LOGIN | HOME | CONTACT

BIOMEDICAL AND CLINICAL RESEARCH FOCUS AREA

Neurological outcomes and recurrence rates after resection of spinal tumors
This project is a retrospective review of spinal cord tumor resections done at Emory over the past five years. The effort will involve a medical records review of patients who presented with spinal cord tumors and underwent surgical resection. The frequency of each spinal cord tumor type seen in our series of patients and outcomes after surgery by tumor type, including rates of recurrence, will be examined. The piece will be further supplemented by operative nuance commentary provided by the senior spine surgeon on faculty at Emory based on his extensive operative experience with this patient population.

Return to the Top of the Page

Retrospective evaluation of the rate of ventriculitis in neurosurgical patients undergoing external ventricular drain placement in the neuro-intensive care unit
This project’s goal is to retrospectively examine the rate of external ventricular drain (EVD) associated ventriculitis in the Emory Neuroscience ICU. The objective is to determine the rate of ventriculitis in our ICU population and any associated risk factors. The project would involve identifying the patients that have received EVDs over the past few years, determining which ones ultimately went on to develop ventriculitis (in order to arrive at our current incidence or rate of ventriculitis), and abstracting data from the medical records of all the patients that received EVDs over this period of time (those that did and did not develop ventricultitis) in order to identify any factors that may be found to correlate with the occurrence of ventriculitis. This retrospective study would i) be written as a manuscript and published; and ii) inform the design of a prospective study planned on this topic at Emory in the coming year.

Return to the Top of the Page

Determining whether low molecular weight heparin places patients at risk for hemorrhage at the time of external ventricular drain removal
Emory University Hospital is one of the major tertiary care centers for patients with subarachnoid hemorrhage secondary to intracranial aneurysm rupture. Depending on the patient’s clinical grade at the time of admission, a number of these patients require the placement of an external ventricular drain (EVD) in their brain, also known as a ventriculostomy, at the time of their admission or at some point during their hospital course. Ruptured aneurysmal subarachnoid hemorrhage patients that survive their initial bleeds generally have a hospital course of two to three weeks, if not longer, and a large majority of that time is spent on bed rest. This prolonged period of immobility places these patients at substantial risk for deep venous thrombosis, the most dreaded complication of which is a fatal pulmonary embolus. To prophylax against the development of deep venous thrombosis, these patients are placed on a low molecular weight heparin (LMWH) during their hospital stay. At the present time, the bleeding complications related to the use of LMWH in aneurysmal subarachnoid hemorrhage patients requiring EVD placement have not been described. This project will retrospectively investigate whether LMWH contributes to the rare complication of post-EVD removal intracranial hemorrhage. To do this, patients that have had this complication after EVD removal while on a LMWH over the past five years will be identified. The computed tomography (CT) scan records of patients admitted to the neurosurgery service with aneurysmal subarachnoid hemorrhage that have undergone EVD placement will be reviewed. Both patients with and without post-EVD removal hemorrhages will be identified. Those patients without post-EVD removal hemorrhage will serve as a control group of patients. However, those patients without post-EVD removal hemorrhages that were not on a LMWH will be excluded. The mean heparin assay (a test used to follow and adjust LMWH dosing) and the standard deviation of the mean for patients in the post-EVD removal hemorrhage group while on a LMWH and for those patients without a hemorrhage post-EVD removal while on a LMWH will be determined. We hypothesize that the average heparin assay in the post-EVD removal hemorrhage group will be higher and have a larger standard deviation that that of the control group. Confirming or refuting this hypothesis will provide useful and needed insight into the optimal use of LMWH in this patient population in the peri-EVD removal period.

