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Biomedical subjects

R I Apfelbaum

Publications and source records attributed to R I Apfelbaum.

At least 19 recordsLinked to original sources

Anatomical suitability of C1-2 transarticular screw placement in pediatric patients.

OBJECT: Craniovertebral instability is a challenging problem in pediatric spinal surgery. Recently, C1-2 transarticular screw fixation has been used to assist in craniovertebral joint stabilization in pediatric patients. Currently there are no available data that define the anatomical suitability of this technique in the pediatric population. The authors report their experience in treating 31 pediatric patients with craniovertebral instability by using C 1-2 transarticular screws. METHODS: From March 1992 to October 1998, 31 patients who were 16 years of age or younger with atlantooccipital or atlantoaxial instability, or both, were evaluated at our institution. There were 21 boys and 10 girls. Their ages ranged from 4 to 16 years (mean age 10.2 years). The most common causes of instability were os odontoideum (12 patients) and ligamentous laxity (eight patients). Six patients had undergone a total of nine previous attempts at posterior fusion while at outside institutions. All patients underwent extensive preoperative radiological evaluation including fine-slice (1-mm) computerized tomography scanning with multiplanar reconstruction to evaluate the anatomy of the C1-2 joint space. Preoperatively, of the 62 possible C1-2 joint spaces in 31 patients, 55 sides (89%) were considered suitable for transarticular screw placement. In three patients the anatomy was considered unsuitable for bilateral screw placement. In three patients the anatomy was considered inadequate on one side. Fifty-five C1-2 transarticular screws were subsequently placed, and there were no neurological or vascular complications. CONCLUSIONS: The authors conclude that C1-2 transarticular screw fixation is technically possible in a large proportion of pediatric patients with craniovertebral instability.

Adolescent↗

A new occipitocervical fusion construct in pediatric patients with occipitocervical instability. Technical note.

Posterior occipitocervical stabilization procedures were successfully performed in 10 patients (nine boys and one girl) 16 years of age or younger by using C1-2 transarticular screws coupled with a rigid occipitocervical construct. The average length of follow-up evaluation was 18.8 months (range 5-37 months). No implant failed and all fusions were successful without the use of an external orthotic halo device.

Adolescent↗

Thoracoscopic microsurgical excision of a thoracic schwannoma. Case report.

A 6-cm-diameter schwannoma located at T-2 was resected completely by using transthoracic microsurgical endoscopy. The partially cystic tumor widened the neural foramen and extended into the apex of the right thoracic cavity but did not extend intradurally. The tumor was accessed by means of three 15-mm incisions made in the intercostal spaces. The operative blood loss was only 200 ml, and there were no complications. The patient was discharged on the 2nd postoperative day and returned to full activity 1 week after surgery. Thoracoscopy provides an excellent alternative to thoracotomy for peripheral thoracic nerve sheath tumors that originate within the neural foramen or more distally along the intercostal nerves within the thorax. An anterior approach is required for intrathoracic tumors but is not suited for intradural tumors. An open posterior or posterolateral approach to the thoracic spine is required for intradural tumors to allow the dura to be closed adequately.

Activities of Daily Living↗

Cerebellopontine angle glioneuronal hamartoma.

Roughly 90% of cerebellopontine angle tumors are acoustic neuromas. Other prevalent lesions include meningiomas and epidermoid tumors; additional lesions are rare. We describe a patient with a neuroglial hamartomatous mass of the internal auditory canal who was thought to have a schwannoma preoperatively. In this case, the hamartomatous tissue containing neuroectodermal elements may have become separated from the developing neuraxis during neural migration. Hamartomas should be considered when masses are discovered originating from eighth nerve branches other than the superior vestibular nerve and when magnetic resonance signal characteristics vary from the T1 enhancement typically seen with schwannomas and meningiomas.

Aged↗

Justification for decreasing the number of views taken in radiologic follow-up of Casper plate cervical spine hardware.

