Journal of neurosurgery
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Journal of neurosurgery · Feb 2012
Case ReportsAn episode of severely suppressed electrocerebral activity recorded by electroencephalography during endoscopic resection of a colloid cyst.
Intraoperative neuromonitoring utilizing electroencephalography (EEG) is rarely performed during neuroendoscopy. The authors present a case in which this monitoring modality was used for a patient with a colloid cyst in preparation for an open craniotomy should an endoscopic approach fail. ⋯ Although they describe a transient phenomenon that resulted in no residual cognitive or neurological deficits, the importance of cautious introduction of ventricular irrigation, the need to carefully monitor intracranial pressure during neuroendoscopic procedures, and the need to pay close attention to irrigation temperature and composition should not be underestimated. Additional studies regarding the utility of EEG in alerting neurosurgeons to adverse electrical cerebral activity during neuroendoscopy are warranted.
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Neuromuscular choristoma (NMC) is a rare peripheral nerve lesion in which mature skeletal muscle fibers lie within the nerve and its fascicles. Given limited follow-up, its natural history is poorly understood. The occurrence of aggressive fibromatosis in one of the authors' patients and its occurrence in reported cases suggests an etiological relationship between the 2 lesions. This study attempts to explain the association and its frequency. ⋯ This study confirms that the development of aggressive fibromatosis in patients with NMC has been underreported. A direct relationship between the NMC and the development of aggressive fibromatosis is suggested by pathological and neuroimaging evidence.
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Journal of neurosurgery · Feb 2012
Meta AnalysisAtypia predicting prognosis for intracranial extraventricular neurocytomas.
The literature, at present, provides limited information about extraventricular neurocytomas (EVNs) and is almost exclusively composed of case reports or small case series. Treatment for EVNs has largely been guided by results from central neurocytoma outcome studies. The authors present an analysis of all reported intracranial EVN cases to establish if tumor histopathological features can substratify EVN into groups with differing prognosis and help guide treatment decisions. ⋯ There are at least 2 distinct histological subtypes of EVN, with different prognostic significances. Atypia or MIB-1 labeling index greater than 3% is a significant predictor of poor prognosis for EVNs. Complete resection or more aggressive attempts at providing adjuvant therapy following STR appear to improve the prognosis for patients with EVNs. Although the authors' results are informative, there are limitations to their analysis. Given the relatively modest total number of cases reported, as well as the nature of the disaggregated analysis, the authors were not able to use formal meta-analytical methods to limit the impact of between center heterogeneity. Additionally, they were not able to control for individual differences in data analysis and presentation across the different studies included in their analysis.
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Journal of neurosurgery · Feb 2012
Prospective evaluation of the characteristics and incidence of adenoma-associated dural invasion in Cushing disease.
Dural invasion by adrenocorticotropic hormone (ACTH)-secreting adenomas is a significant risk factor for incomplete resection and recurrence in Cushing disease (CD). Since ACTH-producing adenomas are often the smallest of the various types of pituitary tumors at the time of resection, examining their invasion provides the best opportunity to identify the precise sites of early dural invasion by pituitary adenomas. To characterize the incidence and anatomical distribution of dural invasion by ACTH-secreting adenomas, the authors prospectively and systematically analyzed features of dural invasion in patients with CD. ⋯ Dural invasion by ACTH-producing adenomas preferentially occurs laterally into the wall of the cavernous sinus. Preoperative MR imaging infrequently detects dural invasion, including cavernous sinus invasion. Invasion is directly associated with tumor size. To provide a biochemical cure and avoid recurrence after resection, identification and removal of invaded sella dura, including the medial cavernous sinus wall, are necessary.
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Journal of neurosurgery · Feb 2012
Case ReportsCraniovertebral junction abnormalities with hindbrain herniation and syringomyelia: regression of syringomyelia after removal of ventral craniovertebral junction compression.
Hindbrain herniation syndrome, or Chiari malformation Type I (CM-I), occurs frequently with craniovertebral junction (CVJ) abnormalities when there is reduction in the posterior fossa volume. Syringomyelia is often present. Posterior fossa dorsal decompression (PFDD) is typically performed but has adverse results when ventral bone abnormality exists. This paper presents the results of a prospective study on CVJ abnormalities in patients with CM-I and syringomyelia. ⋯ Neurological improvement and syringomyelia resolution can occur using only ventral cervicomedullary junction decompression in patients with basilar invagination and basilar impression. This is likely due to the relief of neural encroachment and reestablishment of CSF pathways.