Endoscopic treatment of thalamic neuroepithelial cysts

Different strategies in the management of thalamic space-occupying lesions

Introduction

Thalamic space-occupying lesions (SOL) are considered challenging for microsurgical removal. Unfortunately, the pathological features of lesions occurring in the thalamic region are different with a wide variation in clinical behavior and outcome. Although microsurgery is still the gold standard in the management of these lesions through different approaches, questions remain whether surgery is feasible and safe in these patients and what are the alternatives? It is well known that stereotactic techniques may be favorable especially in cystic, small, multiple lesions and in combination with adjuvant therapy. Transventricular endoscopic approach is also an alternative technique to combine tumor biopsy and treatment of hydrocephalus.

Aim of the study

The identification of the different procedures for the management of thalamic SOL in respect to the age of the patient, the clinical condition, and the site of the lesion as well as its extent and pathology.

Patients and methods

This prospective study included 35 patients having thalamic lesions with a mean age of 27 years old who were treated with different approaches including microsurgical, stereotactic, and endoscopic approaches. The clinical outcome was assessed as the same, improved, deteriorated, or died in comparison to the initial clinical status, while the radiological control was measured as no gross residual, residual < 10% and residual > 10%. Chi-square test was used to test the association between two categorical variables.

Results

Thirty-five patients were included in this study, 20 were males and 15 were females. Eight cases were children, and 27 cases were adults. The most common clinical presentation was contralateral hemiparesis. The most common pathology was pilocytic astrocytoma. Radiological studies showed that the total thalamic type was the most common topographic variant and that 10 cases had hydrocephalus treated with CSF diversion procedures. For the definitive lesion, 2 cases underwent endoscopic biopsy and cystoventriculostomy and 18 cases had stereotactic technique in the form of biopsy, aspiration, and ommaya reservoir application, while 15 cases had microsurgery through different approaches with stereotactic technique preceding surgery in 2 of them.

Conclusion

The main factors involved in choosing the appropriate approach included nature of the lesion (solid or cystic, multiplicity), suspected pathological type, and diffusion tensor imaging. Abscesses are best treated with stereotaxy, while non-neoplastic cystic lesions (other than abscesses) related to the ventricles are best treated with endoscopy. For the remaining pathologies, maximum surgical removal is the best management. Best lesion control was provided by microsurgery.

Trial registration

ISRCTN 1380 registered 6/11/2018

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.

Transcranial endoscopic treatment of thalamic neuroepithelial cyst: case report and review of the literature

Thalamic neuroepithelial cysts are rare, benign lesions. Thirteen cases have been published in eight articles. The most frequent symptoms are headache, hemiparesis, tremor and related signs of hydrocephalus such as gait disturbance, confusion, and Paranaud's syndrome. Surgical interventions include endoscopic fenestration, open surgery and stereotaxic biopsy or aspiration. We report a case of a 63-year-old woman who had headache and right hemiparesis for 1 week, but no hydrocephalus. We treated her with transcranial neuronavigation-guided endoscopic complete resection. The patient recovered completely after cyst removal.

Third Ventricular Cerebrospinal Fluid Cysts of Thalamic Origin: Review of Embryologic Origin, Presentation, and Management Strategies with a Case Series

OBJECTIVE

Third ventricular cerebrospinal fluid (CSF) cysts of thalamic origin are rare. The objective of this study is to review their possible pathogenesis, clinical presentation, and management strategies with a case series describing management via an endoscopic approach with fenestration using a single burr-hole technique.

METHODS

A systematic literature review of reported cases of thalamic cysts was conducted with further meta-analysis of CSF cysts that involve the third ventricle. The mode of presentation, pathologic analysis, surgical management, and outcomes were analyzed.

RESULTS

Twenty-two studies reported between 1990 and 2013 described 42 cases of thalamic cyst. Of those cases, 13 were consistent with CSF cyst that originated in the thalamus and involved the third ventricle. Eight cases (61.5%) were treated via endoscopic fenestration, 2 cases (15.4%) were surgically drained, 2 cases (15.4%) were stereotactically aspirated, and 1 case (7.69%) was observed. The most common presenting symptoms were gait disturbance (26.3%) and headaches (26.3%) followed by tremors (15.8%) and weakness (15.8%). In our series, a single burr-hole technique was a successful definitive treatment, with an average period of 23 months.

CONCLUSIONS

Third ventricular CSF cysts of thalamic origin most commonly present with hydrocephalus. They can be safely definitively treated via endoscopic fenestration to the CSF circulation using a single burr-hole technique. Long-term follow-up shows lasting improvement in symptoms without reaccumulation of the cyst.

Acute triventricular hydrocephalus caused by choroid plexus cysts: a diagnostic and neurosurgical challenge

OBJECTIVE

Intraventricular choroid plexus cysts are unusual causes of acute hydrocephalus in children. Radiological diagnosis of intraventricular choroid plexus cysts is difficult because they have very thin walls and fluid contents similar to CSF and can go undetected on routine CT studies.

METHODS

This study reports the authors' experience with 5 patients affected by intraventricular cysts originating from the choroid plexus. All patients experienced acute presentation with rapid neurological deterioration, sometimes associated with hypothalamic dysfunction, and required urgent surgery. In 2 cases the symptoms were intermittent, with spontaneous remission and sudden clinical deteriorations, reflecting an intermittent obstruction of the CSF pathway.

RESULTS

Radiological diagnosis was difficult in these cases because a nonenhanced CT scan revealed only triventricular hydrocephalus, with slight lateral ventricle asymmetry in all cases. MRI with driven-equilibrium sequences and CT ventriculography (in 1 case) allowed the authors to accurately diagnose the intraventricular cysts that typically occupied the posterior part of the third ventricle, occluding the aqueduct and at least 1 foramen of Monro. The patients were managed by urgent implantation of an external ventricular drain in 1 case (followed by endoscopic surgery, after completing a diagnostic workup) and by urgent endoscopic surgery in 4 cases. Endoscopic surgery allowed the shrinkage and near-complete removal of the cysts in all cases. Use of neuronavigation and a laser were indispensable. All procedures were uneventful, resulting in restoration of normal neurological conditions. Long-term follow-up (> 2 years) was available for 2 patients, and no complications or recurrences occurred.

CONCLUSIONS

This case series emphasizes the necessity of an accurate and precise identification of the possible causes of triventricular hydrocephalus. Endoscopic surgery can be considered the ideal treatment of choroid plexus cysts in children.

[Neuroepithelial thalamo-mesencephalic cyst]

Thalamo-mesencephalic neuroepithelial cysts are rare lesions of the central nervous system. They are thought to arise from neuroectoderm and are also referred to as ependymal cysts due to their origin. It can remain asymptomatic throughout life or rarely can cause symptoms. We describe a 42-year-old woman who presented with thalamic syndrome due to a neuroepithelial cyst of the thalamo-midbrain. Differential diagnosis is made with other cystic lesions in the brain. However a good analysis of imaging feature led to diagnosis. When the lesion is symptomatic, mini-invasive procedure is indicated.

Obstructive hydrocephalus due to a third ventricular neuroepithelial cyst

Cysts occupying the third ventricle are rare lesions and may appear as an unusual cause of obstructive hydrocephalus. Various types of lesions occur in this location, and they generally have an arachnoidal, endodermal, or neuroepithelial origin. The authors present a case of acute hydrocephalus following minor trauma in a child due to cerebrospinal fluid outflow obstruction by a third ventricular cyst. Definitive diagnosis of this cystic lesion was possible only with contrast ventriculography and not routine computed tomography or magnetic resonance imaging. The investigation, treatment, and pathological findings are discussed.