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Biomedical subjects

K Black

Publications and source records attributed to K Black.

At least 55 records · Page 3Linked to original sources

A combined intradural presigmoid-transtransversarium-transcondylar approach to the whole clivus and anterior craniospinal region: anatomic study.

Surgical exposure of the clivus is difficult because of its proximity to vital neurovascular structures. The anatomic bases of a new surgical approach to this area are discussed. A supra-auricular skin incision is extended toward the posterior border of the sternocleidomastoid muscle. The vertebral artery is exposed from C2 to the occiput unroofing the foramen transversarium of C1. The bone removal consists of a posterior temporal craniotomy, a suboccipital craniectomy, including mastoidectomy with sigmoid sinus unroofing, removal of the lateral margin of the foramen magnum, of the medial third of the occipital condyle, and retrolabyrinthine petrous drilling. Posterior retraction of the vertebral artery facilitates occipital condyle drilling. Intradural exposure of the petroclival region is achieved by L-shaped cutting of the dura with the long branch placed infratentorially anterior to the sigmoid sinus. Intradural exposure of the craniospinal/upper cervical areas is achieved by cutting of the dura medial to the distal sigmoid sinus and by longitudinal cutting of the dura anterior to the vertebral artery. This approach allows multiple ports of entry to the clivus with full control of the vertebrobasilar system, and of the dural sinuses, and is anatomically suited for controlled removal of tumors located in these areas. This approach, or segments of it, has been used successfully in the treatment of large neoplasms of the craniovertebral junction.

Journal Article↗

Early childhood intervention. A promising preventative for juvenile delinquency.

Programs to reduce or prevent juvenile delinquency have been generally unsuccessful. Apparently the risk factors that make a child prone to delinquency are based in too many systems--including the individual, the family, and community networks--to make isolated treatment methods effective. Surprisingly, longitudinal studies of some early childhood intervention programs suggest they may help to reduce future delinquency. These programs take an ecological approach to enhancing child development by attempting to promote overall social competence in the many systems impacting on children. Not engaging in criminal acts is one indicator of competence that is related to others, such as being successful in school and in personal relationships. Evaluators must gather more data to confirm this unanticipated benefit of comprehensive interventions.

Child Abuse↗

Transzygomatic approach to the tentorial incisura: surgical anatomy.

A simple transzygomatic approach to the middle fossa centered on the inferior retraction of the temporal muscle after transection of the zygomatic arch is described. This approach allows a very low basal exposure of the middle and temporal fossa, minimizing the amount of temporal lobe retraction needed to approach intradural and extradural lesion in this location. This approach is simple, easily performed, does not require extensive skull base removal, and still offers excellent visualization of the middle fossa and of the region of the tentorial incisura.

Journal Article↗

Steroid-responsive chorea in moyamoya disease.

We report the case of a 13-year-old boy with disabling chorea due to moyamoya disease. His chorea seemed to improve with steroid therapy. We conclude that steroid therapy may ameliorate moyamoya-associated chorea, and perioperative steroids can confound neurosurgical outcome. We are unable to assess the effect of cerebrovascular bypass procedures on the outcome of chorea in this patient.

Adolescent↗

Transzygomatic approach to tumours of the parasellar region. Technical note.

A simple transzygomatic approach to the middle fossa centered on the inferior retraction of the temporal muscle hinged on the transected zygomatic arch is described. This approach allows a very low basal exposure of the middle and temporal fossa minimizing the amount of temporal lobe retraction needed to approach intra and extradural lesion in this location. The upper portion of the infratemporal fossa is also reached after removal of the middle fossa skull base. This approach is simple, easily performed, does not require extensive skull base removal, and still offers excellent visualization of the middle fossa and of the upper infratemporal fossa.

Chondrosarcoma↗

Fungal brain abscesses (aspergillosis/mucormycosis) in two immunosuppressed patients.

Although the mortality rate for fungal brain abscesses in immunosuppressed patients remains unacceptably high, this figure may be reduced if computed tomography or magnetic resonance imaging scans are performed more promptly in susceptible individuals with seemingly mild intracranial complaints. Earlier presumptive amphotericin B treatment and more timely surgical debridement may minimize neurological injury and enhance survival. These assumptions were only tentatively supported by the clinical courses of two patients, one an alert patient with promyelocytic leukemia and an aspergillosis brain abscess who survived, and the other, a comatose intravenous drug abuser with mucormycosis who died.

Adult↗

Relationship between vertical dentofacial morphology and respiration in adolescents.

The relationship between vertical dentofacial morphology and respiration has been debated and investigated from various approaches. The purpose of this study was to use contemporary respirometric techniques to compare the breathing behavior of normal and long-faced adolescents. Sixteen normal and 32 long-faced subjects 11 to 17 years of age were chosen clinically and verified by means of a discriminant function. Vertical and anteroposterior facial form was assessed from lateral cephalometric radiographs according to the following measurement criteria: six skeletal angular, eight skeletal linear, four dental linear, and three skeletal ratios. Breathing behavior was quantified according to tidal volume, minimum cross-sectional nasal area, and percent of nasal breathing as assessed by pneumotachography, measurement of differential pressures, and inductive plethysmography. The data indicated that the normal and long-faced groups were significantly different with respect to lower face form, and each group in the study was comparable to groups that had been chosen by previous investigators. Multiple regression analysis demonstrated that the normal and long-faced groups had similar tidal volumes and minimum nasal cross-sectional areas, but the long-faced subjects had significantly smaller components of nasal respiration. These results illustrate that groups without significant differences in airway impairment can have significantly different breathing modes that may be behaviorally based, rather than airway-dependent.

