Central nervous system cavernomas in the pediatric age group.

Pediatric CNS cavernomas still are diagnostically and therapeutically challenging lesions. With the help of magnetic resonance imaging, the natural history of cavernomas now guiding therapeutic strategies is well documented in adults but remains poorly known in the pediatric age group, since most previous studies dealt with adult and pediatric patients together. This paper focuses on clinical, imaging, and therapeutic features and differential diagnosis of CNS cavernomas with an emphasis on their specificities in the pediatric age group. It is based upon a critical review of the literature and our single-center experience with 36 children (35 with cerebral cavernomas and one with spinal cord cavernoma) operated on during the period of 1985-1999 as well as with seven additional unoperated pediatric cases. Our experience resembles that of other authors regarding the high hemorrhagic risk in children compared to adults. These angiographically occult vascular malformations are often revealed by the sudden onset of intracerebral hematoma with acute focal neurologic deficits, concomitant manifestations, and/or signs of raised intracranial pressure. True epilepsy is less common and may be related to chronic or recurrent microbleeding. Evocative imaging findings are also somewhat different in the two age groups, and we propose here an imaging classification of cerebral cavernomas based on both morphological and signal characteristics that is applicable to the pediatric age group. A sharply demarcated spherical intracerebral hematoma or heterogeneous lesion should always make one consider the hypothesis of a cavernoma. For symptomatic lesions and most rapidly growing asymptomatic lesions, the treatment of choice is complete microsurgical excision preceded by careful anatomical and functional evaluation. Improvements in surgical techniques and anesthesiology over recent years have brought good results in most operated children. The limited role of radiosurgery in the management of pediatric cerebral cavernomas is discussed. There is still a need for well-conducted specific evaluation of the natural history of these lesions in the pediatric age group to aid in systematic research, follow-up, and therapeutic strategies for asymptomatic cavernomas.

Hypothalamic hamartoma: the role of surgery in a series of eight patients.

Hypothalamic hamartoma are rare lesions. We report a new series of eight patients treated for precocious puberty (six cases) or gelastic seizures (two cases). Surgical resection was total in four cases (three pediculated and one sessile). Precocious puberty was controlled by surgical treatment in all cases. Gelastic seizures were controlled by medical treatment, but the patients did not become seizure free. We observed no mortality and no endocrinological or visual morbidity. The fact that a vascular "rete mirabilis" was observed on the surface of the lesion in our surgical material is an argument favoring a vascular mechanism in precocious puberty. Coagulation of this vascular structure can help control precocious puberty. Our series confirms that the hypothalamic hamartoma can be surgically treated when patients fail to respond to medical treatment, when the length of the treatment cannot be tolerated by the chidren and their families, and when there are uncontrolled gelastic seizures

Intracystic chemotherapy with bleomycin in the treatment of craniopharyngiomas.

OBJECT: Since bleomycin has not yet been used very frequently in the treatment of patients with craniopharyngioma, it seemed important to document the course of a series of such patients treated with this preparation. METHODS AND RESULTS: Local chemotherapy with bleomycin was performed in 24 patients (20 children and 4 adults), 16 of whom presented with cystic or mixed (solid/cystic) craniopharyngioma and 8, with recurrent cystic craniopharyngioma. The drug was administered through an Ommaya reservoir, which was placed either by using a direct surgical approach (6 patients) or a stereotactic approach (16 patients), or with endoscopic assistance in patients with hydrocephaly (2 patients). Injection of bleomycin was always preceded by a water-tightness test. Each patient received a 3-mg dose of bleomycin every other day. The total dose of bleomycin injected ranged from 28 mg to 150 mg. Most patients (17, or 70%) were treated only with intracystic chemotherapy. Chemotherapy was followed by surgery in 7 patients. Five were operated on at the beginning of our study, and 2 required surgery because chemotherapy yielded poor results. A toxic dose was injected in 1 patient only: a severe complication, i.e. blindness, was observed. The follow-up period ranged from 2 years to 10 years. CONCLUSION: Our results show that bleomycin can be an alternative in the treatment of cystic craniopharyngiomas or cystic recurrences, as it reduces surgical morbidity and improves clinical results.

Zero rate of shunt infection in the first postoperative year in children--dream or reality?

The rate of infectious complications following shunt implantations at the Pierre Wertheimer Hospital was 6.4% in 1992-1994. In order to improve this infection rate, new recommendations for surgery were applied and a new type of valve was used. The effects of these measures after a 1-year follow-up were analyzed in 70 patients. The rate of infection was zero, 2.8, and 4.3% at 2, 6, and 12 months, respectively. A case-control study did not reveal any significant risk factor among the patient and surgical factors analyzed.