RATIONALE AND OBJECTIVES: We tested the null hypothesis that there would be no difference between the diagnostic yield of the lateral radiograph alone and the yield of the lateral and anteroposterior views combined when assessing patients after placement of an anterior cervical appliance. METHODS: We evaluated 630 radiographic examinations obtained from 117 consecutive patients who had anterior cervical plating. For each examination, we looked at the lateral radiograph first and then at the anteroposterior radiography to determine whether there would be any additional information on the anteroposterior film. RESULTS: Of 501 examinations in which the lateral and anteroposterior views were available, we found that the anteroposterior view added information in 18. In eight of the 18, the added information consisted only of clinically insignificant tilting of the plate. Significant findings were seen in 209 examinations in the lateral view and in 219 examinations with the lateral and anteroposterior views combined. This was not significantly different. CONCLUSION: The anteroposterior view rarely adds significant information. It probably should be obtained early postoperatively to check for tilting of the plate but after that only for specific indications. This will save money and reduce the patient's exposure to radiation.

Adolescent↗

Low-cost high-resolution fast spin-echo MR of acoustic schwannoma: an alternative to enhanced conventional spin-echo MR?

PURPOSE: To determine whether unenhanced high-resolution T2-weighted fast spin-echo MR imaging provides an acceptable and less expensive alternative to contrast-enhanced conventional T1-weighted spin-echo MR techniques in the diagnosis of acoustic schwannoma. METHODS: We reviewed in a blinded fashion the records of 25 patients with pathologically documented acoustic schwannoma and of 25 control subjects, all of whom had undergone both enhanced conventional spin-echo MR imaging and unenhanced fast spin-echo MR imaging of the cerebellopontine angle/internal auditory canal region. The patients were imaged with the use of a quadrature head receiver coil for the conventional spin-echo sequences and dual 3-inch phased-array receiver coils for the fast spin-echo sequences. RESULTS: The size of the acoustic schwannomas ranged from 2 to 40 mm in maximum dimension. The mean maximum diameter was 12 mm, and 12 neoplasms were less than 10 mm in diameter. Acoustic schwannoma was correctly diagnosed on 98% of the fast spin-echo images and on 100% of the enhanced conventional spin-echo images. Statistical analysis of the data using the kappa coefficient demonstrated agreement beyond chance between these two imaging techniques for the diagnosis of acoustic schwannoma. CONCLUSIONS: There is no statistically significant difference in the sensitivity and specificity of unenhanced high-resolution fast spin-echo imaging and enhance T1-weighted conventional spin-echo imaging in the detection of acoustic schwannoma. We believe that the unenhanced high-resolution fast spin-echo technique provides a cost-effective method for the diagnosis of acoustic schwannoma.

Adult↗

Endotracheal tube cuff pressure increases significantly during anterior cervical fusion with the Caspar instrumentation system.

To determine whether endotracheal tube cuff pressure increases significantly with surgical retraction and cervical spine distraction during anterior cervical spine surgery with Caspar instrumentation, we prospectively studied 10 patients undergoing this procedure. The tracheas of all patients were intubated with a Mallinckrodt Hi-Lo endotracheal tube. Tracheal tube cuff pressures measured with a transducer system were 42.4 mm Hg +/- 7.0 mm Hg (SEM) after intubation and cuff inflation. Air was removed from the endotracheal tube cuff until the trachea was just barely sealed at a cuff pressure of 15.2 mm Hg +/- 1.6 mm Hg. The endotracheal tube cuff pressure was readjusted to "just-seal" pressure before the surgeons introduced the Caspar instrumentation. The cuff pressure with traction and distraction was 43.2 mm Hg +/- 5.0 mm Hg. This pressure was significantly increased from the "just-seal" pressure, and from the cuff pressure after instrumentation was discontinued (9.8 mm Hg +/- 2.3 mm Hg). We conclude that anterior cervical spine surgery with Caspar instrumentation is associated with a significant increase in endotracheal tube cuff pressure.

Cervical Vertebrae↗

Neurosurgery image manager.

Computer technology has become standard in many areas of medical practice, but computer-assisted instruction has not replaced standard textbooks and didactic lectures. This paper describes the development of a computer image-based educational system designed for neurosurgical instruction. The advantages and applications of this system for both clinical and academic use and the required software and hardware requirements are delineated. This computerized tutorial can organize and manipulate large amounts of data. The Neurosurgery Image Manager system contains an introductory help section, a self-assessment test in neurosurgery, and a data base of images from the video disc "The Slice of Life," produced at the University of Utah. Questions are taken from the Self-Assessment in Neurological Surgery series. Additionally, the system contains a reference index for all material in the tutorial, a scored clinical problems section, and a several hundred word glossary. The system is programmed using the Macintosh Hypercard authoring system. Large data bases can be manipulated and linked with graphics, text, and peripherals. Images are stored using the MacVision II digitizing system. The hardware necessary to operate the system and the method of implementation of Neurosurgery Image Manager are described. The prototype Neurosurgery Image Manager has been accepted by the Joint Committee on Education of the American Association of Neurological Surgeons and Congress of Neurological Surgeons as one of the computer formats for the next self-assessment tests.

