Value of cine phase contrast magnetic resonance imaging to predict obstructive hydrocephalus.

BACKGROUND: This is a prospective study to evaluate the role of CINE MRI to predict obstructive hydrocephalus in the preoperative work-up. PATIENTS/MATERIAL AND METHODS: A total of 16 patients with aqueductal obstruction demonstrated by CINE MRI who were undergoing ETV were included. MRI was performed preoperatively, at 3 months, at 12 months and at 24 months after surgery. Prior to the fenestration of the third ventricular floor aqueductal patency was evaluated using intraoperative ventriculography. A successful outcome was defined by using radiological and clinical criteria. RESULTS: In 8 patients with aqueductal obstruction on preoperative CINE MRI aqueductal patency was proven intraoperatively. ETV failed in all patients with intraoperatively proven aqueductal patency. Out of these 8 patients, 1 patient had no risk factors for ETV failure, 3 had 1 risk factor, 3 had 2 risk factors, and 1 had 3 risk factors. Most of the failure (6 out of 8 patients) occurred within 8 weeks of the initial procedure. A lumbar puncture was performed in these patients to avoid misinterpretation of the clinical course. CONCLUSION: The present study demonstrates that cine phase constrast MR may be a poorer choice to determine aqueductal patency compared to high resolution structural imaging. Interestingly, intraoperative ventriculography was an adjunct to better predict outcome after ETV in patients with obstructive hydrocephalus. In cases with non-conclusive preoperative imaging, postoperative decision making may be supported by the use of intraoperative ventriculography with the goal of reducing unnecessary tests and procedures. However, the analysis of the study data has to be considered as explorative. Therefore, findings should be validated with a larger patient population.

The awakened intraspinal glass shard.

Penetrating spinal injuries from foreign bodies are an exceedingly rare pathological entity. In this report we present an unusual clinical report of an in-driven shard of glass in the cervical spine that remained without symptoms for many years and became symptomatic possibly because of narrowing of the diameter of the vertebral canal.

Treatment of cervical degenerative disc disease - current status and trends.

Although less frequent than lumbar degenerative disc disease, cervical disc disease may be much more neurologically compromising due to anatomical particularities. Since its first description together with the typical signs and symptoms the operative therapy of cervical disc disease has undergone a changeful evolution over the years. The frequent shifts of paradigms in treatment are particularly noticeable compared to other neurosurgical diseases. Initially, the dorsal decompression of neural structures (laminectomy) with a more or less invasive posterior approach (posterior foraminotomy) was the primary aim of the operation. Because of anatomical limitations, a paradigm shift occurred in the middle of the last century, favouring an anterior approach and discectomy, without and with implantation of various spacers (arthrodesis). A large variety of different materials and designs for these implants as alternatives to autologous iliac crest bone were established, all with the aim of creating a solid fusion of the operated segment. Anterior cervical discectomy and fusion (ACDF), regarded worldwide as the "gold standard" for the treatment of cervical disc disease, was later complemented by modified, minimally invasive or endoscopic techniques using anterior and posterior approaches. The fear of adjacent level disease in the vicinity of a fused cervical segment led to another paradigm shift in the last few years, away from fusing procedures, towards new motion preserving technologies (arthroplasty) and back to minimally invasive dorsal techniques for the treatment of cervical disc disease. This article reviews the evolution of the operative treatment of cervical disc disease in the last 80 years, outlines the advantages and disadvantages of each approach and technique and focuses on the rationale of the paradigm shifts. Current established and alternative treatment concepts are illuminated and discussed together with the currently relevant literature.

Off-midline Sinus Pericranii Associated with Ipsilateral Venous Anomaly: Case Report and Therapeutic Considerations.

A case of lateral sinus pericranii associated with ipsilateral venous anomaly is reported. No treatment was instituted in accordance with the parents' wishes. The role of MRI and cerebral angiography in the diagnostic workup is discussed.