Syringomyelia associated with type I Chiari malformation. A 21-year retrospective study on 75 cases treated by foramen magnum decompression with a special emphasis on the value of tonsils resection.

The purpose of the present study is to evaluate retrospectively the effects of several intra-operative manipulations on the results of foramen magnum decompression (FMD) in patients having syringomyelia associated with type I Chiari malformation. Seventy-five patients having syringomyelia associated with Chiari I malformation were operated on between 1975 and 1996. This population was grouped into 4 subgroups according to the surgical protocol: group I = 42 patients with FMD alone; group II = 16 patients with FMD and third ventricle shunting; group III = 9 patients with FMD and syringosubarachnoid shunting (SSS); group IV = 8 patients with FMD and cerebellar tonsils resection. Pre- and postsurgical magnetic resonance imaging (MRI) studies were analyzed (and compared). Nine patients were lost to follow-up. The results were evaluated in the 66 remaining patients (mean follow-up: 52 months), using the Bidzinski's outcome scale (ref). Two patients (3%) died postoperatively, 31 (47%) had very good results (after additional surgery in 7), 16 (24.2%) had good results (after additional surgery in 7) and 17 (25.7%) had poor results despite further surgery in 9. A total of 27 reoperations were undertaken after primary FMD in 23 patients (35%). Thirty-nine patients (59%) had both pre- and postsurgical MRI evaluation. In 28 (72%) the syrinx had markedly decreased whereas it had remained stable in 11 (28%). Clinical results were not significantly different between the patients of groups I, II and III. Very good or good results were obtained in 24 patients (64.8%) of group I (after additional surgery in 10), in 8 (61.5%) of group II (after additional surgery in 1) and in 7 (87.5%) of group III (after additional surgery in 3). Results in group IV were as follows: 7 patients (87%) had very good results and one had a good result. With a mean follow-up of 28 months, no patient required additional surgery. Postsurgical MRI syrinx reduction was observed in all 8 patients either in the early postoperative course or on delayed followup. It is suggested that tonsils resection might enhance the results of FMD in individuals having Chiari I-related syringomyelia.

[Tethered cord syndrome in adults]. / Syndrome de moelle attachée de l'adulte. Une série de 25 patients.

A series of 25 adult patients surgically treated for a tethred cord syndrome is reported. Preoperatively 19 patients presented with a sensorimotor deficit in their lower limbs, 17 with sphincter disturbances, 12 with pain and/or neuroorthopedic symptoms and 9 with cutaneous lumbar anomalies. At surgery, an isolated anomaly (lipoma, anomalous or adherent filum terminale) was disclosed in 18 patients. In the remaining 7, a more complex form of dysraphism was disclosed. Follow-up ranges from 3 months to 20 years (mean: 6.5 years). Ten patients improved, 6 were stabilized and 9 showed continuous worsening. The best results were obtained in patients in whom the cord tethering resulted from an anomalous filum terminale. Results were significantly worse in patients suffering long standing symptomatology and showing either radiologically or surgically mixed mechanisms of cord tethering. Early surgical correction should be idealy undertaken in patients suffering from minor neurological deficits and in whom magnetic resonance imaging illustrates a low conus medullaris attached by a short thickened filum terminale.

[Para-aortic paraganglioma found by arteriography. Apropos of a case and review of the literature]. / Paragangliome para-aortique découvert en artériographie. A propos d'un cas et revue de la littérature.

A 53 years old man had an angiography for suspected renovascular hypertension (arteritis, renal insufficiency, duplex scanning). It showed a narrow right renal artery streched by a 45 mm mass arising from the adrenal. The computed tomography showed the tumor and the nuclear magnetic resonance imaging indicated a pheochromocytoma. The patient had no complain of headaches, palpitations or sweating. Biochemistry was normal except for a slight serum creatinin elevation and a non significant urinary noradrenaline level. A diagnostic of non functioning pheochromocytoma was made. The therapeutics consisted in a surgical ablation of the tumor and the right kidney (non functioning) and the patient became normotensive thereafter without treatment. The histologic feature was an aortico-sympathetic paraganglia, the adrenal was normal. Paraganglias are arising from the paraganglion system including chemodectoma and glomus jugulare tumor. Non functioning retroperitoneal paraganglias are uncommon: less than 50 in the literature between 1902 and 1992.

Cerebral oligodendrogliomas in children: an analysis of 15 cases.

