✓ The long-acting somatostatin analogue SMS 201-995 has been shown to be efficient in the treatment of somatotropic and thyrotropic adenomas. In some cases, it can suppress adenoma secretion and lead to tumor shrinkage. Pituitary macroadenomas are often associated with a vision-threatening chiasmal syndrome. In this series, SMS 201-995 was administered subcutaneously to eight patients with pituitary macroadenomas of various types responsible for severe long-lasting visual defects. An obvious improvement of both visual fields and acuity occurred in six patients, in two of these during the first 4 to 6 hours of treatment; in two patients, gonadotropic adenomas were unresponsive. Maximal improvement (normalization of visual fields in three cases) occurred within 6 to 45 days and was sustained during the 1- to 12-month follow-up period. This effect seems independent of the type of adenoma since the adenomas secreting growth hormone (GH) and thyroidstimulating hormone and silent corticotropic-secreting adenomas responded as well as did two of the non-functioning adenomas. In one acromegalic patient visual improvement was obtained while the abnormal GH secretion remained unaltered. In all cases but one, no tumor shrinkage could be demonstrated. These data demonstrate that SMS 201-995 can rapidly improve the chiasmal syndrome due to pituitary macroadenoma, and suggest that this effect might be independent of a reduction in tumor volume.
André Warnet, José Timsit, Philippe Chanson, Pierre-Jean Guillausseau, Françoise Zamfirescu, Alan G. Harris, Patrick Derome, Jean Cophignon and Jean Lubetzki
Gordon H. Baltuch, Jean-Pierre Farmer, Kathleen Meagher-Villemure, Augustin M. O'Gorman and José L. Montes
✓ The authors present the case of a 10-year-old boy admitted for evaluation of a generalized seizure and a history of headaches. Computerized tomography (CT) and gadolinium-enhanced magnetic resonance (MR) imaging demonstrated a large nonhomogeneous contrast-enhancing mass of the left frontal lobe, with a large cystic component. Cerebral angiography revealed the lesion to be highly vascular and fed entirely by the internal carotid artery system. The patient underwent craniotomy and the lesion was completely removed. Neuropathological study revealed that the tumor was a ganglioglioma. On review of the literature, it was found that gangliogliomas often present in the second and third decade, are known to have cystic components, and are contrast-enhancing on CT and MR imaging; however, they are classically known to be avascular on angiography. This case of a markedly vascular ganglioglioma emphasizes that these tumors should be included in the differential diagnosis of vascular supratentorial lesions.
José L. Montes, David B. Clarke and Jean-Pierre Farmer
✓ The authors describe a technique of stereotactic transtentorial hiatus ventriculoperitoneal shunting for the treatment of the sequestered fourth ventricle, used successfully in the care of four patients. They recommend it as a safe, effective treatment of patients suffering from an isolated fourth ventricle.
Michael Vassilyadi, Jean-Pierre Farmer and José L. Montes
✓ Two cases of children with closed myelodysplasia, Arnold-Chiari malformation, and shunted hydrocephalus who underwent spinal arachnoid cystopleural shunting are presented. Postoperatively, both patients developed craniovertebral symptomatology accompanied by radiologically documented ventricular dilation in spite of negative intracranial pressure and functional ventriculoperitoneal (VP) shunts. Both patients recovered after the cystopleural shunts were revised to increase the resistance to flow within the system. The authors believe that some communication between the arachnoid cyst and the subarachnoid space existed in both cases and that the negative pleural pressure was transmitted preferentially to the spinal and cerebral convexity subarachnoid spaces with relative sparing of the ventricular system. A transmantle pressure gradient was thereby established, leading to ventricular dilation. The authors further suggest that a craniospinal gradient was possibly established as well, leading to craniovertebral symptomatology in the patients. Return of flow in the VP shunts was obtained by correcting this iatrogenic transmantle pressure gradient.
Olivier Vernet, Jean-Pierre Farmer and José L. Montes
✓ Case records from the Montreal Children's Hospital containing the diagnosis of shunted syringomyelia were retrospectively reviewed. From 1984 to 1994, 31 patients had their syrinx treated by either syringopleural (19 cases, Group A) or syringosubarachnoid (13 cases, Group B) shunting. One patient was included in both groups.
