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Biomedical subjects

N Akalan

Publications and source records attributed to N Akalan.

31 records · Page 2Linked to original sources

Bilateral cavernous carotid artery aneurysms in a 4-year-old child: endovascular treatment with mechanically detachable coils.

We present a 4-year-old child who suffered bilateral third nerve palsies secondary to bilateral giant saccular cavernous carotid artery aneurysms. Endovascular treatment was performed by means of direct endosaccular aneurysm occlusion on the right side and parent vessel occlusion on the left, using mechanically detachable coils. No complication occurred during or after the procedure. The bilateral third nerve palsies resolved over 3 months. Follow-up angiography at 1 year is presented.

Aneurysm↗

Occipital encephalocele associated with mediastinal enteric duplication cyst.

Enteric duplication is a rare developmental anomaly. This anomaly can be seen anywhere along the gastrointestinal tract, and less than 2% of the cases extend to the mediastinum. Developmental neuroectodermal and cutaneous ectodermal abnormalities, especially vertebral midline fusion abnormalities, are frequently associated with enteric duplications. We report a case of a newborn with occipital encephalocele, also having a mediastinal enteric duplication cyst. The clinical course of this case is described in detail to emphasize the occurrence of life-threatening complications of these associated developmental abnormalities during the treatment of the primary pathology in the neurosurgery practice. In the literature, we failed to demonstrate any co-existence of these two developmental abnormalities and review the embryogenesis of the association of these congenital malformations presented here.

Abnormalities, Multiple↗

Spinal injuries in the pediatric age group: a review of 82 cases of spinal cord and vertebral column injuries.

A review of 82 children with spinal cord and/or vertebral column injury treated in our department between 1968 and 1993 showed that 67% of the patients were boys and the average age was 11.4 years. The cause, vertebral level, and type of injury, and the severity of neurological injury varied with the age of the patient. The cause of pediatric injuries differed from that of adult injuries in that falls were the most common causative factor (56%) followed by vehicular accidents (23%). The most frequent level of spinal injury was in the cervical region (57%, 47 patients) followed by the lumbar region (16.5%, 13 patients). In our series, 18% of the patients had complete injury and the overall mortality rate was 3.6%. Eleven children (13%) had spinal cord injury without radiographic abnormality (SCIWORA), whereas 39 (47%) had evidence of neurological injury. Although the spinal injury patterns differed between children and adolescents, the outcome was found to be predominantly affected by the type of neurological injury (P < 0.05). Children with complete myelopathy uniformly remained with severe neurological dysfunction; children with incomplete myelopathy recovered nearly normal neurological function. Finally, the authors conclude that most spinal injuries can be successfully managed with nonoperative therapy. The literature is reviewed as to the treatment and outcome of pediatric spinal injuries.

Child↗

Subependymal giant cell astrocytoma associated with tuberous sclerosis: diagnostic and surgical characteristics of five cases with unusual features.

Five children with tuberous sclerosis and intracranial tumors were surgically treated at Neurosurgery Department of Hacettepe University School of Medicine. Two of the five patients presented with the giant cell astrocytoma filling the third ventricle. Direct surgical intervention and tumor removal was carried out in all four patients (three with a total surgical resection and one with a subtotal resection) and cerebrospinal fluid shunting procedure in one. Histopathological examination revealed giant cell astrocytomas in four patients. Postoperatively, one died and the rest four patients survived with minor focal neurologic difficulties. The surgical results and the changing concepts in the treatment of tuberous sclerosis are discussed and the literature is reviewed.

Adolescent↗

Angiogenesis and the blood-brain barrier in intracerebral solid and cell suspension grafts.

Solid and suspension grafts of fetal central nervous system (CNS) tissue rapidly reform an intact blood-brain barrier (BBB), whereas solid grafts of peripheral nervous system (PNS) tissue fail to establish a BBB as detected by horseradish peroxide (HRP) leakage, administrated intravenously. We examined the acute changes in the BBB after grafting of fetal CNS tissue in solid and suspension form and superior cervical ganglion (SCG) and PNS tissue in the same manner. Adult rats (n = 20) received fetal (day 14-15) forebrain grafts (either solid or cell suspension) to their rostral corpus callosum bilaterally. A second group (n = 20) received SCG solid and cell suspension grafts at the same coordinates with the same technique. The animals were killed on first, third, seventh, and tenth days after grafting. Intravenous HRP (Sigma, type VI, 75 mg/5-g rat) was given 1 hour before perfusion with mixed aldehydes. Fifty-micron coronal sections were examined for the presence and location of the graft by cresyl violet and AChE staining and Mesulam's TMB method to detect HRP leakage. HRP leakage was detected in the parenchyma in all groups on the first and the third days post-transplantation indicating a disrupted BBB. No HRP reaction was seen at days 7 and 10 in groups receiving fetal forebrain tissue whether solid or cell suspension. Solid grafts of SCG consistently demonstrated HRP leakage from the first through the tenth day. However, cell suspension of SCG established a BBB by 7 days. These results suggest that within the solid grafts of CNS and PNS tissue, the permeability of the vessels is dictated by the transplanted tissue itself. When cell suspensions of the same tissue are introduced, host CNS tissue dominates as the local environment resulting in non-leaky vasculature within the graft.