The cases of 15 children operated on for cerebral pure oligodendroglioma were studied. Two groups of children were distinguished. Group I children presented with epilepsy (7 cases); their tumor was histologically benign in all cases. These children are all alive after a median follow-up of 72 months: however, 2 of them presented with a local recurrence, which was operated on, and are actually disease-free. Group 2 children presented with intracranial hypertension (8 cases); the tumor was anaplastic in 7 cases. Despite postoperative radiotherapy and chemotherapy 6 children died; their median survival time was 17 months. The present series shows the existence of a clear correlation between clinical presentation, histological grading and survival in childhood cerebral oligodendrogliomas.

Stereotactic radiosurgery for arteriovenous malformations of the brain using a standard linear accelerator: the Lyon experience.

Radiosurgery (RS) was initiated in Lyon in October 1989. The technique was adapted from that described by Lutz and Saunders in Boston (BRW stereotactic frame). Irradiation is delivered with 18-MV photons produced by a LINAC. From December 1989 to December 1992, 41 patients with arteriovenous malformations were treated by RS; the median age was 33 years. The largest lesion diameter was 11.2-38.5 mm. Fifteen to 20 Gy were delivered on the 70% isodose line. Angiography was performed at 2 years post-treatment in 32 patients demonstrating an overall complete thrombosis rate of 81.3%. This incidence was significantly correlated with the Spetzler and Martin grade before RS (P = 0.0055). Two patients (4.9%) experienced haemorrhage after radiosurgical treatment and one died from an intracerebral-intraventricular haemorrhage. Four patients (9.7%) experienced permanent radiation-induced neurological complications.

Late MR follow-up of hypothalamic hamartomas.

The absence of changes over time in the diagnostic features of suspected hypothalamic hamartomas is of paramount importance. Since magnetic resonance (MR) imaging is very sensitive to modifications in the brain parenchyma, a late MR follow-up study was performed in five children. In all cases, the diagnosis of hypothalamic hamartoma has been suspected on the basis of the association of central precocious puberty and the presence of a mass in the inferior aspect of the hypothalamus, demonstrated on previous MR studies. Late MR evaluation (after a mean of 39 months) demonstrated stability of the lesions in shape, size, and signal intensity. In three cases the lesions demonstrated a rim of isointense signal with a hyperintense center on T2-weighted sequences. In two cases a Chiari I malformation was found in association with the hypothalamic malformation. In one case a pineal cyst was demonstrated. These unusual findings are discussed. Late MR follow-up showed the absence of changes in the lesions over time, allowing the diagnosis to be confirmed.

[Anterior and anterolateral surgery of the lower cervical spine (25 years after H. Verbiest). I: Technical bases]. / Chirurgie antérieure et antéro-latérale du rachis cervical inférieur. (Vingt-cinq ans après H. Verbiest). Première partie: les bases techniques.

The anterior approach to the cervical spine is currently a worldwide traditional surgical technique used by neurosurgeons or orthopedists in the treatment of traumatic, degenerative or tumoral cervical spinal lesions. Many original rules of these techniques were raised by pioneers as R. Cloward and H. Verbiest, and are still valid. Advances in the surgical armentarium and in bio-materials markedly improved the original technique and subsequently improved the clinical results. The present course was organized for the neurosurgery trainees by the French Speaking Neurosurgical Society, and was helded during the winter meeting in December 1995. The aim of this course is to recall the basic technical principles of the microsurgical anterior cervical approach, and to discuss the main indications of this surgical treatment. Many theoretical points are strengthened by the author's personal experience and comments. Part I presents the different anterior or antero-lateral approaches which any surgeon involved in cervical spine surgery actually needs to know. Secondly, the materials and technical basis needed to achieve an interbody graft or fusion or fixation are described. Lastly, some practical applications are detailed as a microdiscectomy, a medial or lateral cervical spine decompression, and the use of acrylic plastic or prothesis for a cervical vertebral replacement.

[Anterior and antero-lateral surgery of the lower cervical spine (25 years after H. Verbiest). 2: Indications, results, complications)]. / Chirurgie antérieure et antéro-latérale du rachis cervical inférieur. (Vingt-cinq ans après H. Verbiest).Deuxième partie: Indicaions, rèsultats, complications.

The present course on the anterior and antero-lateral surgical approach of the lower cervical spine was organized for the neurosurgery trainees by the French Speaking Neurosurgical Society, and was held during the winter meeting in December 1995. The aim of this course was to recall the basic technical principles of the microsurgical anterior cervical approach, and to discuss the main indications of this surgical treatment. Many theoretical points were strengthened by the author's personal experience and comments. In Part I, the technical bases of the different anterior or antero-lateral approaches were presented (1996, 42 : 105-122). In the present Part II, the main indications of the anterior surgical approach to the cervical disk or the vertebral body are detailed, and the requirement of a bone graft and/or an osteosynthesis are discussed with their consequences on the final results. Secondly, variants of the surgical technics in use in case of cervical spinal instability are commented. Then various approaches to the cervical spinal tumors and to the vertebral artery are detailed and commented. Lastly, general and specific complications of the anterior cervical approach are listed with their rate of occurrence, and their prevention and management are discussed.

