| ORIGINAL ARTICLE |
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| Year : 2007 | Volume
: 2
| Issue : 2 | Page : 58-66 |
Pediatric vestibular schwannoma with or without neurofibromatosis: Characteristic features and operative nuances
Pallav Garg, Sanjay Behari, Shishir Jaiswal, Awadesh Jaiswal, Vijendra K Jain, Ashok K Mahapatra
Department of Neurosurgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow - 226 014, India
Correspondence Address:
Sanjay Behari
Department of Neurosurgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Rae Bareli Road, Lucknow - 226 014, UP
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/1817-1745.36764
Vestibular schwannomas (VSs) are rarer in children than in adults and are often associated with neurofibromatosis 2 (NF2). We focus on characteristic presentations of VSs in children (< 16 years old) both with and without NF2 and illustrate essential surgical steps using the retromastoid suboccipital approach. Materials and Methods: Three patients had unilateral tumors and five had bilateral tumors with associated NF2. On computed tomography (CT)/ magnetic resonance (MR) imaging, tumor diameters were measured parallel and perpendicular to the petrous ridge and vertically in coronal slices. The size of the VS was taken as the largest diameter in any one axis. Tumors were categorized as: Small: < 1 cm in size; Medium: 1-2.5 cm; Large: 2.5-4 cm and Giant: > 4 cm. Surgery was done in the park-bench position using the suboccipital retromastoid approach. Results: Raised intracranial pressure (ICP), often with visual deterioration, was the most commonly found presentation. Preoperative VIIth nerve involvement was grade IV in three, III in two and II in two patients. One of the patients with NF2 with proptosis did not have any VIIth nerve deficit. None of the patients had any functionally useful hearing on the side of larger tumor. Tumors were giant in six and large in two patients. In NF2 patients, two patients had large, two had medium-sized and one patient had a small contralateral tumor. Seven patients had significant hydrocephalus out of which three underwent ventriculoperitoneal shunt. Total excision of the larger lesion was performed in six patients. A small tumor remnant was left adherent to the preserved VIIth nerve in one patient. A patient with NF2 underwent excision of orbital neurofibroma and is awaiting surgery for VS. Two patients underwent bilateral VS excision. Anatomical preservation of the VIIth nerve was possible in six out of seven patients who underwent tumor excision. Postoperatively, symptoms of raised intracranial pressure and ataxia improved; visual deficits continued to deteriorate in two and VIIth nerve function deteriorated from grade III to V. Conclusions: In children, only a high degree of awareness facilitates early diagnosis of VS; otherwise, initial complaints may be neglected and the underlying tumor detected only after incapacitating raised ICP features appear. The retromastoid suboccipital approach is an effective approach for safe removal of large to giant-sized tumors.
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