Treatment strategies and outcome in patients with non-tuberculous spinal epidural abscess--a review of 46 cases.

OBJECTIVES: Spinal epidural abscess (SEA) is a rare disease and its early detection and appropriate treatment is essential to prevent high morbidity and mortality. There are only few single-institution series who report their experiences with the microsurgical management of SEA and treatment strategies are discussed controversially. Within the last 15 years the authors have treated 46 patients with SEA. This comparatively high number of cases encouraged us to review our experiences with SEA focussing on the clinical presentation, microsurgical management and outcome. METHODS: Clinical charts of 46 cases with a spinal epidural abscess treated between 1990 and 2004 were reviewed. There were 30 men and 16 women, the age ranged between 32 and 86 years (mean: 57 years). The clinical mean follow-up was 8.5 months (range: 2-84). The clinical presentation and severity of neurological deficits were measured by the Frankel grading system on admission and on follow-up visit. RESULTS: The abscess was located in the cervical spine in 8, the thoracic spine in 17 and the lumbar spine in 21 patients. On admission 8 patients were in Frankel grade A, 7 in B, 15 in C, 8 in D and 8 in E. During follow-up 1 patient was in Frankel grade A, 1 in B, 5 in C, 13 in D and 24 in E. 37 patients underwent primary microsurgery with abscess drainage or removal of chronic granulomatous tissue. The clinical symptoms in 4 patients worsened shortly after the operation due to a compression fracture of the vertebral body (n=2) or progress of the abscess (n=2) making re-operation necessary. 9 patients with severe critical illness or without neurological deficits had primarily a CT-guided puncture for assessment of the causative organism. 3 of them needed additional surgical therapy within the hospital stay because of a new neurological deficit. All patients were immobilised and treated with antibiotics for at least 6 weeks. The mortality was 6.5%. As for complications we noted septicaemia (n=5), meningitis (n=1) and a transient malresorptive hydrocephalus (n=1). CONCLUSION: Early diagnosis, microsurgical therapy with appropriate antibiotic therapy and careful observation of patients are the keys to successful management of SEA. The goal of surgical treatment is to isolate the causative organism and to perform a decompression at the site of maximal cord compression in cases of neurological deterioration or severe pain. Instrumentation with primary fixation does not seem to be imperative. In cases of post-operative worsening, a fracture of additionally infected bony elements has to be considered and a stabilisation should be discussed on an individual basis.

Management of hydrocephalus in children with plasminogen deficiency.

Congenital plasminogen deficiency is an infrequent disorder, which usually becomes symptomatic as ligneous conjunctivitis. However, pseudomembranous lesions in the mucosa of the pharynx, tracheobronchial tree, and the peritoneum may likewise occur. An accompanying hydrocephalus is extremely rare; only 16 cases have been reported to date. The reports indicate that hydrocephalus, even if treated by ventriculoperitoneal (VP) cerebrospinal fluid (CSF) shunting, worsens the prognosis substantially. Thus, VP CSF shunting does not seem to be the optimal therapy for hydrocephalic children with plasminogen deficiency. We add two cases to the literature, and, on the base of our experience, we propose a management strategy for the hydrocephalus. We report the case history of two children with plasminogen deficiency and associated hydrocephalus. Both children initially were treated with VP shunts and had a very similar clinical course with multiple shunt malfunctions due to nonabsorption by the peritoneum. In the first child, the attempt to treat the hydrocephalus with a ventriculoatrial (VA) shunt failed due to catheter thrombosis. Finally, a ventriculocholecystic shunt was placed in both children, which worked well. In patients with plasminogem deficiency and associated hydrocephalus, special care must be taken in the management of hydrocephalus. The absorptive capacity of the peritoneum is reduced by pseudomembrane formation, which results in VP shunt malfunction. The plasminogen deficiency results in early thrombus formation if atrial catheters are used. Therefore, the authors believe that ventriculocholecystic shunting should be considered early on in the course of the disease.

