rTMS stimulation to induce plastic changes at the language motor area in a patient with a left recidivant brain tumor affecting Broca's area.

INTRODUCTION: Extent of resection is one of the most powerful predictors of outcome in surgery of gliomas. Tumors located within areas governing eloquence may impede a total tumor resection. Functional plasticity may be induced by therapeutic means, such as cortical stimulation with repetitive transcranial magnetic stimulation (rTMS). Thus, rTMS is a potential tool to induce an improvement of functions of eloquence menaced by brain tumors. MATERIAL AND METHODS: We report a case of a 59-year-old woman operated for a left sided precentral oligodendroglioma with awake intraoperative stimulation, whose tumor could not be completely removed because it affected areas governing language. Nine months later the tumor progressed and the motor language functions worsened. We submitted the patient to rTMS directed to Broca's area, next to the anterior pole of the tumor, with the aim of improving motor language function before a new tumor resection attempt. We performed 12 daily sessions of theta-burst rTMS followed by intensive language rehabilitation for 10 minutes, and 5 different aspects of language were measured before, immediately after and 10 minutes after each session. RESULTS: Repetition and nomination worsened immediately after each rTMS session, and improved after 10 min of rehabilitation. However, basal values improved globally along the experiment. Also, the impact of rTMS on motor language was increasingly less along the procedure. CONCLUSIONS: rTMS induces changes in Broca's area and this effect can be potentially used to improve language function in tumors located at or close to eloquent cortical areas.

Nocardia farcinica abscess of the cerebellum in an immunocompetent patient: A case report and review of the literature.

Nocardial brain abscesses are uncommon and rarely occur in patients without predisposing factors. They may be mistaken for gliomas or necrotic metastases, and surgical intervention may be required to make the diagnosis. We report the first case of Nocardia farcinica cerebellar abscess in a patient without immunosuppression. He presented to us with headache and instability beginning a week before. Brain magnetic resonance imaging (MRI) revealed a cystic lesion located at the right cerebellar hemisphere, hypointense in T1 and hyperintense in T2, with a fine wall that enhanced after injection of gadolinium. Image tests also showed a cavitated lesion at the upper lobule of the right lung. The patient underwent craniotomy and drainage of the cerebellar abscess. Initial post-operative treatment with linezolid produced a limited response. He was re-operated and vancomycin, imipenem and ciprofloxacin were added with an excellent outcome of the cerebellar and lung lesions.

C8-T1 Radiculopathy Due to an Intradural Extramedullary Metastasis of a Pancreatic Neuroendocrine Tumor: Case Report and Review of the Literature.

Pancreatic neuroendocrine tumors (pNETs) are usually well-to-moderately differentiated neuroendocrine tumors (NETs) that most often metastasize to the liver and lymph nodes with other locations being uncommon. We present a case of intradural pNET metastasis and conduct a review of the literature. Forty-five cases, including the case presently reported, of spinal cord compression due to well-differentiated NETs were found: carcinoid (80%), pNET (13.3%), and NETs of unknown primary (6.7%). Seventy-eight percent of cases consisted of extradural compressions from vertebral bone metastases, whereas there were only 5 cases of intradural extramedullary spinal cord compression. Most cases were managed with surgery and/or radiotherapy with a good clinical outcome in the majority. We report the first case of a pNET intradural extramedullary metastasis and conduct the largest review to date of an infrequent complication of well-differentiated NETs such as malignant spinal cord compression. Aggressive local treatment is warranted in most cases because it usually achieves neurologic improvement and symptomatic relief in patients who may still have a long life expectancy.

Scalp Metastases of Recurrent Meningiomas: Aggressive Behavior or Surgical Seeding?

OBJECTIVE: Scalp metastases of meningiomas seldom have been reported. Here, we report a series of 4 cases of this rare event and discuss the relevant potential risk factors. METHODS: We performed a retrospective review of patients treated for scalp metastases of meningiomas at our institution. A literature review was performed for the terms "scalp meningioma," "cutaneous meningioma," "skin meningioma," "extracranial meningioma," and "subcutaneous meningioma." RESULTS: Four patients showed scalp metastases of recurrent meningiomas with the following associated clinical features: multiple reoperations (n = 4), immunosuppression (n = 2), radiation therapy (n = 3), surgical wound complications with cerebrospinal fluid fistula (n = 2), and histologic grade progression (n = 2). The timescale for development of scalp metastasis was between 5 months and 13 years after intracranial meningioma surgery. In all cases, the metastases were located close to the surgical scalp incision for the craniotomy. Previously, 11 cases of meningioma with scalp metastasis, with similar features to those described here, were reported in the literature. CONCLUSIONS: Spreading of meningioma cells during surgery is a possible mechanism for scalp metastases of recurrent meningiomas. Factors associated with scalp metastases include reoperations, immunosuppression, radiation therapy, torpid course of the surgical wound with cerebrospinal fluid fistula, and histologic progression. Awareness of these features is advisable for neurosurgeons involved in the care of patients with similar profiles.

High-frequency cortical subdural stimulation enhanced plasticity in surgery of a tumor in Broca's area.

Functional areas located near or within brain gliomas prevent the complete resection of these tumors. It has recently been described that slow tumor invasion promotes neural reorganization, and even topographic plasticity, allowing a staged resection of those tumors. Thus, our aim was to promote plasticity by mimicking the tumor's capability to displace brain function. This proceeded through the production of a 'virtual lesion' in eloquent areas within a tumor using continuous high-frequency cortical electrical stimulation (cHFCS). An anaplastic astrocytoma located in Broca's area progressed in a patient whose lateralization of language to the side of the lesion was demonstrated with functional MRI. After partial tumor resection using awake cortical monitoring, we implanted a subdural grid over the eloquent cortex located within residual tumor. We then applied cHFCS for 25 days, using a frequency of 130 Hz and a pulse width of 1 ms. Stimulus intensity was set to the threshold wherein mild speech disturbance was evident without any other neurological effects. This treatment successfully achieved the displacement of speech functions, and a more radical resection of the tumor was possible in a second surgery. Critically, a reorganization of motor language areas was demonstrated both with functional MRI and cortical stimulation. Furthermore, motor language areas were also identified in the right hemisphere, where previously they were absent. The patient's speech fluency improved both after stimulation and resection. We therefore demonstrate the first evidence of induced topographic plasticity using cHFCS in eloquent areas within a tumor, which allowed for increased tumor removal. Our results open the possibility to induce plasticity before the resection of brain tumors near eloquent areas, in order to increase the extent of resection.