Adolescent↗

Middle cranial fossa transtemporal approach to the intrapetrous internal carotid artery.

Diseases involving the proximity of the internal carotid artery at the skull base require identification of this vessel in the temporal bone to gain vascular control for any maneuver in its vicinity. This article details the technique of surgical dissection and exposure of the internal carotid artery within the skull base through a transtemporal middle cranial fossa approach. The anatomic landmarks important in utilizing this procedure include the greater superficial petrosal nerve, the mandibular branch of the trigeminal nerve, and the middle meningeal artery. With this approach, the internal carotid artery can be followed throughout the carotid canal and beyond the formen lacerun to the region of the cavernous sinus. The indications and limitations of this procedure are described and several clinical applications are provided.

Journal Article↗

Chinese hamster ovarian cells transfected with the murine interleukin-6 gene cause hypercalcemia as well as cachexia, leukocytosis and thrombocytosis in tumor-bearing nude mice.

The effects of interleukin-6 (IL-6) in vivo were assessed by inoculating Chinese hamster ovarian (CHO) cells which were transfected with the murine IL-6 gene in nude mice. Nude mice bearing CHO cells expressing IL-6 developed hypercalcemia. Tumor-bearing mice also showed increases in white cell count, platelet count, and decreases in body weight. In nude mice carrying CHO tumors which had not been transfected with the IL-6 gene, there were no changes in these parameters. These results suggest that increased circulating concentrations of IL-6 in patients with malignant disease may contribute to a number of paraneoplastic syndromes including hypercalcemia, cachexia, leukocytosis and thrombocytosis.

Animals↗

Extended retrolabyrinthine transtentorial approach to petroclival lesions.

In this communication, an extension of the retrolabyrinthine approach that has permitted safe, effective access to the petrous tip and clivus is presented. The basic technique involved complete mastoidectomy, preservation of the middle and inner ear structures, removal of the sigmoid and middle fossa plates, middle and posterior fossa craniotomies, ligation of the superior petrosal sinus, and division of the tentorium. Nine cases that exemplified the versatility of this approach constituted the basis of this paper: 2 cholesteatomas, 2 basilar artery aneurysms, 2 chordomas, and 3 meningiomas. The indications for, and complications of, this method have been discussed.

Adult↗

Intradural spinal cord tumor presenting as a subarachnoid hemorrhage: magnetic resonance imaging diagnosis.

Negative findings on four-vessel angiography after a subarachnoid hemorrhage are seen in 5 to 30% of patients. A previously silent lesion in the spinal canal may be responsible for the ictus in a small percentage of this group. The etiological factors include tumors and arteriovenous malformations; however, investigations of such lesions have been limited to patients with signs and symptoms of spinal cord or nerve root pathological processes. This report describes the management of a 56-year-old woman with clinical findings typical of an aneurysmal subarachnoid hemorrhage and negative findings on cerebral angiography, in whom magnetic resonance imaging with gadolinium enhancement revealed an intradural extramedullary cervical schwannoma. For this reason, cervicothoracic magnetic resonance imaging with gadolinium enhancement should be considered as an adjunctive scanning examination in all patients with a subarachnoid hemorrhage and negative findings on angiography.

Diagnosis, Differential↗

Intraoperative digital subtraction angiography and the surgical treatment of intracranial aneurysms and vascular malformations.

Intraoperative digital subtraction angiography using commercially available equipment was employed to confirm the precision of the surgical result in 105 procedures for intracranial aneurysms or arteriovenous malformations (AVM's). Transfemoral selective arterial catheterization was performed in most of these cases. A radiolucent operating table was used in all cases, and a radiolucent head-holder in most. In five of the 57 aneurysm procedures, clip repositioning was required after intraoperative angiography demonstrated an inadequate result. In five of the 48 AVM procedures, intraoperative angiography demonstrated residual AVM nidus which was then located and resected. In two cases intraoperative angiography failed to identify residual filling of an aneurysm which was seen later on postoperative angiography, and in one case the intraoperative study failed to demonstrate a tiny residual fragment of AVM which was seen on conventional postoperative angiography. Two complications resulted from intraoperative angiography: one patient developed aphasia from cerebral embolization and one patient developed leg ischemia from femoral artery thrombosis. This technique appears to be of particular value in the treatment of complex intracranial aneurysms and vascular malformations.

Angiography, Digital Subtraction↗

Anterior thoracic extradural hematoma in a 5-year-old child.

Four hours following a motor vehicle accident, a 5-year-old girl developed a complete motor and sensory paraplegia below the sixth thoracic level (T6). The plain X-rays and MRI scan identified nondisplaced compression fractures of the T3-T6 vertebrae, associated with an anterior T3-T5 epidural hematoma. Following an emergency T3-T6 laminectomy, the sensory findings disappeared, while the motor deficit took 2 weeks to resolve. This case report emphasizes the value of the MRI scan in assessing pediatric spinal trauma, while underscoring the unique characteristics of acute epidural spinal hematomas.

Accidents, Traffic↗