Surgical adverse events of deep brain stimulation in the subthalamic nucleus of patients with Parkinson's disease. The learning curve and the pitfalls.

BACKGROUND: Several surgical adverse events (SAEs) have been associated with Deep Brain Stimulation (DBS) of the subthalamic nucleus (STN) in Parkinson's Disease (PD) patients, leading to certain confusion about the risk/benefit ratio of this technique, and giving rise to the need of more and more extensive control studies over longer periods. The aim of this article is to identify and quantify the factors associated with the most frequent AEs from STN DBS in PD-diagnosed patients. METHODS: The following variables were studied: aborted procedure, misplaced leads, intracranial haemorrhage, and seizures. This study was carried out in 233 patients diagnosed with PD, with 455 STN electrodes implanted and follow-up after 7 (8-14) years follow up. RESULTS: A total amount of 56 SAEs occurred in 49 patients (11.76 % of total procedures, 12.31 % of implanted leads, 21.03 % of patients). SAEs were: five aborted procedures, 26 misplaced leads, ten intracranial haemorrhages, and 15 seizures. Of all the SAEs, long-term effects only happened in two cases of hemiparesis caused by intracranial haemorrhage; the other SAEs were reversible and didn't leave any long-term clinical consequences (0.42 % of procedures, 0.44 % of leads, and 0.86 % of patients). CONCLUSIONS: STN DBS in PD patients is a safe surgical procedure, with good risk/benefit ratios: procedure reliability/correct lead implantation in 95.59 %, 0 mortality/implanted lead, 0.12 morbidity/implanted lead, and 0.0043 neurological sequelae/implanted lead.

Subtemporal-preauricular approach in the management of infratemporal and nasopharyngeal tumours.

OBJECTIVES: To evaluate the indication, advantages, and results of the subtemporal-preauricular approach in the resection of tumours arising in the infratemporal fossa and related structures of the lateral cranial base. DESIGN: Retrospective analysis of patients treated by the subtemporal-preauricular approach to resect nasopharyngeal and infratemporal tumours. SETTING: Tertiary hospital. METHODS: Forty patients with lateral skull base lesions were managed with the subtemporal-preauricular approach. There were 19 benign lesions and 21 malignant tumours, the most common being nasopharyngeal carcinomas, juvenile angiofibromas, and adenoid-cystic carcinomas. Most of the tumours were at an advanced stage, with skull base involvement in 13 benign tumours and in 14 malignant ones. RESULTS: Major complications occurred in 6 (14%) patients, and there were 2 (5%) postoperative deaths. All 19 patients with benign tumours are alive, although 5 of them (26%) presented with residual or recurrent disease. The 5-year estimated survival rate of the 21 patients with malignant neoplasms was 39%. CONCLUSIONS: The subtemporal-preauricular approach is a safe and versatile approach to the infratemporal fossa and neighbouring areas of the lateral cranial base, offering satisfactory oncologic results in the absence of intracranial involvement.

Prognostic factors in sinonasal tumors involving the anterior skull base.

BACKGROUND: Anterior craniofacial resection is a standardized procedure for the treatment of ethmoid and frontal orbital tumors with intracranial invasion. METHODS: A retrospective review of 100 patients with sinonasal tumors involving the anterior skull base who underwent combined craniofacial surgery at the Hospital Central de Asturias. RESULTS: The most frequent pathologic entity was adenocarcinoma (53 cases) and other epithelial tumors (29 cases). Five-year actuarial survival according to the Kaplan-Meier method was 40%. Factors such as involvement of surgical margins, orbital periosteum involvement, frontal sinus invasion, or spread into the dura had no significant effect on survival. Survival, however, was affected by the histologic findings of the tumor (p=.03), brain involvement (p=.04), deep soft tissue involvement of the orbit (p=.003), involvement of the sphenoid sinus (p=.001), previous treatment (p=.05), and postoperative recurrence (p=.0000). Neither the INT staging system nor the UICC system showed statistical prognostic significance. After multivariate analysis and Cox regression analysis, only recurrence after craniofacial resection, involvement of soft tissues of the orbit, and invasion of the sphenoid sinus significantly influenced survival. CONCLUSIONS: Standard staging systems did not show statistical prognostic significance. Only involvement of some critical areas was reliable as predictor of an unfavorable outcome.