Return to the Top of the Page

Determining the effect of creatinine clearance on low molecular weight heparin dosing in subarachnoid hemorrhage patients.
Emory is a tertiary care center for aneurysmal subarachnoid hemorrhage and is one of the major centers in the nation for the treatment of these patients. Aneurysmal subarachnoid hemorrhage is caused by the rupture of an aneurysm, a weakened area in the wall of an artery, in the brain. Subarachnoid hemorrhage patients are hospitalized for an extended period of time on bed rest and are at risk for thromboembolic complications including deep venous thrombosis and pulmonary embolism, which in the worst case can be fatal. For this reason, these patients are started on low molecular weight heparin (LMWH) for prophylaxis against the development of thromboembolic complications. The best and most appropriate means of following and adjusting LMWH dosing in this patient population is currently unknown. It is believed that LMWH effectiveness should be monitored using a heparin assay to ensure patients are maintained in a therapeutic but not hypertheraputic state. A therapeutic state is one that is believed to effectively prophylax them against thromboembolic complications without subjecting them to an undesirably high risk for bleeding complications. A hypertheraputic state is one that is felt to exceed that which is necessary for effective prophylaxis placing a patient at an undesirable and unnecessary increased risk for bleeding complications. One of the parameters felt to impact LMWH dosing is kidney function. A proxy for kidney function is creatinine clearance. Those patients with poorer kidney function (lower creatinine clearance and therefore higher creatinine) likely do not clear LMWH as readily as patients with better kidney function. This study will investigate the impact of creatinine clearance on LMWH by examining the average heparin assay results in patients with normal creatinine as compared to those with elevated creatinine. The results of this study will better inform physicians on whether monitoring LMWH should be conducted differently in aneurysmal subarachnoid hemorrhage patients with poor kidney function as compared to those with normal kidney function.

Return to the Top of the Page

Safety of hypertensive hypervolemic therapy for vasospasm in aneurysmal subarachnoid hemorrhage patients with additional unruptured, unprotected aneurysms.
Emory is a tertiary care center for aneurysmal subarachnoid hemorrhage and is one of the major centers in the nation for the treatment of these patients. Aneurysmal subarachnoid hemorrhage is caused by the rupture of an aneurysm, a weakened area in the wall of an artery, in the brain. At times, patients that present with this problem not only have a ruptured intracranial aneurysm which caused the subarachnoid hemorrhage but in addition they have other non-ruptured intracranial aneurysms. Generally, shortly after hospital admission, a patient’s ruptured aneurysm is treated by either endovascular coiling or surgical clip ligation. However, for several days after the initial bleed, even though the ruptured aneurysm has been treated, these patients are at risk for a complication called vasospasm (spasm of the muscle in the walls of the brain’s arteries) caused by blood products from the bleed in the brain which irritate the arteries and cause the vasospasm. This vasospasm can result in critical narrowing of the brain arteries which can lead to strokes. One of the treatments for vasospasm is something called hypertensive hypervolemic therapy. Hypertensive hypervolemic therapy is believed to be safe in aneurysmal subarachnoid hemorrhage patients harboring unruptured aneurysms in addition to their ruptured aneurysm after treatment; however, this is not well documented. This project would involve investigating and writing up the Emory experience with hypertensive hypervolemic therapy for vasospasm in this patient population.

Return to the Top of the Page

Examining the incidence of ectopic or hypertrophic bone formation in the neural foramen in transforaminal lumbar interbody fusion procedures in which bone morphogenic protein was used.
Transforaminal lumbar interbody fusion (TLIF) back surgery is done through the posterior (back) part of the spine to treat various conditions including abnormal slippage and motion of the vertebra (spondylolisthesis), degenerative disc disease, or recurrent disc herniations. Surgical hardware is applied to the spine to help enhance the fusion rate. Specifically, pedicle screws and rods are attached to the back of the vertebra and an interbody fusion spacer is inserted into the disc space from one side of the spine. Bone graft is placed into the interbody space and alongside the back of the vertebra to be fused. Bone graft is obtained from the patient’s pelvis, although bone graft substitutes are also sometimes used. As the bone graft heals, it fuses the vertebra above and below and forms one long bone. A TLIF fuses the anterior (front) and posterior (back) columns of the spine through a single posterior approach. The anterior portion of the spine is stabilized by the bone graft and interbody spacer. The posterior column is locked in place with pedicle screws, rods, and bone graft. The TLIF procedure has several theoretical advantages over some other forms of lumbar fusion, including: i) bone fusion is enhanced because bone graft is placed both along the gutters of the spine posteriorly but also in the disc space; ii) a spacer is inserted into the disc space helping to restore normal height and to open up the nerve foramina taking pressure off the nerve roots; and iii) a TLIF procedure allows the surgeon to insert bone graft and a spacer into the disc space from a unilateral approach laterally without having to forcefully retract the nerve roots as much, which may reduce injury and scarring around the nerve roots when compared to some alternative procedures. Often times, bone morphogenic protein (BMP) is used “of label” in TLIF procedures in an attempt to maximize the probability of fusion. BMPs are a group of growth factors and cytokines known for their ability to induce the formation of bone and cartilage. Members of the BMP family are potentially useful as therapeutics in areas such as spinal fusion. BMP-2 and BMP-7 have been shown in clinical studies to be beneficial in the treatment of a variety of bone-related conditions including delayed union (delayed fusion or fracture healing) and non-union (failure of fusion or fracture healing). BMP-7 has FDA approval in certain long bone non-unions where alternatives have failed. BMP-2 has one FDA approved indication; a single-level anteriorly approached lumbar interbody fusion between spinal levels L4 and S1 with a particular implant placed between the two vertebral bodies (the LT-Cage, Medronic Sofamor Danek, Memphis, TN) in degenerative disc disease with up to a grade 1 spondylolisthesis (slippage between two vertebral levels of 25% or less) in non-pregnant skeletally mature patients. However, BMP-2 is widely used “off-label” for unapproved indications in a multitude of spinal fusion procedures, including at times in TLIF procedures as mentioned above. This study will retrospectively examine the incidence of ectopic (occurring in an abnormal position or place) or hypertrophic bone formation (bone overgrowth) in the foramen (an opening between vertebrae through which nerves leave the spine and extend to other parts of the body) in TLIF patients whose procedures were done using BMP in the disc space at the time of surgery. Bony overgrowth into the neural foramen can result in compression of exiting nerve roots causing pain and possibly neurological deficits that require reoperation. This study will provide useful information about the frequency of this phenomenon with the use of BMP in TLIF procedures; it may also offer insights suggesting further investigation is warranted into when BMP should be used in TLIFs and what dose is ideal.

