Biomedical subjects

Nejat Akalan

Publications and source records attributed to Nejat Akalan.

At least 19 recordsLinked to original sources

PubMed2006

Astrocytic tumors in children: treatment results from a single institution.

OBJECTIVE: The aims of this study are to evaluate the patients with astrocytomas and to investigate survival rates and prognosis. PATIENTS AND METHODS: Five hundred fourteen patients diagnosed with brain tumor between 1972 and 2003 were retrospectively analyzed. Three different chemotherapy regimens were used according to years. CCNU-based protocols were used in the early years; COPP (cyclophosphamide, oncovin, procarbazine, prednisolone) and CDDP+VP16 (cisplatinum + etoposide) were the other protocols used in the following years. Radiotherapy was used after 3 years of age according to protocols. RESULTS: Ninety-eight (19%) out of 514 patients have astrocytic histopathology. The histopathologic distribution was as follows: low grade, 55 patients; high grade, 43 patients. COPP regimen was given to 24 patients, CCNU-based regimen to 13, and CDDP+VP16 to 10 patients. We did not use any chemotherapy in 51 patients. Overall survival (OS) and event free-survival rates were 59.2 and 45.7% in whole group. OS rates were 93.3 and 22.4% for low-grade and high-grade histopathology, respectively (p=0.0001). OS for CCNU, CDDP+VP16, and COPP were 35.9, 22.8, and 30.4%, respectively. CONCLUSION: Low-grade astrocytomas are highly responsive to the surgery, and they do not need any further treatment unless the patient has relapse or recurrence. Still, the treatment of the high-grade tumors is a problem, and it needs new treatment approaches.

Adolescent↗

PubMed2006

Extraneural metastasis in intracranial tumors in children: the experience of a single center.

Our aim is to evaluate the clinical features and outcomes of children with primary central nervous system (CNS) tumors who develop extraneural metastasis (ENM). We retrospectively evaluated children diagnosed with primary CNS tumors treated at our institution between 1972 and 2004. Of 1,011 patients these tumors, 10 (0.98%) developed ENM. The histopathologic diagnosis was medulloblastoma in six patients, germ cell tumors in two patients, and ependymoma and atypical teratoid rhabdoid tumor (ATRT) in one patient each. In six patients, the primary tumor was located in the posterior fossa; it had a supratentorial location in the patient with ATRT, was located in the sellar and suprasellar region in the two patients with germ cell tumors, and was found in the distal spinal cord in the patient with an ependymoma. In two patients ENM was detected at the time of diagnosis. In other patients ENM developed between 9 and 25 months after diagnosis. Metastatic sites included bone, bone marrow, lung, cervical lymph nodes, liver, and paranasal sinuses. Of the 10 patients who developed ENM, 8 died of their disease 0.27-16.2 months (median, 2.60 months) after it was detected. One patient with dysgerminoma is alive, without disease, 117.80 months after diagnosis of the ENM. One patient with germ cell tumor is alive with disease 11.3 months after diagnosis of the ENM. Systemic metastasis to other extraneural sites is extremely rare in children with intracranial tumors. In our series the rate of ENM is 0.98%. The liver and lung are the most common site for metastasis, followed by the bone and bone marrow. The outcome is poor in patients with CNS tumors with ENM.

Adolescent↗

PubMed2006

Congenital cerebellar primitive neuroectodermal tumor in a newborn.

Neonatal primitive neuroectodermal tumor is a rare clinical entity. The initial presentation in affected newborns is often subtle, nonspecific, and rarely includes neurological signs. Here we report a newborn with congenital cerebellar primitive neuroectodermal tumor. We had detected hydrocephalus and enlarged biparietal diameter at the 36th week of gestational age by fetal ultrasonography.

Cerebellar Neoplasms↗

PubMed2006

Outcome and long term follow-up after corpus callosotomy in childhood onset intractable epilepsy.

INTRODUCTION: Epilepsy surgery is a standard of care in the treatment of medically intractable epilepsy. Twenty five percent of patients with intractable epilepsy in childhood can be candidates for epilepsy surgery. Corpus callosotomy is a surgical treatment option for patients with potentially injurious drop attacks and disabling generalized seizures. Postoperative improvement of cognition and speech are important gains after epilepsy surgery particularly during childhood. The aim of this study is to evaluate the outcome of corpus callosotomy for the treatment of childhood onset medically intractable epilepsy in a developing pediatric epilepsy surgery center. METHOD: We report 16 patients who underwent two thirds anterior corpus callosotomy for treatment of refractory seizures in childhood. RESULTS: All patients had drop attacks or multiple types of seizures, yet some showed focal onset with secondary generalization on electroencephalogram (EEG). One patient was seizure free (class 1 outcome), five had class 2A outcome, five had class 2B outcome, and five had class 3 outcome. Overall 11/16 (69%) of our patients improved significantly after anterior callosotomy. CONCLUSION: Corpus callosotomy remains to be a fairly good choice of surgical treatment for childhood onset medically intractable epilepsy in selected patients.

