Ersin Erdogan

The added value of the apparent diffusion coefficient calculation to magnetic resonance imaging in the differentiation and grading of malignant brain tumors.

Objective: ADC calculation can improve the diagnostic efficacy of MR imaging in brain tumor grading and differentiation. Methods: Apparent diffusion coefficient (ADC) values and ratios of 33 low-grade (23 astrocytomas, 10 oligodendrogliomas) and 40 high-grade (25 metastases and 15 high-grade astrocytomas) malignant tumors were prospectively evaluated. Results: Tumoral ADC values (r = −0.738, P < 0.000) and ratios (r = −0.746, P < 0.000) were well correlated with higher degree of malignancy and quite effective in grading of malignant brain tumors (P < 0.000). By using cutoff values of 0.99 for tumoral ADC value and 1.22 for normalized ADC ratio, the sensitivity of MR imaging could be increased from 72.22% to 93.75% and 90.63%, the specificity from 81.08% to 92.68% and 90.24%, PPV from 78.79% to 90.91% and 87.88%, and NPV from 75.00% to 95.00% and 92.50%, respectively. Conclusion: ADC calculation was quite effective in grading of malignant brain tumors but not in differentiation of them and added more information to conventional contrast-enhanced MR imaging.

Pyogenic brain abscess

Brain abscesses have been one of the most challenging lesions, both for surgeons and internists. From the beginning of the computed tomography (CT) era, the diagnosis and treatment of these entities have become easier and less invasive. The outcomes have become better with the improvement of diagnostic techniques, neurosurgery, and broad-spectrum antibiotics. Atypical bacterial abscesses are more often due to chemotherapy usage in oncology, long life expectancy in patients with human immunodeficiency virus (HIV) infection, and immunosuppression in conjunction with organ transplantation. Surgical treatment options showed no significant difference with respect to mortality levels, but lower morbidity rates were achieved with stereotactically guided aspiration. Decompression with stereotactically guided aspiration, antibiotic therapy based on results of pus culture, and repeated aspirations if indicated from results of periodic CT follow-up scans seem to be the most appropriate treatment modality for brain abscesses. Immunosuppression and comorbidities, initial neurological status, and intraventricular rupture were significant factors influencing the outcomes of patients. The pitfalls and evolution in the diagnosis and treatment of brain abscesses are discussed in this study.

The evaluation of surgical treatment options in the Chiari Malformation Type I.

AIM There have been several treatment modalities to reduce the volume of the syringomyelic cavity and the pressure on the brainstem in Chiari Malformation Type I (CM-I). Foramen magnum decompression with and without duroplasty were compared in this retrospective study. MATERIAL AND METHODS From 2003 to 2006, 27 patients suffering from CMI were operated on at our institute. The following were measured: the ratio of the syringomyelic cavity to the spinal cord; pre-operative tonsillar herniation from the foramen magnum; pre- and postoperative tonsillo-dural distance; and spinoposterior fossa dural angle. RESULTS 83.3 % of the patients in the non-duroplasty and 73.3% of the patients in the duroplasty group were symptom free. The ratio of syrinx regression was 28+/-10% in the non-duroplasty and 36+/-33% in the duroplasty group. The tonsillodural distance was 3.1+/-1.8 mm in the non-duroplasty and 4.6+/-2.1 mm in the duroplasty group (p>0.05). The spino-posterior fossa dural angle was 133.6+/-9.44 degrees preoperatively and 136.7+/-9.78 degrees postoperatively in the non-duroplasty (p=0.376); 123.7+/-11.7 degrees preoperatively and 129.8+/-11.1 degrees postoperatively in the duroplasty group (p=0.885); no significant difference was found postoperatively (p=0.55, z=1.92), respectively. One patient was re-operated in the non-duroplasty group and thereafter duroplasty was performed. CONCLUSION Almost the same clinical outcomes can be achieved with and without duroplasty. There might be an option to perform duroplasty if simple procedure fails.

Antiepileptic activity of melatonin in guinea pigs with pentylenetetrazol-induced seizures

Abstract Background: Antiepileptic and neuroprotective effects of melatonin (N-acetyl-5-methoxytryptamine) have been shown at higher doses (50–160 mg/kg). We aimed to investigate the antiepileptic effects of low-dose melatonin (10 mg/kg) on pentylenetetrazol (PTZ)-induced experimental epilepsy model. Materials and Methods: Twelve male albino guinea pigs weighing 500–800 g were used in our work. Initially, latent period, seizure intensity and mortality parameters were evaluated during the epileptic seizure induced by PTZ. After a recovery period of 7 days, effects of the neuroprotective agent, melatonin (which is dissolved in 2.5% ethanol–saline solution), on epileptic seizures induced by PTZ were evaluated. Effects of 2.5% ethanol, which is an anticonvulsant agent when administered acutely in high concentrations, on PTZ-induced seizures were also evaluated. Results: Data obtained from the study groups (PTZ, PTZ + melatonin and PTZ + ethanol) were evaluated by paired t-test, and p<0.005 was considered statistically significant. The differences of latent periods between the PTZ and PTZ + melatonin groups were found to be statistically significant (p<0.001). Conclusion: Although melatonin does not have a primary anticonvulsant effect at low doses (10 mg/kg), it lowers the mortality rates and attenuates seizure severity while increasing the latent period.

Cerebellar aspergillosis: case report and literature review.