Return to the Top of the Page

Examining the safety, efficacy and fusion rates using bone morphogenic protein in posterolateral spinal fusion procedures.
A posterolateral fusion is a lumbar spine operation often used in the treatment low back pain caused by motion of the vertebrae. The concept is that by removing the motion the pain will be reduced. This abnormal and painful motion can be caused by painful discs (discogenic pain or degenerative disc disease), abnormal slippage and motion of the vertebra (spondylolisthesis or spondylolysis), or other degenerative spinal conditions, including but not limited to facet joint degeneration. A posterolateral fusion can also be used to treat any condition that causes excessive instability of the spine, such as certain fractures, infections, tumors, and spinal deformity (such as scoliosis). In a posterolateral fusion, the disc space is left intact and a bone graft is placed between the transverse processes in the back of the spine. This allows the bone to heal and stabilizes the spine from the transverse process of one vertebra to the transverse process of the next vertebra. When a posterolateral fusion is done, pedicle screws and rods are inserted to stabilize the spine until the bone graft heals. With the rationale that it will improve fusion rates, often times bone morphogenic protein (BMP) is used in posterolateral spinal fusion procedures. BMPs are a group of growth factors and cytokines known for their ability to induce the formation of bone and cartilage. Members of the BMP family are potentially useful as therapeutics in areas such as spinal fusion. BMP-2 and BMP-7 have been shown in clinical studies to be beneficial in the treatment of a variety of bone-related conditions including delayed union (delayed fusion or fracture healing) and non-union (failure of fusion or fracture healing). BMP-7 has FDA approval in certain long bone non-unions where alternatives have failed. BMP-2 has one FDA approved indication; a single-level anteriorly approached lumbar interbody fusion between spinal levels L4 and S1 with a particular implant placed between the two vertebral bodies (the LT-Cage, Medronic Sofamor Danek, Memphis, TN) in degenerative disc disease with up to a grade 1 spondylolisthesis (slippage between two vertebral levels of 25% or less) in non-pregnant skeletally mature patients. However, BMP-2 is widely used “off-label” for unapproved indications in a multitude of spinal fusion procedures. This project will examine the safety, efficacy, and fusion rates when using bone morphogenic protein (BMP) “off-label” with local autologous bone grafting (bone from the patient) in posterolateral fusion procedures.