Associated diagnoses included: in Group A, two cases of Chiari I and 14 of Chiari II malformations, 14 cases of shunted hydrocephalus, 13 cases of spina bifida aperta, and three cases of spina bifida occulta; Group B, four cases of Chiari I and two of Chiari II malformations, four cases of shunted hydrocephalus, two cases of spina bifida aperta, and five cases of spina bifida occulta. Eight Group A and six Group B patients had undergone prior posterior fossa decompression. Motor deficits predominated in both groups and arachnoiditis was a uniform operative finding.
Neurological follow-up examinations showed 11 Group A patients improved and eight stabilized, whereas on magnetic resonance imaging, 12 cavities appeared to have collapsed, five were markedly reduced, and one had increased. One patient underwent reoperation for pleural effusions and one for shunt displacement. In Group B, one patient improved, eight stabilized, three worsened neurologically, and one was lost to follow-up review. Radiologically, one cavity appeared to have collapsed, six were significantly reduced, two were unchanged, and three had enlarged.
The authors conclude that syringopleural shunting is a valuable option for controlling syringomyelia in patients without Chiari malformation or in patients who have previously undergone a craniovertebral decompression or are otherwise asymptomatic from their Chiari malformation.
Olivier Vernet, Jean-Pierre Farmer, Anne-Marie Houle and José L. Montes
✓ To determine the usefulness of urodynamic studies in the management of children with a suspected tethered spinal cord, the authors retrospectively reviewed case records of 25 patients evaluated both pre- and postoperatively using this diagnostic adjunct. All patients were also evaluated with magnetic resonance imaging or computerized tomography myelography. Seven patients who presented initially with orthopedic deformity, skin stigmata, and neurological problems underwent primary cord untethering (Group 1). All seven patients were urologically asymptomatic; all but one had normal findings on urodynamic study. Eighteen patients with prior myelomeningocele closure underwent secondary untethering (Group 2). They presented with urological (11 cases), neurological (three cases), or both urological and neurological (four cases) deterioration. All patients underwent surgery via a microsurgical technique. At a mean follow-up time of 2 years, the only Group 1 patient with preoperative abnormal urodynamic findings normalized following untethering, whereas another asymptomatic patient showed worsened results on his postoperative study. In Group 2, all seven patients with preoperative neurological deterioration improved. Ten of the 15 patients who had isolated or associated preoperative clinical urological deterioration improved or stabilized, whereas five displayed continued deterioration in their bladder function. With respect to urodynamic studies, there was a significant increase in total and pressure-specific bladder capacities following untethering. We conclude that urodynamic studies are useful both diagnostically and in follow-up examinations of patients with tethered cord, that disturbances identified by these studies often precede clinical manifestations of deterioration, and that spinal cord untethering favorably influences the urological status in most patients.
Sandeep Mittal, Jean-Pierre Farmer, Bernard Rosenblatt, Frederick Andermann, José L. Montes and Jean-Guy Villemure
✓ Residual seizures after functional hemispherectomy occur in approximately 20% of patients with catastrophic epilepsy. These episodes are traditionally attributed to incomplete disconnection, persistent epileptogenic activity in the ipsilateral insular cortex, or bilateral independent epileptogenic activity. The authors report on the case of an 8-year-old boy with an intractable seizure disorder who had classic frontal adversive seizures related to extensive unilateral left hemispheric cortical dysplasia. The initial intervention consisted of extensive removal of the epileptic frontal and precentral dysplastic tissue and multiple subpial transections of the dysplastic motor strip, guided by intraoperative electrocorticography. Subsequently, functional hemispherectomy including insular cortex resection was performed for persistent attacks. After a seizure-free period of 6 months, a new pattern ensued, consisting of an aura of fear, dystonic posturing of the right arm, and unusual postictal hyperphagia coupled with an interictal diencephalic-like syndrome. Electroencephalography and ictal/interictal single-photon emission computerized tomography were used to localize the residual epileptic discharges to deep ipsilateral structures. Results of magnetic resonance imaging indicated a complete disconnection except for a strip of residual frontobasal tissue. Therefore, a volumetric resection of the epileptogenic frontal basal tissue up to the anterior commissure was completed. The child has remained free of seizures during 21 months of follow-up review.