Adolescent↗

PubMed2006

Central nervous system tumors in patients under three years of age: treatment results of a single institute.

Eighty-six patients under 3 years of age with central nervous system tumors were retrospectively analyzed between 1972 and 2003. Surgical resection was done in all patients except for those with optic glioma, pons glioma and pineal tumor. Three different chemotherapy regimens were used in different time periods. In 48 patients, the tumor was located in the posterior fossa, and 29 patients had a supratentorial tumor. We had 32 (37.2%) patients with embryonic tumors (21 medulloblastoma, 4 ependymoblastoma, 5 with atypical teratoid rhabdoid and 2 with supratentorial primitive neuroectodermal tumors), 21 (24.4%) with ependymoma, 14 (16.3%) with optic glioma, 10 (11.6%) with astrocytoma, 3 (3.5%) with pons glioma and 6 (7.0%) with others. Overall (OS) and event-free survival rates were 49.5 and 40.9%. OS rates according to the tumor localizations were 40.9 and 68.1% in the posterior fossa and supratentorial localizations, respectively (p=0.001). OS rates were 33.7, 41.3 and 88.8% for the medulloblastoma+primitive neuroectodermal tumor groups, ependymoma and astrocytoma, respectively (p=0.0001). Most of the patients had primitive embryonic tumors (37.2%). The best prognostic factors were tumor localization and histology.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2006

Second malignant neoplasms following the treatment of brain tumors in children.

We investigated retrospectively 992 children with central nervous system tumors who were treated at our center between 1970 and 2004. All of the patients were treated by surgery, chemotherapy, and/or radiotherapy. Six patients developed second malignant neoplasms, and their clinical and histopathologic characteristics are reviewed in this article. The second malignant neoplasms were diagnosed as non-Hodgkin lymphoma, myelodysplastic syndrome, basal cell carcinoma, malignant melanoma, Kaposi sarcoma, and high-grade neuroectodermal tumor. The initial diagnoses were ependymoblastoma in one, medulloblastoma in three, and low-grade astrocytoma in two patients. The median latency time was 3.03 years (range 0.39-22.93 years). The outcome varied according to the histopathologic type of the second tumor. The patients who developed non-Hodgkin lymphoma and myelodysplastic syndrome died of progressive disease. The patients with second skin neoplasms are alive as of the time of this writing. The patient with Kaposi sarcoma developed one of the rare reported second malignant neoplasms following a primary brain tumor in childhood. A wide spectrum of second malignant neoplasms was detected after treatment of primary brain tumors with surgery, radiotherapy, and chemotherapy. Long-term follow-up is therefore necessary for the child who has survived a primary central nervous system tumor.

Brain Neoplasms↗

PubMed2006

Evaluation of parenchymal changes at the operation site with early postoperative brain diffusion-weighted magnetic resonance imaging.

PURPOSE: To evaluate diffusion changes in the brain parenchyma at the operation site during the first 24 hours following surgery. MATERIALS AND METHODS: The study group consisted of 52 patients, 39 who had tumor resection surgery and 13 who had epilepsy surgery. Early postoperative magnetic resonance imaging (MRI) included diffusion-weighted imaging (DWI) and routine contrast-enhanced cranial MRI, together with T2* weighted images on a 3T system. DWI findings and the presence of hemorrhage in the brain parenchyma were evaluated. Correlation between the findings, the primary lesion leading to surgery, and operation site were evaluated. RESULTS: Diffusion restriction in the parenchyma surrounding the resection cavity was seen in 17 tumor patients (32.7%, n=52) and in 8 epilepsy patients (15.4%, n=52). DWI showed increased diffusion in 7 patients and no abnormality in 4 patients. Twenty patients showed restricted diffusion pattern related to hemorrhage (38.5%, n=52). CONCLUSION: Restricted diffusion was the most common abnormality observed in the early postoperative DWI of brain parenchyma at the operation site after surgery, which suggested tissue injury caused by surgery. Yet, hemorrhaging in the operation bed can constitute another cause of a reduced apparent diffusion coefficient (ADC) value. Increased diffusion and normal diffusion can also be observed, though rarely.

Adolescent↗

PubMed2005

Epidermoid cyst of the brain stem symptomatic in childhood.

