Aneurysmal and non-aneurysmal SAH--is initial computed tomography predictive?

PURPOSE: Diagnostic workup in patients with angiographically negative subarachnoid hemorrhage (SAH) remains controversial. We discuss the relevance of bleeding patterns on CT as they pertain to the prediction of angiographic results. MATERIALS AND METHODS: We compared bleeding patterns on 112 CTs of patients with non-aneurysmal subarachnoid hemorrhage (non-ASAH) and 104 CTs of patients with aneurysmal SAH (ASAH) taken within 48 hours according to a CT-based grading system (Type 0 - 4). RESULTS: Bleeding patterns differed between ASAH and non-ASAH patients (p < 0.0001). Non-ASAH patients had no or prepontine blood (type 0 + 1) in 40% of cases, extension into the medial (type 2) or lateral (type 3) Sylvian fissure in 60% of cases and no intracerebral hemorrhage (type 4). All type 0 and 1 patients had negative initial and repeat angiographies. CONCLUSION: A CT classification of bleeding patterns helps to predict angiographic results. Digital subtraction angiography (DSA) should remain the gold standard as it allows detection non-aneurysmal bleeding sources at low-risk. Repeat angiography may be omitted in the case of type 0 and 1 bleeding if a complete, high quality DSA was obtained initially.

Surgical planning for retrosigmoid craniotomies improved by 3D computed tomography venography.

OBJECTIVE: It is impossible to precisely anticipate the crooked course of the transverse and sigmoid sinuses and their individual relationship to superficial landmarks such as the asterion during retrosigmoid approaches. This study was designed to evaluate this anatomical relationship with the help of a surgical planning system and to analyze the impact of these in vivo findings on trepanation placement in retrosigmoid craniotomies. METHODS: In a consecutive series of 123 patients with pathologies located in the cerebellopontine angle, 72 patients underwent surgical planning for retrosigmoid craniotomies based on 3D volumetric renderings of computed tomography venography. By opacity modulation of surfaces in 3D images the position of the asterion was assessed in relationship to the transverse-sigmoid sinus transition (TST) and compared to its intraoperative localization. We evaluated the impact of this additional information on trepanation placement. RESULTS: The spatial relationship of the asterion and the underlying TST complex could be identified and recorded in 66 out of 72 cases. In the remaining 6 cases the sutures were ossified and not visible in the 3D CT reconstructions. The asterion was located on top of the TST in 51 cases, above the TST in 4 cases, and below the TST in 11 cases. The location of the trepanation was modified in 27 cases due to the preoperative imaging findings with major and minor modifications in 10 and 17 cases, respectively. CONCLUSION: Volume-rendered images provide reliable 3D visualization of complex and hidden anatomical structures in the posterior fossa and thereby increase the precision in retrosigmoid approaches.

Image-guided craniotomy for frontal sinus preservation during meningioma surgery.

OBJECTIVE: Preservation of the frontal sinus (FS) during the frontolateral approach to the skull base reduces morbidity, enhances patient comfort, and speeds up the surgical procedure. Due to its irregular outline, mental reconstruction of the borders of FS from two-dimensional images is challenging during surgery. This study was designed to evaluate the impact of neuronavigation on identification and preservation of the FS during frontolateral craniotomies. METHODS: Forty-five patients with pathologies located in the anterior skull base and in the parasellar region were included. A standard computed tomography (CT) sequence was obtained from each patient and uploaded onto an image-guidance system for volumetric rendering of 3D images. The outline of the FS was visualized and the distance between its lateral border and the mid-pupillary line (MPL) was measured. The results were used for navigated craniotomies and compared to the intra-operative findings. RESULTS: The FS was located medial, on and lateral to the MPL in 32, 4 and 9 cases, respectively. The individual outline of the FS could be identified with a mean target registration error of 1.4mm (+/-0.7 mm). The craniotomy could be custom-tailored for each patient according to the individualized landmarks while visualizing the lesion and the surgical landmarks simultaneously. Unintended opening of the frontal sinus or orbit did not occur in any of these cases. CONCLUSION: Image-guided craniotomies based on 3D volumetric image rendering allow for fast and reliable demarcation of complex anatomical structures hidden from direct view in frontolateral approaches. The outline of the frontal sinus and the orbit can be appraised at a glance providing additional safety and precision during craniotomy.

[Multidisciplinary management of skull base and craniocervical chordoma]. / Clivuschordome -- multidisziplinäre Fortschritte und prognostische Relevanz.

