Patients with multiple congenital abnormalities and mental retardation are the most frequent patient group who are referred to a genetic clinic. Specific diagnosis for these patients will provide a better understanding of the possible reasons of pathogenesis, thereby providing more true information to families on recurrence risk, prognosis, possible treatment options and prenatal diagnosis. With the aim of finding out the etiology of the genetic diseases, 4659 patients who were classified into mental retardation or multiple congenital anomaly and mental retardation (MR or MCA/MR) group who were referred to Istanbul University, Departments of Medical Genetics of Cerrahpasa Medical Faculty and Istanbul Medical Faculty in between 1985 and 2005 were analyzed retrospectively and a two step study was generated: first step involved the etiologic classification of MR or MCA/MR group and the second evaluation of the factors that help in finding out the etiologies such as age at first observation, number and periods of observations and completion of laboratory tests. In the first part of the study, etiologic classification of the patients with MR or MCA/MR who were referred to genetic clinics of the two medical faculty of Istanbul University were mentioned. 2847 patients have had an etiological diagnosis (61.10%): from these patients, 1541 out of them had a chromosomal abnormality (33.07%), 555 were known single gene mutations (11.91%), 20 were recognized syndromes (00.42%), 567 were sequences (12.16%), 6 were associations (00.12%), 29 had spectrums (00.62%), 98 had structural abnormality of CNS (2.10%), and finally, 31 suffered from prematurity and its complications, toxic drugs, infections and hypoxic ischemic encephalopathy. This study will be the one of the biggest studies in Turkey and also around the world, evaluating the most frequent patient group referred to genetic clinics: MCA or MR.

Two thousand nine hundred and seventy-five patients with mental retardation or multiple congenital anomaly and mental retardation (MR or MCA/MR), who were referred to Istanbul University (Departments of Medical Genetics of Cerrahpasa Medical Faculty and Istanbul Medical Faculty) in between 1985 and 2005, were evaluated in order to find out the factors that elucidate the etiology (age at first observation, number and periods of observations and completion of laboratory tests). This is a complementary study of the first part revealing the etiologic classification of MR or MCA/MR patients in our clinics that were performed by 4659 patients. For this part of the study, cases with clinically diagnosed Down Syndrome patients (n: 1179) and neural tube defects (n: 505) were excluded out of the 4659 patients because of availability of diagnosis at first sight. Thus, 2975 patients with MR or MCA/MR were evaluated for the factors that help in the elucidation of the etiologic diagnosis such as age at first observation, number and periods of observations, completion of laboratory tests and the way of diagnosis). The most frequent ages of the MR or MCA/MR patients who were referred for the first time to our genetic clinics were between 1 and 5 years. Moreover, the maximum diagnosis rate was found to be between 1 and5 years of life (50.92%). The ratio of diagnosis at first examination was 27.59% in MR or MCA/MR patients. However, most of them did not attend following examinations (954/2975, 34.31%). From the patients that had a diagnosis, 70.50% of them underwent diagnosis at first examination. The patients who had an etiological diagnosis were mostly examined during 0 to 1 year. Further, a significant number of the diagnosed cases belonged to this group (86.15%). In these patients, 32.67% of undiagnosed cases had incomplete investigation results and 24.83% of them had none of the test results. This quotient was less in diagnosed cases. Etiologically diagnosed 1163 patients were investigated for the method of diagnosis. The results were determined as follows: 459 had a clinical diagnosis (45.48%) and 634 had a specific diagnosis by applying particular laboratory tests (54.51%). This study will be the one of the biggest study in Turkey and also around the world, evaluating the most frequent patient group referred to genetic clinics - MCA or MR.

