Biomedical subjects
Publications and source records attributed to S Keskil.
The spontaneous regression of cervical disc herniations is a rare occurrence. Six herniated cervical discs that had regressed spontaneously are presented. All radiological disc regressions correlated well with clinical improvements. We want to underscore the potential for regression that should be considered in the evaluation and management of any patient with a herniated cervical disc.
Pott's puffy tumor is a rare clinical entity characterized by subperiosteal abscess associated with osteomyelitis. It is usually seen as a complication of frontal sinusitis or trauma. This is the unique report of a Pott's puffy tumor located over the vertex of a type 1 diabetic patient with an unusual latency of 14 years following injury. A 27-year old man presented with pain and a soft swelling on his vertex. Magnetic resonance imaging demonstrated subperiosteal abscess in the vertex region associated with dural thickening and perisinusal irregularities of epidural space. Further history revealed that he had a trauma to the same location when he was 13 years old. Considering possible complications due to proximity of the lesion to the sagittal sinus, we retrained from aggressive surgical interventions. We treated our patient with a simple surgical abscess drainage followed by prolonged use of antibiotics and achieved complete therapy. The cellular and humoral elements of the immune system may be disrupted in diabetic patients resulting in such atypical courses and complications of infections. We want to emphasize both importance of the prompt diagnosis of Pott's puffy tumor as intracranial invasion may cause severe neurologic problems, and importance of a surgical intervention tailored for the individual lesion.
In neurosurgery, ceftriaxone is a widely used, third generation cephalosporin for the treatment of CNS infections and perioperational prophylaxis. Recent studies have demonstrated that ceftriaxone induces reversible precipitates in the gallbladder. This complication is referred to as "biliary pseudolithiasis", and it has symptoms similar to the raised intracranial pressure (ICP) symptoms of the perioperative period. Symptomatic biliary pseudolithiasis should be kept in mind in all pediatric neurosurgery cases under ceftriaxone therapy in order to prevent unnecessary postoperative investigations and surgery.
Decreasing size of disc material that has herniated, whether "contained" or "protruded" has previously been described and sometimes this can be so complete that residual material is barely visible. In a retrospective clinical survey, from among almost 2180 consecutive patients admitted during 1994 - 2002 with low back pain; due to our low follow-up ratios and high price of the magnetic resonance imaging (MRI), only 42 patients with a lumbar disc protrusion could be found who had two MRI scans obtained at least five weeks apart. Among these, 4 patients were spotted with a totally resolved disc protrusion. T (2)-weighted MRI images were suggesting shrinkage due to dehydration and regression within the annulus of protruded disc fragments that had not fully migrated. Our patients are further examples for total resolution of the large "protruded" disc without any treatment; and since concomitant disc protrusions at other levels persisted, the resolution of these discs is supposed to be spontaneous.
A preliminary investigation was planned so as to evaluate the effectiveness of ultrasonography for bed- side evaluation of patients with suspected spinal pathology. Its application by anterior approach in 37 cases showed that herniated disc material, bone, epidural fat, scar tissue, tumoral masses and their relation to the interspace and dural sac could be visualized. A short description of the sonographic appearance of normal and pathological structures was also given in comparison to Computed Tomography or Magnetic Resonance images. Ultrasonographic examination was inadequate in five of the patients due to obesity, meteorism or diminution of the intervertebral disc space. Advantages of this technique are the availability almost in every hospital, the ease of obtaining images at various angles, avoiding the use of x-rays and the low price. The disadvantages are its relatively poor definition as compared to Computed Tomography or Magnetic Resonance Imaging and its inability to see through bone.
Destruction and denervation atrophy in skeletal muscles caused by the injection of local anaesthetics was investigated by injecting lidocaine or bupivacaine around the rabbit facial nerve to produce facial paralysis. Animals were then sacrificed at 2, 4, 6, and 8 weeks post-injection, and changes in mimic muscle tissue were assessed at each stage by light microscopy and electron microscopy. Atrophic changes were observed at 2-6 weeks after injection, and regeneration started at 6-8 weeks. Compared to bupivacaine, lidocaine caused more dramatic atrophic changes and was associated with slower muscle regeneration.