Return to the Top of the Page

Determining the effectiveness of 100% oxygen in the treatment of pneumocephalus.
Pneumocephalus (intracranial air) is a common consequence of intracranial surgery. In a retrospective review of head computed tomography (CT) scans reported by one group, 100% of the patients examined had pneumocephalus in the first 3 days after craniotomy. Although usually asymptomatic, postoperative pneumocephalus has been linked to a variety of clinical conditions, most commonly headache and lethargy. In severe cases, more serious sequelae can occur including brain herniation or death. To treat pneumocephalus, 100% oxygen is widely used in severe cases to speed the reabsorption of intracranial air when it has been identified on imaging in symptomatic patients. In addition, some institutions routinely administer supplemental oxygen to post operative craniotomy patients. Though this use of 100% oxygen for pneumocephalus is recommended by many neurosurgical textbooks, it has never been clinically proven to be effective. Moreover, the use of 100% oxygen is not benign; in fact, prolonged exposure to elevated levels of oxygen can have adverse side effects, resulting in long-term lung injury that resembles acute respiratory distress syndrome (ARDS). The use of 100% oxygen in the treatment of pneumocephalus is based on a theoretical mathematical model of inert gas absorption. Based on this theoretical model, the proposed mechanism of benefit from 100% oxygen therapy is the replacement of nitrogen with oxygen by increasing the diffusion gradient for nitrogen between the air collection and the surrounding cerebral tissue. Given the potential adverse side effects of the use of 100% oxygen for pneumocephalus, rather than relying solely on a theoretical rationale, it would be valuable to assess clinically whether it is truly an effective treatment or not. If ineffective, then the use of 100% oxygen for this indication may place patients at risk for its potentially severe side effects without any true benefit. This project will retrospectively analyze the effectiveness of treatment with 100% oxygen for the resolution of pneumocephalus assessed radiographically in the Emory neurosurgical patient population.

Return to the Top of the Page

The risk factors, complications, and management outcomes of patients with dialysis-associated spondyloarthropathy
Dialysis-associated spondyloarthropathy (DAS) is a rare cause of cervical spine disease and deformity, and it is often mischaracterized as renal osteodystrophy. It characteristically is believed to be a complication arising from the deposition of beta-2 microglobulin amyloid. The risk factors, complications, and management practices of these patients are poorly-understood. In normal renal function, the protein beta-2 microglobulin is removed from circulation; however, in renal dialysis beta-2 microglobulin accumulates into insoluble fibers called amyloid. Increased levels of beta-2 microglobulin amyloid result in deposition on cartilage surfaces, tendons, and ligaments. Spinal disease, specifically cervical spine disease called cervical arthropathy, occurs by deposition of this amyloid largely in the anterior column and facets of cervical vertebrae, potentially causing cervical spinal cord and nerve root compression, which may cause myriad and severe downstream radicular pain and even neurological deficits. As many of the characteristics of DAS are not well-understood, we propose to: i) author a literature review on cervical disease requiring surgical management in this patient population; and ii) conduct a retrospective study focusing on patients with DAS that ultimately underwent surgery with the purpose of identifying common predisposing risk factors, complications, and management outcomes in the surgical management of this patient population. Specific Aims:

Aim 1: Conduct a retrospective analysis of cervical spine surgery in dialysis patients. This patient population is prone to degenerative pathology of the cervical spine resulting from renal osteodystrophy (ROD) and dialysis associated spondyloarthropathy (DAS) and have to date never been analyzed in a large retrospective series. The primary objective will be to define and investigate the typical presentation, surgical management strategies and outcomes of cervical spine surgery in this patient population.

Aim 2: Synthesize a prototype for a novel neurosurgery patient registry to facilitate this and similar neurosurgery efforts in the future leveraging some existing common data elements (CDEs) representing general electronic health records (EHR) data of general interest for research and quality improvement; Harmonize these general demographic and medical history CDEs with new claims specific and neurosurgery specific CDEs. The end result will be a robust and integration-ready prototype data management system.

Return to the Top of the Page

Determining the effectiveness of simple targeting in deep brain stimulator procedures.
Prior to movement disorder surgery (i.e. for Parkinson’s disease), ‘indirect’ targeting techniques are used to plan a trajectory for the placement of the deep brain stimulator into the desired surgical target such as the subthalamic nucleus (STN) or the globus pallidus interna (GPI). This project will examine the effectiveness of ‘indirect’ targeting answering the following questions: How often is the microelectrode placed in the STN or GPI on the first pass? If the first pass misses the desired target, how often is the microelectrode placed in the desired target on the second pass? How many passes were necessary to hit the desired target? This project requires experience with excel and comfort with i) manipulating a large set of quantitative data; and ii) generating tables and graphs. The student that works with this project will be updating existing data with that from patients that more recently underwent surgery. The writing of the manuscript for this project is in large part complete. Once the new data has been added this manuscript will be very close to being ready for submission.