Vestibular schwannomas (VSs) are rarer in children than in adults and are often associated with neurofibromatosis 2 (NF2). We focus on characteristic presentations of VSs in children (< 16 years old) both with and without NF2 and illustrate essential surgical steps using the retromastoid suboccipital approach. Materials and Methods: Three patients had unilateral tumors and five had bilateral tumors with associated NF2. On computed tomography (CT)/ magnetic resonance (MR) imaging, tumor diameters were measured parallel and perpendicular to the petrous ridge and vertically in coronal slices. The size of the VS was taken as the largest diameter in any one axis. Tumors were categorized as: Small: < 1 cm in size; Medium: 1-2.5 cm; Large: 2.5-4 cm and Giant: > 4 cm. Surgery was done in the park-bench position using the suboccipital retromastoid approach. Results: Raised intracranial pressure (ICP), often with visual deterioration, was the most commonly found presentation. Preoperative VIIth nerve involvement was grade IV in three, III in two and II in two patients. One of the patients with NF2 with proptosis did not have any VIIth nerve deficit. None of the patients had any functionally useful hearing on the side of larger tumor. Tumors were giant in six and large in two patients. In NF2 patients, two patients had large, two had medium-sized and one patient had a small contralateral tumor. Seven patients had significant hydrocephalus out of which three underwent ventriculoperitoneal shunt. Total excision of the larger lesion was performed in six patients. A small tumor remnant was left adherent to the preserved VIIth nerve in one patient. A patient with NF2 underwent excision of orbital neurofibroma and is awaiting surgery for VS. Two patients underwent bilateral VS excision. Anatomical preservation of the VIIth nerve was possible in six out of seven patients who underwent tumor excision. Postoperatively, symptoms of raised intracranial pressure and ataxia improved; visual deficits continued to deteriorate in two and VIIth nerve function deteriorated from grade III to V. Conclusions: In children, only a high degree of awareness facilitates early diagnosis of VS; otherwise, initial complaints may be neglected and the underlying tumor detected only after incapacitating raised ICP features appear. The retromastoid suboccipital approach is an effective approach for safe removal of large to giant-sized tumors.

The insertion of a ventriculoperitoneal shunt is one of the most common pediatric neurosurgical procedures. A majority of these operations are efficient by junior doctors. Any modification to the technique that makes the procedure easier may decrease the number of complications. The authors describe a quick modification to the ventriculoperitoneal shunt introducer. This enables the easy and fast tunneling for catheter insertion, even in the patient with a massive head due to neglected hydrocephalus, thereby decreasing the operative time and possibly the risk of infection.

Congenital brain tumors are very rare neoplasms. The diagnosis of glioblastoma multiforme in a newborn infant is a rarity. Prognosis of congenital glioblastoma has been uniformly fatal with most of the cases reported in literature having a very short survival in spite of all modalities of treatment. The authors report a case of congenital glioblastoma involving the pan right cerebral hemisphere in a two month-old infant who expired six months after tumor decompression. Literature is reviewed in light of the present case and various treatment modalities for this rare tumor are highlighted.

Hydatid disease is caused by the infestation of the larvae of Taenia echinococcus. The definite hosts of echinococcus are various carnivores, the common being the dog. All mammals (more often being sheep and cattle) are hosts. Humans are infected through the feco-oral route by the ingestion of food or milk contaminated by dog feces that contain the ova of the parasite or by direct contact with dogs. The eggs lose their enveloping layer in the stomach, releasing the embryos. The embryos pass through the wall of the gut into the portal system and are carried to the liver where most of the larvae are entrapped and encysted. Some may reach the lungs, and occasionally, some may pass through the capillary filter of the liver and lungs and enter into the systemic circulation. We report a case of giant intracranial left temporoparietooccipital extra-axial hydatid cyst with a size of 12.5 x 8.5 cm in a 5-year-old male presented with holocranial headache with the diminution of vision and papilledema with right hemiperesis successfully managed in our department surgically.

Epidermoids are inclusion tumors of the central nervous system and are rare, benign slow-growing tumors. They are estimated to constitute 0.5-1.8% of the brain tumors and have an affinity for the subarachnoid cisterns at the base of the brain, the suprasellar cistern being one of the most favoured sites. We report a case of suprasellar epidermoid in a 2-year-old male child with an unusual CT and MRI appearance, who presented to us in February 1995 with features of precocious puberty. In October 2004, at the age of 11 years, he presented with symptoms and signs of raised ICP.

Osteosarcoma is the most common type of bone malignancy. The primary mode of metastasis is hematogenous. Lung metastasis is common. Isolated hemorrhagic intra-cerebral metastasis has not been reported earlier. This case report is of an 11-year-old boy with proximal tibial osteosarcoma who presented with right focal seizures secondary to a hemorrhagic solitary deposit in the left posterior frontal region. Histopathology confirmed this to be a metastasis from an osteosarcoma.

Medullomyoblastoma (MMB) is a rare embryonal cerebellar neoplasm with both primitive neuroectodermal and striated muscle components. It occurs exclusively in children. It typically arises from the cerebellar vermis. There are only 54 case reports in the published literature. We report an additional case of a 7-year-old boy with fourth ventricular MMB that is unique in its site of origin, intratumoral hemorrhage and calcification.

Bilateral symmetric calcification involving striatum pallidum with or without deposits in the dentate nucleus, thalamus and white matter is commonly referred to as Fahr's syndrome. Symptoms of the disorder may include deterioration of motor function, spasticity, spastic paralysis, dysarthria, dementia, seizures, headache and athetosis. The clinical and imaging abnormalities are restricted to the central nervous system (CNS). We report an unusual association of Fahr's syndrome with polyarticular juvenile idiopathic arthritis in a girl.