Low-dose aspirin before intracranial surgery--results of a survey among neurosurgeons in Germany.

BACKGROUND: Increasing numbers of patients presenting for intracranial surgery are receiving concurrent medication with low-dose aspirin, leading to dysfunctional circulating platelets, which might increase the peri-operative risk of bleeding. OBJECTIVE: To survey the opinions and working practices of neurosurgical facilities in Germany regarding patients who present with low-dose aspirin medication before elective intracranial surgery. Methods. Questionnaires were sent to 210 neurosurgical facilities asking five main questions: (1) the adherence of any policy of stopping aspirin pre-operatively, (2) the personal risk assessment for patients with brain surgery under low-dose aspirin medication, (3) the preferred method of treatment for excessive bleeding in this context, (4) personal knowledge of haemorrhagic complications in this group of patients, and (5) the characteristics of the neurosurgical units concerned. RESULTS: There were 138 (65.7%) valid responses. Of the respondents, 111 (80.4%) had a departmental policy for the discontinuation of pre-operative aspirin treatment. The mean time for discontinuation of aspirin pre-operatively was 7.3 days (range: 0-21 days). 107 respondents (77.5%) considered that patients taking low-dose aspirin were at increased risk for excessive peri-operative haemorrhage, and 80 (58%) reported having personal experience of such problems. Ninety-seven respondents (70.3%) would use special medical therapy, preferably desmopressin, if haemorrhagic complications developed intra-operatively. The mean amount of intracranial operations per year in each neurosurgical facility was 494 (range: 50-1700). CONCLUSIONS: The majority of neurosurgical facilities in Germany have distinct departmental policies concerning the discontinuation of low-dose aspirin pre-operatively, with an average of 7.3 days. Three-quarter of the respondents felt that aspirin was a risk factor for haemorrhagic complications associated with intracranial procedures, and more than half of the interviewees reported having personal experience of such problems. Various medicamentous methods of counteracting aspirin-induced platelet dysfunction and excessive bleeding in this context are discussed and evaluated.

[Application of a stand-alone interbody fusion cage based on a novel porous TiO2/glass ceramic--2: Biomechanical evaluation after implantation in the sheep cervical spine]. / Anwendung eines Bandscheibenersatzimplantats aus einer neuartigen porösen TiO2/Glas-Keramik--Teil 2: Biomechanische Untersuchungen nach Implantation in die Schafs-Halswirbelsäule.

Animals are becoming more and more common as in vivo models for the human spine. Especially the sheep cervical spine is stated to be of good comparability and usefulness in the evaluation of in vivo radiological, biomechanical and histological behaviour of new bone replacement materials, implants and cages for cervical spine interbody fusion. In preceding biomechanical in vitro examinations human cervical spine specimens were tested after fusion with either a cubical stand-alone interbody fusion cage manufactured from a new porous TiO2/glass composite (Ecopore) or polymethylmethacrylate (PMMA) after discectomy. Following our first experience with the use of the new material and its influence on the primary stability after in vitro application we carried out fusions of 20 sheep cervical spines levels with either PMMA or an Ecopore-cage, and performed radiological examinations during the following 2-4 months. In this second part of the study we intended the biomechanical evaluation of the spine segments with reference to the previously determined morphological findings, like subsidence of the implants, significant increase of the kyphosis angle and degree of the bony fusion along with the interpretation of the results. 20 sheep cervical spines segments with either PMMA- or Ecopore-fusion in the levels C2/3 and C4/5 were tested, in comparison to 10 native corresponding sheep cervical spine segments. Non-destructive biomechanical testing was performed, including flexion/extension, lateral bending and axial rotation using a spine testing apparatus. Three-dimensional range of motion (ROM) was evaluated using an ultrasound measurement system. In the native spine segments C2/3 and C4/5 the ROM increased in cranio-caudal direction particulary in flexion/extension, less pronounced in lateral flexion and axial rotation (p < 0.05). The overall ROM of both tested segments was greatest in lateral flexion, reduced to 52% in flexion/extension and to 16% in axial rotation. After 2 months C2/3- and C4/5-segments with PMMA-fusion and C2/3-segments with Ecopore-interposition showed decrease of ROM in lateral flexion in comparison to the native segments, indicating increasing stiffening. However, after 4 months all operated segments, independent from level or implanted material, were stiffer than the comparable native segments. The decrease of the ROM correlated with the radiological-morphological degree of fusion. Our evaluation of the new porous TiO2/glass composite as interbody fusion cage has shown satisfactory radiological results as well as distinct biomechanical stability and fusion of the segments after 4 months in comparison to PMMA. After histological analysis of the bone-biomaterial-interface, further examinations of this biomaterial previous to an application as alternative to other customary cages in humans are necessary.

