Surgical Management of Trigeminal Schwannomas
Surgical Management of Trigeminal Schwannomas
Object: The authors provide a detailed review of the surgical management of trigeminal schwannomas (TSs) and also discuss the best surgical approach based on the surgical anatomy and tumor extension.
Methods: A series of 17 patients with TSs who were surgically treated between 1987 and 2008 at the authors' institution is reported. The lesions were small (< 3 cm) in 2, medium (between 3 and 4 cm) in 5, large (> 4 cm) in 6, and giant (> 5 cm) in 4 cases. Preoperative symptoms included trigeminal hypesthesia (53%), facial pain (53%), headaches (35.3%), hearing impairment (17.6%), seizures (17.6%), diplopia (11.8%), ataxia (11.8%), and hemiparesis and increased intracranial pressure with papilledema (5.9%). The mean follow-up duration was 10.5 years (121.6 months), with an average of 0.8 patients per year.
Results: Total tumor excision was possible in 16 patients, with no surgery-related deaths. Postoperative trigeminal anesthesia was observed in 7; trigeminal motor function was preserved in 7. Two developed cerebrospinal fluid leakage, 2 presented with mild facial palsy, and 1 patient with neurofibromatosis Type 2 had recurrence of the tumor, which was uneventfully removed. Of the 9 who reported facial pain, only 1 remained symptomatic postoperatively.
Conclusions: The best treatment for TSs is complete microsurgical removal. Postoperative preservation of trigeminal nerve function is possible when resection of the lesion is performed at well-established skull base neurosurgical centers. Although good results have been reported with radiosurgery, no cure can be obtained with this therapeutic modality. Instead, this treatment should be reserved only for nonresectable and residual tumors within the cavernous sinus.
Schwannomas originating from cranial nerves are usually benign, isolated, and slow growing. They may occur in multiple sites when associated with NF2. Schwannomas arising from the trigeminal nerves are the second most common type of intracranial schwannomas, representing 0.8-8% of these tumors. Trigeminal schwannomas tend to occur in middle-aged patients; the highest incidences are between the ages of 38 and 40 years, and are more common in women. Patients with TS frequently complain of trigeminal nerve-related symptoms, but they may also be asymptomatic. In a recent review of the literature, Samii et al. reported trigeminal nerve symptoms in 51% of patients, followed by headaches (16%) and diplopia (11%). The treatment of choice remains resection. In 1918, Frazier reported the first surgical removal of a TS. Prior to the advent of CT and MR imaging, the diagnosis of TS was difficult. Indeed, high death rates had been associated with surgical treatment prior to the late 1950s. Since then, in addition to a large series of 111 patients, several small series have demonstrated positive results and low mortality and morbidity rates associated with complete resection. Different surgical approaches may be used depending on the location and extension of the lesion.
Object: The authors provide a detailed review of the surgical management of trigeminal schwannomas (TSs) and also discuss the best surgical approach based on the surgical anatomy and tumor extension.
Methods: A series of 17 patients with TSs who were surgically treated between 1987 and 2008 at the authors' institution is reported. The lesions were small (< 3 cm) in 2, medium (between 3 and 4 cm) in 5, large (> 4 cm) in 6, and giant (> 5 cm) in 4 cases. Preoperative symptoms included trigeminal hypesthesia (53%), facial pain (53%), headaches (35.3%), hearing impairment (17.6%), seizures (17.6%), diplopia (11.8%), ataxia (11.8%), and hemiparesis and increased intracranial pressure with papilledema (5.9%). The mean follow-up duration was 10.5 years (121.6 months), with an average of 0.8 patients per year.
Results: Total tumor excision was possible in 16 patients, with no surgery-related deaths. Postoperative trigeminal anesthesia was observed in 7; trigeminal motor function was preserved in 7. Two developed cerebrospinal fluid leakage, 2 presented with mild facial palsy, and 1 patient with neurofibromatosis Type 2 had recurrence of the tumor, which was uneventfully removed. Of the 9 who reported facial pain, only 1 remained symptomatic postoperatively.
Conclusions: The best treatment for TSs is complete microsurgical removal. Postoperative preservation of trigeminal nerve function is possible when resection of the lesion is performed at well-established skull base neurosurgical centers. Although good results have been reported with radiosurgery, no cure can be obtained with this therapeutic modality. Instead, this treatment should be reserved only for nonresectable and residual tumors within the cavernous sinus.
Schwannomas originating from cranial nerves are usually benign, isolated, and slow growing. They may occur in multiple sites when associated with NF2. Schwannomas arising from the trigeminal nerves are the second most common type of intracranial schwannomas, representing 0.8-8% of these tumors. Trigeminal schwannomas tend to occur in middle-aged patients; the highest incidences are between the ages of 38 and 40 years, and are more common in women. Patients with TS frequently complain of trigeminal nerve-related symptoms, but they may also be asymptomatic. In a recent review of the literature, Samii et al. reported trigeminal nerve symptoms in 51% of patients, followed by headaches (16%) and diplopia (11%). The treatment of choice remains resection. In 1918, Frazier reported the first surgical removal of a TS. Prior to the advent of CT and MR imaging, the diagnosis of TS was difficult. Indeed, high death rates had been associated with surgical treatment prior to the late 1950s. Since then, in addition to a large series of 111 patients, several small series have demonstrated positive results and low mortality and morbidity rates associated with complete resection. Different surgical approaches may be used depending on the location and extension of the lesion.
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