Ayse Karatas

Microsurgical management of pineal region lesions: personal experience with 119 patients

BACKGROUND Lesions of the pineal region are histopathologically heterogeneous but often accompanied with severe progression of clinical signs. Surgical treatment remains challenging because of the close vicinity of the deep venous system and the mesencephalo-diencephalic structures in this region. We present the surgical approaches and techniques in a consecutive series of 119 patients treated by the senior author (J.H.) between 1980 and 2007 at 2 different neurosurgical university centers in Kuopio and Helsinki, Finland. METHODS Of the included patients, 107 (90%) presented with pineal region tumors and 12 (10%) with vascular malformations. The ITSC route was used for removal of the lesion in 111 (93%) patients and the OIH approach in 8 (7%) patients. All except one patient were operated on in a sitting position. RESULTS We reviewed all clinical data and radiographic images and analyzed all surgical videos. The pineal lesions were removed completely in most cases (88%). There was no surgical mortality. Twenty-two (18%) of the patients had complications in the postoperative period; these included 1 epidural hematoma, 9 transient Parinaud syndrome, 2 meningitis, 3 wound infections, 2 transient memory disturbances, 2 mild hemiparesis, 1 CSF fistula, and 2 cranial nerves palsies (IV and VI). During a 3.5-year follow-up, 12 patients with malignant lesions died; all patients with benign tumors survived. CONCLUSIONS The ITSC route is a safe and effective surgical approach, associated with low morbidity, complete lesion removal, and definitive histopathologic diagnosis. Considering risk vs benefit, we therefore believe that the surgical treatment can be offered in most cases as the first treatment option for pineal tumors.

Regional anatomic structures of the elbow that may potentially compress the ulnar nerve

HYPOTHESIS Traumatic injuries to the ulnar nerve at the elbow are a frequent problem as it is vulnerable to stretching and compression with motion of the upper limb. The aim of the present study was to explore the course of the ulnar nerve at the elbow and forearm and to determine possible anatomical structures that may cause compression of this structure. MATERIALS AND METHODS We examined 12 upper limbs from cadavers. The length of any fibrous bands, and if present, their distance to the medial epicondyle was recorded. RESULTS On 5 sides a fibrous band originating from the medial intermuscular septum was observed to cross over the ulnar nerve. The average length of the fibrous band was 5.7 cm, and it attached to the medial epicondyle. The mean length of the ulnar nerve as it coursed in the cubital tunnel was 3.8 cm. In 4 of the cases, the ulnar nerve was covered by muscle fibers originating from the flexor digitorum superficialis and extending to the flexor carpi ulnaris. On 5 sides we observed fibrous thickenings, and on 8 sides vascular structures were found crossing over the ulnar nerve. DISCUSSION The cubital tunnel is the most common site of compression of the ulnar nerve. Numerous surgical procedures are recommended for cubital tunnel syndrome. Simple decompression is used most commonly. Although surgical procedures are reported to provide efficient pain relief and functional recovery, residual or recurrent symptoms have been reported. Reasons for such recurrences may be more proximal or distal compression of the ulnar nerve as seen in our study. CONCLUSION Knowledge of possible compression sites of the ulnar nerve is important to the surgeon so that complications are avoided and postoperative recurrence is decreased. LEVEL OF EVIDENCE Basic science study.

Aneurysmal bone cyst of the temporal bone: case report

BACKGROUND Aneurysmal bone cysts (ABCs) are uncommon lesions of the temporal bone and their occurrence in the calvarium is rare. CASE DESCRIPTION A case of a right temporal ABC is reported in a 14-year-old boy who presented swelling of the right temporal region. Magnetic resonance imaging showed a destructive and expansile bone lesion on the right anterior temporal and orbital bone. The lesion was removed in total by the right temporal craniotomy and orbitozygomatic osteotomy. ABC was diagnosed in the pathologic examination. The patient had good recovery during the postoperative course. CONCLUSIONS This report presents the diagnosis and imaging of an ABC in the temporal bone. This localization is very rare for ABC. Total excision, if feasible, is the ideal treatment.

Temporal lobe ictal behavioral patterns in hippocampal sclerosis and other structural abnormalities.

Ictal behavioral characteristics may provide clues in determining the nature of the epileptic focus. We defined ictal behavioral characteristics in patients with intractable temporal lobe epilepsy (TLE) who underwent anterior temporal lobectomy (ATL) and lived seizure-free for 2 years of follow-up. Video/EEG data on 282 seizures observed in 48 patients who suffered from TLE and underwent ATL were analyzed. All patients were seizure-free after surgery. We divided the patients into two groups on the basis of the pathological examination. Two hundred and two seizures in 35 patients with hippocampal sclerosis (Group 1) and eighty seizures in 13 patients with other pathological findings, such as tumors, cavernoma, and hamartoma (Group 2), were analyzed. Ictal behavior characteristics were evaluated for each of the seizures recorded in the two groups. Behavioral arrest, bilateral hand automatisms, oral and leg automatisms, and ictal aggression were significantly more frequent in Group 2 (P<0.05), whereas contralateral dystonia of the upper extremity (P<0.05), ipsilateral hand automatisms (P<0.05), ipsilateral hand automatisms in the presence of contralateral dystonia of the upper extremity (P<0.001), contralateral forced head deviation (P<0.05), and secondary generalization (P<0.05) were more significant in Group 1. There was no significant difference in vocalization and ipsilateral nonforced head deviation between the two groups (P>0.05). The number of seizures observed during ictal speech, crying, and postictal nose wiping was not large enough, so differences could not be analyzed. It was concluded that although ictal behavioral characteristics differed between the two groups, certain behavioral patterns may be helpful in differentiating between hippocampal sclerosis and other pathology.

