Search Results

You are looking at 1 - 10 of 23 items for

  • Author or Editor: Albert H. Kim x
Clear All Modify Search
Restricted access

Timing of surgical stabilization after cervical and thoracic trauma

Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004

Todd J. Albert and David H. Kim

✓ Appropriate timing for surgical intervention following destabilizing cervical or thoracic spine trauma remains controversial. Clinical investigators have failed to provide convincing evidence that the timing of surgery significantly affects neurological outcome in most situations. Nevertheless, early surgical stabilization of the injured spine has been shown to provide significant nonneurological benefits such as more rapid patient mobilization, facilitation of treating associated injuries, reduction in rates of pulmonary and pressure sore complications, reduction in duration of intensive care unit and hospital stays, and a decrease in overall medical costs.

The findings of basic science studies have improved our understanding of the molecular and cellular events surrounding initial and secondary spinal cord injury (SCI), and analysis of these findings suggests that the early postinjury period may present a unique opportunity for meaningful intervention. This possibility has been supported by results obtained in animal studies that demonstrate the potential for improving functional outcome when surgical intervention is performed within a few hours following experimental SCI. Despite the absence of significant neurological recovery in most clinical studies, the results of most recent clinical studies strongly support the overall clinical benefits of early surgical intervention, particularly in the setting of unstable thoracic spinal column injury with associated SCI. Based on the best available scientific and clinical evidence, the authors report that it is therefore recommended that surgical stabilization be performed in as timely a fashion as possible, particularly for unstable thoracic spine trauma, within the constraints of the patient's overall medical condition and availability of appropriate resources.

Free access

Sam Q. Sun, Ammar H. Hawasli, Jiayi Huang, Michael R. Chicoine and Albert H. Kim

The management of WHO Grade II “atypical” meningiomas (AMs) and Grade III “malignant” meningiomas (MMs) remains controversial and under-investigated in prospective studies. The roles of surgery, radiation therapy, radiosurgery, and chemotherapy have been incompletely delineated. This has left physicians to decipher how they should treat patients on a case-by-case basis. In this study, the authors review the English-language literature on the management and clinical outcomes associated with AMs and MMs diagnosed using the WHO 2000/2007 grading criteria. Twenty-two studies for AMs and 7 studies for MMs were examined in detail. The authors examined clinical decision points using the literature and concepts from evidence-based medicine. Acknowledging the retrospective nature of the studies concerning AM and MM, the authors did find evidence for the following clinical strategies: 1) maximal safe resection of AM and MM; 2) active surveillance after gross-total resection of AM; 3) adjuvant radiation therapy after subtotal resection of AM, especially in the absence of putative radioresistant features; and 4) adjuvant radiation therapy after resection of MM.

Free access

Carl D. Hacker, Jarod L. Roland, Albert H. Kim, Joshua S. Shimony and Eric C. Leuthardt

Resting-state functional MRI (rs-fMRI) is a well-established method for studying intrinsic connectivity and mapping the topography of functional networks in the human brain. In the clinical setting, rs-fMRI has been used to define functional topography, typically language and motor systems, in the context of preoperative planning for neurosurgery. Intraoperative mapping of critical speech and motor areas with electrocortical stimulation (ECS) remains standard practice, but preoperative noninvasive mapping has the potential to reduce operative time and provide functional localization when awake mapping is not feasible. Task-based fMRI has historically been used for this purpose, but it can be limited by the young age of the patient, cognitive impairment, poor cooperation, and need for sedation. Resting-state fMRI allows reliable analysis of all functional networks with a single study and is inherently independent of factors affecting task performance. In this review, the authors provide a summary of the theory and methods for resting-state network mapping. They provide case examples illustrating clinical implementation and discuss limitations of rs-fMRI and review available data regarding performance in comparison to ECS. Finally, they discuss novel opportunities for future clinical applications and prospects for rs-fMRI beyond mapping of regions to avoid during surgery but, instead, as a tool to guide novel network-based therapies.

Free access

David Y. A. Dadey, Ashwin A. Kamath, Matthew D. Smyth, Michael R. Chicoine, Eric C. Leuthardt and Albert H. Kim

OBJECTIVE

The precision of laser probe insertion for interstitial thermal therapy of deep-seated lesions is limited by the method of stereotactic guidance. The objective of this study was to evaluate the feasibility of customized STarFix 3D-printed stereotactic platforms to guide laser probe insertion into mesiotemporal and posterior fossa targets.