Return to the Top of the Page

Comparing the accuracy of two techniques used for stereotactic placement of microelectrodes used to identify the appropriate location for deep brain stimulator placement in movement disorder surgery.
Stereotactic techniques are used in movement disorder surgery to precisely place deep brain stimulators into desired surgical targets. At the present time, two different stereotactic set-ups are used at Emory in our movement disorder surgeries. This project will investigate and compare the accuracy of the two techniques and determine the frequency and directionality of any bias (inaccuracy in placement) identified. This project requires experience with excel and comfort with manipulating numerical data and generating tables and graphs.

Return to the Top of the Page

Comparing deep brain stimulator placement versus ablation in movement disorder surgery.
Before the development of deep brain stimulator technology, most movement disorder surgery involved surgical lesioning or ablation of specific brain nuclei. These were successful surgeries and many are still done today with good outcomes in other countries where deep brain stimulator technology is too expensive. Though deep brain stimulators are routinely implanted in patients with movement disorders in the Unites States, they do have some disadvantages when compared to ablation. Deep brain stimulators are surgical implants; thus, as a foreign body there is always the risk of infection of the implant requiring possible removal. In addition, deep brain stimulators require a power source (a battery) which has a limited life and at the present time, when the battery is depleted, replacement requires an additional surgical procedure. Moreover, most magnetic resonance imaging (MRI) facilities will not image patients with deep brain stimulators complicating the diagnosis and work-up of other medical conditions in which MRI imaging would be helpful. Finally, deep brain stimulators are expensive and, therefore, there are patients that that cannot afford these procedures who could alternatively be treated successfully with ablation. Moreover, ballooning healthcare costs continue to be a large problem in the United States. Surgical ablation procedures offer a good alternative to deep brain stimulators with comparable outcomes at a significantly lower cost (particularly if the costs of any complications or reoperations associated with deep brain stimulators are considered). At present we are starting two projects focused in this area.

Return to the Top of the Page

Developing an MRI compatible lead for subthalamic nucleus ablation and a protocol for its use.
This is a bioengineering project involving the development of an MRI compatible lead for controlled lesioning of deep brain nuclei for movement disorder surgery as an alternative to deep brain stimulator placement. It will involve technology development and the development of a protocol for the use of this new technology. This is an innovation in ablation surgery as it would allow for concurrent imaging during lesioning. This technology would potentially improve the accuracy of lesion placement and allow for fine tuning of the size of the lesion. Currently we are exploring development of this device in conjunction with biomedical engineering faculty at Georgia Tech. This project is in early stages, so a student interested in participating in this would likely benefit most from participating throughout the academic year.

Return to the Top of the Page

Parkinson’s patient survey – subthalamic nucleus ablation versus deep brain stimulation.
This project would involve interviewing Parkinson’s patients that have already undergone deep brain stimulator placement to determine whether, after having undergone deep brain stimulator placement, they would consider STN ablation in lieu of deep brain stimulator placement if they were to make the decision again today. The project would involve creating a survey to assess this, mailing the survey out to patients and following up on the survey via phone and in person. It is likely that most data would be collected via phone interview or in person visit (i.e. at a follow up visit or a battery test visit in neurology clinic). In addition to reporting the findings, the manuscript for this project would also involve a discussion on the rationale for ablation as compared to deep brain stimulator placement referring to neuropsychology studies done in deep brain stimulator patients and a discussion about the potential cost and complication differences between therapies (ablation vs. deep brain stimulator).

Return to the Top of the Page

Examining actual versus intended deep brain stimulator electrode placement.
To date, three deceased Parkinson’s patients that previously underwent deep brain stimulator placement at Emory have donated their brains to Emory for research. This provides a unique opportunity to investigate the actual location in which their deep brain stimulators were placed which can then be compared to the location that they were believed to have been placed intraoperatively based on microelectrode mapping. The brains will be i) imaged using Emory’s 3 Tesla magnetic resonance imaging scanner; and ii) Nissel stained and sectioned for histological examination. Doing this will permit the identification of the deep brain nuclei in order to determine the previously implanted electrode’s relative location. This project will be an interesting investigation into the accuracy of intraoperative targeting techniques. One brain to date has been stained and sectioned. The student participating in this project will complete the analysis of the remaining two brains, conduct the comparative analysis and write up a manuscript detailing the results.