OBJECTIVE AND IMPORTANCE An unusual, but not unique, case of cerebellar aspergillosis associated with autologous peripheral blood stem cell transplantation for breast cancer is presented. CLINICAL PRESENTATION A 45-year-old woman with breast cancer underwent chemotherapy and radiotherapy as well as autologous peripheral blood stem cell transplantation. She developed a cerebellar aspergillosis abscess that was treated successfully with two surgical resections. INTERVENTION After removal of pus and the abscess wall, the patient received local application of amphotericin B (AmB). She received AmB 1 mg/kg/d for 3 months and itraconazole 100 mg/kg/d for 1 year. After 3 months of AmB treatment, magnetic resonance imaging revealed that disease had not recurred. CONCLUSION In cases of central nervous system aspergillosis, to increase the therapeutic efficiency, AmB can also be applied to the abscess cavity. Computed tomographic and contrast-enhanced magnetic resonance imaging scans play an important role in establishing early diagnosis in high-risk, immunocompromised patients.

Craniocerebral Gunshot Wounds

Cranial gunshot wounds frequently produce devastating injuries to central nervous system (CNS) structures. Surgical therapy and primary and secondary debridement, including repair of dural defects and removal of retained intracranial bone and metal fragments, were applied to 374 cranial gunshot wound victims at Gulhane Military Medical School in Turkey from 1992 to 1999. Dural defects were closed primarily or with temporalis fascia, pericranium, and cadaver grafts. Central nervous system infections were mostly observed in cases with cerebrospinal fluid (CSF) fistulas. All patients underwent computed tomography (CT) scans periodically. In 119 of 374 (32%) patients, bone and metal fragments were determined on control CT scans. We also performed angiography in some patients to reveal traumatic vascular pathologic findings. Most of the deaths in this group of patients were attributed to the direct effects of brain injury and occurred within the first month after injury. Fragments retained after the first debridement were followed periodically by CT scan. Surgery was not performed until infection developed. Retained fragments did not increase the infection risk, but high rates of infection did occur in cases with CSF fistulas. The presence of diffuse brain damage, brainstem injury, CNS infection, or ventricular injury was associated with a poor outcome.

Transmaxillary approach to the orbit: An anatomic study

OBJECTIVEVarious approaches to expose the orbit have been used, such as cranial, lateral, and medial approaches. In an effort to gain exposure to the orbit without necessitating a craniotomy, we have developed a transmaxillary approach to the orbit. METHODSAn approach was developed that uses data obtained by performing 24 orbit dissections in 12 cadaveric heads. After sublabial incision to expose the maxilla, maxillotomy is performed and the course of the infraorbital nerve is identified. The orbital floor is opened, and the orbit is accessed. RESULTSThis technique offers access to the inferomedial and inferolateral orbit and to the inferior aspect of the optic nerve. CONCLUSIONThe transmaxillary approach provides an entirely extradural approach to the orbit. This technique combines the benefits of a cosmetically acceptable approach with orbitotomy and avoids the use of craniotomy and brain retraction to access the deep medial, lateral, and inferior orbit. We advocate the transmaxillary approach to the orbit in cases of inferomedial posterior intraconal and inferolateral lesions as an alternative and adjunct to the standard techniques of orbital surgery.

Primary dural lymphoma mimicking a subdural hematoma

Intracranial marginal zone B-cell lymphoma presenting as a dural-based mass is rare. A 45-year-old woman who had generalized tonic-clonic seizures and speech disturbance for 6 months was referred to our hospital. Radiology suggested a subdural hematoma (SDH). No improvement in the radiological findings or symptoms occurred with conservative follow-up. Therefore, she underwent a craniotomy for drainage of the suspected SDH. Intraoperatively, dural plaque-like thickening was observed, with no SDH, and a biopsy was performed. After histopathological and immunohistochemical studies, a mucosa-associated lymphoid tissue (MALT) lymphoma was diagnosed. The patient underwent radiotherapy with no postoperative complications or recurrence. Early diagnosis and treatment of primary dural lymphoma is important. Histopathological evaluation is necessary for diagnosis. MRI cannot reliably differentiate between SDH and some dural lesions that present as diffuse infiltration. Therefore, these differential diagnoses should be considered.

Ventricular Injury following Cranial Gunshot Wounds: Clinical Study

Gunshot wounds to the head are usually fatal injuries, despite all medical and surgical interventions. Ventricular injury is a poor prognostic factor-for penetrating cranial gunshot wounds. Intraventricular hemorrhage and ventricular lacerations are the main components of such injuries. The incidence, management, and outcomes of cases of ventricular injury secondary to cranial gunshot wounds that were treated during a 9-year period at Gülhane Military Medical Academy were examined. The study group consisted of 67 consecutive patients who were admitted to the Department of Neurosurgery with the diagnosis of ventricular injury, with different penetration sites. The patients had been injured by either bullets or shrapnel. Surgical treatment was performed for all patients with ventricular injuries and 22 (32.8%) died. Ventricular injury in cranial gunshot wounds is a complex severe type of trauma that requires serious treatment. Early radiological diagnosis and accurate treatment frequently had lifesaving roles for these patients.

Foot drop due to cranial gunshot wound.

OBJECTIVE We present a case of foot drop from hemorrhagic contusion after cranial gunshot, which has never been reported. METHODS A 21-year-old man was admitted with inability of dorsiflexion 1 day after a tangential gunshot wound of the scalp. The scalp skin was cut by the rifle bullet. He had foot drop and his neurological examination was normal except for weakness at dorsiflexion of the right foot. Pathological reflexes and sensation failure were not detected. T1- and T2-weighted magnetic resonance images showed hyperintense contusion at the right superior frontal gyrus and mild subdural hemorrhage. Peripheral nervous system examination was electrophysiologically normal. Motor-evoked potentials showed the location of the lesion at the motor cortex because no electrical record was obtained from the right anterior tibial and extensor digitorum brevis muscles, and there was a normal record on the left. Six months later, the patients neurological examination was uneventful. CONCLUSION When a cranial gunshot wound injury victim presents with foot drop, the central causes should be included in the differential diagnosis list.