[Show abstract][Hide abstract] ABSTRACT: For the resection of anteriorly located meningiomas, various approaches have been used. Posterior approach is less invasive and demanding; however, it has been associated with increased risk of spinal cord injury. We evaluated ten consecutive patients that underwent surgery for spinal meningiomas. All patients were preoperative assessed by neurological examination, computed tomography and magnetic resonance imaging. All tumors were ventrally located and removed via a posterior approach. Transcranial motor-evoked potentials (TcMEPs), somatosensory-evoked potential (SSEP) and free running electromyography (EMG) were monitored intraoperative. Postoperative all patients had regular follow-up examinations. There were four males and six females. The mean age was 68.2 years (range 39-82 years). In nine out of ten cases, the tumor was located in the thoracic spine. A case of a lumbar meningioma was recorded. The most common presenting symptom was motor and sensory deficits and unsteady gait, whereas no patient presented with paraplegia. All meningiomas were operated using a microsurgical technique via a posterior approach. During the operation, free running EMG monitoring prompted a surgical alert in case of irritation, whereas TcMEP and SSEP amplitudes remained unchanged. Histopathology revealed the presence of typical (World Health Organisation grade I) meningiomas. The mean Ki-67/MIB-1 index was 2.75% (range 0.5-7). None of our patients sustained a transient or permanent motor deficit. After a mean follow-up period of 26 months (range 56-16 months), no tumor recurrence and no instability were found. Posterior approach for anteriorly located meningiomas is a safe procedure with the use of intraoperative monitoring, less invasive and well-tolerated especially in older patients. Complete tumor excision can be performed with satisfactory results.
European Spine Journal 07/2010; 19(7):1195-9. DOI:10.1007/s00586-010-1295-z · 2.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Spinal stenosis refers to narrowing of the spinal canal with encroachment of the neural structures by adjacent bone and soft tissue. Surgical treatment usually offers greater pain relief and functional recovery than non-surgical treatment. Nevertheless, neurological complications from decompressive laminectomy have been reported to range between 1% and 33%. Therefore, the purpose of this prospective study was to evaluate the efficacy of transcranial motor evoked potentials (TcMEP) and continuous electromyography (EMG) to prevent irreversible pyramidal tract damage during decompressive laminectomy. We prospectively evaluated 25 patients (11 males and 14 females) who underwent decompressive laminectomy for lumbar spinal stenosis. TcMEP and EMG were monitored intraoperatively. Postoperatively all patients had regular follow-up examinations. Electrophysiological monitoring was not performed in two patients because of the use of incompatible anaesthetic regimens. In 17/25 patients there was an increase in TcMEP amplitudes of more than 50%, whereas in six patients the amplitudes only slightly increased or remained unchanged. The 17 patients with the increased TcMEP amplitudes had the greatest improvement 3 and 12 months postoperatively, based on neurological examination and the visual analog scale pain ratings (p<0.001). Intraoperative monitoring may allow rapid identification of potential damage of the neural structures and avoidance through corrective action. TcMEP and continuous EMG monitoring is an effective method for monitoring neural function cord during surgical decompression of the lumbar spine and may additionally give prognostic information for the assessment of patient outcome.
[Show abstract][Hide abstract] ABSTRACT: Colloid cysts are rare intracerebral lesions that are predominantly located in the third ventricle. Extraventricular colloid cysts have only rarely been reported but so far there are no reports of a colloid cyst residing in the olfactory groove. A 74-year-old patient underwent a brain computed tomography scan for a mild head trauma that incidentally revealed a space-occupying lesion near the olfactory groove. Brain magnetic resonance imaging that ensued demonstrated a hyperintense lesion in T1, T2, and FLAIR sequences, without evidence of surrounding brain edema. To evaluate the metabolic status of the lesion, brain single-photon emission computed tomography with 99mTc-Tetrofosmin was then performed, revealing no tracer uptake, a finding consistent with benignity. Due to the diagnostic uncertainty the excision of the lesion was proposed. The patient underwent surgery and intraoperative a cyst was revealed. Furthermore the cyst seemed to erode the dura and due to its location there was an imminent danger for cerebrospinal fluid leak. Therefore a repair of the dura was performed and the cyst was excised totally. Histology verified the presence of a colloid cyst. Colloid cysts should be included in the differential diagnosis of lesions in the anterior fossa and although benign they may have an aggressive presentation by eroding the dura and producing CSF leak.