula, both of which were excised. The patient's condition was unchanged 6 months later. The different types of spinal lipomas and spinal AV malformations are reviewed, and mechanisms are proposed to explain the clinical deterioration in this patient. Venous hypertension seems to be the most likely possibility. The lipoma may have produced local hypervascularization of the dura mater with a subsequently acquired AV fistula.
Michel Djindjian, Patrick Ayache, Pierre Brugieres and Jacques Poirier
Michel Djindjian, Patrick Ayache, Pierre Brugières, Denis Malapert, Marielle Baudrimont and Jacques Poirier
✓ The clinical and pathological features of a giant cauda equina paraganglioma arising from the intradural filum terminale is described. Scattered mature large neurons characterized the tumor as a gangliocytic paraganglioma. Histologically, these neoplasms have considerable similarity with ependymoma and the diagnosis can be easily missed unless special techniques are employed.
Philippe Decq, Pierre Brugières, Caroline Le Guerinel, Michel Djindjian, Yves Kéravel and Jean-Paul Nguyen
✓ The use of an endoscope in the treatment of suprasellar arachnoid cysts provides an opening of the upper and lower cyst walls, thereby allowing the surgeon to perform a ventriculocystostomy (VC) or a ventriculocystocysternostomy (VCC). To discover which procedure is appropriate, magnetic resonance (MR)—imaged cerebrospinal fluid (CSF) flow dynamics in two patients were analyzed, one having undergone a VC and the other a VCC using a rigid endoscope. Magnetic resonance imaging studies were performed before and after treatment, with long-term follow-up periods (18 months and 2 years). The two patients were reoperated on during the follow-up period because of slight headache recurrence in one case and MR—imaged CSF flow dynamics modifications in the other. In each case surgery confirmed the CSF flow dynamics modifications appearing on MR imaging.
In both cases, long-term MR imaging follow-up studies showed a secondary closing of the upper wall orifice. After VCC, however, the lower communication between the cyst and the cisterns remained functional.
The secondary closure of the upper orifice may be explained as follows: when opened, the upper wall becomes unnecessary and tends to return to a normal shape, leading to a secondary closure. The patent sylvian aqueduct aids this phenomenon, as observed after ventriculostomy when the aqueduct is secondarily functional.
The simplicity of the VCC performed using endoscopic control, which is the only procedure to allow the opening in the cyst's lower wall to remain patent, leads the authors to advocate this technique in the treatment of suprasellar arachnoid cysts.
Philippe Decq, Caroline Le Guérinel, Jean-Christophe Sol, Pierre Brugières, Michel Djindjian and Jean-Paul Nguyen
Object. Hydrocephalus associated with Chiari I malformation is a rare entity related to an obstruction in the flow of cerebrospinal fluid (CSF) in the foramen of Magendie. Like all forms of noncommunicating hydrocephalus, it can be treated by endoscopic third ventriculostomy (ETV). The object of this study is to report a series of five cases of hydrocephalus associated with Chiari I malformation and to evaluate the use of ETV in the treatment of this anomaly.
Methods. Five patients (four women and one man with a mean age of 29.6 years) underwent ETV for hydrocephalus associated with Chiari I malformation between April 1991 and February 1997. All patients had presented with paroxysmal headaches, which in two cases were associated with visual disorders. All patients had also presented with hydrocephalus (mean transverse diameter of the third ventricle 12.79 mm; mean sagittal diameter of the fourth ventricle 18.27 mm) with a mean herniation of the cerebellar tonsils at 13.75 mm below the basion—opisthion line. Surgery was performed in all patients by using a rigid endoscope. No complications occurred either during or after the procedure, except in one patient who experienced a wound infection that was treated by antibiotic medications.
The mean duration of follow up in this study was 50.39 months. Four patients became completely asymptomatic and remained stable throughout the follow-up period. One patient required an additional third ventriculostomy after 1 year, due to secondary closure, and has remained stable since that time. Postoperative magnetic resonance images demonstrated a significant reduction in the extent of hydrocephalus in all patients (mean transverse diameter of the third ventricle 6.9 mm [p = 0.0035]; mean sagittal diameter of the fourth ventricle 10.32 mm [p = 0.007]), with a mean ascent of the cerebellar tonsils from 13.75 mm below the basion—opisthion line to 7.76 mm below it (p = 0.01). In addition, CSF flow was identified on either side of the orifice of the third ventriculostomy in all patients postoperatively.
Conclusions. Results in this series confirm the efficacy of ETV in the treatment of hydrocephalus associated with Chiari I malformation. It is a reliable, minimally invasive technique that also provides a better understanding of the pathophysiology of this malformation.