Kimberly Thill

The role of regulatory T-cells in glioma immunology.

Despite recent advances in treatment, the prognosis for glioblastoma multiforme (GBM) remains poor. The lack of response to treatment in GBM patients may be attributed to the immunosuppressed microenvironment that is characteristic of invasive glioma. Regulatory T-cells (Tregs) are immunosuppressive T-cells that normally prevent autoimmunity when the human immune response is evoked; however, there have been strong correlations between glioma-induced immunosuppression and Tregs. In fact, induction of Treg activity has been correlated with glioma development in both murine models and patients. While the exact mechanisms by which regulatory T-cells function require further elucidation, various cytokines such as interleukin-10 (IL-10) and transforming growth factor-β (TFG-β) have been implicated in these processes and are currently under investigation. In addition, hypoxia is characteristic of tumor development and is also correlated with downstream induction of Tregs. Due to the poor prognosis associated with immunosuppression in glioma patients, Tregs remain a promising area for immunotherapeutic research.

Clinical outcomes of middle fossa craniotomy for superior semicircular canal dehiscence repair

OBJECTIVE Superior semicircular canal dehiscence (SSCD) is a rare disorder characterized by the formation of a third opening in the inner ear between the superior semicircular canal and the middle cranial fossa. Aberrant communication through this opening causes a syndrome of hearing loss, pulsatile tinnitus, disequilibrium, and autophony. This study analyzed the clinical outcomes of a single-institution series of patients with SSCD undergoing surgical repair by the same otolaryngologist and neurosurgeon. METHODS All patients who underwent SSCD repair at the University of California, Los Angeles, between March 2011 and November 2014 were included. All patients had their SSCD repaired via middle fossa craniotomy by the same otolaryngologist and neurosurgeon. Outcomes were analyzed with Fishers exact test. RESULTS A total of 18 patients with a mean age of 56.2 years (range 27-84 years) and an average follow-up of 5.0 months (range 0.2-21.8 months) underwent 21 cases of SSCD repair. Following treatment, all patients (100%) reported resolution in ≥ 1 symptom associated with SSCD. Autophony (p = 0.0005), tinnitus (p = 0.0059), and sound- and/or pressure-induced dizziness (p = 0.0437) showed significant symptomatic resolution. Following treatment, 29% (2/7) of patients developed imbalance, 20% (1/5) of patients developed sound- and/or pressure-induced dizziness, and 18% (2/11) of patients developed aural fullness. Among patients with improved symptoms following surgical repair, none reported recurrence of symptoms at subsequent follow-up visits. CONCLUSIONS SSCD remains an underdiagnosed and undertreated condition. Surgical repair of SSCD using a middle fossa craniotomy is associated with a high rate of symptom resolution. Continued investigation using a larger patient cohort and longer-term follow-up could further demonstrate the effectiveness of using middle fossa craniotomy for SSCD repair.

Clinical Manifestations of Central Neurocytoma

Central neurocytomas (CNs) are rare central nervous system tumors that occur in the lateral ventricles. They are prevalent in young adults and are typically benign with excellent prognosis following surgical resection. Because of the rarity of the disease and its similar features with more common tumors, misdiagnosis becomes an issue. Optimal treatment is achieved only when the correct tumor types are distinguished. Typical clinical manifestations include symptoms of increased intracranial pressure, although no clinical feature is pathognomonic to CN. Radiologic imaging, histology, magnetic resonance spectroscopy, and immunohistochemistry must be used to elucidate tumor characteristics and properly diagnose CN.

Characteristics and treatments of large cystic brain metastasis: radiosurgery and stereotactic aspiration.

Brain metastasis represents one of the most common causes of intracranial tumors in adults, and the incidence of brain metastasis continues to rise due to the increasing survival of cancer patients. Yet, the development of cystic brain metastasis remains a relatively rare occurrence. In this review, we describe the characteristics of cystic brain metastasis and evaluate the combined use of stereotactic aspiration and radiosurgery in treating large cystic brain metastasis. The results of several studies show that stereotactic radiosurgery produces comparable local tumor control and survival rates as other surgery protocols. When the size of the tumor interferes with radiosurgery, stereotactic aspiration of the metastasis should be considered to reduce the target volume as well as decreasing the chance of radiation induced necrosis and providing symptomatic relief from mass effect. The combined use of stereotactic aspiration and radiosurgery has strong implications in improving patient outcomes.