BACKGROUND: Epidermoid cysts may remain asymptomatic for a long period of time due to their slowly growing pattern corresponding with the normal human skin turnover time and due to soft and light cyst content. They do not cause compression of neural and vascular structures initially that is why almost all of the cases in the literature are diagnosed during adulthood. METHODS: We report here an epidermoid cyst in childhood, which was located in the medulla oblongata, unusually and atypically with liquefied cyst content. The liquefaction may occur due to an intrauterine or early childhood infection. The reported case also suffered previously a severe respiratory infection. Although the cyst is located in and around a highly eloquent neural area, plasticity of the brain stem prevented neurological deterioration due to this very slow growing extraaxial mass lesion. The ordinary cyst content found in the center of the cyst cavity during the operation suggested that the same ordinary material, which was previously at the periphery, ran to get liquefied in time. CONCLUSION: We suggest that the symptoms of this present case appeared very early due to liquefaction of the cyst content with compression and displacement of the brain stem caudally. The recent infection process may predispose the pathological condition.

Adolescent↗

PubMed2005

An unusual presentation of classic polyarteritis nodosa in a child.

Classic polyarteritis nodosa (c-PAN) is a rare disease in adults and extremely rare in children. We report a 3-year-old girl with c-PAN who presented with disturbances of consciousness and hypertension. Cranial tomography showed a subarachnoid hemorrhage. Subsequent magnetic resonance imaging and magnetic resonance angiography demonstrated subarachnoid hemorrhage and acute ischemic lesions. Renal angiography revealed bilateral multiple aneurysms. Due to her constitutional symptoms and hypertension and radiological findings she was diagnosed as having c-PAN. She was successfully treated with hydralazine followed by angiotensin-converting enzyme inhibitor, calcium channel blocker, intravenous pulse methylprednisolone, and subsequently oral prednisolone and oral cyclophosphamide. To our knowledge this is the youngest patient with c-PAN presenting with subarachnoid hemorrhage. Malign hypertension at this young age deserves a meticulous investigation of the vascular origin. Furthermore, treatment with pulse methyl prednisolone followed by oral prednisolone and oral cyclophosphamide is a successful modality of treatment in such a life-threatening presentation of c-PAN in childhood.

Acute Disease↗

PubMed2005

Carbidopa/levodopa-loaded biodegradable microspheres: in vivo evaluation on experimental Parkinsonism in rats.

The purpose of this study was to prepare and characterize injectable carbidopa (CD)/levodopa (LD)-loaded Poly(L-lactides) (L-PLA), Poly(D,L-lactides) (D,L-PLA) and Poly(D,L-lactide-co-glycolide) (PLAGA) microspheres for the intracerebral treatment of Parkinson's disease. The microspheres were prepared by solvent evaporation method. The polymers' (L-PLA, D,L-PLA and PLAGA) concentrations were 10% (w/w) in the organic phase; the emulsifiers [sodium carboxymethylcellulose (NaCMC):sodium oleate (SO) and Polyvinyl alcohol (PVA):SO mixture (4:1 w/v)] concentrations were 0.75% in the aqueous phase. Microspheres were analyzed for morphological characteristics, size distribution, drug loading and in vitro release. The release profile of CD/LD from microspheres was characterized in the range of 12-35% within the first hour of the in vitro release experiment. The efficiency of CD- and LD-encapsulated microspheres to striatal transplantation and the altering of apomorphine-induced rotational behavior in the 6-hydroxydopamine (6-OHDA) unilaterally lesioned rat model were also tested. 6-OHDA/CD-LD-loaded microsphere groups exhibited lower rotation scores than 6-OHDA/Blank microsphere groups as early as 1 week postlesion. These benefits continued throughout the entire experimental period and they were statistically significant during the 1, 2 and 8 weeks (p<0.05). CD/LD-loaded microspheres were specifically prepared to apply as an injectable dosage forms for brain implantation.

Animals↗

PubMed2005

Multilevel myelopathy in Maroteaux-Lamy syndrome and review of the literature.

An 18-year-old male with Maroteaux-Lamy syndrome was presented with spastic quadriparesis. Magnetic resonance imaging of whole spinal canal revealed stenosis at multiple levels of cervical, thoracic and lumbar regions. By the guidance of combined evaluations of neurological examination, neuroradiological and electrophysiological findings, the most responsible spinal segment was detected each time he developed myelopathy and he underwent craniocervical, cervical and thoracolumbar decompressions consecutively. Ligamentum flavum hypertrophy was found to be the principal pathology responsible for the cord compression and myelopathy for all levels. The etiology of myelopathy and priority of the level for which decompression should be done in diffuse spinal stenosis were discussed with the literature review of Maroteaux-Lamy syndrome.

