Evoked potentials in acute head injured patients with MRI-detected intracerebral lesions.

BACKGROUND: Magnetic resonance imaging (MRI) allows precise detection of intracranial lesions in head injured patients. We compared intracranial lesions detected in MRI to somatosensory evoked potentials (SEP) and brainstem auditory evoked potentials (BAEP) concerning their prognostic value. METHODS: Thirty patients with traumatic brain injury and prolonged recovery were studied. Size, side and number of 474 intra- and extraparenchymal lesions as well as lesion localisation based on a specific anatomical classification were entered into a database (a total of 7080 data). In addition, we recorded median-nerve SEP (M-SEP), tibial nerve SEP (T-SEP) and BAEP in all of the patients. FINDINGS: M-SEP and Glasgow-Outcome-Score (GOS) one year after injury correlated significantly to patients with lesions in the brainstem (p<0.0001) and corpus callosum (p<0.001). Similar results were found for T-SEP (p<0.0001). All patients with bicortical loss of M-SEP had an unfavourable outcome (GOS 2). Among the analysis of lesion volume, only the volume of brainstem lesions correlated to GOS (p<0.001), but this was not found for callosal lesions. However, comparing the vegetative (GOS 2) to the non-vegetative group (GOS 3-5), for both callosal (p<0.02) and brainstem (p<0.005) lesions a significant correlation was found. INTERPRETATION: MRI does not improve the prognostic reliability of SEP in head injury but offers possibilities for clarifying electrophysiological and clinical pathologies. This explains that the volume of brainstem lesions, essentially influencing the clinical outcome, is strongly correlated to T-SEP and M-SEP. In contrast, callosal lesions did not show a clear relationship to outcome despite large callosal lesions (>4 ml) which tended to poor outcome. In conclusion, we suggest that MRI and SEP are supplementary to each other concerning prognostic evaluation.

Initial hyperglycemia as an indicator of severity of the ictus in poor-grade patients with spontaneous subarachnoid hemorrhage.

An association between hyperglycemia and outcome in spontaneous subarachnoid hemorrhage (SAH) has been sporadically reported. Our hypothesis was that hyperglycemia is a sign of central metabolic disturbance linked with specific appearances on computerized tomography (CT) scans reflecting different degrees of corresponding brain injury. The admission plasma glucose level, initial CT findings, and outcome after 6 months were analysed in a cohort of 99 patients with SAH in Hunt & Hess Grade IV or V. The CT scans were quantitatively assessed for subarachnoid blood, intracerebral hematoma, intraventricular hemorrhage, hydrocephalus, midline shift and compression of the perimesencephalic cisterns. These findings were combined to determine a three-point CT severity score. All patients showed elevated (>5.8 mmol/l) plasma glucose levels on admission. Mortality among 33 patients with glucose concentration below 9.0 mmol/l was 33.3%, 71.1% for the 45 patients with glucose level between 9.0 and 13.0 mmol/l, and 95.2% for the 21 patients with concentration above 13.0 mmol/l (P<0.0001). Glucose level was higher in Grade V than in Grade IV patients (mean+/-SD) (11.8+/-3.2 vs 9.8+/-2.9 mmol/l; P=0.0012). Patients with mild CT findings (n=10) had the lowest glucose level (8.9+/-1.8 mmol/l; P=0.0082), whereas patients with severe findings (n=56) had the highest glucose (11.4+/-3.5 mmol/l; P=0.011). Despite association with clinical grade and extent of CT findings, logistic multiple regression revealed the admission plasma glucose level to be an independent prognosticator of outcome. The prognostic potential of the initial plasma glucose level may be beneficial in management protocols of poor-grade SAH patients.

Effect of intracerebral lesions detected in early MRI on outcome after acute brain injury.