Computer Graphics↗

Neurenteric cysts of the posterior fossa: recognition, management, and embryogenesis.

Neurenteric cysts are endothelium-lined structures most commonly encountered in the lower cervical or upper thoracic spinal cord. The occurrence of neurenteric cysts within the cranial vault is unusual. We present three patients with neurenteric cysts located within the posterior fossa: one near the jugular foramen deforming the 4th ventricle, a second in the cerebellopontine angle, and a third in the prepontine cistern. Several different theories have been advanced to explain the embryogenesis of neurenteric cysts. We review these theories and conclude that cranial neurenteric cysts may arise from a disturbance of early gastrulation, shortly after the onset of primitive streak regression.

Adult↗

Trigeminal neuralgia (tic douloureux): MR imaging assessment.

The magnetic resonance (MR) imaging studies and clinical records of 29 patients with typical or atypical trigeminal neuralgia (TN) were retrospectively reviewed and compared with the MR studies of 30 patients imaged for reasons unrelated to the fifth cranial nerve. The symptomatic patients were in three groups. Group 1 included those without masses or multiple sclerosis (MS) and those who had not undergone microvascular decompression; group 2, those who underwent microvascular decompression; and group 3, those with masses or MS. Twenty-seven percent of the control group and 57% of the symptomatic patients without masses or MS showed vessel contact with the root entry zone of the preganglionic segment of the fifth cranial nerve. Vessel contact in the symptomatic groups was generally indistinguishable from that seen in the normal group. Fifteen percent of the patients had MS or masses. It is concluded that MR imaging is useful in evaluating patients with TN by facilitating identification of MS or masses but is not helpful in selecting patients with vascular contact who might benefit from microvascular decompression.

Humans↗

Anterior cervical fusion with the Caspar instrumentation system.

Twenty-eight patients with a variety of cervical spine abnormalities underwent anterior cervical spine stabilization with the Caspar osteosynthetic plate/intervertebral body bone graft technique. The available hardware and operative technique are presented, and case reports illustrate clinical applications. Complications and results of the series are presented. A brief discussion of applicable biomechanical principles and of technical pitfalls leading to potential fusion failures and a review of experience and developments in cervical plating techniques are included.

Adolescent↗

Nocardial cerebral abscess in the acquired immunodeficiency syndrome.

Nocardial cerebral abscess is an unusual neurologic manifestation of the acquired immunodeficiency syndrome. A 20-year-old woman with the acquired immunodeficiency syndrome presented with headache and fever. Nocardia asteroides was cultured from a stereotaxic brain biopsy specimen. Despite antibiotic therapy to which the pathogen was sensitive, resolution of the abscess followed only after complete surgical excision.

Acquired Immunodeficiency Syndrome↗

Lumbar spinal stenosis associated with renal osteodystrophy.

A case of coexisting lumbar spinal stenosis and renal osteodystrophy is reported. The presence of renal osteodystrophy is known to have predated the onset of neurological complaints. The patient's symptoms were relieved with surgery. Although a causative relationship between renal osteodystrophy and spinal stenosis has not been reported previously, it seems likely in this case.

Aged↗

Surgical decompression of the facial nerve in the treatment of chronic cluster headache.

The nervus intermedius (NI) appears to be the main conduit for the associated symptoms of cluster headache (CH) and perhaps for the pain as well. Subtle injury of the facial nerve and NI might initiate mechanisms responsible for CH. Five patients with chronic CH unresponsive to medication underwent surgical decompression of the root exit-entry zone of the facial nerve, and in two patients the trigeminal nerve root was also decompressed. In two patients, the pain syndrome was markedly relieved for as long as two years. In one patient, initial improvement was obscured by narcotic addiction. In two patients, the operation was a failure. The NI was identified as a separate bundle in only one of five patients and decompressions may not have affected that component of the facial nerve.

Adult↗