BACKGROUND: Craniocervical chordomas often only become manifest in an advanced stage. The localisation and locally-destructive growth require a multidisciplinary diagnostic and therapeutic concept early on. The goal of the present study was to present a reproducible strategy for quality assurance. PATIENTS AND METHOD: We retrospectively analysed the hospital records of 10 consecutive patients (4 women and 6 men) whom we had treated during a period of 7 years. RESULTS: The first step in therapy was tumour resection in 9 cases. One patient initially underwent stereotactic radiation. Postoperative radiation was not included a priori, but discussed individually depending on the degree of resection, the patient's age and physical condition. After an average 5 years follow up, 100 % of patients are alive. In all patients, tumour control was achieved. CONCLUSIONS: The prognosis for patients with chordomas of the skull base has improved considerably in recent years. New technologies like intraoperative navigation and improved radiation procedures have contributed to this improvement. The basis for treatment remains, however, the greatest possible surgical exstirpation with minimal surgical morbidity. Special attention should be paid in this connection to the stability of the cervical spine and the craniocervical transition border. In advanced tumour growth, complete resection is often not possible. Proton and heavy-ion radiation are promising new forms of therapy, which can also be applied after conventional radiation has been performed. A directed multidisciplinary procedure guarantees years of survival with good quality of life in many cases.

[Rupture of the arteria subscapularis following reduction of an anterior shoulder dislocation]. / Verletzung der A. subscapularis durch Reposition einer vorderen Schulterluxation.

Anterior shoulder dislocations are one of the most common problems seen in an emergency department. Doubtless, immediate reduction is necessary for treatment, a procedure that is extremely rarely accompanied by complications. In these cases early diagnosis and treatment may be limb saving. We report a case with rupture of the arteria subscapularis following reduction of an anterior shoulder dislocation with formation of an axillary hematoma and consecutive paresis of the plexus brachialis. Interdisciplinary operative revision was necessary to remove the hematoma, stop the hemorrhage and for neurolysis of the plexus brachialis. Treatment resulted in a speedy recovery of the patient. Gentle reduction of a dislocated shoulder is a prerequisite for a low complication rate. Contrast-enhanced computed tomography facilitated diagnosis of the hematoma and identification of the bleeding vessel.

The neurosurgeon on duty -- quality and quantity of acute care.

OBJECTIVE: An important part of the daily routine in neurosurgery is the treatment of emergency room admissions, acute cases from other departments or from outside hospitals. This acute care is not normally included in performance figures or budget management nor analysed scientifically with respect to quantity and quality of care provided by neurosurgeons. METHOD: Over a one-year period, all acute care cases managed by two neurosurgical on-call teams in Hannover (Northern Germany, 522 000 inhabitants) were recorded prospectively on a day-by-day basis. A large database of 1 819 entries was created and analysed using descriptive statistics. RESULTS: The minimum incidence of neurosurgical acute care cases was estimated to be 75-115/100 000 inhabitants/year. This corresponds to a mean of approximately 6 per day. The majority of patients was admitted after 5 p. m. and on weekends. Only 30 % of cases came directly via the emergency room. The fate of 70 % of patients depended initially on the "neurosurgical qualification" of primary care doctors and here deficits existed. Over one year the additional workload from acute care amounted to 1 000 unplanned admissions, 900 acute imaging procedures and almost 600 emergency operations. CONCLUSION: The current policy in public health which includes cuts in resources, transport facilities and manpower is not compatible with the demonstrated extent of acute neurosurgical care. In addition to routine elective work, a high number of extra admissions, evening or night-time surgery, and imaging procedures has to be carried out. These conclusions hold a special importance if health authorities wish to not just maintain present standards but to improve existing deficits.

Osteolytic intra-osseous meningiomas: illustrated review.

While bone invasion and hyperostosis are frequent phenomena in meningiomas, primary intra-osseous meningiomas are rare. With only 15 reported cases, the osteolytic form of primary intra-osseous meningiomas is most uncommon. Its occurrence in the skull base is an extra-ordinary exception. We have reviewed and categorized the pertinent literature on intra-osseus meningiomas with special emphasis on osteolytic tumours and discuss their clinical implications on the basis of a new case located in the petrous bone without contact with the meninges. It is concluded that due to their different clinical, radiological and pathological features, hyperostotic and osteolytic variants of intra-osseus meningiomas should be distinguished from tumours with soft tissue components and from en-plaque lesions.

The prognostic value of progesterone receptor status in meningiomas.