OBJECTIVE: The aim of this clinical retrospective review was to emphasize the recently observed high incidence of ventriculomegaly, a wellknown complication of brain abscesses. MATERIALS AND METHODS: Among twelve brain abscess cases operated on in our institution during five years, the most common surgical procedure was burr-hole aspiration applied in ten of the cases, while in the remaining two a standard craniotomy and total excision was performed. Ventriculomegaly was assessed by the "Evans' Ratio" values calculated using the frontal ventricular horn measurements made on axial tomographic images. RESULTS: The signs, symptoms, radiological findings and clinical features of the patients were in accordance to the pertinent literature. The only finding worth commenting on was the surprisingly high incidence of ventriculomegaly (5/12) and periventricular edema (4/12). Concerning the outcome, there was only one death. CONCLUSIONS: The "Evans' Ratio" either worsened or remained the same in four out of five cases during the early postoperative period (ranging from one to three months) and it got better in one case in the late postoperative control (1.5 years). Furthermore, periventricular edema persisted just in the same manner in three of the four cases.
The alterations due to the long-term degeneration and regeneration of the rabbit facial nerve were investigated. The facial nerve was blocked with conventional lidocaine and bupivacaine solutions. The rabbits were sacrificed and facial nerves were removed 2, 4, 6 and 8 weeks after the administration of normal saline, lidocaine and bupivacaine. The samples were then processed for electron microscopic observation. Degenerations were seen 2-4 weeks after the injection of normal saline, lidocaine and bupivacaine. In the normal saline group the regeneration process was observed after 6 weeks, whereas in the lidocaine and bupivacaine groups this process was first noticed after 8 weeks. In the lidocaine and bupivacaine groups, regeneration was not completed at the end of 8 weeks; however, it was faster in the bupivacaine group. Bupivacaine is therefore suggested as the drug of choice for neural blockade as it caused less damage and a faster regeneration.
Contrary to what has long been suggested, the biological clock is not a poor timekeeper. In fact, it has been working in precision for millions of years as a genetically set clock, independent of environmental periodicity. However, as the Earth's rotation has gradually slowed, this internal clock has gone through a relative phase shift. Extrapolating of changes backwards through time shows that the clock was set when mammals first appeared on the planet. Interestingly, primates are the only beings that have a free-running cycle longer than 24 hours. This bioclock may be set by lunar entrainment, or may be set extraterrestrially?
The aim of this study was to compare the effects of trauma and pain on the pituitary gland so as to determine whether pain is a significant component in the general acute hormonal trauma response. Adenohypophysis of rabbits that have undergone either diffuse traumatic brain injury or pain were investigated using immunohistochemistry. The ACTH staining pattern of the pain-administered rabbits was not as strong as the head-trauma-administered group, whereas PRL staining pattern of the former group was not so weak as the later group. As a conclusion, since adrenocorticotrophic hormone and prolactin staining patterns were different in the trauma administered and pain induced groups; it may be postulated that pain alone may not be an important factor in the hormonal response to trauma.
The aim of this study was to investigate the contributions of Serefeddin Sabuncuoğlu (1385-1468?)--who was born and practiced in Amasya in northern part of central Anatolia--to the field of endoscopy. He was a humble, curious and intelligent surgeon, and also a calligrapher and a miniature artist. This remarkable pioneer used the classification of the Andalusian surgeon, Abdul-Kasim Kalaf Ibni Abbas El Zahravi, known as Albucasis of Cordoba (936-1013); but improved it by adding many important and major new observations and chapters. He described "a thin and hollow tube of almost 35 cm, which was made of silver" and used it to inspect the interior of the bladder.
OBJECTIVES: Disc degeneration probably begins in childhood although low back pain and radicular leg pain is not as common a complaint as in adults. However as yet no explanation exists for the appearance of advanced degenerative changes seen occasionally in patients in their twenties. PATIENTS AND METHODS: We report 12 adolescents between the ages of 15 and 20 among a total of 1068 cases with radiologically demonstrated lumbar disc herniations treated between March 1991 and March 1996. RESULTS: Most of their findings were in good agreement with earlier and more recent reports. The only different findings worth commenting upon were the common presence of multiple level disc herniations, and the occasional presence of a so called "fractured epiphysial plate". CONCLUSION: Depending on magnetic resonance imaging findings coupled with computed tomographic images; we suppose that the so called "fractured bone fragments of the vertebral epiphysial rim impinging on the spinal canal at multiple levels" and "wedges of bone attached to the disc end plate and associated bony defects in the margins of the posterior vertebral bodies" reported to be demonstrated on computed tomographic (CT) images may in fact be false images. Inappropriately angled CT scan slices may cut partly through the epiphysial ring which has totally been distracted backwards together with the firmly attached avulsed disc annuli, designated as an "epiphysial avulsion"; giving rise to the mistaken interpretation as a "fractured epiphysial ring" appearance. Such a mechanism may also involve the posterior longitudinal ligament, which is firmly attached to the neighboring annuli, accounting for the common multilevel involvement.
