Intracerebral arachnoid cyst treated with ommaya reservoir implantation in a patient younger than two years

[Brainstem arachnoid cyst: case report and review]

There are no literature data on brainstem arachnoid cysts in humans.

OBJECTIVE

To describe the clinical case of brainstem (pontomesencephalic) arachnoid cyst and to analyze classification, pathogenesis, differential diagnosis and treatment of this pathology considering literature data and own experience.

MATERIAL AND METHODS

A 29-year-old patient with pontomesencephalic arachnoid cyst is reported. The disease manifested in childhood with a headache aggravated by bending and pushing. Later, syncope, vegetative-visceral paroxysms, mild oculomotor disturbances, transient paresthesia and numbness of the left half of the face occurred. Headaches became significantly more severe and resulted nausea and vomiting. Magnetic resonance imaging (MRI) revealed a two-chambered arachnoid cyst. A smaller chamber was localized in interpeduncular cistern, a larger one - in brainstem.

RESULTS AND DISCUSSION

Differential diagnosis included cystic glioma and Virchow-Robin space enlargement. Fenestration of the cyst wall within interpeduncular cistern was performed via right-sided pterional approach. The diagnosis was verified by histological examination. The follow-up period was 14 months. We observed postoperative cyst reduction confirmed by MR data and regression of all symptoms except for minimal signs of medial longitudinal fasciculus dysfunction.

CONCLUSION

Correct surgical approach for brainstem arachnoid cyst complicated by progressive neurological deterioration is confirmed by postoperative regression of cyst and symptoms.

[Changes in treatment paradigm for neurosurgical patients in the era of stereotactic irradiation. By the 15th anniversary of the Neuroradiosurgery in Russia]

INTRODUCTION

Stereotactic method and new irradiation techniques ensured radiosurgical treatment with high precision and conformity and significantly expanded the indications for stereotactic irradiation in neurosurgery.

MATERIAL AND METHODS

Over 15-year period, 29 976 patients underwent irradiation in various modes of fractionation on linear accelerators and Gamma Knife system at the first national radiosurgery center.

RESULTS

Stereotactic radiotherapy and radiosurgery are followed by minimal number of complications and side reactions. At the same time, 5-year control of tumor growth for skull base meningioma was 96.8%, neuroma - 97%, glomus tumor - 94%, pituitary adenoma - 96-98%, craniopharyngioma - 95% in overall 10-year survival 86%, pilocytic astrocytoma - 97.5% in overall 5-year survival 99%. In intracranial metastases, median overall survival after radiosurgery was 10.1 months, 24- and 36-month overall survival - 25.9% and 19.2%, respectively. In patients with recurrent high-grade glioma, overall survival was 27.4 months. In case of metastatic spine lesions, control of tumor growth within 1 year was achieved in 90% of patients, pain relief - in more than 50% of cases. Obliteration of AVM and dural fistula was found in more than 80% of patients in years after treatment. Reduction or disappearance of pain was also observed in 80% of patients with trigeminal neuralgia.

CONCLUSION

Stereotactic irradiation is effective and safe in patients with various pathologies of the central nervous system and characterized by high socio-economic indicators. Our own data indicate more significant role of stereotactic irradiation in the treatment of neurosurgical patients and make it possible to revise the existing treatment standards.

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.

"Countersinking" of reservoir in an irradiated patients can decrease tension on scalp closure

Background:

Subcutaneous reservoirs are used to provide therapy by establishing access to cerebrospinal fluid. However, it is associated with complications such as hemorrhage, infection, malfunction, and malpositioning. In an irradiated field with thin skin, use of reservoir can result in wound dehiscence, wound infection, and device extrusion.

Case Description:

We introduced a “countersinking” technique for the reservoir placement which involves the creation of bony recess in the skull to effectively accommodate the reservoir and decrease the protrusion. “Countersinking” of the reservoir can result in tension-free closure of the scalp and allow durable coverage of the reservoir. In the representative case, the incisional wound healed completely without any concern for wound dehiscence and the countersink technique may have contributed to effective healing of the radiated scalp.

Conclusion:

Countersinking of the reservoir can be a strategy to prevent complications such as wound dehiscence, and device extrusion in any patient, but in irradiated patients with very thin skin it also enables tension-free closure of the wound.