Adolescent↗

PubMed2005

Answer to hypotonia: a simple hemogram.

A 1-year-old boy with weight loss, decreased activity, and psychomotor regression is presented. He was subjected to an extremely detailed evaluation, including electroencephalography (EEG) and magnetic resonance imaging (MRI), until a simple hemogram in our center revealed that he had macrocytic anemia with megaloblastic changes in the bone marrow. His history revealed that he had been exclusively breast-fed by his vegetarian mother. Further investigations showed low serum vitamin B12 concentration, methylmalonic aciduria, and homocysteinemia, indicating that the macrocytic anemia was due to vitamin B12 deficiency. This boy represents a case of macrocytic anemia and hypotonia owing to vitamin B12 deficiency that developed because of exclusive breast-feeding by a vegetarian mother.

Anemia, Macrocytic↗

PubMed2005

Surgical management of temporal lobe tumor-related epilepsy in children.

OBJECT: Slow-growing, low-grade temporal lobe tumors are one of the most common causes of epilepsy in children. Although there are numerous consistent features in this patient group, consensus about the management and surgical approach is lacking. In this study the authors review the clinical, pathological, and radiological features as well as outcome data obtained in 29 pediatric patients with temporal lobe tumor-related epilepsy and discuss the surgical treatment strategies. METHODS: In patients who presented with intractable seizures secondary to mass lesions and underwent comprehensive epilepsy workup, the tumor was resected and the diagnosis confirmed by pathological examination. A minimum follow-up period of 16 months was required. Medical records were reviewed for details of seizure type and duration, electrophysiological data, imaging studies, operative notes, pathological examination reports, and follow-up data. The surgical approach was as follows. The lesionectomy with/without cortical resection was performed in all cases of lateral temporal tumors. Lesionectomy was performed with/without cortical resection in cases of basal temporal tumors if the mesial structures were radiologically normal. Mesial temporal tumors were excised, as were the remaining mesial temporal structures in the nondominant hemisphere; however, if the tumor was in the dominant hemisphere, lesionectomy was performed only if the remaining mesial structures were radiologically normal. Twenty-nine patients between 2 and 18 years of age were identified. Most tumors were located in the mesial temporal lobe. All patients underwent resection of the tumor with or without mesial and cortical structures. The most common pathological entity was dysembryoplastic neuroepithelial tumor. Sixty-nine percent of the patients remained seizure free (Engel Class I) and 14% experienced significant improvement (Engel Class II) after surgery. Outcome was better in the patients who underwent gross-total tumor resection. CONCLUSIONS: Mesially located low-grade neoplasms were the most frequently observed mass lesions in children with temporal tumor-related epilepsy in this series. Resection of the tumor with or without amygdalohippocampectomy provides a high rate of seizure-free outcome. It is the author's opinion that temporal lobe tumors should be managed based on the subgroups defined by their anatomical locations. If the tumor is located in or in proximity to eloquent cortex, we recommend functional magnetic resonance imaging and invasive monitoring techniques to map the eloquent cortex and epileptogenic zone, thereby tailoring the resection.

Adolescent↗

PubMed2004

Diastematomyelia: a case with familial aggregation of neural tube defects.

Intrauterine neural tube defects, meningomyelocele, and diastematomyelia are developmental errors at different stages of the closure of the neural tube. The familial aggregation of these neural tube defects is not previously reported in the literature and should make one think about a common embryogenesis and a possible common mechanism of etiopathogenesis leading to anomalies at different stages of this embryogenesis. This paper presents a 12-year-old Turkish boy with diastematomyelia who was suspected with a demonstrative dermatologic finding without any neurologic sign and diagnosed with magnetic resonance imaging (MRI). He has a positive family history of a stillbirth with neural tube defect, an exitus with meningomyelocele, and an epileptic child in his female siblings.

Adult↗

PubMed2004

Eosinophilic granuloma of the skull associated with epidural haematoma: a case report and review of the literature.

INTRODUCTION: Eosinophilic granuloma (EG), a benign bone lesion, represents a focal form of histiocytosis X. Here, the authors report a case of an extremely rare presentation of a solitary EG of the skull. CASE REPORT: A 9-year-old boy presented with headache and vomiting for 3 days. His examination was unremarkable except for a tender mass in his left occipital region. Radiological studies revealed a huge bilateral epidural haematoma under the occipital bone, extending supratentorially and infratentorially, and a nonenhanced, epidural, soft tissue mass overlying the left transverse sinus. Evacuation of the epidural haematoma was performed and it was noted that the left transverse sinus wall was eroded by the EG at one point with venous oozing. REVIEW OF THE LITERATURE: The acute presentation of a solitary EG of the skull with an epidural haematoma was described in only four cases in the literature. This is the first documented case in terms of the origin of an epidural haematoma.

