Ilkay Isikay

Thalamic tumors in children.

IntroductionThalamic tumors are rare tumors which are usually diagnosed in the pediatric age group. Although recent developments in neurosurgical practice allow more radical treatments, information about outcome is scarce for these deep-seated challenging tumors.MethodsMedical records of 45 pediatric patients who presented with thalamic tumors between 1999 and 2012 were reviewed.DiscussionPrognostic implication of tumor characteristics and patient variables are discussed. Although challenging, recent innovations in the field of neurosurgery and refinements in technique may prolong survival in some cases.

A potential non-invasive glioblastoma treatment: Nose-to-brain delivery of farnesylthiosalicylic acid incorporated hybrid nanoparticles

Abstract New drug delivery systems are highly needed in research and clinical area to effectively treat gliomas by reaching a high antineoplastic drug concentration at the target site without damaging healthy tissues. Intranasal (IN) administration, an alternative route for non‐invasive drug delivery to the brain, bypasses the blood‐brain‐barrier (BBB) and eliminates systemic side effects. This study evaluated the antitumor efficacy of farnesylthiosalicylic acid (FTA) loaded (lipid‐cationic) lipid‐PEG‐PLGA hybrid nanoparticles (HNPs) after IN application in rats. FTA loaded HNPs were prepared, characterized and evaluated for cytotoxicity. Rat glioma 2 (RG2) cells were implanted unilaterally into the right striatum of female Wistar rats. 10 days later, glioma bearing rats received either no treatment, or 5 repeated doses of 500 &mgr;M freshly prepared FTA loaded HNPs via IN or intravenous (IV) application. Pre‐treatment and post‐treatment tumor sizes were determined with MRI. After a treatment period of 5 days, IN applied FTA loaded HNPs achieved a significant decrease of 55.7% in tumor area, equal to IV applied FTA loaded HNPs. Herewith, we showed the potential utility of IN application of FTA loaded HNPs as a non‐invasive approach in glioblastoma treatment. Graphical abstract Figure. No Caption available.

Early rehabilitation improves neurofunctional outcome after surgery in children with spinal tumors

To investigate the effect of early rehabilitation on neurofunctional outcome after surgery in children with spinal tumors, this study reviewed the medical charts and radiographic records of 70 pediatric patients (1–17 years old) who received spinal tumor surgical removal. The peddiatric patients received rahabilitation treatment at 4 (range, 2–7) days after surgery for 10 (range, 7–23) days. Results from the Modified McCormick Scale, Functional Independence Measure for Children, American Spinal Injury Association Impairment Scale and Karnofsky Performance Status Scale demonstrated that the sensory function, motor function and activity of daily living of pediatric children who received early rehabilitation were significantly improved. Results also showed that tumor setting and level localization as well as patientss clinical symptoms have no influences on neurofunctional outcomes.

Comparison of nimodipine delivery routes in cerebral vasospasm after subarachnoid hemorrhage: an experimental study in rabbits.

BACKGROUND nimodipine is the most widely preferred and administered calcium channel blocker in cerebral vasospasm prevention and treatment. There is no experimental or clinical study investigating the comparative effects of routine treatment modalities. METHOD 35 male New Zealand White rabbits were assigned randomly to one of seven groups: Control, only SAH, SAH/oral nimodipine, SAH/IV nimodipine, SAH/IT nimodipine, SAH/IA nimodipine, SAH/angiography. FINDINGS basilar artery vessel diameters are measured by angiography. Basilar artery vessel diameters and luminal sectional areas are measured in pathology slides. Basilar artery thicknesses were significantly higher in group 2 and 7 than the others (p < 0.05). Luminal sectional areas in group 5 and 6 were significantly higher than other groups (p < 0.05). We found no significant difference in group 1, 5 and 6 (p > 0.05). Basilar section areas in group 3 and 4 were significantly higher than group 2 but lower than group 1. CONCLUSION this is the first study to show the most effective drug delivery route in CVS after SAH. Nimodipine treatment in cerebral vasospasm is useful. This study showed that selective IA nimodipine treatment and IT nimodipine treatment must be preferred to IV and oral treatments of chronic vasospasm following SAH.

Unilateral Teleoperation Design for a Robotic Endoscopic Pituitary Surgery System

The aim of this study is to develop a teleoperation system which will be used to support the endoscopic pituitary surgery procedures. The proposed system aims to enable the surgeon to operate with three different operation tools (one of them is the endoscope) simultaneously. By this way, it is expected that the productivity of the surgical operation will be improved and the duration of the operation will be shortened. In the proposed system, a main control unit that can be attached to any of the surgical tools that are used in the operation (other than the endoscope) will be developed to capture the motion of the surgeon’s hand motion as demanded by the surgeon, to process the captured motion and to send it to the robot that handles the endoscope. In this way, the endoscope will be directed simultaneously by the surgeon throughout the operation while he/she is using the other surgical tools with his/her two hands. In this paper, the study to determine the type and processing of information that is sent from the surgeon’s side to the endoscope robot is presented.