Identification and removal of an epileptogenic lesion using Ictal-EEG, functional-neuronavigation and electrocorticography

PURPOSE Cases with intractable epilepsy may present with multiple lesions in their brains. Ictal-EEG carries a great value in identification of the primary epileptogenic source. On the other hand, removal of low-grade tumors located around the eloquent cortex may be risky with conventional techniques. Functional-neuronavigation (f-NN) is the integration of functional magnetic resonance imaging and stereotactic technologies; and provides interactive data regarding localization of the motor cortex. This report presents a case with dysembryoplastic neuroepithelial tumor (DNET), which was removed using f-NN and electrocorticography (ECoG) techniques. METHODS A 19-year-old patient with intractable complex partial and secondary generalized seizures is presented. MRI revealed a low-grade tumor located in right parietal region just behind the motor cortex, and a contralateral temporal arachnoid cyst. Ictal-EEG demonstrated the right parietal origin of the seizures. The patient underwent a right parietal craniotomy and tumor excision using f-NN and ECoG techniques intraoperatively. ECoG findings correlated with epileptogenicity of the parietal lesion. RESULTS Postoperative course was uneventful. No postoperative deficit was observed. The patient was seizure free in eight months follow-up. Pathological examination reported the lesion as DNET. CONCLUSIONS Ictal-EEG has a very important role in identification of the epileptogenic focus in cases with multiple brain lesions. Preservation of the functional cortex is the most prominent aim during lesional surgery of epilepsy. Intraoperative mapping using f-NN and ECoG supports the orientation of the neurosurgeon to the functional and epileptogenic cortical areas; and thus, increase the safety and efficacy of surgical procedures.

Assessment of the Circle of Willis with Cranial Tomography Angiography

Background The circle of Willis is a major collateral pathway important in ischemic conditions. The aim of our study was to assess the structural characteristics of the circle of Willis within the Turkish adult population, along with variations and arteries involved in the measurement of diameters and lengths on cranial computed tomography angiography (CTA). Material/Methods One hundred adult patients who underwent CTA images were evaluated retrospectively. Results Results of the study revealed 82% adult, 17% fetal, and 1% transitional configurations. A complete polygonal structure was observed in 28% of cases. Variations of the circle of Willis were more common in the posterior portion. Hypoplasia was found to be the most common variation and was observed as a maximum in the posterior communicating artery (AComP). Conclusions The patency and size of arteries in the circle of Willis are important in occlusive cerebrovascular diseases and cerebrovascular surgery. Although CTA is an easily accessible non-invasive clinical method for demonstrating the vascular structure, CTA should be evaluated taking into account image resolution quality and difficulties in the identification of small vessels.

The Anatomy of Circulus Arteriosus Cerebri (Circle of Willis): A Study in Turkish Population.

AIM The function of the circle of Willis, an arterial polygon, is to protect the brain from ischemia. The aim of this study is to define the structural characteristics of the circle of Willis within the Turkish adult population, along with variations and arteries involved in the measurement of diameters and lengths on cadavers. MATERIAL AND METHODS The circle of Willis was evaluated in 100 fresh adult cadavers. Structures of the circle of Willis were evaluated as being typical or atypical images and according to the diameter of AComP. All arteries forming the circles length and diameters were measured. RESULTS All arteries forming the circle of Willis as 91% were anatomically observed. The typical structure in which hypoplasia arteries is not involved was obtained as 8%. The atypical circle of Willis with aplasia was seen as 9%. 87% of adult, 9% fetal, and 4% transitional configuration in the samples were detected. The variations of the circle of Willis were more common in the posterior portion. Hypoplasia was found to be the most common variation and noted as a maximum in AComP (85%). Aplasia was noted as the second most common variation after hypoplasia and again the most common in AComP (5%). CONCLUSION Advances in radiological methods which provide images of cerebral vessels and the development of cerebrovascular surgery have increased the importance of the circle of Willis in neurosurgery and neurology. The structure of the circle of Willis is of great importance in occlusive cerebrovascular diseases and cerebrovascular surgery.

Angiographic assessment of variants of basal vein of Rosenthal in idiopathic subarachnoid hemorrhage.

Previous studies have reported the possible contribution of a primitive variant of the basal vein of Rosenthal (BVR) in the cause of idiopathic subarachnoid hemorrhage (ISAH). The purpose of this study was to assess the drainage patterns of the BVR among ISAH patients. The venous phase at cerebral angiography was retrospectively analyzed in 19 patients with ISAH and then compared with patients with unruptured aneurysms as controls. A relationship was found between ISAH and the presence of a primitive variant. However, the venous configuration effect on bleeding is still unknown.

Growing Hemorrhagic Choroidal Fissure Cyst

Choroidal fissure cysts are often incidentally discovered. They are usually asymptomatic. The authors report a case of growing and hemorrhagic choroidal fissure cyst which was treated surgically. A 22-year-old female presented with headache. Cranial MRI showed a left-sided choroidal fissure cyst. Follow-up MRI showed that the size of the cyst had increased gradually. Twenty months later, the patient was admitted to our emergency department with severe headache. MRI and CT showed an intracystic hematoma. Although such cysts usually have a benign course without symptoms and progression, they may rarely present with intracystic hemorrhage, enlargement of the cyst and increasing symptomatology.