Brain↗

PubMed2004

Radiation-induced malignant triton tumor associated with severe spinal cord compression. Case report and review of the literature.

Malignant triton tumor (MTT) is a variant of malignant peripheral nerve sheath tumors. The authors report a case of radiation-induced MTT in a patient with severe cervicothoracic cord compression and review the related literature. This 36-year-old man presented with pain and weakness in his left arm. His medical history was significant for a biopsy procedure involving the sampling of an aneurysmal bone cyst located at T1-3 near the left lung apex; this was performed 6 years prior to presentation and was followed by radiotherapy. Neurological examination demonstrated radicular findings involving the left C-8 and T-1 nerve roots. Neuroimaging studies revealed a large mass lesion extending from C-6 to T-2 along the vertebral column, invading the upper thoracic cavity and the adjacent lung apex, and infiltrating the paravertebral muscles. A subtotal resection was performed, but the tumor regrew extensively within a short time. It invaded the spinal canal and caused significant cord compression. The patient underwent surgery two more times for tumor debulking and to relieve progressive airway and spinal canal compromise. He eventually became quadriplegic, however, and died 13 months after diagnosis of MTT. This is the seventh case of radiation-induced MTT and the fifth of MTT with spinal canal involvement to be reported in the literature.

Adult↗

PubMed2003

The efficacy of convex hemiepiphysiodesis in patients with iatrogenic posterior element deficiency resulting from diastematomyelia excision.

STUDY DESIGN: Retrospective analysis was performed. OBJECTIVE: To investigate the safety and efficacy of anterior and posterior hemiepiphysiodesis in patients with iatrogenic posterior element deficiency. SUMMARY OF BACKGROUND DATA: Anterior and posterior convex hemiepiphysiodesis is a well-accepted treatment method for severe and progressive congenital scoliosis in young children. Many patients with congenital spinal deformities have intraspinal pathologies that require neurosurgical intervention with laminectomy. The efficacy of this method has not been studied in these patient populations. METHODS: Between 1990 and 2001, among 82 patients with congenital spinal deformity, 38 were treated with convex epiphysiodesis. This study included 18 of these patients (2 males and 16 females) who underwent diastematomyelia excision and had at least 2 years of follow-up evaluation. Diastematomyelia excision was performed before the orthopedic procedure in 8 patients and at the same anesthetic setting sequentially in 10 patients. The mean age at the time of the fusion was 20 months (range, 6-60 months), and the average follow-up period was 39 months (range, 24-120 months). RESULTS: The mean Cobb angle was 54 degrees (range, 31-90 degrees) before surgery and 48 degrees (range, 30-84 degrees) at the final follow-up assessment. Any increase of more than 6 degrees was accepted as progression. Eight patients (44%) had a true epiphysiodesis effect: 58 degrees (range, 40-90 degrees ) before surgery and 39 degrees (range, 30-70 degrees) at follow-up evaluation. Eight patients (44%) had a fusion effect: 49 degrees (range, 31-68 degrees) before surgery and 50 degrees (range, 37-74 degrees) at follow-up assessment. Two patients (12%) had a postoperative progression of deformity: 63 degrees (range, 54-72 degrees) before surgery and 75 degrees (range, 65-84 degrees) at follow-up evaluation. CONCLUSIONS: Convex epiphysiodesis is an effective method for patients with midline laminectomy defect as those with intact posterior elements. Because the facet joints and transverse processes usually are unaffected, the presence of midline defect does not diminish the efficacy of the technique.

Abnormalities, Multiple↗

PubMed2003

Acute blindness as a presenting sign in childhood non-Hodgkin lymphoma.

Non-Hodgkin lymphoma is the third most common malignancy in childhood. Occasionally, a patient with lymphoma may present with neuroophthalmologic symptoms and signs. It is usually associated with 3rd, 4th, and 6th cranial nerve palsies. Here, we report three children presenting with loss of vision. Two of them were cured with modified LMB-89 (lymphoma malignant B) chemotherapy regimen and radiotherapy. In one patient, loss of vision returned to normal in the left eye but persisted in the right eye. The second patient suffered from permanent visual loss, although the primary disease responded well to treatment. Unfortunately, the third patient died at an early phase of treatment. Acute blindness as a presenting symptom is rare in lymphoma. Early diagnosis and treatment is critical to increase the survival rate and to improve the quality of the vision.

Acute Disease↗