A Systematic Analysis of the Reliability of Diffusion Tensor Imaging Tractography for Facial Nerve Imaging in Patients with Vestibular Schwannoma

Surgeons need to visualize the facial nerve reliably in relation to the vestibular schwannoma (VS) in surgical planning. Diffusion tensor imaging (DTI) tractography has enabled unprecedented in vivo preoperative visualization. We collected data to measure the accuracy of DTI for an accurate location of the nerve in preoperative VS resection planning. A PubMed search for relevant studies was conducted. Inclusion criteria were gross total resection of VS, preoperative DTI identification of the facial nerve, and intraoperative cranial nerve localization by the surgeon. Exclusion criteria were tumors other than VS and unsuccessful preoperative location of the cranial nerve. Accuracy rate was calculated by comparing the intraoperative and preoperative locations detailed by DTI. The query identified 38 cases of VS that fit our inclusion criteria. Overall, 89% had surgical findings that agreed with the DTI location of the facial nerve. Of these cases, 32 patients had a postoperative House-Brackmann grade I or II. Our findings suggest that DTI is a reliable method for facial nerve imaging. Implementation of this technique may help decrease facial nerve injury during surgery. Limitations and further studies are needed to better understand what factors correlate with successful location of the facial nerve and DTI in patients with VS.

Clinical characteristics and diagnostic imaging of cranial osteoblastoma

Benign osteoblastoma is a rare, vascular, osteoid-forming bone tumor that occurs even less frequently in the cranial bones. Benign osteoblastoma of the cranium affects women slightly more often than men and typically presents in the first three decades of life. Although clinical presentation can vary depending on location, cranial osteoblastoma usually presents as a painful, non-mobile, subcutaneous mass or swelling. On CT scan, it generally presents as a well-demarcated, mixed lytic and sclerotic lesion, with enlarged diploe, thinning outer and/or inner tables, and varying degrees of calcification. It is hypo to isointense on T1-weighted MRI and has variable presentation on T2-weighted MRI. Gross total resection is the definitive treatment, while subtotal resection is utilized when it is necessary to preserve critical adjacent neurovascular structures.

Systematic Analysis of Outcomes for Surgical Resection and Radiotherapy in Patients with Papillary Meningioma.

Introduction Papillary meningiomas (PMs) are characterized by their aggressive nature and high rate of recurrence. Due to their rarity, studies examining the relationship between treatment and clinical outcomes for this disease are limited. Gross total resection (GTR) with or without radiotherapy (RT) is considered the standard treatment; however, when GTR is not feasible, subtotal resection (STR) followed by RT may be an effective alternative. In this study, we analyzed the clinical outcomes in patients who either underwent GTR alone, GTR followed by RT, STR alone, or STR followed by RT. Methods A systematic analysis was performed to identify PM patients with sufficient follow-up and outcome data, as measured by recurrence. Patient data lacking extent of resection, follow-up, or recurrence information were excluded. Results A total of 29 patients with PM were treated with resections (23 GTRs and 6 STRs).The mean age and mean follow-up of patients in this study were 32.3 years and 42.1 months, respectively. Of these patients, 58.6% experienced recurrence. Overall, 47.8% of patients who underwent GTR experienced recurrence. These patients also demonstrated improved survival compared with STR. Among patients whose tumors were only partially excised, a recurrence rate of 83% was observed. Conclusion Our results confirm that GTR results in fewer recurrences compared with STR, supporting GTR as the treatment of choice for PM. Furthermore, GTR in conjunction with RT resulted in improved survival compared with GTR alone. When GTR was not feasible, STR with RT was associated with improved survival compared with STR alone. Future studies with more outcome data are needed to elucidate the optimal treatment for this rare disease.