A non-midline spheno-orbital encephalocele in a newborn.

Basal encephaloceles in western countries occur in 1 of every 35 000-40 000 live births; with an incidence of less than 10% they are the least common of all encephaloceles. Certain subtypes such as transsphenoidal variants may be as rare as 1 in 700 000 live births. These rare encephaloceles are classified into five anatomic types: spheno-ethmodial, transsphenoidal, spheno-orbital, transethmoidal, and spheno-maxillary. Here we present an exceedingly rare variant of a non-midline basal encephalocele of the spheno-orbital type, which was treated by resection of the encephalocele, which contained dysplastic central nervous system tissue, on day four post partum. The patient had no neurological deficits and a six year follow-up showed a normal intellect and a good cosmetic result.

Time-domain and spectral-domain optical coherence tomography in the analysis of brain tumor tissue.

INTRODUCTION: Detection of residual tumor during resection of glial brain tumors remains a challenge because of a low inherent contrast of adjacent edematous brain, the surrounding infiltration zone, and the solid tumor. Therefore, new technologies that may facilitate an intraoperative analysis of the tissue at the resection edge are of great interest to neurosurgeons. MATERIALS AND METHODS: For ex vivo imaging of gliomas in a mouse model and human biopsy specimens of brain tumors and nervous system tissue we have used a time-domain Sirius 713 Tomograph with a central wavelength of 1,310 nm and a coherence length of 15 microm equipped with a mono mode fiber and a modified optical coherence tomography (OCT) adapter containing a lens system for imaging at a working distance of 2.5 cm. A spectral-domain tomograph using 840 nm and 930 nm superluminescence diodes (SLD) with a central wavelength of 900 nm was used as a second imaging modelity. RESULTS: Both time-domain and spectral-domain coherence tomography delineated normal brain, the infiltration zone and solid tumor in murine intracerebral gliomas. Histological evaluation of H&E sections parallel to the optical plain demonstrated that tumor areas of less than a millimeter could be detected and that not only solid tumor, but also brain invaded by a low-density single tumor cells produced an OCT signal different from normal brain. Spectral-domain OCT (SD-OCT) demonstrated a significantly more detailed microstructure of tumor and normal brain up to a tissue depth of 1.5-2.0 mm, whereas the interpretation of time-domain OCT (TD-OCT) was difficult at a tissue depth >1.0 mm. Because of rapid scanning times SD-OCT data could be acquired as 3D data maps, which allowed a multi-planar analysis of the tumor to brain interface. Similar to our findings in experimental gliomas, images of human nervous system tissue acquired using SD-OCT showed a characteristic signal of normal brain tissue and a detailed microstructure of tumor parenchyma. CONCLUSION: Spectral-domain OCT of experimental gliomas and human brain tumor specimens differentiates solid tumor, diffusely invaded brain tissue, and adjacent normal brain based on microstructure and B-scan signal characteristics. In conjunction with the rapid image acquisition rates of SD-OCT, this technology carries the potential of a novel intraoperative imaging tool for the detection of residual tumor and guidance of neurosurgical tumor resections.

Infarction of the right hemisphere in a patient with antiphospholipid antibody syndrome.

Hemicraniectomy as a surgical treatment for intracranial pressure following large ischemic lesions is widely practiced in selected patients. The antiphospholipid antibody syndrome (APS), a disorder characterized by recurrent arterial and venous thrombosis, is a very rare cause of space occupying ischemic lesions. We present a case of a 35 year old female diagnosed with APS who initially presented with small ischemic lesions and within days developed a massive near-total infarction of the right hemisphere. Because of central nervous system, skin and systemic manifestations Sneddon's syndrome and catastrophic antiphospholipid antibody syndrome (CAPS) remained a possible diagnoses. Sneddon's syndrome is a non-inflammatory occlusive arteriopathy of small and medium size arteries predominantly of the skin and brain, whereas the catastrophic antiphospholipid antibody syndrome is characterized by acute multi-organ system thrombosis of small and large vessels. In addition to the diagnostic criteria for APS a heterozygous factor V Leiden mutation was found in this patient, which may be a contributing risk factor for cerebral ischemia. When considering invasive decompressive procedures the neurosurgeon has to be aware of the poor prognosis of some forms of APS with systemic manifestations.

[Preservation of olfaction in bifrontal craniotomies for lesions of the anterior and middle cranial fossa]. / Dauerhafter Erhalt der Riechnervenfunktion nach bifrontaler Kraniotomie bei Läsionen der vorderen und mittleren Schädelgrube.

OBJECTIVE: The preservation of the olfactory tract during bifrontal approach for lesions located in the frontal skull base and the supra- and parasellar region has not previously been investigated. METHODS: In our study 12 patients underwent surgery for various lesions via the basal subfrontal route. All patients were observed prospectively, olfaction testing was performed pre- and postoperatively by an independent otorhinolaryngologist. RESULTS: We obtained complete preservation of the olfactory tracts and normal postoperative olfaction in all 12 cases. CONCLUSION: The bifrontal approach allowed a bilateral, wide operative field with excellent orientation and views of important structures. The shortcoming of this method, damage of the olfactory tracts and postoperative anosmia can be overcome.