BACKGROUND: Meningiomas are known to recur frequently, and their longterm management remains controversial. Previous studies indicate that progesterone and its receptors can play a role in the recurrence of meningiomas, but the correlation between the presence of these receptors and patients' outcome is unclear. AIM: To conduct a retrospective analysis to investigate the prognostic relevance of progesterone receptor (PR) expression in meningiomas. METHODS: Five hundred and eighty eight meningiomas operated on over a period of 10 years were examined immunohistochemically to determine the PR status using monoclonal antibodies. Several factors including recurrence (mean follow up of 65 month), sex, tumour tissue consistency, location, vascularity, and en plaque appearance were analysed. RESULTS: PR status showed comparable values for men and women. World Health Organisation (WHO) grade II and III tumours had significantly fewer receptors than benign meningiomas. There was no significant correlation between PR status and recurrence rates in WHO grade I totally removed meningiomas. However, a combination of PR status and proliferation indices was shown to predict recurrence reliably. CONCLUSIONS: Together with routine histological evaluation, PR status can help to describe the biological behaviour of meningiomas. Only a combination of clinical and biological features can describe the behaviour of meningiomas, predict their recurrence, and help to devise more effective follow up strategies.

[Initial chronic results of flexible sieve electrodes as interface to nerve stumps]. / Erste chronische Ergebnisse von flexiblen Siebelektroden als Schnittstelle zu Nervenstümpfen.

Since more than 20 years, nerve stumps have been interfaced with sieve-like microsystems with integrated electrodes in experimental studies. In most cases, silicone tubes have been assembled on the microsystems to adapt the nerve and deliver a guidance structure for regeneration. Flexible, polyimide-based sieve electrodes with integrated fixation aids have been implanted chronically in an animal model. They have been adapted between the transsected ends of the sciatic nerve of rats and on the proximal stump in an amputation model. First electrophysiological experiments proved the functional reinnervation. Combining embryonic motor neurons with the sieve electrode, we propose a biohybrid system that is under investigation to functionally interface the distal part of a transsected peripheral nerve.

Natural history of chondroid skull base lesions--case report and review.

Long-term follow-up reports on chondroid lesions of the skull base are rarely presented in the literature. There are virtually no data on natural growth rates of these tumors based on MRI obtained over a period of 10 years or longer. We followed a patient who has had such a lesion for more than 12 years. A non-progressive, slight abducens palsy has been the only associated symptom so far. Even though the patient was operated on for an additional intracranial arterio-venous malformation, clinical features and chromosomal testing excluded Maffucci's syndrome. The MRI follow-up in this case provides an extraordinary perspective on the natural history of chondroid skull base tumors.

Single cerebral metastasis 3 and 19 years after primary renal cell carcinoma: case report and review of the literature.

Cerebral metastasis in general is associated with a relatively short survival time. However, brain deposits may occur rather late during follow up. Nine cases of solitary brain metastasis of renal cell carcinoma with a latency period of more than 10 years after nephrectomy have been reported in the literature so far. This is the first report of a case describing a second solitary brain metastasis which occurred 16 years after a first metastatic brain lesion. Complete microsurgical resection alone led to an excellent outcome in this particular case as the patient refused any adjuvant therapy at the same time. Regular nuclear morphology, a low mitotic index, and the absence of chromosomal abnormalities in tumour cells may be indicative for a relative benign clinical course.

Far-field responses to stimulation of the cochlear nucleus by microsurgically placed penetrating and surface electrodes in the cat.

OBJECT: A new generation of penetrating electrodes for auditory brainstem implants is on the verge of being introduced into clinical practice. This study was designed to compare electrically evoked auditory brainstem responses (EABRs) to stimulation of the cochlear nucleus (CN) by microsurgically implanted surface electrodes and insertion electrodes (INSELs) with stimulation areas of identical size. METHODS: Via a lateral suboccipital approach, arrays of surface and penetrating microelectrodes with geometric stimulation areas measuring 4,417 microm2 (diameter 75 microm) were placed over and inserted into the CN in 10 adult cats. After recording the auditory brainstem response (ABR) at the mastoid process, the CN, and the level of the inferior colliculus, EABRs to stimulation of the CN were recorded using biphasic, charge-balanced stimuli with phase durations of 80 microsec, 160 microsec, and 240 microsec at a repetition rate of 22.3 Hz. Waveform, threshold, maximum amplitude, and the dynamic range of the responses were compared for surface and penetrating electrodes. The EABR waveforms that appeared for both types of stimulation resembled each other closely. The mean impedance was slightly lower (30 +/- 3.4 kohm compared with 31.7 +/- 4.5 kohm, at 10 kHz), but the mean EABR threshold was significantly higher (51.8 microA compared with 40.5 microA, t = 3.5, p = 0.002) for surface electrode arrays as opposed to penetrating electrode arrays. Due to lower saturation levels of the INSEL array, dynamic ranges were almost identical between the two types of stimulation. Sectioning of the eighth cranial nerve did not abolish EABRs. CONCLUSIONS: Microsurgical insertion of electrodes into the CN complex may be guided and monitored using techniques similar to those applied for implantation of surface electrodes. Lower thresholds and almost equivalent dynamic ranges indicate that a more direct access to secondary auditory neurons is achieved using penetrating electrodes.