METHODS

The authors conducted a retrospective review of 5 patients (12–55 years of age) treated with laser interstitial thermal therapy (LITT) in which STarFix platforms were used for probe insertion. Bone fiducials were implanted in each patient's skull, and subsequent CT scans were used to guide the design of each platform and incorporate desired treatment trajectories. Once generated, the platforms were mounted on the patients' craniums and used to position the laser probe during surgery. Placement of the laser probe and the LITT procedure were monitored with intraoperative MRI. Perioperative and follow-up MRI were performed to identify and monitor changes in target lesions.

RESULTS

Accurate placement of the laser probe was observed in all cases. For all patients, thermal ablation was accomplished without intraoperative complications. Of the 4 patients with symptomatic lesions, 2 experienced complete resolution of symptoms, and 1 reported improved symptoms compared with baseline.

CONCLUSIONS

Customized stereotactic platforms were seamlessly incorporated into the authors' previously established LITT workflow and allowed for accurate treatment delivery.

Restricted access

Albert H. Kim, Manish K. Kasliwal, Brendan McNeish, V. Michelle Silvera, Mark R. Proctor and Edward R. Smith

Object

Spinal cord tethering due to a thickened filum terminale is a well-described entity that can be treated surgically. Postoperative MR imaging of the lumbar spine is performed for unrelated issues or for the development of new symptoms suggestive of cord retethering. A lack of radiological criteria for successful detethering makes interpretation of postoperative MR images challenging. The delineation of postoperative radiological characteristics of a sectioned filum terminale is therefore valuable to clinicians managing these often complex cases.

Methods

The clinical data for 16 patients who underwent sectioning of a fatty and thickened filum between 2001 and 2010 and in whom pre- and postoperative MR imaging studies were available were analyzed. Medical records were interrogated for preoperative neurological examination, operative details, and postoperative follow-up. The MR images were examined by both a neurosurgeon and a neuroradiologist to assess postoperative radiological characteristics.

Results

The patients' age at time of surgery ranged from 0.3 to 19.8 years (mean 7.5 years). Postoperative MR imaging was performed between 0.03 and 7.36 years after the procedure (mean 2.5 years). Indications for postoperative imaging included new neurological symptoms (11 of 16 patients), routine interval imaging (3 of 16), and possible development of pseudomeningocele (2 of 16). Filum discontinuity was confirmed in 79% of cases postoperatively. Filum remnants appeared thicker after surgery in most cases (80%), a phenomenon most often appreciated in the cephalad end of the sectioned filum. Postoperatively, the conus was elevated in 5 cases (31%) and was found to be more ventrally located in 7 cases (44%).

Conclusions

Discontinuity, along with thickening of the upper and lower remnants of a sectioned filum, may constitute important radiological features of a detethered filum. Radiological signs of conus relaxation, signified by elevation or a more ventral position, although reassuring, were less reliably observed postoperatively. Because it may be difficult to know if the goals of surgery were met on purely clinical grounds in this patient population, knowledge of the postoperative characteristics of a sectioned filum may aid the practicing neurosurgeon in the management of these complex cases.

Free access

Diane J. Aum, David H. Kim, Thomas L. Beaumont, Eric C. Leuthardt, Gavin P. Dunn and Albert H. Kim

There has been increasing awareness that glioblastoma, which may seem histopathologically similar across many tumors, actually represents a group of molecularly distinct tumors. Emerging evidence suggests that cells even within the same tumor exhibit wide-ranging molecular diversity. Parallel to the discoveries of molecular heterogeneity among tumors and their individual cells, intense investigation of the cellular biology of glioblastoma has revealed that not all cancer cells within a given tumor behave the same. The identification of a subpopulation of brain tumor cells termed “glioblastoma cancer stem cells” or “tumor-initiating cells” has implications for the management of glioblastoma. This focused review will therefore summarize emerging concepts on the molecular and cellular heterogeneity of glioblastoma and emphasize that we should begin to consider each individual glioblastoma to be an ensemble of molecularly distinct subclones that reflect a spectrum of dynamic cell states.