In the present study we classified intracerebral lesions likely to influence the outcome of head injured patients according to localization, lesion type, lesion number and lesion volume. A score of intracerebral lesions based on findings in early MRI is presented. Early MRI studies were performed in 30 patients (average 5-6 days after trauma) and outcome (GOS) was determined after 3 and 12 months. Lesions were classified and lesion volume V was calculated (V = pi abc/6). The applied intracerebral lesion score included lesions in the frontal cortex, basal ganglia, corpus callosum and brainstem. Patients in a persistent vegetative state (PVS) showed a higher number (p = 0.018) and volume (p = 0.013) of frontal lesions as compared to the non-vegetative group (NPVS). Lesion volume in basal ganglia differed significantly between PVS and NPVS (p = 0.01) and correlated to outcome (r = -0.65, p < 0.005). Volume difference in the corpus callosum between PVS and NPVS was significant (p = 0.02). The number (r = -0.61, p < 0.005) and volume (r = -0.62, p < 0.005) of brainstem lesions correlated to outcome and PVS differed in number (p = 0.012) and volume (p = 0.006). The intracerebral lesion score correlated to the GOS (r = -0.57, p = 0.001) and PVS and NPVS differed significantly. A lesion volume exceeding 40 ml in the frontal cortex, 3.5 ml in the basal ganglia, 4 ml in the corpus callosum or 1.5 ml in the brainstem is likely to lead to an unfavorable outcome. More than 4 lesions in the frontal cortex or 3 lesions in the brainstem appeared more frequent in patients with unfavorable outcome. Treatment strategies in the early phase after brain injury could be modified by the knowledge of certain lesions only visible on MRI.

Occult malformations of the skull base.

Occult malformations of the skull base are rare anomalies. They are often not detected until they give rise to complications such as meningitis or cerebrospinal fluid rhinorrhea. We used high-resolution computed tomography, fluorescein endoscopy, cisternography, magnetic resonance imaging, and duraplasty to diagnose occult malformations of the skull base in 4 patients. The four patients had had between 4 and 6 attacks of meningitis. Cerebrospinal fluid rhinorrhea was confirmed in 3 cases. The following occult malformations were found: (1) an encephalocele of the glabella/cribriform plate and a meningocele at the petrous bone apex, (2) a meningoencephalocele at the petrous bone apex, (3) dural lesions in the regions foramen rotundum/sphenoid sinus and frontal sinus/cribriform plate, and (4) a dural lesion of the sphenoid sinus. In patients presenting with recurrent meningitis, meningitis with isolation of upper airway pathogens, or cerebrospinal fluid rhinorrhea, modern diagnostic methods should be used to search for dural lesions. Diagnosis of an occult malformation makes it possible to perform the necessary surgical repair and thus prevent the further occurrence of potentially fatal episodes of meningitis.

[Ophthalmologic symptoms in meningioma of the orbits and in the anterior and medial cranial fossa]. / Ophthalmologische Symptomatik bei Meningeomen in der Orbita und in der vorderen und mittleren Schädelgrube.

UNLABELLED: The records of 182 patients treated for a meningioma of the orbit or the periorbital region between 1971 and 1989 were analyzed. PATIENTS: There were 138 women (76%) and 44 men (24%). Twenty patients had a meningioma of the optic nerve sheath, 78 patients a meningioma involving the sphenoid wing, 29 a meningioma within the sella region, 36 patients a meningioma of the anterior cranial fossa and 19 patients a meningioma of the medial cranial fossa. RESULTS: As an initial symptom 53% complained of decreased vision, 25% of headaches and 16% had exophthalmos. At the first ocular examination visual acuity was decreased below 0.1 in 22%. In 58 eyes we found papilledema and in 60 eyes optic atrophy. Other manifestations were visual field defects, ocular motility deficits in 20%. Histologically the meningiomas were most commonly of the endotheliomatous type (72%). In 23% of the patients, the tumor recurred, which manifested itself in a third by ocular symptoms.

Deliberate arterial hypotension does not reduce intraocular pressure in pigs.