Microsurgical removal of a petrous apex meningioma after stereotactic radiation: technical case report.

OBJECTIVE AND IMPORTANCE: Stereotactic radiation is increasingly advocated as a primary treatment option for benign cranial base lesions. The clinical course of the patient reported herein raises questions regarding the rationale for initiation of radiotherapy to a petrous apex meningioma before microsurgery. CLINICAL PRESENTATION: We report a 50-year-old woman who experienced medically refractory trigeminal pain. She was diagnosed with a meningioma around the petrous apex and treated by fractionated stereotactic radiation. After a short period of alleviation accompanied by hypesthesia, the pain returned in a previously unknown and violent fashion. INTERVENTION: Complete tumor removal through a retrosigmoid intradural suprameatal approach resulted in immediate and permanent pain cessation. CONCLUSION: Radiotherapy should be withheld for benign and accessible tumors of the cranial base until the option of radical microsurgical treatment has been explored.

Acute care in neurosurgery: quantity, quality, and challenges.

OBJECTIVE: Part of the daily routine in neurosurgery is the treatment of emergency room admissions, and acute cases from other departments or from outside hospitals. This acute care is not normally included in performance figures or budget management, nor analysed scientifically in respect of quantity and quality of care provided by neurosurgeons. METHOD: Over a 1 year period, all acute care cases managed by two neurosurgical on call teams in a large northern German city, were recorded prospectively on a day by day basis. A large database of 1819 entries was created and analysed using descriptive statistics. RESULTS: The minimum incidence of patients requiring neurosurgical acute care was estimated to be 75-115/100 000 inhabitants/year. This corresponds to a mean of about 6/day. Only 30% of patients came directly via the emergency room. The fate of 70% of patients depended initially on the "neurosurgical qualification" of primary care doctors and here deficits existed. Although most intracerebral and subarachnoid haemorrhages were managed with the participation of neurosurgeons, they were not involved in the management of most mild and moderate traumatic brain injuries. Within 1 year the additional workload from acute care amounted to 1000 unplanned admissions, 900 acute imaging procedures, and almost 400 emergency operations. CONCLUSION: The current policy in public health, which includes cuts in resources, transport facilities, and manpower, is not compatible with the demonstrated extent of acute neurosurgical care. In addition to routine elective work, many extra admissions, evening or night time surgery, and imaging procedures have to be accomplished. An education programme for generalists is required to improve overall patient outcome. These conclusions hold special importance if health authorities wish to not only maintain present standards but aim to improve existing deficits.

Acoustic evoked response following transection of the eighth nerve in the rat.

OBJECT: The auditory brainstem response (ABR) is the most widely used means of intra-operative monitoring of the integrity of the auditory nerve and brainstem pathways during surgery in the cerebellopontine angle (CPA). Reliability of this and other electrophysiological techniques has been questioned because of persisting potentials in direct nerve recordings despite complete eighth nerve section. The study was designed to assess the extent to which an acoustic evoked response persists after the cochlear nerve is lesioned in the CPA of the adult rat. METHODS: The eighth nerve was exposed microsurgically via a lateral suboccipital approach without damage to surrounding structures. The auditory brainstem response to monaurally presented click stimuli was recorded using needle electrodes and a bandpass of 10 to 5000 Hz. FINDINGS: Complete sharp sectioning of the nerve in the CPA resulted in immediate disappearance of brainstem-generated potentials but persistence of a large primary, vertex-positive wave in all but one case. This response was also abolished in recordings three days later and after emptying the inner ear canal. Provided that the cochlea remained intact, two weeks later a single, vertex-positive potential in the latency range of wave Ia of the ABR reappeared, reaching its peak amplitude six weeks after sectioning of the nerve. CONCLUSIONS: The short-latency electrical potential recorded following damage of the eighth nerve in the cerebellopontine angle can be mistaken for an indication that nerve function is still preserved. The evoked injury potential is probably the major contributor to this potential that resembles wave I of the ABR. Monitoring of functional auditory integrity must neither be limited to early components of the ABR, nor to the electrocochleogram (EcoG) and the peripheral compound nerve action potential (CNAP), respectively.