[Recurrence of a retrobulbar neuritis? Classic VEP and missing periocular pain]. / Rezidiv einer Retrobulbärneuritis? Klassisches VEP und fehlender Bewegungsschmerz.

BACKGROUND: In young patients with the clinical symptoms of a neuritis neuroradiological imaging is not always necessary. This case report describes a young patient who suffered from a recurrence after 5 years. Since all findings, particularly visual evoked potentials, were classic for neuritis, the patient was treated for neuritis although periocular pain was not present. CASE REPORT: Five years after a neuritis of the left eye (OS), the patient was again referred with a visual loss (VA 0.3 OS). In addition to an afferent pupillary defect OS and a constricted visual field OS, an inter-eye latency difference was demonstrated in the visually evoked potentials. The patient was treated with megadose steroid therapy. Although periocular pain as a classic symptom was absent, no neuroradiological imaging was performed. Six weeks later visual acuity and visual fields further worsened, such that a nuclear magnetic resonance imaging was indicated revealing a meningioma fronto-basally compressing the optic nerve. After neurosurgical intervention visual acuity and field stabilized. CONCLUSIONS: In rare cases, meningioma may mimic the symptoms of neuritis. Therefore, neuroradiological imaging is indicated in recurrences or complicated disease courses, particularly if classic symptoms such as periocular pain are missing.

[Application of a stand-alone interbody fusion cage based on a novel porous TiO2/glass composite. I. Implantation in the sheep cervical spine and radiological evaluation]. / Anwendung eines Bandscheibenersatzimplantats aus einer neuartigen porösen TiO2/Glas-Keramik--Teil 1: Einsatz in der Schafs-Halswirbelsäule und radiologische Verlaufsuntersuchungen.

Animals are becoming more and more common as in vitro and in vivo models for the human spine. Especially the sheep cervical spine is stated to be of good comparability and usefulness in the evaluation of in vivo radiological, biomechanical and histological behaviour of new bone replacement materials, implants and cages for cervical spine interbody fusion. In preceding biomechanical in vitro examination human cervical spine specimens were tested after fusion with either a cubical stand-alone interbody fusion cage manufactured from a new porous TiO/glass composite (Ecopore) or polymethyl-methacrylate (PMMA) after discectomy. First experience with the use of the new material and its influence on the primary stability after in vitro application were gained. After fusion of 10 sheep cervical spines in the levels C2/3 and C4/5 in each case with PMMA and with an Ecopore-cage, radiologic as well as computertomographic examinations were performed postoperatively and every 4 weeks during the following 2 and 4 months, respectively. Apart from establishing our animal model, we analysed the radiological changes and the degree of bony fusion of the operated segments during the course. In addition we performed measurements of the corresponding disc space heights (DSH) and intervertebral angles (IVA) for comparison among each other, during the course and with the initial values. Immediately after placement of both implants in the disc spaces the mean DSH and IVA increased (34.8% and 53.9%, respectively). During the following months DSH decreased to a greater extent in the Ecopore-segments than in the PMMA-segments, even to a value below the initial value (p>0.05). Similarly, the IVA decreased in both groups in the postoperative time lapse, but more distinct in the Ecopore-segments (p<0.05). These changes in terms of a subsidence of the implants, were confirmed morphologically in the radiological examination in the course. The radiologically evaluated fusion, i.e. bony bridging of the operated segments, was more pronounced after implantation of an Ecopore-cage (83%), than after PMMA interposition (50%), but did not gain statistical significance. In this first in vivo examination of our new porous ceramic bone replacement material we showed its application in the spondylodesis model of the sheep cervical spine. Distinct radiological changes regarding evident subsidence and detectable fusion of the segments, operated on with the new biomaterial, were seen. We demonstrated the radiological changes of the fused segments during several months and analysed them morphologically, before the biomechanical evaluation will be presented in a subsequent publication.