A new collagen biomatrix of equine origin versus a cadaveric dura graft for the repair of dural defects--a comparative animal experimental study.

OBJECT: Numerous types of materials have been evaluated over the past decades in the quest for the ideal dural replacement, but no product fully meets all the applicable criteria. This paper presents the long-term results of an animal trial of a collagen biomatrix (TISSUDURA, Baxter AG, Vienna/Austria) for the repair and regeneration of dural defects. This product provides a matrix with a special layer structure and consists of pure naturally cross-linked collagen of equine origin. The comparable material is Tutoplast Dura, a human cadaveric-derived dural graft preserved in a multiple stage chemical process. METHODS: Bihemispheric parietotoccipital dural defects of a defined size were induced in 25 sheep and subsequently closed with the collagen graft or Tutoplast Dura, respectively. RESULTS: Postoperative neurological abnormalities did not occur in any animal. There were no signs of graft rejection or formation of cerebrospinal fluid fistulae. The collagen graft site displayed histological signs as early as 2 weeks postoperatively consistent with a moderate Iymphocytic inflammatory response and infiltration with fibroblasts and macrophages. The graft subsequently developed a neodura-like connective tissue architecture. The Tutoplast Dura showed only minimal cellular infiltration, and again the surrounding structures displayed a mild inflammatory response. 24 weeks postoperatively, the dura and neomembrane were barely distinguishable at the collagen biomatrix site, but the Tutoplast Dura displayed inadequate fusion with the dural border and was encapsulated in a connective tissue layer. CONCLUSION: The outcomes demonstrate that the collagen graft can be used for dura reconstruction as a temporary dural replacement and at the same time as a biomatrix for dural regeneration.

CAD generated mold for preoperative implant fabrication in cranioplasty.

Intraoperative fabrication of acrylic cranial implants may be difficult and will increase operation time. In addition forming implants directly on the defect, intracranial tissues are exposed to heat of polymerization and residual monomer, that occurs, when autopolymerizing methyl methacrylate is used intraoperatively. Furthermore the cosmetical result may be unacceptable. Preoperatively formed acrylic implants may reduce these disadvantages compared to conventional techniques in cranioplasty. We will present methods for preoperative fabrication of cranial implants for a cadaver specimen. Implants were fabricated using a Rapid prototyping (RP) models of the skull built by Fused Deposition Modeling (FDM). In addition a mold of the defect was generated by CAD techniques, that can serve as a template for implant design.

Cerebral haemodynamic pathologies in HELLP syndrome.

The syndrome of haemolysis, elevated liver enzymes and low platelets (HELLP syndrome) is understood as a unique variant of severe preeclampsia. This disorder complicates between 2 and 7% of gestations and is associated with a high perinatal morbidity and a maternal morbidity ranging between 1 and 4%. Intracerebral complications only rarely occur, especially intracerebral haemorrhage was described only in single cases, often correlated with fatal maternal outcome. The analysis of patients with HELLP syndrome treated at our hospital revealed three cases with severe neurological deterioration. Possible pathogenetic factors are discussed.

The combined subtemporal-suboccipital approach: a modified surgical access to the clivus and petrous apex.

OBJECTIVE: The surgical access to the clivus and the petrous apex is still a challenge. A combined approach is best fitted to lesions located in the middle and posterior cranial fossa. The approach described is centered on the petrous bone and requires an extensive bone resection; nevertheless, no osteoplastic bone flap is necessary. METHODS: In contrast to approaches described before, the petrous bone is drilled away anterior to the sigmoid sinus more extensively, the sinus is unroofed. For exposure of the middle cranial fossa the petrous bone should be resected down to the roof of the external meatus, the total extent of the craniotomy is significantly smaller. RESULTS AND CONCLUSION: The surgical access as described above provides a wide operative field under preservation of important intracranial structures. This modified approach minimizes the cerebellar and temporal lobe retraction. The neural and vascular structures can be preserved under direct vision to the tumor. The blood supply is interrupted at the beginning of the operation.

Transcranial sonography of brain tumors in the adult: an in vitro and in vivo study.