Animals↗

Benign extramedullary tumors in the foramen magnum region.

We present 16 cases of benign extramedullary tumors of the foramen magnum region who were operated on between the years 1984 and 1992. On admission, no case was neurologically intact and over 50% had had symptoms for more than 1 year. Nine patients had erroneous diagnoses initially. CT myelography and magnetic resonance (MR) imaging were the most appropriate diagnostic tools in visualizing tumors of this region. All operations except one, were performed by the posterior approach without surgical mortality. Histopathological examination revealed 8 meningiomas, 6 neurinomas, one tuberculous abscess and one neurenteric cyst which has not been reported at this location before. Patients with minor to moderate disability on admission showed good functional results without any recurrences during follow-up.

Adolescent↗

Pneumocephalus at the cerebellopontine angle secondary to chronic otitis media.

Intracranial air is usually asymptomatic but carries a potential risk of increased intracranial pressure or meningitis which require immediate therapy. Although pneumocephalus is quite common following trauma, especially with a fracture involving paranasal sinuses it is a rare manifestation of chronic otitis media. In this report, a case with a tension pneumocephalus at the cerebellopontine angle following a chronic mastoid infection is presented and the possible mechanism, diagnostic measures and the surgical management is discussed.

Adult↗

Fetal pituitary transplants into the hypothalamic area of hypophysectomized rats.

The pituitary tissue, when transplanted to extracerebral sites other than the normal anatomic position, fails to perform its secretory function properly. Several works on experimental intracerebral pituitary transplantation have shown that the transplanted tissue has been able to survive histologically. In this study, fetal pituitary tissue was implanted into the anterior hypothalamic area of the hypophysectomized rat by stereotactic methods. Electron-microscopic examination and hormonal blood levels demonstrated that ectopic pituitary tissue was able to survive to establish the correct anatomic relationship and thus perform secretory functions when transplanted intracerebrally.

Animals↗

Intracranial solitary chondroma. Case report.

A patient is described who had a solitary left frontal intracranial chondroma originating from the falx cerebri. The tumor was totally removed. The diagnostic value of computerized tomography and the surgical findings in this rare pathological condition are discussed.

Adult↗

Spinal hydatid cysts.

Eleven cases of spinal hydatid cyst are reported. The patients were admitted with symptoms of compression of the spinal cord. The cysts were localized epidurally in 10 patients and intradurally but extramedullarily in one, and were confirmed histopatholgically after surgical intervention. The results are compared with those reported in the literature. Six of the patients were female and five were male. Their ages ranged from 10 to 65 years. All of the patients were treated surgically, with an incidence of cyst recurrence of 18% and no mortality. Mebendazole (Vermox) was given to two of the patients after their operations.

Adolescent↗

The in-vitro and in-vivo characterization of PLGA:L-PLA microspheres containing dexamethasone sodium phosphate.

Dexamethasone sodium phosphate (DSP) is a widely used corticosteroid in the treatment of brain oedema associated with brain tumours. DSP has many side effects that limit its usage at an effective concentration. The objective of this study was to minimize these side effects by encapsulating DSP using biodegradable synthetic polymers, to extend the release time from microspheres and to evaluate the effectiveness in the treatment of brain oedema. Microspheres containing 5% DSP were formulated by the solvent evaporation method by using a 1:1 mixture of two synthetic polymers, poly(lactic-co-glycolic acid) and L-polylactic acid (PLGA and L-PLA). The surface morphologies and particle size distribution of the microspheres were investigated. The in-vitro release studies were performed in pH 7.4 phosphate buffer solution. For determining the effectiveness of microspheres in the treatment of brain oedema, Sprague-Dawley rats weighing 200-250g were used as an animal model. Brain oedema was generated by the cold lesion method, and the effectiveness of the microspheres in treatment of oedema was investigated by the wet-dry weight method, lipid peroxidation ratios and histological evaluations. The average particle size of the microspheres was 13.04 +/- 2.05 microm, and the in-vitro release time of the microspheres was 8 h for 100/release. The degree of oedema was significantly different from the control group for the wet-dry weight method and lipid peroxidation ratio (p < 0.05). Similarly, histological evaluation of the tissues shoved that degree of oedema was significantly decreased with respect to the control group. All these results showed that implantation of microspheres was significantly more effective with respect to the systemic administration of DSP.

Animals↗

Risk factors associated with corrective surgery in congenital scoliosis with tethered cord.

Severe neglected congenital scoliosis with tethered cord presents major difficulties in management. The primary objective of this study was to identify the risk factors associated with corrective scoliosis surgery in neglected cases presenting with severe deformity. Six patients who presented with such problems draw attention to the importance of a staged anterior and posterior approach in order to obtain satisfactory functional results. However, corrective surgery is associated with major neurologic and systemic complications, and every effort should be made to intervene with the progression of the deformity before corrective measures becomes necessary.

Adolescent↗