Non-metastatic childhood ependymomas.

PURPOSE: Intracranial ependymomas of childhood are relatively infrequent. There are significant disagreements concerning optimal postoperative treatment as well as the patterns of relapse following treatment. The purpose of this retrospective study was the analysis of the recurrence pattern and therefore the implication on the extent of the radiotherapy fields. Data from 37 patients referred within 19 years were used for this study. PATIENTS AND METHODS: From April 1975 to July 1993, 37 children aged 1-14 years were referred for postoperative treatment of an intracranial ependymoma. Twenty-eight children received postoperative radiation therapy and 26 patients received chemotherapy. The median follow-up is 6 years (range 2 months to 19 years). RESULTS: Overall survival and event free survival at 5 and 10 years were 40%. Eighteen children relapsed. Relapses occurred from 1.5 months to 3.6 years post treatment. Relapses were distant in four cases and local in 14. Age, sex, extent of primary resection, chemotherapy and type of radiation therapy did not influence the outcome. Children with poorly differentiated tumors who did not receive postoperative radiation therapy had a higher relapse rate but this difference is not statistically significant. CONCLUSIONS: Despite doses of radiation > or = 50 Gy the majority of recurrences were local. Our results, despite the small number of patients are in accordance to those previously published, suggest that prophylactic craniospinal irradiation is superfluous. Better means of achieved local control are required, such as three-dimensional conformal radiation therapy with dose-escalation study or hyperfractionation regimen.

Auditory evoked potentials in a patient with a unilateral lesion of the inferior colliculus and medial geniculate body.

Brain-stem, middle latency and late auditory evoked potentials (BAEPs, MLAEPs and LAEPs, respectively) were recorded in a patient 2 months after removal of affecting the quadrigeminal plate. Simultaneously, MRI showed a left unilateral lesion involving the inferior colliculus, brachium colliculi and the medial geniculate body (MGB). On dichotic listening, there was complete extinction of the right ear input, without subjective auditory disturbance. BAEPs were abnormal after stimulation of the right ear alone. Wave V was delayed and reduced in amplitude, and the I-V interval was augmented. Above all, MLAEPs of both ears were very abnormal. The Pa and Na components over the left hemisphere were abolished (Pa) or very reduced in amplitude or abolished (Na) whereas both Pa and Na components over the right hemisphere were normal. LAEPs were asymmetrical, with reduced P1N1P2 complex over the left hemisphere and absence of polarity reversal over the mastoid. It has been demonstrated that a lesion affecting only the inferior colliculus and MGB unilaterally and not extending beyond the MGB can abolish Na and Pa ipsilaterally. Any discussion of Na and Pa sources should take into account the output of the MGB to the auditory radiations, the MGB, the brachium colliculi and the inferior colliculus.

Auditory early- and middle-latency evoked potentials in patients with quadrigeminal plate tumors.

Both early auditory evoked potentials (BAEPs) and middle-latency auditory evoked potentials (MLAEPs), were recorded in nine patients suffering from a quadrigeminal plate tumor. These recordings were performed before surgery in six cases and after surgery in three cases. The results of these examinations were correlated with impairments of the midbrain auditory pathways as shown by magnetic resonance imaging. BAEPs and MLAEPs were abnormal in five of nine cases and eight of nine cases, respectively. The two examinations yielded normal results in only one case. These data show that the functional evaluation of the midbrain should not be limited to the recording of BAEPs, routinely performed for brain stem functional evaluation, but should also include recording of MLAEPs, although the technique is a little more delicate. In the five patients with abnormal BAEPs, I-V conduction time was increased unilaterally (three patients) and bilaterally (two patients), and the I/V amplitude ratio was abnormal in two patients. In one of these two patients, isolated destruction of the right inferior colliculus was responsible for an abnormality affecting Wave V of the BAEP that was visible only after left ear stimulation. The most frequently observed MLAEP abnormality was a delay in the peaking of the Pa component, assumed to be of cortical origin. Therefore, a limited impairment of the midbrain may delay the peaking latency of Pa. Unilateral hypovoltage of Na-Pa was also observed. In only one case were Na and Pa components unilaterally abolished, in a patient suffering from a postoperative lesion extending from the right inferior colliculus to the right medial geniculate body.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural and ultrastructural characteristics of human pineal gland, and pineal parenchymal tumors.