BACKGROUND: Few reports indicate the potential of transcranial sonography (TCS) in detecting human brain tumors. METHODS: With an Agilent Sonos 2500 ultrasound device, the authors studied 4 brain tumor phantoms and compared the findings with magnetic resonance imaging (MRI). TCS was performed on 40 patients with intracranial tumors in a follow-up design. Sonographic tumor volume and affection of the ventricular system were compared with MRI findings. RESULTS: The authors found a good correlation between TCS and MRI volumetry in the in vitro study. TCS showed good intraobserver and interobserver reliability. A new volumetric formula for TCS measurement was determined. TCS detection rate of brain tumors in vivo was 40%. When the investigators were given access to radiological findings, the rate of tumor identification was 80%. Despite a sufficient acoustic window, 40% of gliomas grade II and III were not detected. One glioblastoma was not identified owing to an insufficient temporal acoustic window. Tumor volumes measured with MRI and TCS correlated well. MRI volumes exceeded TCS volumes by 41%. In the postoperative examinations (mean = 8 days postoperative, n = 15), the resection cavity was displayed as hyperechogenic. It appeared impossible to differentiate between residual tumor tissue and normal repair mechanisms or blood. In the follow-up examination (mean = 99 days postoperative, n = 15) in 5 patients, neither MRI nor TCS showed tumor regrowth. Ten patients had residual tumors that were detected by sonography. CONCLUSIONS: The value of TCS for the diagnostics of brain tumors is at present limited. Once the tumor has been identified, sonographic results match well with those of MRI.

Osteoplastic lateral suboccipital approach for acoustic neuroma surgery.

OBJECTIVE: Persistent headache remains a significant problem in a small group of patients after acoustic neuroma surgery via the lateral suboccipital approach. We describe a modified technique of osteoplastic lateral suboccipital craniotomy for surgery of the cerebellopontine angle. This simple and elegant technique provides a superior cosmetic result and a significant reduction in patients' symptoms. METHODS: We report on our series of 75 patients who underwent surgery for acoustic neuroma. The maximal follow-up period was 4 years. RESULTS: No patients reported headache postoperatively. Cerebrospinal fluid fistulae were not observed. CONCLUSION: This modified approach minimizes cerebellar retraction, and the neural and vascular structures can be preserved under direct visualization of the tumor. This lateral suboccipital approach is a useful modification of previous approaches in acoustic neuroma surgery. It provides successful tumor resection and excellent functional results.

HELLP syndrome with haemaglobin vasospasm.

The syndrome of haemolysis, elevated liver enzymes and low platelets (HELLP syndrome) is a life threatening, severe complication of pre-eclampsia with typical laboratory findings. An unusual case of a 36-year-old woman with HELLP syndrome and the initial complication of intracerebral haemorrhage is presented. The diagnosis of HELLP syndrome was confirmed by elevated liver enzymes, low platelets, increased total bilirubin and increased lactate dehydrogenase. The intracranial haematoma was removed with good neurological recovery ensuing. However, this case was complicated by cerebral vasospasm on the eleventh day, confirmed by cerebral angiography and computer tomographic findings. The patient died from brain swelling. Possible vasospam should be considered during the treatment of patients with HELLP syndrome.

Preservation of the olfactory tract in bifrontal craniotomy for various lesions of the anterior cranial fossa.

OBJECTIVE: Preservation of the olfactory tract during use of the bifrontal approach for the treatment of lesions located in the frontal cranial base and the supra- and parasellar regions has not been previously investigated. METHODS: In our study, 12 patients underwent surgery, via the basal subfrontal route, for treatment of various lesions. All patients were observed prospectively, and olfactometry was performed pre- and postoperatively by an independent otorhinolaryngologist. RESULTS: We obtained complete preservation of the olfactory tracts and normal postoperative olfaction in all 12 cases. CONCLUSION: The bifrontal approach yields a bilateral wide operative field with excellent orientation and views of important structures. The shortcomings of this method, i.e., damage to the olfactory tracts and postoperative anosmia, can be overcome.

A new technique for attaching a stereotactic frame to the head: technical note.

The aim of this study was to develop a device which allows an intermediate, painless fixation of a stereotactic frame prior to definite pin fixation. To stabilize the stereotactic frame rubber coated metal springs were used. By testing the springs on 30 volunteers with different head diameters and circumferences the optimal shape was determined. In the clinical setting 15 patients undergoing stereotactic surgery were tested, stability and patient's convenience were measured. The procedure was well tolerated and measurements revealed symmetric distances between head and frame. Therefore these metal springs are a useful accessory to the Leksell stereotactic system.

How to perforate safely a resistant floor of the 3rd ventricle? Technical note.

Third ventriculostomy for acquired non-communicating hydrocephalus is an excellent alternative to shunting procedures. Nevertheless, complications can be severe and even fatal (e.g., lesion of the basilar artery), especially if the floor of the 3rd ventricle is very tough and/or opaque. The authors describe a safe method of sharp perforation of the floor, which should be applied if blunt fenestration cannot be achieved easily.

[DNA cytometric studies of cholesteatoma of the middle ear]. / DNA-zytometrische Untersuchungen von Cholesteatomen des Mittelohrs.

Thirteen smears of middle ear cholesteatomas were investigated by the recently developed interactive DNA cytometry. The demonstration of DNA aneuploidy in 9 of the 13 cholesteatomas possibly indicates that these lesions are neoplasms.