Stereotactic neurosurgery in children and adolescents

Endoscopic management of benign cystic lesions of the thalamus with fenestrated stent placement

Benign intracranial cystic lesions of the thalamus are an uncommon clinical entity rarely requiring operative decompression. In combination with cyst fenestration, cerebrospinal fluid (CSF) flow diversion or fenestrated stent placement may be performed at the time of surgery. We describe a method of treatment of these cysts using endoscopic cyst fenestration with fenestrated transventricular stent placement. Three patients with benign cystic lesions were treated with stereotactic-guided, endoscopic fenestration and fenestrated stent placement. All 3 had radiographic and clinical improvement. There were no complications. Endoscopic fenestration and transventricular fenestrated stent placement is a minimally invasive, effective, and safe method to decompress benign, symptomatic cystic lesions of the thalamus.

Update on the management of pineal cysts: Case series and a review of the literature

OBJECTIVE

The natural history of pineal cysts still remains unclear. Incidental pineal cysts have become more common which raises the question of their management. Symptomatic pineal cysts may require a surgical solution but therapeutic indications have not yet been clearly established.

METHOD

From 1986 to 2012, 26 patients with pineal cysts were identified. Their medical records were retrospectively assessed focusing on the initial symptoms, imaging characteristics of the cyst, management strategy, operative technique and their complications, as well as the latest follow-up. A systematic review of the literature is also presented.

RESULTS

Twenty-six patients with pineal cysts were identified. The mean age was 23.5 years ranging from 7 to 49 years. Symptoms included intracranial hypertension with obstructive hydrocephalus in 18 cases and oculomotor anomalies in 12 cases. Two adult cases presented with non-specific headaches and did not require surgery. Twenty patients were operated via a suboccipital transtentorial approach with total removal of the cyst in 70% of the cases, while the remaining 4 cases were treated with an intraventricular endoscopic marsupialization associating a third ventriculostomy. Four patients required a preoperative ventriculo-peritoneal shunt due to life-threatening obstructive hydrocephalus. Overall, peri-operative mortality was nil. In the two non-operated patients, the cyst remained stable and no recurrences were observed in all operated patients with a mean follow-up of 144 months.

CONCLUSION

In the majority of incidental pineal cysts, a clinical and imaging follow-up is sufficient but occasionally not required especially in adults as very rare cases of increase in size have been reported.

Pineal cysts in children: case-based update

PURPOSE

Pineal cysts (PC) are found in children as often asymptomatic and without change in their size over the time. However, there are some debatable issues about their evolution and management in the pediatric population. The aim of the present paper is to update the information regarding pathogenesis, clinical presentation, and management of these lesions.

METHODS

All the pertinent literature was reviewed, and a meta-analysis of operated on cases was carried out. An illustrative case regarding the clinical evolution of a 13-year-old girl is also presented.

RESULTS AND CONCLUSIONS

PC are often asymptomatic and do not evolve over the time. However, since there is a certain risk of clinical and/or radiological progression, or even sudden and severe clinical onset (apoplexy), both a clinical and radiological follow-up is recommended in the pediatric age. The surgical excision is usually limited to symptomatic patients or to cases with clear radiological evolution.

Interstitial stereotactic radiosurgery of pilocytic astrocytomas in paediatric patients

OBJECTIVE

To evaluate the clinical presentation, tumour response, clinical improvement and complications in 12 children and young people with a pilocytic astrocytoma, WHO I grade 1, who were treated with interstitial radiosurgery using Iodine-125 seed implants.

PATIENTS AND METHODS

Retrospective analysis of 12 patients aged under 18 years (mean 8.4 years, ranging from 8 months to 17 years of age) with a pilocytic astrocytoma treated between 1993 and 2006. Iodine-125 seeds were used as temporary implants with low-dose rate (<or=10 cGy/h) and a calculated reference dose of 60 and 100 Gy to the outer ring of the tumour.

RESULTS

There was no perioperative mortality. Two patients worsened transiently, but thereafter each patient improved clinically. Eleven out of 12 tumours shrank after the treatment. The mean volume of the tumours before implantation was 17.9 cm(3). and was reduced to 60% of this volume at 6 months, to 26.5% at 12 months, to 8% at 24 months, and was less than 1% at 30-36 months One patient underwent a reimplantation to treat a recurrence 3 years after the initial treatment. Ten patients were alive 2 years after the first intervention. In the longest surving patient, there was no evidence of progression after 13.4 years of follow up.

Management of child optic pathway gliomas: new therapeutical option

OBJECTIVE

To present our experience in the treatment of child optic pathway gliomas in the last 25 years.

