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ABSTRACT: We aimed to evaluate the efficacy and reliability of gamma-knife radiosurgery (GKR) in 22 patients with acromegaly at the Endocrinology-Metabolism Clinic of Cerrahpasa Medical School. We collected data retrospectively from hospital records on disease activity and other pituitary functions, pituitary MRI and visual fields, before GKR and 6, 12, 24, 36, 48 and 60 months after GKR. The median follow-up duration after GKR was 60 months (interquartile range [IQR]: 24-60 months). The remission rate was 54.5% after the 60 months of follow-up. The median growth hormone (GH) level at 60 months after GKR (0.99 ng/mL [IQR: 0.36-2.2]) was significantly lower than the median GH level before GKR (5.65 ng/mL [IQR: 3.85-7.2] (p=0.002). The median insulin-like growth factor-1 (IGF-1) level 60 months after GKR (221.5 ng/mL [IQR: 149-535]) was significantly lower than the median IGF-1 level before GKR (582.5 ng/mL [IQR: 515-655]) (p=0.008). Tumour growth was well controlled in 20 patients (95.2%). Six patients (28.6%) developed new-onset hypopituitarism. We concluded that GKR is an effective adjuvant treatment to control tumour growth, lower GH and IGF-1 levels, and to increase remission rates in patients with acromegaly who were refractory to surgical and medical treatment.
Journal of Clinical Neuroscience 12/2011; 18(12):1616-20. · 1.25 Impact Factor
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ABSTRACT: We present the outcomes of 35 uveal melanoma patients treated with gamma knife stereotactic radiosurgery. All cases were previously untreated. During follow-up, regular MRI examinations were used to detect any changes in tumor size and estimate the local long-term tumor control rate. Treatment-related complications were also recorded. During follow-up, systemic dissemination was observed in two patients, one of whom died of metastases. The most frequent complication was retinal detachment (17.1%). Three patients required enucleation. Cumulative 1-year and 3-year local tumor growth control rates were 97% and 83%, respectively. The mean and median times to local tumor progression were 48.0 and 51.7 months, respectively. Gamma knife surgery may be a suitable alternative for the treatment of low-volume uveal tumors without intraocular complications, as the control rate and long-term outcomes compare favorably with those of surgical excision and brachytherapy.
Journal of Clinical Neuroscience 04/2010; 17(4):441-5. · 1.25 Impact Factor
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ABSTRACT: The treatment of glomus jugulare tumors represents a challenge for the neurosurgeon, since they invade major vessels and compress critical cranial nerves, resulting in significant morbidity from tumor resection. Among alternative and complementary treatment options, gamma knife radiosurgery is a less invasive procedure and may provide better protection of vital structures. This study aimed to evaluate the efficacy and long-term outcomes of gamma knife surgery in the treatment of these tumors in a large series with the longest follow-up period compared with previous reports. A total of 18 patients with glomus jugulare tumors that underwent gamma knife radiosurgery (GKS) were included. Eleven patients had a history of previous microsurgical treatment. The mean marginal radiation dose was 15.6 Gy (median 15 Gy, range 13-20 Gy). Patients were followed for a mean period of 52.7 months (median 41.5 months); the effect of gamma knife radiosurgery was evaluated using magnetic resonance (MR) images. Based on the last MR images, tumor control could be achieved in 17 out of 18 patients (94.4%). No complications such as radiation-induced peritumoral edema or radiation necrosis occurred. Neurological follow-up examinations revealed improved clinical status in ten patients (55.6%), stable neurological status in seven (38.9%), and deterioration in one patient (5.5%). At the last visit, 17 out of 18 patients were alive. Our results indicate that stereotactic radiosurgery is an effective and safe treatment modality in the management of glomus jugulare tumors, particularly for residual or previously untreated small tumors.
Journal of Neuro-Oncology 09/2009; 97(1):101-8. · 3.21 Impact Factor
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ABSTRACT: The trigemino-cardiac reflex (TCR) is a well-known reflexive response in which bradycardia, hypotension, and gastric hypermotility are induced by stimulation of a peripheral or central portion of the trigeminal nerve. This reflex occurs during craniofacial surgery and other operations on or near the cerebellopontine angle, petrosal sinus, orbit and trigeminal ganglion. TCR is a well-known, although not well documented, phenomenon commonly observed during trans-sphenoidal surgery for resection of pituitary adenomas. We report a case in which asystole occurred during trans-sphenoidal surgery on a pituitary adenoma that was infiltrating the right cavernous sinus. When the anesthesiologist reported asystole, the team stopped manipulation and administered intravenous atropine. Intra-operative MRI showed a small tumour remnant in the right cavernous sinus. The operation was terminated but subsequent radiosurgery was planned for the residual tumor. Although TCR is rare and usually self-limiting, this case led us to change our treatment strategy. Surgeons who perform trans-sphenoidal surgery should be aware of this potential problem. Invasive pituitary adenomas should be removed gently and the risk of triggering TCR should be kept in mind.
Journal of Clinical Neuroscience 01/2009; 16(2):338-40. · 1.25 Impact Factor
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ABSTRACT: Medical treatment is usually ineffective for Holmes' tremor, and surgery is the treatment of choice for many patients. Here we report the case of a 14-year-old girl who developed Holmes' tremor related to a thalamic abscess and was successfully treated with thalamic deep brain stimulation.