Among 1142 patients with head injuries hospitalized in the Neurosurgery Department of Gazi University Medical School during the period between 1979 and 1992, 583 had initial CT scans. A retrospective analysis of these initial CT images revealed intracranial air on admission in only 21 cases. These were classified as acute traumatic intracranial pneumocephalus: a potentially serious complication of head injury. CT scans were re-evaluated so as to reveal whether air was situated in the epidural, subdural, or subarachnoid spaces or intracerebrally; whether associated space-occupying lesions were present and whether the air bubbles were single or multiple. Clinical data such as the presence of persistent rhinorrhea and/or otorrhea, tension pneumocephalus, severity and type of trauma, and outcome were were also assessed to determine the significance of this rare finding.
BACKGROUND: Sometimes charring or popping occurs and the bipolar blades get stuck to the vessel. METHODS: The tips of one of the many commercially available bipolar forceps were coated in a striped manner with Teflon--50 micro in thickness. RESULTS: The new bipolar coagulator coated with Teflon reduced the incidence of tissue sticking. CONCLUSIONS: Experience with this instrument was still quite limited, but preliminary results were promising.
The effects of ZK-118.182, a stable analogue of PGD2, were evaluated in an endothelin-1-induced cerebral ischemia rabbit model. Ischemia was induced by endothelin-1 injection (0.25 ng bolus) into subcavian artery and ischemic changes were assessed histologically by the number of ischemic neurons in the brain stem. ZK-118.182 (2 micrograms/kg, bolus into subclavian artery) reduced the number of ischemic neurons when injected 20 min after endothelin-1 injection, Iloprost, a stable analogue of PGI2, was also effective in reducing the number of ischemic neurons in a dose of 0.5 microgram/kg (bolus into subclavian artery). The results suggested that ZK-118.182 has a potent antiischemic effect which is comparable to that of iloprost in rabbits.
Mechanically induced vasospasm observed in the immediate post-operative period was investigated, and the effect of factors such as temporary clip applications and post-operative intervals were studied. Guinea pig "cervical internal carotid arteries" were used and temporary clips, chosen according to the diameter of the artery and systolic pressure, were applied for a standard period. The same procedure was applied on arteries in which periadventitial tissue had been removed using appropriate microsurgical techniques. On postoperative days 1, 5, and 10, arterial rings were removed while the animals were still alive and Endothelium Dependent Relaxations were measured using a bioassay system. Morphological investigations were also performed using light microscopy on the same arterial preparations. We observed no difference between perioperative and first day postoperative results. The relaxations were minimum. The most striking pathological changes were observed on postoperative day 5, and the relaxation responses began to rise on day 10 together with morphological improvement. It was also found that periadventitial tissue stripping could be used to prevent subacute post-operative vasoconstriction, since its effect was marked on postoperative day 5 and began to resolve on day 10.
Mechanically induced vasoconstriction observed throughout surgery and in the immediate postoperative period was investigated to assess the effects of various microsurgical manipulations. Factors such as the type of aneurysm clip, duration of temporary clipping and peri-adventitial tissue stripping were the variables in this study. Microsurgical clips were applied on guinea pig "cervical carotid arteries" in which peri-adventitia had been removed microsurgically. Arterial rings were removed immediately after surgery. Endothelium dependent relaxations were measured and morphological investigations were performed using light microscopy. It was observed that as the clip application period increased, relaxation responses decreased. Peri-adventitial tissue stripping caused a marked decrease in the relaxation responses in all types of the clips. Microvascular clips, in spite of their lower closing forces, had the greatest deleterious effect on relaxation responses of the vessel, in both normal and peri-adventitial tissue stripped. When the peri-adventitial tissue of the vessel had been stripped, convolutions of the lamina elastica interna were found to be lost in parallel with the decreased tonus of the artery. In the vessels subjected to clipping endothelial denudation and cracking took place. As a conclusion it can be stated that both peri-adventitial tissue stripping and microvascular clip application have deleterious effects in the early postoperative period. While choosing clips from minimal occlusion force tables, care must be taken to choose clips with less width; and while performing microvascular anastomosis, temporary clips with a lesser width must be used in place of microvascular clips. Adventitial stripping must not be unnecessarily generous during microvascular anastomosis.
Since widespread applications of microsurgery are being employed for aneurysms, clival tumors, etc., precise knowledge of the skull base measurements has become vital, and a study of 307 adult skulls--130 female and 177 male--has been undertaken. Measurements were made between the landmarks chosen in accordance with the study of Lang in 1983 and our average values were similar to his series, being closer to his female data. There was no significant difference between the right and left sides of the skull.