Free access

Judith M. Wong, John E. Ziewacz, Allen L. Ho, Jaykar R. Panchmatia, Albert H. Kim, Angela M. Bader, B. Gregory Thompson, Rose Du and Atul A. Gawande

Object

As part of a project to devise evidence-based safety interventions for specialty surgery, we sought to review current evidence concerning the frequency of adverse events in open cerebrovascular neurosurgery and the state of knowledge regarding methods for their reduction. This review represents part of a series of papers written to consolidate information about these events and preventive measures as part of an ongoing effort to ascertain the utility of devising system-wide policies and safety tools to improve neurosurgical practice.

Methods

The authors performed a PubMed search using search terms “cerebral aneurysm”, “cerebral arteriovenous malformation”, “intracerebral hemorrhage”, “intracranial hemorrhage”, “subarachnoid hemorrhage”, and “complications” or “adverse events.” Only papers that specifically discussed the relevant complication rates were included. Papers were chosen to be included to maximize the range of rates of occurrence for the reported adverse events.

Results

The review revealed hemorrhage-related hyperglycemia (incidence rates ranging from 27% to 71%) and cerebral salt-wasting syndromes (34%–57%) to be the most common perioperative adverse events related to subarachnoid hemorrhage (SAH). Next in terms of frequency was new cerebral infarction associated with SAH, with a rate estimated at 40%. Many techniques are advocated for use during surgery to minimize risk of this development, including intraoperative neurophysiological monitoring, but are not universally used due to surgeon preference and variable availability of appropriate staffing and equipment. The comparative effectiveness of using or omitting monitoring technologies has not been evaluated.

The incidence of perioperative seizure related to vascular neurosurgery is unknown, but reported seizure rates from observational studies range from 4% to 42%. There are no standard guidelines for the use of seizure prophylaxis in these patients, and there remains a need for prospective studies to support such guidelines.

Intraoperative rupture occurs at a rate of 7% to 35% and depends on aneurysm location and morphology, history of rupture, surgical technique, and surgeon experience. Preventive strategies include temporary vascular clipping.

Technical adverse events directly involving application of the aneurysm clip include incomplete aneurysm obliteration and parent vessel occlusion. The rates of these events range from 5% to 18% for incomplete obliteration and 3% to 12% for major vessel occlusion. Intraoperative angiography is widely used to confirm clip placement; adjuncts include indocyanine green video angiography and microvascular Doppler ultrasonography. Use of these technologies varies by institution.

Discussion

A significant proportion of these complications may be avoidable through development and testing of standardized protocols to incorporate monitoring technologies and specific technical practices, teamwork and communication, and concentrated volume and specialization. Collaborative monitoring and evaluation of such protocols are likely necessary for the advancement of open cerebrovascular neurosurgical quality.

Free access

Ammar H. Hawasli, Albert H. Kim, Gavin P. Dunn, David D. Tran and Eric C. Leuthardt

Evolving research has demonstrated that surgical cytoreduction of a high-grade glial neoplasm is an important factor in improving the prognosis of these difficult tumors. Recent advances in intraoperative imaging have spurred the use of stereotactic laser ablation (laser interstitial thermal therapy [LITT]) for intracranial lesions. Among other targets, laser ablation has been used in the focal treatment of high-grade gliomas (HGGs). The revived application of laser ablation for gliomas parallels major advancements in intraoperative adjuvants and groundbreaking molecular advances in neuro-oncology. The authors review the research on stereotactic LITT for the treatment of HGGs and provide a potential management algorithm for HGGs that incorporates LITT in clinical practice.

Restricted access

Ganesh M. Shankar, Li Chen, Albert H. Kim, Gina L. Ross, Rebecca D. Folkerth and Robert M. Friedlander

Extraadrenal paragangliomas are most commonly found in the carotid body and are also found with lower frequency in the CNS. These lesions are derived from the sympathoadrenal lineage of neural crest cells. Here, the authors report a rare case of a composite paraganglioma with ganglioneuromatous components found at the filum terminale in a patient who presented with a brief history of low-back pain and paresthesias in the inguinal region. Immunohistochemical analysis of the resected lesion revealed admixed elements of neuroendocrine and neuroblastoma lineages, indicating the presence of divergent differentiation of sympathoadrenal progenitor cells. This case represents a unique opportunity to understand the cell fate of sympathoadrenal progenitor cells. Here, the authors propose that paragangliomas at the filum terminale can revert to a neural crest cell precursor fate, giving rise to divergent neoplastic populations.