MRI and intraoperative findings in cavernous haemangiomas of the spinal cord.

More sensitive imaging techniques, such as MRI, have led to an increase in the number of reported cases of spinal cord cavernous haemangioma (SCCH). Complete surgical resection has been performed with good outcomes. However, operative findings do not always confirm preoperative MRI as to the size and site (superficial or deep) of the lesion. We evaluated whether MRI can be used to predict whether or not SCCH reach the surface of the spinal cord, since this has an impact on surgical strategy. We reviewed the preoperative MRI, case-notes and video recordings of 12 patients who underwent surgery, at which five superficial and seven deep-seated lesions were identified. T1-weighted images correctly indicated the site of the lesion in ten, T2-weighted images in only eight. One deep lesion was thought to be superficial on both T1- and T2-weighted images. Intravenous contrast medium was not helpful in diagnosis or localisation. In no case was a surgically proven superficial lesion interpreted as deep in the spinal cord.

Recurrent intracranial sarcoma mimicking chronic subdural haematoma.

Primary sarcomas of the central nervous system and their coincidence with a subdural haematoma are each rare. We describe an unusual case of unsuspected dural spreading of a recurrent spindle cell sarcoma concealed in a chronic subdural haematoma, which occurred months after microsurgical resection and external radiation of a temporal parenchymatous sarcoma.

Extended pterional orbital decompression in severe orbital cellulitis.

BACKGROUND: Bacterial orbital cellulitis is a relatively uncommon infective process, which can threaten the function of orbital structures. Apart from antibiotic therapy, sinus surgery with or without abscess drainage via an orbito-otorhinolaryngological approach might be necessary. CASE DESCRIPTION: We present three cases of severe orbital cellulitis, leading to increasing loss of vision, proptosis, afferent pupillary disturbances and restriction of extra-ocular movements, despite antibiotic therapy. After extended pterional orbital decompression and reducing the orbital pressure by removal of the lateral and superolateral orbital walls, all patients showed distinct improvement of initial symptoms, without any complications related to the operation. INTERPRETATION: Extended pterional orbital decompression represents an effective treatment alternative and supplement in cases of a severe, threat to ocular function due to orbital cellulitis, where acute reduction of pressure on orbital, neural and vascular structures is intended.

Experience with a new concept to lower non-infectious complications in infants with programmable shunts.

In neonates and infants less than 1 year of age who are treated with a ventriculo-peritoneal shunt, non-infectious complications are almost as frequent and dangerous as infectious complications. While the incidence of infections can be reduced, using perioperative antibiotics, special surgical techniques and postoperative care non-infectious complications such as wound break-down, cerebrospinal fluid (CSF) fistula and subcutaneous CSF collection are preventable, but seem difficult to manage, especially in the group of patients at a susceptible age. The authors present their experience with the programmable Hakim valve in 40 neonates and infants less than 1 year of age, who were treated with de novo implantation of a ventriculo-peritoneal shunt due to various pathologies. The uneventful wound healing during the first weeks after shunt implantation, avoiding the above mentioned non-infectious complications, was supported by initial, temporary overdrainage and readjustment of the programmable valve after completed wound healing. All patients tolerated this procedure well and showed no pathological signs or symptoms of overdrainage like premature closure of cranial sutures, clinical low-pressure syndrome, slit ventricle syndrome (SVS), subdural fluid collection or brain collapse during an average follow-up period of 2.6 years (2 - 65 months). Infectious and other mechanical, non-infectious complications were analysed as well during the follow-up period. These results suggest that an initial, temporary overdrainage in infants and neonates with shunted hydrocephalus may contribute to further lower the incidence of non-infectious complications like wound break-down, CSF-fistula or subcutaneous CSF accumulation, without negative side effects. This technique could be a valuable option in the regimen of shunt-treatment of this age group in order to optimise the overall success rate and lower the general complication rate.