Remission of superior oblique myokymia after microvascular decompression.

Superior oblique myokymia (SOM) is an ocular motility disorder characterized by oscillopsia, vertical or torsional diplopia, sometimes combined with pressure sensation. Although the pathophysiological basis is unclear, isolated case reports have documented its association with intracranial pathological processes. We present a case of SOM associated with a vascular compression of the fourth nerve at the root exit zone. Following microneurosurgical decompression, SOM completely resolved and paralysis of the fourth nerve occurred. This was less disturbing.

Solitary follicular thyroid carcinoma of the skull base and its differentiation from ectopic adenoma--review, use of galectin-3 and report of a new case.

With only four histologically proven cases in the literature, solitary skull base metastasis of thyroid carcinoma is extremely rare. Having treated another patient harboring a lesion with osseous destruction in the petroclival region and downward soft tissue extension we analyzed this case in conjunction with previous reports. In contrast to parenchymal brain metastasis that usually consists of the papillary type, histological examination revealed differentiated follicular tumors in all cases. All were located around the clivus. The radiographic picture resembled that of chordomas or chondrosarcomas. In the tissue obtained during thyroidectomy no evidence of primary malignancy was found in any of the cases according to standard histological criteria. In our case, a recently developed immunocytological marker - galectin-3 - was applied to differentiate between ectopic thyroid adenoma and carcinoma. The results were indicative of anaplastic growth. Tumor remnants responded well to postoperative 131I internal radiation and TSH suppression therapy. Distant metastasis of follicular thyroid carcinoma has to be considered in the differential diagnosis of destructive skull base lesions. Histological evaluation should include immunohistochemistry or clonal analysis to differentiate between adenomatous and carcinomatous growth and initiate effective radiotherapy early. Prognosis is by far not as poor as in brain metastases and appears to depend largely on location, size and histological appearance.

Monitoring of blood parameters following anterior cervical fusion.

OBJECT: Both C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR) were measured prospectively in 51 cases in which uncomplicated cervical anterior fusion was performed. The object of the authors was to quantify the differences in the responses of these parameters recorded in the immediate postoperative period and to determine factors influencing their course. METHODS: Nineteen one-level, 23 two-level, and nine three-level procedures for disc herniation and degenerative disease of the cervical spine were performed in 22 female and 29 male patients (mean age 49.2 years). Blood samples were obtained 1 day before as well as on 10 consecutive days and 3 months following anterior cervical fusion. Serum CRP level was measured using a fluorescence polarization immunoassay and ESR was determined from the same samples. Operative time, the number of blood transfusions, and drugs administered in the postoperative period were recorded. In addition, hemoglobin, hematocrit, red blood cell count, platelet count, white cell count, and axillary body temperature were checked daily. CONCLUSIONS: Monitoring of CRP level is superior to that of ESR for early detection of infections after cervical spine surgery. Although CRP was not related to any of the factors that have been proposed to explain its peak value variance in previous studies, individual acute-phase protein metabolism response to tissue affection appears to be a more decisive element in this respect.

De novo formation of an aneurysm in a case of unusual intracranial fibromuscular dysplasia.

Intracranial fibromuscular dysplasia (FMD) is a vascular disease of unknown origin occurring predominantly in young women. The internal carotid artery is most often involved, but other cerebral arteries may also be affected. We report the case of a young woman presenting with an unusual angiographic appearance of intracranial FMD of the internal carotid artery (ICA) that could not be categorized into any type of the Osborn-Anderson classification. During follow up the patient presented with an intracerebral and subarachnoid hemorrhage. Repeated angiography revealed multiple aneurysms in the pathologic segment of the vessel. The patient underwent surgical treatment with clipping of the aneurysms, wrapping of the pathologic segment of the ICA and biopsy of the superficial temporal artery. Histopathological sections revealed FMD of the intimal type. alpha(1)-antitrypsin blood levels were normal. Cases of intracranial FMD previously reported in the literature are reviewed and various aspects of this rare disease are discussed.