Viscoelastic Modeling of Human Nasal Tissues with a Mobile Measurement Device

Modeling the dynamic of tool-tissue interaction for the robotic minimally invasive surgeries is one of the main issues for designing appropriate robot controllers. A mobile measurement device is produced in order to model some nasal tissues of a human. This mobile device is a hand-held one which measures the applied moments and relative angular displacements about a fixed pivot point. The ex-vivo measurements are realized by surgeons on a relatively fresh human cadaver head. The tip of the nose and the nasal concha are the two tissues that are investigated. In this study, five different viscoelastic models are considered; Elastic, Kelvin-Voight, Kelvin-Boltzmann, Maxwell and Hunt-Crossley. The results are evaluated and cross-validated on each data set. Hunt-Crossley and Kelvin-Boltzmann models provided the minimum root-mean-square (RMS) error among the other models.

An extremely rare complication following frontoorbital advancement: infarction of the recurrent artery of Heubner.

Many intracranial as well as extracranial complications can be seen following craniosynostosis surgeries. In this article, we would like to share an extremely rare complication of the infarction of the recurrent artery of Heubner, occurred following frontoorbital advancement. In this case, an 18-month-old male patient underwent supraorbital bar and frontal bone remodeling surgery for nonsyndromic metopic suture synostosis. The preoperative neurosurgical evaluation revealed no signs of increased intracranial pressure. On the 3rd postoperative day, the patient developed asymmetric smile and weakness on the left extremities. Computerized tomography showed a hypodense infarction region around the right basal ganglia and internal capsule, concordant with the region supplied by the recurrent artery of Heubner. The patient’s symptoms started to regress on the 2nd day of enoxaparine treatment and he was discharged on 12th postoperative day with almost no signs of the event. In this paper, we presented an unlikely complication after frontoorbital advancement. Keeping in mind the long operating time and the proximity of the procedure to the central nervous system, assessment of the neurological function of the patients both before and after the operation and rapid intervention in case of development of neurologic symptoms are of great importance.

Splitting of the Optic Nerve by a Pituitary Macroadenoma

BACKGROUND Splitting of the optic nerve by a pituitary adenoma is an extremely unusual condition with only 3 cases reported to date. CASE DESCRIPTION A 41-year-old woman presented with visual loss as a result of an aggressive pituitary macroadenoma causing the splitting of the right optic nerve. Possible mechanisms of this condition are discussed, and the literature is reviewed. CONCLUSIONS In aneurysm and tumor cases, awareness of the exact anatomy is particularly important to preserve function. An overlooked duplication or penetration of cranial nerves may result in inadvertent injury to important structures and loss of function.

Somatotroph adenoma cells may populate paranasal sinus mucosa.

Dear Editor, We would like to present a case, which we believe, is an interesting one. A 39-year-old acromegalic male patient was referred to our institute with a pituitary adenoma which was diagnosed in another center after he had had three nasoplasty operations on his nose due to increasing size. On admission, growth hormone (GH) level was measured to be 16.0 ng/mL (0.06–1 ng/mL). He had a Hardy grade III B adenoma. The remaining laboratory workup and medical history was unremarkable. An endoscopic transsphenoidal pituitary surgery was performed and adenoma was thought to be excised totally evident with postoperative MRI findings (Fig. 1a). The patient was discharged on the second postoperative day without any complication. During his endocrinological follow-up, a random GH level was 5.65 ng/mL and IGF-1 level was 912 ng/mL (100–494 ng/mL), which were above the acceptable limits in regard to cure criteria [3]. Another radiological and endocrinological workup was performed in postoperative month 4, and residual adenoma was diagnosed on sphenoid sinus mucosa and residue-free sellar space was documented (Fig. 1b). The patient was reoperated 4 months later via endoscopic transsphenoidal route; sellar floor was not opened and only mucosal excision was performed targeting to excise the adenoma on sphenoid sinus mucosa and adenoma tissue was histopathologically confirmed. Examination of the tissues from the sphenoid sinus mucosa revealed a hyalinized tissue containing perivascular chronic inflammation and areas of old hemorrhage. Surface respiratory epithelium was denuded and a cell group with clear cytoplasm is attached to the tissue. These cells had histological features reminiscent of the pituitary adenoma removed previously. Further studies revealed collapsed reticuline architecture, diffuse GH positivity, and focal and weak prolactin positivity (Fig. 1c). Postoperative MRI revealed gross total excision of residual tumor (not shown here). Follow-up GH and IGF-1 levels were 0.862 and 244 ng/mL, respectively. Although we had residue-free early postoperative images, because of continuing high levels of GH, we repeated the MRI scan. We believe that diagnosis of a residual somatropinoma on sphenoid sinus mucosa is interesting since there is no other example in the printed literature. Some ectopic sources of GH and ectopic somatotropinoma have been reported; however, none of them are due to parasellar seeding of the primary tumor [1, 2]. Endoscopic transsphenoidal route was used in both operations which provided a panoramic vision and a much closer view to the surgical target. Some pituitary adenomas are leaky in consistency which was also true for the presented case. During surgery, the flow of adenoma particles through the mucosal lining of sphenoid sinus could be seen. There had been much attempt for suction of these but it seems that some of the particles had escaped from our vision despite the enhanced capabilities of endoscopic route. In this regard, it would be honest to say that this case represents an iatrogenic I. Isikay (*) :M. Berker Department of Neurosurgery, Hacettepe School of Medicine, Ankara, Turkey e-mail: ilkayisikay@yahoo.com