[Biomechanicsl evaluation of a stand-alone interbody fusion cage based on porous TiO2/glass-ceramic on the human cervical spine]. / Biomechanische Untersuchungen eines Bandscheibenersatzimplantats aus einer neuartigen porösen TiO2/Glas-Keramik an der humanen Halswirbelsäule.

Recently, there has been a rapid increase in the use of cervical spine interbody fusion cages, differing in design and biomaterial used, in competition to autologous iliac bone graft and bone cement (PMMA). Limited biomechanical differences in primary stability, as well as advantages and disadvantages of each cage or material have been investigated in studies, using an in vitro human cervical spine model. 20 human cervical spine specimens were tested after fusion with either a cubical stand-alone interbody fusion cage manufactured from a new porous TiO2/glass composite (Ecopore) or PMMA after discectomy. Non-destructive biomechanical testing was performed, including flexion/extension and lateral bending using a spine testing apparatus. Three-dimensional segmental range of motion (ROM) was evaluated using an ultrasound measurement system. ROM increased more in flexion/extension and lateral bending after PMMA fusion (26.5%/36.1%), then after implantation of the Ecopore-cage (8.1%/7.8%). In this first biomechanical in vitro examination of a new porous ceramic bone replacement material a) the feasibility and reproducibility of biomechanical cadaveric cervical examination and its applicability was demonstrated, b) the stability of the ceramic cage as a stand alone interbody cage was confirmed in vitro, and c) basic information and knowledge for our intended biomechanical and histological in vivo testing, after implantation of Ecopore in cervical sheep spines, were obtained.

Prognostic factors for patients with microsurgically resected brain metastases.

BACKGROUND: With the advent of new therapies for metastatic carcinoma to the brain, patterns of intracranial disease and factors influencing survival become important considerations when examining treatment options. This study was conducted at a single institution to determine prognostic factors for tumor response and patient survival after microsurgical resection of brain metastases. PATIENTS AND METHODS: 187 consecutive patients who underwent microsurgical resection of brain metastases between July 1989 and September 1996 were retrospectively reviewed and statistically analyzed. The primary cancers included lung cancer (85), gastrointestinal cancer (20), renal cell cancer (19), breast cancer (17), malignant melanoma (8) and 38 cases of various other carcinomas or of unknown primary site. 111 patients received whole-brain radiation therapy (WBRT) with a mean dose of 32 Gy after tumor resection. The influence of number, size, and localization of brain metastases as well as histology of the primary tumor, preoperative performance status, presence of extracranial systemic disease, time course and adjuvant radiation therapy were statistically evaluated (uni- and multivariate) as prognostic factors for survival. RESULTS: Early postoperative Karnofsky score was improved in 59%, unchanged in 32% and worse in 9% of patients. Median survival time (MST) was 9.8 months (range 1 day-5.3 years). The most important parameter showing a significant influence on survival time was the histology of the primary tumor, with prediction of a bad outcome especially for patients with metastases from renal-cell cancer and malignant melanomas. Patients with breast cancer showed longer survival than patients with other primary cancers. Furthermore, survival varied significantly depending on location of brain metastases, performance status at time of craniotomy and duration of symptoms. None of the other studied variables gained prognostic significance. CONCLUSION: Microsurgical resection of one or more brain metastases followed by WBRT still is a useful and efficient treatment in a carefully selected patient group to prolong median survival and improve or stabilize the performance status. Among the factors determining the survival times in this patient group, histology of the primary tumor is most important, together with preoperative Karnofsky score, location of metastasis and preoperative duration of symptoms.

