Search Results

You are looking at 1 - 10 of 18 items for

  • Author or Editor: Timothy B. Mapstone x
  • Refine by Access: all x
Clear All Modify Search
Full access

Vagus nerve stimulation: current concepts

Timothy B. Mapstone

Vagus nerve stimulation (VNS) has become an accepted treatment option for pharmacologically resistant epilepsy. Although initially approved for adults, it increasingly has gained acceptance in children. In this article the author reviews the current state of knowledge of VNS therapy and discusses its potential utility.

Restricted access

Expression of platelet-derived growth factor and transforming growth factor and their correlation with cellular morphology in glial tumors

Timothy B. Mapstone

✓ This study was undertaken to evaluate the role of two sets of growth factors, platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-β), in the induction and maintenance of glial tumors and their phenotypic expression. Explants from eight malignant tumors, five benign tumors, and two nontumor glial cells were analyzed for levels of messenger ribonucleic acid (mRNA) expression of PDGFA, PDGFB, TGF-β1, and TGF-β2. Results were normalized to the mRNA expression of tubulin, a “housekeeping” gene present in glial cells. Of the 15 explants tested, PDGFB was seen in six, all of which were malignant tumors; PDGFA was seen in all 15 with much higher levels expressed in malignant tumors; and TGF-β1 and TGF-β2 were seen in all 15 without a clear difference between cell types, although expression tended to be higher in malignant tumors. This project supports the theory that the induction and maintenance of glial tumors is likely to be a multifactorial phenomenon.

Restricted access

Fred Epstein, M.D.

Timothy B. Mapstone

Restricted access

A rare cause of benign ventriculomegaly with associated syringomyelia: BRESEK/BRESHECK syndrome

Case illustration

Luis M. Tumialán and Timothy B. Mapstone

Restricted access

Intradural chordoma without bone involvement: nuclear magnetic resonance (NMR) appearance

Case report

Timothy B. Mapstone, Benjamin Kaufman, and Robert A. Ratcheson

✓ This paper presents a rare case of intradural chordoma which involved the pons but had no radiological or surgical evidence of bone involvement. The appearance of this tumor on nuclear magnetic resonance imaging is presented.

Restricted access

Migration of a ventricular tapping reservoir into the third ventricle

Case report

William B. Schueler, Timothy B. Mapstone, and Naina L. Gross

The authors present a case of migration of a ventricular tapping system into the third ventricle of a 6-year-old boy who is was born prematurely. As an infant, the patient was treated with serial lumbar punctures for hydrocephalus associated with intraventricular hemorrhage. The patient progressed to requiring a ventricular tapping reservoir and eventually a ventriculoperitoneal shunt. The patient presented for suspected shunt malfunction 4 years after placement of his ventriculoperitoneal shunt, and the migrated ventricular tapping system was discovered. The authors discuss several management strategies that could be used to prevent this complication.

Full access

Divergence insufficiency alleviated by posterior fossa decompression with duraplasty in a patient with Chiari type 1.5 malformation

Allison Strickland, Cordell M. Baker, R. Michael Siatkowski, and Timothy B. Mapstone

The authors present a case of Chiari type 1.5 malformation with the uncommon presenting symptoms of esotropia and diplopia due to divergence insufficiency in a 12-year-old girl. Imaging at initial diagnosis revealed cerebellar herniation with extension of the tonsils to the C2 vertebral body, a retroflexed odontoid, and a small cervical syrinx. The patient was initially treated with an uncomplicated Chiari malformation decompression without dural opening. Repeat imaging revealed an adequate decompression. Three months postoperatively the patient’s diplopia recurred and she underwent repeat posterior fossa decompression with dural opening and duraplasty. Following repeat decompression with dural opening and duraplasty, the patient’s diplopia had not recurred by the 2-year follow-up.

Restricted access

History of the current understanding and management of tethered spinal cord

Sam Safavi-Abbasi, Timothy B. Mapstone, Jacob B. Archer, Christopher Wilson, Nicholas Theodore, Robert F. Spetzler, and Mark C. Preul

An understanding of the underlying pathophysiology of tethered cord syndrome (TCS) and modern management strategies have only developed within the past few decades. Current understanding of this entity first began with the understanding and management of spina bifida; this later led to the gradual recognition of spina bifida occulta and the symptoms associated with tethering of the filum terminale. In the 17th century, Dutch anatomists provided the first descriptions and initiated surgical management efforts for spina bifida. In the 19th century, the term “spina bifida occulta” was coined and various presentations of spinal dysraphism were appreciated. The association of urinary, cutaneous, and skeletal abnormalities with spinal dysraphism was recognized in the 20th century. Early in the 20th century, some physicians began to suspect that traction on the conus medullaris caused myelodysplasia-related symptoms and that prophylactic surgical management could prevent the occurrence of clinical manifestations. It was not, however, until later in the 20th century that the term “tethered spinal cord” and the modern management of TCS were introduced. This gradual advancement in understanding at a time before the development of modern imaging modalities illustrates how, over the centuries, anatomists, pathologists, neurologists, and surgeons used clinical examination, a high level of suspicion, and interest in the subtle and overt clinical appearances of spinal dysraphism and TCS to advance understanding of pathophysiology, clinical appearance, and treatment of this entity. With the availability of modern imaging, spinal dysraphism can now be diagnosed and treated as early as the intrauterine stage.

Restricted access

Perioperative outcomes and complications associated with allogeneic duraplasty for the management of Chiari malformations Type I in 48 pediatric patients

Clinical article

Paul Foreman, Sam Safavi-Abbasi, Melanie C. Talley, Lindsay Boeckman, and Timothy B. Mapstone


The authors debate the optimal management for Chiari malformation Type I (CM-I) while sharing their experience with posterior fossa decompression and duraplasty (PFDD).


The charts of 48 consecutive pediatric patients surgically treated for CM-I were retrospectively reviewed.


Patients ranged in age from 2 to 17 years with an average age of 9.8 years. The most common presentations were headache, affecting 34 patients (71%), and pain (neck, back, or extremities), affecting 21 patients (44%). Twenty-seven patients (56%) had a syrinx. All 48 patients underwent PFDD utilizing acellular tissue matrix. The average hospital stay overall was 3.56 days, whereas the average stay for patients with (29 [60%] of 48) or without (19 [40%] of 48) scoliosis and/or syringomyelia was 3.72 and 3.32 days, respectively. The odds of a patient having a hospital stay of 4 or more days was nearly 3 times greater in patients with scoliosis and/or syringomyelia as compared with patients without either condition (OR 2.73, 95% CI 0.74–10.11, p = 0.1330). The average hospital stay for patients 0–8 years of age was 3.29 days; and for those 9–17 years of age, 3.78 days. The odds of a patient having a hospital stay of 4 or more days was nearly 4 times greater in 9- to 17-year-olds as compared with 0- to 8-year-olds (OR 3.73, 95% CI 1.03–13.52, p = 0.0455). Forty patients (89%) experienced early improvement in their signs and symptoms following PFDD. There were 2 revision PFDDs (4%).


Posterior fossa decompression and duraplasty is a safe and effective surgical option in the management of pediatric CM-I.

Restricted access

Lead encephalopathy presenting as a posterior fossa mass

Case report

J. Frederick Harrington, Timothy B. Mapstone, Warren R. Selman, Pamela Galloway, and Carl Bundschuh

✓ A case of lead encephalopathy with clinical and computerized tomography evidence of a midline posterior fossa mass is presented. The pathophysiology and the predilection for posterior fossa involvement are discussed.