Return to the Top of the Page

Quantitative assessment of the relative uptake of FolateScan in non-functioning pituitary tumors.
Pituitary tumors occur in 20 % of the population and make up 10 % of all of intracranial tumors. They cause significant morbidity from compression of regional structures and the inappropriate expression of pituitary hormones. Functional pituitary tumors, which produce specific hormones, can result in life-threatening diseases, infertility and impotence. Non-functional (NF) pituitary tumors, which do not secrete hormones, are the most common pituitary tumors and are typically not life threatening. However, unlike functional pituitary tumors, there is no available effective medical therapy for the NF pituitary tumors. Due to the lack of symptoms from hormonal production, clinically NF pituitary tumors often do not present until there is compression of surrounding regional structures which can result in hypopituitarism or blindness. Surgery to remove these tumors is the treatment of choice but can be challenging because of their proximity to the carotid artery and the optic nerve. Some residual tumor may remain after surgery and patients are at risk of recurrence for several years post surgery. At Emory, it has been demonstrated that folate receptor alpha is significantly over expressed in NF pituitary adenomas but not in functional adenomas (specifically those secreting adrenocorticorticotropic hormone, growth hormone, and prolactin) and this project seeks to exploit this characteristic with a novel diagnostic imaging study. This project aims to quantitatively elucidate how selectively FolateScan (a standard imaging radionuclide, technetium-99m, conjugated to a ligand known as EC20—the vitamin folate—which facilitates binding to folate receptor alpha) is taken up by the pituitary gland (as compared to other intracranial structures) in 80 patients with NF pituitary tumors undergoing FolateScan SPECT/CT scanning (NIH R01 funded project). Selective uptake of FolateScan would suggest that folate receptor alpha may represent a means of delivering targeted chemotherapy or radiopharmaceutical therapy to these tumors with limited side effects. This has the potential to change the management paradigm for NF pituitary tumors by distinguishing a group of these patients whose disease may be amenable to medical management, something that is not an option at the present time. If successful, medical management may prove to be a valuable adjunct to surgical management, or even better, if curative, may become a first line therapy for folate receptor alpha positive NF pituitary tumor patients preventing the need for surgical intervention all together and sparing the patient the associated risks and potential morbidity of surgery. Specifically, this project will entail determining the relative uptake of FolateScan on SPECT/CT imaging comparing uptake in the NF pituitary tumor as compared with that in other intracranial structures in each patient.

Return to the Top of the Page

Determining whether the clinical characteristics differ among three subgroups of non-functional pituitary adenoma patients believed to have different “molecular fingerprints” based on prior gene expression profiling and proteomic analysis.
Pituitary adenomas comprise 10% of intracranial tumors and occur in about 20% of the population. They can cause significant morbidity by compressing adjacent regional structures. Their molecular pathogenesis is unclear and the current classification of clinically nonfunctional (NF) pituitary tumors does not reflect any molecular distinctions between the subtypes. To further elucidate the molecular changes that contribute to the development of these tumors and reclassify them according to the molecular basis, 11 NF pituitary adenomas and eight normal pituitary glands were investigated, using 33 oligonucleotide GeneChip microarrays. Microarray results were validated with the reverse transcription real-time quantitative PCR, using a larger number of NF adenomas. Proteomic analysis was also used to examine protein expression in these nonfunctional adenomas. The gene expression profiles of all nonfunctional pituitary subtypes were compared and genes that were unique in each subtype were identified. The results, published in Cancer Research, showed three distinct gene and protein expression patterns or “molecular fingerprints” in: i) NF tumors with immunohistochemistry (IHC) positive for luteinizing hormone (LH+) only; ii) NF tumors with IHC positive for follicle stimulating hormone (FSH) only; and iii) NF tumors with negative IHC (NF-), providing new insight into the pathogenesis and molecular classification of nonfunctional pituitary adenomas. With the assumption that these findings can be generalized to all NF pituitary tumors that share the same IHC properties, this investigation will determine whether these molecularly unique NF pituitary tumor subgroups have any clinically distinct characteristics. The clinical characteristics of patients with LH+, FSH+, and NF- IHC will be compared and any differences will be identified.

Return to the Top of the Page