Search Results

You are looking at 1 - 10 of 25 items for

  • Author or Editor: Vivek Mehta x
  • Refine by Access: all x
Clear All Modify Search
Full access

Grace Lam, Vivek Mehta, and Gabriel Zada

Object

Spontaneous and medically induced CSF leaks are uncommonly associated with pituitary adenomas. The aim of this study was to further characterize the clinical scenarios most closely associated with this phenomenon.

Methods

A review of the literature was conducted to identify all cases of nonsurgical CSF leaks associated with pituitary adenomas. The authors aimed to identify associated risk factors and management strategies used to treat these tumors and repair the CSF leak site.

Results

Fifty-two patients with spontaneous or medically induced CSF leaks in the setting of a pituitary adenoma were identified from 29 articles published from 1980 through 2011. In 38 patients (73%), CSF rhinorrhea developed following initiation of medical therapy, whereas spontaneous CSF leakage developed as the presenting symptom in 14 patients (27%). The patients' mean age was 42.8 years (range 23–68 years). There were 35 males and 17 females. Forty-two patients (81%) had a prolactinoma, with the remaining patients having the following tumors: nonfunctioning pituitary adenoma (6 patients), growth hormone–secreting adenoma (2 patients), mammosomatotroph cell adenoma (1 patient), and ACTH-secreting adenoma (1 patient). Infrasellar tumor invasion into the paranasal sinuses was specifically reported in 56% of patients. The medical agents associated with CSF leakage were dopamine agonists (97%) and somatostatin analogs (3%). The average time from initialization of medical treatment to onset of rhinorrhea was 3.3 months (range 3 days–17 months). Nonsurgical management was successful in 4 patients, including 1 who had successful resolution with a temporary lumbar drain. Forty-six patients (88%) underwent surgical intervention to treat the CSF leak and/or resect the tumor. In 2 patients, surgery was not performed due to medical contraindications or patient preference.

Conclusions

Nonsurgical development of CSF rhinorrhea may occur in the setting of pituitary adenomas, especially following favorable response of invasive prolactinomas to initiation of dopamine agonist therapy. Additional cases have been reported as the presenting symptom of a pituitary adenoma and are likely to be related to decreased tumor volume due to intrinsic infarction or hemorrhage, ongoing invasion, and/or increases in intracranial pressure. Surgical repair, preferentially via a transsphenoidal approach, is the recommended initial treatment for definitive repair of the CSF leak and achievement of maximal tumor resection.

Restricted access

Vivek A. Mehta, Chetan Bettegowda, and George I. Jallo

Tumoral calcinosis (TC), a calcium hydroxyapatite–based mass, is common in the extremities and hips, but has rarely been reported in the spine, and has never been reported within the spinal cord. It may occur sporadically, in familial form, or as a consequence of disorders that promote soft-tissue calcification. Gross-total resection appears to be curative, but the diagnosis of TC is rarely considered prior to surgery. In this report, the authors describe the management of the first case of intramedullary TC located at the T-5 level in a 20-month-old boy who presented with lower-extremity spasticity. Additionally, salient features of the TC diagnosis, radiological patterns, histological findings, treatment, and outcomes are discussed.

Free access

Vivek Mehta, Joshua Bakhsheshian, Amir H. Dorafshar, and Edward S. Ahn

The authors describe the case of a boy with Muenke syndrome, an autosomal dominant disorder associated with craniosynostosis. The family history was significant for syndromic craniosynostosis in the patient’s maternal grandmother, who died in adulthood after a craniofacial reconstruction. The patient, her grandson, underwent craniofacial reconstruction surgery at the age of 9 months and developed upward transtentorial herniation. Imaging findings revealed remote cerebellar hemorrhage after a large quantity of supratentorial CSF was drained during postoperative Day 1. The clinical course was further complicated by cerebral sinus thrombosis, which was diagnosed after a fourth surgical procedure. Upward transtentorial herniation can occur when a significant increase in intracranial pressure in the posterior fossa causes displacement of the central lobule and superior surfaces of the cerebellum upward through the incisura tentorii. This is a rare but well-documented phenomenon that commonly occurs in the setting of an expansive posterior fossa lesion or excessive supratentorial CSF loss. To help clinicians recognize and prevent this rare but potentially fatal complication, the authors review the postulated mechanisms by which this process may occur.

Free access

Amit Persad, Keith Aronyk, Wendy Beaudoin, and Vivek Mehta

OBJECTIVE

Surgical treatment of sagittal synostosis involves various surgical modalities. Long-term follow-up issues include increased intracranial pressure, secondary sutural fusion, incomplete reossification, and suboptimal cosmetic appearance. The authors’ objective in this study was to review their long-term endoscopic surgical results in children with sagittal synostosis using 3D CT.

METHODS

The authors reviewed the long-term results of their first 38 patients who underwent endoscopic sagittal synostosis repair at age 16 weeks or younger. A standard vertex craniectomy with biparietal wedges was done in each case. After surgery, the children were fitted with a helmet, which they wore until 8 months of age. Patients were followed up for 5 years or longer, at which point a 3D CT scan was obtained. The authors examined data on the cranial index, area of bony defect, presence or absence of secondary sutural fusion, neosuture formation, and scalloping of the inner table of the skull.

RESULTS

Thirty-two of 38 children met inclusion criteria. There was a small but significant recession of the cranial index after the completion of helmeting (from 0.772 after completion of helmeting to 0.755 at 5 years). Of 32 children, 14 had a bony defect area > 4 cm2. Three children had secondary sutural fusion (two unilateral coronal, one bicoronal). Ten of 32 patients had partial neosuture formation.

