RESUMO
BACKGROUND: Navigated transcranial magnetic stimulation (nTMS) is a well establish a noninvasive method for preoperative brain motor mapping. We commonly use magnetic resonance imaging (MRI) to supply the nTMS system. In some cases, MRI is not possible or available, and the use of computed tomography (CT) is necessary. We present the first report describing the association of CT and nTMS motor mapping for brain lesion resection. CASE DESCRIPTION: CT imaging of a 59-year-old man suffering from acquired immune deficiency syndrome for 17 years, presenting with seizure and right hemiparesis, revealed a small single hypodense ring-enhancing lesion in the left central sulci suggesting cerebral toxoplasmosis. After 3 weeks of neurotoxoplasmosis treatment, due to four consecutive tonic-clonic seizures, a new CT scan was performed and showed no lesion changes. MRI was in maintenance at that time. Infectious diseases department suggested a brain lesion biopsy. Due to lesion's location, we decided to perform a presurgical nTMS motor mapping. After a small craniotomy, we could precisely locate and safely totally remove the lesion. The pathology report revealed a high suspicious toxoplasmosis pattern. The patient was discharged after 2 days and continued toxoplasmosis treatment. After 6 months follow-up, he showed no signs of any procedure-related deficits or radiological recurrence. CONCLUSION: We report the feasibility and applicability of nTMS motor mapping using CT scan as an image source. It gives neurosurgeons another possibility to perform motor mapping for brain lesion removal, especially when MRI is not available or feasible.
RESUMO
Microsurgery remains the gold standard treatment for intraventricular lesions, but it is not without limitations. The cerebral ventricles approach is considered a challenge for neurosurgeons because of their deep location and their intimate association with critical areas of the brain. It has been shown that direct endoscopic view is superior to magnetic resonance imaging (MRI) in identifying intraventricular structures and lesions. Also, during neuroendoscopy, there is no cerebrospinal fluid leak causing brain collapse as seen in microsurgery. Different surgical strategies should be shared and may improve and facilitate intraventricular lesions resection. Herein, a case of a successful microsurgical cavernoma resection with prior ventriculoscopy is described. A 28-year-old woman was admitted with intense holocranial headache. A mild stiff neck was observed. MRI showed a 3-cm lesion with heterogeneous signal intensity and no contrast enhancement suggestive of cavernoma. Initially, a ventriculoscopy was done to inspect the lesion and the surrounding ventricular structures. After that, a conversion technique from endoscopy to microsurgery was performed. The initial corticectomy was extended and the endoscope pathway was followed into the ventricular cavity. Then, the cavernoma was completely removed by microsurgical technique. No complications were observed. Control MRI showed total tumour removal. The patient remained asymptomatic with no recurrence after 1 year. This case illustrates a successful prior endoscopic approach followed by microsurgery as an alternative to a direct microsurgical approach for intraventricular cavernoma. A previous direct endoscopic view of the lesion and its relation with intraventricular structures may ensure a safe and complete resection by microsurgery.