Standard hemispherectomy methods provide extensive disconnection, despite the presence of residual frontal basal cortex. However, rarely, and especially if it is dysplastic, this tissue can represent a focus for refractory seizures. This is an important consideration in determining the source of ongoing seizures posthemispherectomy in patients with extensive cortical dysplasia. It remains important to assess them fully before considering their disease refractory to surgical treatment.
François Proust, Patrick Toussaint, José Garniéri, Didier Hannequin, Daniel Legars, Jean-Pierre Houtteville and Pierre Fréger
Object. The exceptional pediatric aneurysm can be distinguished from its adult counterpart by its location and size; however patient outcomes remain difficult to evaluate based on the published literature.
Methods. Twenty-two children, all consecutively treated in three neurosurgery departments, were included in this study. Each patient's preoperative status was determined according to the Hunt and Hess classification. Routine computerized tomography scanning and angiography were performed in all children on the 10th postoperative day. Each patient's clinical status was evaluated 2 to 10 years postoperatively by applying the Glasgow Outcome Scale (GOS).
Twenty-one children presented with a subarachnoid hemorrhage (SAH) and one child harbored an asymptomatic giant aneurysm. Thirteen patients were in good preoperative grade (Hunt and Hess Grades I to III) and eight in poor preoperative grade (Hunt and Hess Grade IV or V). The symptomatic aneurysms were located on the internal carotid artery bifurcation (36.4%); middle cerebral artery (36.4%), half of which were found on the distal portion; anterior communicating artery (18.2%); and within the vertebrobasilar system (9.1%). A giant aneurysm was observed in 14% of patients. Overall outcome was favorable (GOS Score 5) in 14 children (63.6%) and death occurred in five (22.7%). Causes of unfavorable outcome included the initial SAH in four children, a complication in procedure in three children, and edema in one child.
Conclusions. Pediatric aneurysms have a specific distribution unlike that of aneurysms in the adult population. The incidence of giant aneurysms and outcomes were similar to those in the adult population. The major cause of poor outcome was the initial SAH, in particular, the high proportion of rebleeding possibly due to a delay in diagnosis.
Sandeep Mittal, José L. Montes, Jean-Pierre Farmer, Bernard Rosenblatt, François Dubeau, Frederick Andermann, Nicole Poulin and André Olivier
Surgery is an accepted treatment for carefully selected patients with focal epilepsy. In the present study, the authors assessed clinical and surgery-related data obtained in a large series of children suffering from intractable temporal lobe epilepsy (TLE).
Etiological, pathological, and clinical features of possible prognostic significance were studied in 109 children who underwent surgery for TLE at the Montreal Neurological Institute and Hospital and the Montreal Children's Hospital between 1985 and 2000.
The mean age of patients at seizure onset was 5.5 years and the duration of epilepsy ranged from 0.1 to 17.6 years. Preoperative magnetic resonance imaging revealed mesial sclerosis in 51 patients, a mass lesion in 45, and no visible abnormalities in 12. In six patients invasive monitoring was required. Cortical amygdalohippocampectomy was performed in 72% of patients, whereas 20% underwent transcortical selective amygdalohippocampectomy. In 23 patients a second surgical intervention was necessary. Low-grade tumors were found in 35% and mesial sclerosis was confirmed on pathological evaluation in 45%. Outcome was excellent (seizure free or > 90% reduction) in 94 patients (86%). The patients were followed prospectively for a median of 10.9 years (range 5–20.2 years). There were no permanent neurological complications and no deaths.
Successful postsurgical outcomes, especially in patients treated for mesial temporal lobe sclerosis and lesion-related epilepsies, can be obtained in pediatric patients suffering minimal complications. Unfavorable outcomes are most likely to occur when epileptiform discharges are bitemporal or multifocal in distribution and in cases involving incomplete resection of mesiotemporal structures.