CONCLUSIONS

The authors report their experience with 32 of their first 38 children who underwent endoscopic sagittal synostosis repair at 16 weeks of age or younger. With a minimum duration of 5 years, this is the longest clinicoradiological follow-up utilizing 3D CT to date in children with sagittal synostosis treated with endoscopic surgery. The authors report detailed measurements of bony loss, adjacent sutural fusion, and neosuture formation.

Full access

Vivek Mehta, Murray Hong, Julian Spears, and Ivar Mendez

The goal of this study was to investigate the ability of fetal dopaminergic neurons to improve complex sensorimotor behavior.

The authors obtained ventral mesencephalic tissue from 14-day-old rat fetuses. The cells were exposed to glial cell line-derived neurotrophic factor (GDNF) prior to transplantation into rats with unilateral 6-hydroxydopamine lesions of the dopaminergic nigrostriatal pathway. Animals that received 400,000 cells exposed to GDNF demonstrated significant improvement in contralateral forelimb function and showed improvement in rotational behavior faster than animals that received cells not exposed to GDNF. Increasing the number of implanted cells to 800,000 exposed to GDNF did not result in any additional improvement in functional recovery.

As neural grafting procedures in the nervous system evolve and genetically engineered cells or stem cells replace fetal tissue, crucial questions about cell number and trophic regulation will need to be addressed. This study demonstrates that grafting of 400,000 cells exposed to GDNF before transplantation has a beneficial effect in the restoration of complex sensorimotor behavior.

Restricted access

Jonathan Loree, Vivek Mehta, and Ravi Bhargava

In this report, the authors illustrate the potential shortfalls of early postoperative MR imaging following resection of a posterior fossa tumor. The authors present the cases of a 10-month-old boy and a 14-year-old boy with posterior fossa tumors that were surgically resected and monitored immediately postoperatively with MR imaging. The MR imaging study obtained immediately postresection while the children were still anesthetized revealed enhancing elements in both patients, which were suggestive of leptomeningeal metastases. When this signal was followed on subsequent MR images, it was no longer visible. The patients are both recurrence free at the time of this publication. These cases demonstrate that early postoperative MR imaging findings for leptomeningeal metastases may be unreliable after excision of posterior fossa tumors and may have potential implications for intraoperative MR imaging techniques currently under development.

Restricted access

Vivek Mehta, Murray Hong, Julian Spears, and Ivar Mendez

Object. The goal of this study was to investigate the ability of fetal dopaminergic neurons to improve complex sensorimotor behavior.

Methods. The authors obtained ventral mesencephalic tissue from 14-day-old rat fetuses. The cells were exposed to glial cell line—derived neurotrophic factor (GDNF) prior to transplantation into rats with unilateral 6-hydroxydopamine lesions of the dopaminergic nigrostriatal pathway. Animals that received 400,000 cells exposed to GDNF demonstrated significant improvement in contralateral forelimb function and showed improvement in rotational behavior faster than animals that received cells not exposed to GDNF. Increasing the number of implanted cells to 800,000 exposed to GDNF did not result in any additional improvement in functional recovery.

Conclusions. As neural grafting procedures in the nervous system evolve and genetically engineered cells or stem cells replace fetal tissue, crucial questions about cell number and trophic regulation will need to be addressed. This study demonstrates that grafting of 400,000 cells exposed to GDNF before transplantation has a beneficial effect in the restoration of complex sensorimotor behavior.

Full access

Vivek A. Mehta, Chetan Bettegowda, George I. Jallo, and Edward S. Ahn

Craniosynostosis, the premature closure of cranial sutures, has been known to exist for centuries, but modern surgical management has only emerged and evolved over the past 100 years. The success of surgery for this condition has been based on the recognition of scientific principles that dictate brain and cranial growth in early infancy and childhood. The evolution of strip craniectomies and suturectomies to extensive calvarial remodeling and endoscopic suturectomies has been driven by a growing understanding of how a prematurely fused cranial suture can affect the growth and shape of the entire skull. In this review, the authors discuss the early descriptions of craniosynostosis, describe the scientific principles upon which surgical intervention was based, and briefly summarize the eras of surgical management and their evolution to present day.

Free access

Brian Lee, Vivek A. Mehta, Arun P. Amar, Matthew S. Tenser, and William J. Mack

Open surgical disconnection has long been the treatment of choice for dural arteriovenous fistulas (dAVFs) of the anterior cranial fossa. However, advanced patient age and the presence of medical comorbidities can substantially increase the risk of craniotomy and favor a less invasive endovascular approach. Optimal positioning within the distal ophthalmic artery, beyond the origin of the central retinal branch, is achievable using current microcatheter technology and embolic materials. Here we present the case of an 88-year-old female with an incidentally discovered dAVF of the anterior cranial fossa. Angiographic cure was achieved with one-stage Onyx embolization.

The video can be found here: http://youtu.be/KVE0fUIECQM.

Free access

Brian Lee, Vivek A. Mehta, William J. Mack, Matthew S. Tenser, and Arun P. Amar

Type 1 spinal dural arteriovenous fistula (dAVF) constitute the vast majority of all spinal vascular malformations. Here we present the case of a 71-year-old male with progressive myelopathy, lower-extremity weakness and numbness, and urinary incontinence. MRI imaging of the thoracic spine demonstrated cord edema, and catheter spinal angiography confirmed a type 1 spinal dAVF. The fistula was supplied by small dural branches of the left L-2 segmental artery. Angiographic cure was achieved with a one-stage procedure in which coils were used to occlude the distal segmental vessels, followed by balloon-assisted embolization with Onyx.

The video can be found here: http://youtu.be/8aehJbueH0U.