The patient presented with left hemiparesis and headache and was hospitalized. Investigation revealed a thalamic abscess in the left cerebral hemisphere. The abscess was drained via stereotactic surgery and a course of antibiotic treatment was completed. Four months after treatment, the patient developed Holmes' tremor in her left upper extremity. When attempts at medical treatment with levodopa, clonazepam, and trihexyphenidyl all failed, an implant was placed and deep brain stimulation of the ventral intermediate nucleus of the thalamus was initiated. During 2.5 years of follow-up, her tremor diminished by 90%.
This case demonstrates that medically resistant Holmes' tremor related to a thalamic lesion can be successfully treated with thalamic deep brain stimulation.
Child s Nervous System 07/2008; 24(9):1057-62. · 1.54 Impact Factor
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ABSTRACT: Superficial siderosis of the central nervous system is a rare, progressive, irreversible and debilitating neurological disease characterized by the deposition of haemosiderin in the leptomeninges and the subpial layers of the brain and spinal cord. The main clinical findings are progressive bilateral sensorineural hearing loss, cerebellar ataxia and pyramidal tract signs. The present report describes a 49-year-old woman who presented with intermittent headache of 5 years duration. The pain had become more severe in the previous 6 months. Neurological examination revealed nothing abnormal. Computed tomography showed a cystic mass with apparent internal haemorrhage in the right frontal lobe and T(2)-weighted magnetic resonance imaging showed material of low signal intensity coating the entire surface of the brain. The mass was completely excised via craniotomy. A histopathological study identified the mass as a papillary glioneuronal tumour. The patient recovered well and is still neurologically normal 1 year later. This is the first documented case of superficial siderosis caused by this type of tumour.
Journal of Clinical Neuroscience 12/2006; 13(9):950-2. · 1.25 Impact Factor
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Journal of Neurosurgery 06/2005; 102(5):962-3; author reply 963-4. · 2.96 Impact Factor
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ABSTRACT: The aim of this study was to investigate whether the tumor parameters of spinal intramedullary ependymomas are significant predictors of clinical presentation and postsurgical outcome.
The study involved 21 cases of intramedullary ependymoma that were operated on between 1988 and 2001. The patients were 13 males (62%) and 8 females (38%), with an age range of 9-70 years (median 38 years).
In most cases (13; 62%), preoperative neurologic examination revealed a sensorimotor deficit in at least one limb. Complete tumor removal was achieved in all cases. The patients with wider tumors had poorer preoperative neurologic condition and poorer neurologic outcome. Tumor length (equivalent to myelotomy length) was not correlated with preoperative neurologic status, but longer length was significantly associated with development of dysesthesia post surgery. In contrast to tumor length, tumor/cord ratio (ratio of the tumor width to the largest cord width at the tumor site) was identified as a significant predictor of preoperative neurologic status and outcome. Ratio values of >0.80 were correlated with poorer preoperative clinical status and poorer neurologic outcome. Neither extent of edema (determined from length [in millimeters] of hyperintensity on T2-weighted images) nor presence of a cyst in the tumor was significant relative to postoperative neurologic recovery in these cases.
This study demonstrated that the width of the tumor relative to the cord is the main predictor of neurologic presentation and postoperative status. The length of the tumor affects the postoperative dysesthesia development.
Journal of Spinal Disorders & Techniques 12/2004; 17(6):516-21. · 1.50 Impact Factor
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ABSTRACT: The aim of this study was to evaluate how timing of irradiation after brain surgery in rats relates to overall extent of brain radiation damage. Extent of injury was determined according to lipid peroxidation (malondialdehyde; MDA) levels in brain tissue. Thirty female rats were randomly assigned to five equal groups (Groups A-E). Four groups underwent trephination and scalpel hemisection of right frontal lobe. Rats in Groups B and D received 25 Gy cranial irradiation in a LINAC system at 10 and 20 days after surgery, respectively. Twenty-four hours later they were killed and their right frontal lobes were removed for lipid peroxidation determination. Groups A and C were not irradiated; these groups were killed and had their frontal lobes removed on day 11 and day 21 post-surgery, respectively. The remaining six animals (Group E, sham surgery) underwent trephination only, and were killed and had their frontal lobes removed 24 h later. There was a significant difference between the mean MDA levels in the control group and Group D, and between the levels in Group B and Group D (P < 0.05 for both). The difference between the mean for Group A and the mean for Group B was even more significant (P < 0.01). The most striking differences were between the control group and Group B, and between Group B and Group C (P < 0.001 for both). The data from this rat model suggest that, in humans, starting radiotherapy early (1-2 weeks) after debulking of a brain tumor may result in significantly higher levels of tissue damage than if the radiation is started 3 weeks or more postoperatively. Further experimental research is needed to project these findings in rats to human subjects.
Journal of Neuro-Oncology 10/2004; 70(1):17-21. · 3.21 Impact Factor
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ABSTRACT: Trigeminal neuralgia (TN) is most commonly caused by vascular compression of the trigeminal nerve root entry zone. Secondary trigeminal neuralgia due to ischemic lesion of the pons is very rare. Here we report a patient with a pontine infarct transecting the central trigeminal pathways resulting with trigeminal neuralgia.
Headache The Journal of Head and Face Pain 44(10):1043-5. · 2.52 Impact Factor