We have studied 20 pineal parenchymal tumors (PPT) and 4 normal or cystic pineal glands both by light and electron microscopy and immunohistochemistry with antibodies against glial markers [glial fibrillary acidic protein (GFAP) and protein S-100] or neural/neuroendocrine markers [neurofilaments (NF), synaptophysin and chromogranin A]. Light microscopy revealed the cellular organization of pinealocytes in the normal gland and in different morphological types of pineal tumors (typical pineocytomas, PPT with intermediate differentiation, mixed PPT exhibiting elements of both pineocytoma and pineoblastoma and pineoblastomas). Immunohistochemistry showed the presence of GFAP and protein S-100 in interstitial cells in non-neoplastic pineal gland. Cell processes were labeled with anti-synaptophysin and anti-NF antibodies. No immunoreactivity was found for chromogranin A in non-neoplastic pineal gland. In pineocytomas, GFAP and protein S-100 were observed in interstitial cells. Synaptophysin and NF were present in the large rosettes of pineocytomas. Synaptophysin, NF and chromogranin A were present in pineocytomas with a lobular arrangement of cells. Anti-chromogranin A immunoreactivity was also seen in lobular areas of some PPT with intermediate differentiation. Analysis of normal human pineal gland by electron microscopy showed the presence of vesicle-crowned rodlets (VCR or synaptic ribbons), fibrous filaments (F), paired twisted filaments but few dense-core vesicles (DCV) in normal pinealocytes. Tumoral pineal cells appeared to differentiate either towards a neurosensory pathway characterized by the presence of sensory cells elements (VCR and F), or towards a neuroendocrine pathway, with the occurrence of many DCV. Immunogold labeling demonstrated the presence of chromogranin A in neurosecretory granules.

Tectal plate gliomas. Part I: Microsurgery of the tectal plate gliomas.

A series of 12 patients with tectal plate gliomas, is presented treated by direct surgery. Mean age was 19 years. All patients presented with signs of raised intracranial pressure and supratentorial hydrocephalus on CT scan. Diplopia was the most common local sign. CT scan and MR imaging showed 4 intrinsic, 6 exophytic, and 2 ventrally infiltrating tectal tumours. The histological diagnosis was low-grade astrocytoma in 7, high-grade astrocytoma in 2, oligodendroglioma in one, oligo-astrocytoma in one, and ependymoma in one case. The suboccipital supra- and transtentorial approach was used in every cases. Tumour resection was generous at the level of the superior colliculi, but on the contrary, resection was limited at the level of inferior colliculi due to the auditory risk. Tumour removal was total (macroscopically) in 9 cases and partial in 3 cases. There were 4 surgical complications and one death related to surgery. Parinaud's syndrome was the most-common postoperative sequelae. Auditory hallucinations and the acoustic neglect syndrome were seen once. In three cases additional radiotherapy and chemotherapy were given once with severe sequelae. The treatment of tectal plate gliomas is controversial. The role of different therapeutic options remains open. We consider the tectal plate as a relatively safer territory for surgery than the ventral part of the midbrain. The brain stem auditory evoked potentials (BAEPs) and middle latency potentials (MLPs) monitoring can help to determine the appropriate limit of surgery.

Tectal plate gliomas. Part II: CT scans and MR imaging of tectal gliomas.

CT scans and MR images were analyzed in 12 patients with histologically proved tectal plate gliomas. In an attempt to identify the nature of these lesions, their radiological characteristics were correlated with the histological results. In four of our patients CT scan failed to show the tumour. MR imaging demonstrated the tectal distortion in all cases. Contrast enhancement, calcification, cystic portions, exophytic nature were observed in both high and low-grade gliomas. We conclude that in the case of intrinsic tectal tumours, the most probable diagnosis is that of low-grade astrocytoma while in the case of exophytic tectal tumours, the differential diagnosis from pineal region tumour is required and a histological verification is necessary.

Tectal plate gliomas. Part III: Apparent lack of auditory consequences of unilateral inferior collicular lesion due to localized glioma surgery.

The authors present one of their cases operated on for intrinsic tectal plate glioma. The complete resection of the right inferior colliculus (I.C.) had no apparent auditory consequences. The pre- and post-operative tonal and vocal auditory tests were normal. The brain-stem auditory evoked potentials (BAEPs) and middle latency potentials (MLPs) were recorded pre-, post- and intraoperatively. At the end of surgery all waves were present with a marked delay of wave V and a slight delay of the Pa component. The dichotic test showed a significant right ear extinction but admittedly much less important than expected. The role of inferior colliculus (I.C.) in hearing is discussed.