[Pterional orbital decompression in traumatic orbital hematomas]. / Die pterionale Orbitadekompression bei traumatischen Orbitahämatomen.

The results are presented for pterional orbital decompression in 12 patients with symptomatic traumatic retrobulbar hematoma after various traumatic mechanisms. Pre- and postoperative course, neuroradiological findings, additional brain or facial injuries as well as outcome of eye function are analyzed in detail. Mean time delay between trauma and decompression was 56 h (2.4 days), with a wide range from 2 h to 15 days. Preoperative exophthalmos and pupillary disturbances as well as restrictions of extraocular movements decreased in all patients after orbital decompression and removal of the retrobulbar hematoma if the bleeding was localized. Visual acuity remained normal or showed significant improvement in seven patients, four of whom experienced complete recovery. In three patients the eye remained amaurotic. No complications related to the operation were seen. The pterional orbital decompression described here represents an effective alternative approach for patients with sight-threatening retrobulbar hematoma, especially in cases where it is necessary to gain space for the orbit in addition to evacuating space-occupying blood or bone clots and treating neighbouring lesions. Immediate detection and adequate treatment of orbital hematomas is mandatory to achieve an acceptable outcome of eye function.

[Treatment options in traumatic epidural hematomas]. / Behandlungsmöglichkeiten bei traumatischen Epiduralhämatomen.

The authors report 118 consecutive cases of patients with traumatic extradural hematoma (EDH) which were analyzed according to different clinical parameters and treatment modalities. Patients, treated for EDH between 1992 and 1998 in our department were distributed into 5 treatment groups depending on their clinical and neuroradiological findings on admission and during the hospitalization. Group I consisted of 75 patients (64%) who required immediate surgical evacuation of the hematoma after admission. Group II included 12 patients (10%) with initially conservative treatment despite visible EDH on the first CT-scan, which had to be operated on in the course because of neurological deterioration or increase of hematoma size. The 14 patients (12%) forming group III developed an acute EDH after the initial CT-scan revealed no extradural blood; 7 patients (6%) out of group IV showed a chronic EDH (delay trauma/diagnosis > 72 h), which required operative evacuation. All 10 patients (8%) comprising group V were treated conservatively. In each group the following parameters were analyzed: patient age, size and location of hematoma, trauma mechanism, additional intracranial lesions or skull fractures, intraoperative findings and neurostatus on admittance and during the hospitalization. The decision for non-operative treatment of EDH and the timing of a delayed intervention has to be made individually in each case in dependence of parameters like patient age, hematoma-size and -location and neurological status and course. Chronic EDH should be operated immediately, as well as hematomas presenting with an increase in size. Delayed developing EDH imply worse outcome and make adequate surveillance of high-risk patients mandatory.

Proton magnetic resonance spectroscopy of neurocytoma outside the ventricular region--case report and review of the literature.

Central neurocytoma is classically considered as an intraventricular benign tumour, largely based on data from small retrospective series and single case reports. We report on a 16-year-old girl who suffered from a large parietooccipital tumour that was diagnosed histologically as central neurocytoma. The features of CT, MRI and proton MR spectroscopy studies are discussed. This is the first report on spectroscopic findings in a case of extraventricular neurocytoma. As well as elevated choline (Cho), the tumour spectrum showed strongly decreased N-acetylaspartate (NAA). NAA is assumed to be produced in mature neurons, and we therefore expected to find high amounts of NAA in this well-differentiated tumour, which was histologically composed of mature neuronal tissue. This observation leads to the conclusion that even the highly differentiated cells of neurocytomas are too immature to produce NAA.