MATERIAL AND METHODS

Seventeen children under 10 years of age have been analyzed and assessed from clinic, ophthalmologic, endocrinologic, neurological, neuropathologic, and imaginologic points of view.

RESULTS

Predominance of female patients, 10 girls and 7 boys between 6 and 122 months old; mean age was 3 years and 8 months. The most frequent symptoms have been ophthalmologic and visual alterations in all 17 patients, endocrine alterations in 10, and neurological signs in 6. One of the patients presented neurofibromatosis type 1 (NF1), another patient had Down syndrome. Diagnosed using computed tomography or/and magnetic resonance imaging, histological studies showed pilocytic astrocytomas in 13 cases and a fibrillary astrocytoma grade II in 1 case. There were three patients without histological diagnosis; one of them had NF1. The treatment consisted of surgery, external beam radiotherapy, chemotherapy, and brachytherapy with iodine 125, separately or combined. Five patients died; the causes were secondary tumors in two children, tumor recurrence in one, sepsis secondary to respiratory and urinary tract infections in the child with Down syndrome, and finally, hydrocephaly due to hyperproteinorachia of tumor origin in one. Average survival was 89 months.

CONCLUSION

Chemotherapy and brachytherapy are therapeutic methods to be considered, especially in children under 5. Marsupialization of the residual cyst into the ventricular system postradio or oncolytic treatment through endoscopic or stereotactic techniques is useful in the treatment of endocranial hypertension and/or hypothalamic compression in these patients.

Endoscopic treatment of thalamic neuroepithelial cysts

✓ Thalamic neuroepithelial cysts are rare lesions of the central nervous system. Surgical management of these lesions has varied and yielded mixed results. The authors identified 10 reported cases in the literature, five of which involved symptomatic lesions. The authors present three unique cases of symptomatic thalamic neuroepithelial cysts associated with hydrocephalus, which were all successfully treated using endoscopic third ventriculostomy and fenestration of the cyst into the third ventricle.

Neuroepithelial cysts presenting with movement disorders: two cases

BACKGROUND

The authors present two cases of movement disorders caused by neuroepithelial cysts and highlight their management. Neuroepithelial cysts are ependymal or epithelial lined fluid collections of unknown etiology within the central nervous system parenchyma with no obvious ventricular or subarachnoid connection. Most cysts are asymptomatic, however, some present with seizures, mass effect, or rarely with movement disorders.

CASE REPORTS

The first patient, a 27-year-old female, presented with progressive weakness, dystonic posturing, tremor, ballismus and choreoathetotic movements of her right upper extremity. Her symptoms improved after stereotactic drainage of a neuroepithelial cyst in her basal ganglia but recurred within a year. The second case, a 56-year-old female, presented with diplopia, nystagmus, gait imbalance and hemiparesis. Her symptoms improved after stereotactic drainage of a midbrain neuroepithelial cyst. The cyst reaccumulated over the next few years and she became symptomatic with left arm tremor and facial weakness. Aspiration was again performed with symptomatic improvement for nine months. Her tremor recurred and a cyst access device was placed stereotactically. She improved and has remained stable for over a year.

CONCLUSION

Simple stereotactic drainage of neuroepithelial cysts has a high recurrence rate. The authors recommend considering placement of a drainage device to facilitate aspiration of the cyst fluid during follow-up, if needed.

A planned combined stereotactic approach for cystic intracranial tumors

✓ Cyst-associated tumors are classified as cysts with neoplastic mural nodules and intratumoral cysts. The solid component of many of these tumors may be appropriate for gamma knife radiosurgery (GKS). At present there is no systematic protocol for GKS treatment of patients harboring tumors with a cystic component. The purpose of this paper is to suggest such a program.

Two cases are presented. One patient had a hemangioblastoma with a cyst and a mural nodule. The second patient had a craniopharyngioma with one large and two small intratumoral cysts. The course in both cases has been satisfactory in the short term. Although the 1-year follow-up period, however, does not provide a basis for determining the correct overall management of such tumors, the treatment strategy does illustrate a program for the management of tumors with associated cysts.

Cysts with tumor nodules in their walls should first be treated with GKS followed by aspiration of the cyst contents, unless special circumstances make this unsuitable. This strategy enables treatment planning to take advantage of the natural barrier a cyst may place between a tumor and important surrounding structures.

Intratumoral cysts may be aspirated and then treated with GKS, with every attempt made to cover the entire target volume including any residual cyst with the prescription dose. This form of treatment requires very careful follow up.

It is probable that in some cases reaccumulation of cyst fluid may require the insertion of an Ommaya reservoir for repeated aspiration or the installation of cytotoxic agents such as bleomycin. This form of treatment is much less traumatic than surgery and does not hinder the performance of subsequent surgery, should this become necessary.