Among the accepted advantages of general anesthesia in ophthalmic surgery is improved control of intraocular pressure (IOP). Although standard textbooks advocate deliberate arterial hypotension to facilitate intraocular surgery by reducing IOP, scientific proof of such an effect is lacking. The authors investigated effects of induced arterial hypotension on IOP in an anesthetized porcine model. Forty-two piglets were anesthetized with piritramide, were placed in the prone position, and had the anterior chamber of one eye punctured with a small Teflon cannula to measure IOP. Six pigs were used in a pilot study to establish dose-response relationships for the hypotensive agents; 36 pigs were randomly allocated to one of three groups (n = 12) to receive nitroprusside, adenosine, or isoflurane to reduce mean arterial pressure (MAP) by 50%. Measurements were made after initial stabilization of hemodynamic variables and IOP (control), when a stable MAP of 0.5x control was maintained for 10 min or longer, and after return of MAP to a posthypotensive steady state. The median of differences between time intervals was analyzed statistically for all variables. Nitroprusside and adenosine produced hyperdynamic hypotension (cardiac index increased); isoflurane-induced hypotension was hypodynamic. Control IOPs were 12.9, 12.5, and 11.1 mmHg in the nitroprusside, adenosine, and isoflurane groups, respectively. Median change in IOP during hypotension was -1.5, +1.5, and 0 mmHg in the nitroprusside, adenosine, and isoflurane groups, respectively. The IOP during adenosine-induced hypotension was significantly higher than that during either nitroprusside- or isoflurane-induced hypotension. Return of MAP to control levels was frequently associated with intraocular rebound hypertension when arterial hypotension had been induced with adenosine or nitroprusside.(ABSTRACT TRUNCATED AT 250 WORDS)

Occlusion of the pig superior sagittal sinus, bridging and cortical veins: multistep evolution of sinus-vein thrombosis.

Cerebral sinus-vein thrombosis may lead to severe hemodynamic changes, elevated intracranial pressure (ICP), and brain edema. It is supposed that progression of the thrombus from the sinus into bridging and cortical veins plays a key role in the development of these pathophysiological changes, but this hypothesis lacks experimental proof. The aim of this study, using a novel animal model of sinus-vein thrombosis, was to evaluate the effects of a standardized occlusion of the superior sagittal sinus and its bridging and cortical veins on hemodynamic alterations, on brain water content, and on ICP in domestic pigs. In 10 animals, the middle third of the superior sagittal sinus was occluded with a catheter-guided balloon. Five of these pigs received an additional injection of 1 ml fibrin glue into the superior sagittal sinus anterior to the inflated balloon, leading to an obstruction of bridging and cortical veins. In five control animals the balloon was inserted but not inflated. Five pigs underwent cerebral angiography. Four hours after occlusion, the brains were frozen in liquid nitrogen, and coronal slices were examined for Evans blue dye extravasation, regional water content, and histological changes. Occlusion of the superior sagittal sinus alone did not affect ICP or cerebral perfusion pressure (CPP). The additional injection of fibrin glue caused an obstruction of cortical and bridging veins as well as severe increases in mean (+/- standard deviation) ICP to 49.4 +/- 14.3 mm Hg, compared with 8.3 +/- 4.5 mm Hg in sham-treated controls and 7.1 +/- 3.9 mm Hg in animals with occlusion of the superior sagittal sinus alone. There was also a steep fall in the mean CPP to 34.2 +/- 19.6 mm Hg compared with 96.4 +/- 13.8 mm Hg in the control group. White-matter water content anterior to the occlusion site was elevated to 81.9 +/- 3.7 gm/100 gm frozen weight in the fibrin group as compared to 70.7 +/- 2.2 gm/100 gm in controls. Posterior to the occlusion site, water content did not differ among the three groups. Angiography demonstrated collateral flow via cortical and bridging veins in animals with occlusion of the superior sagittal sinus alone. Additional fibrin glue obstructed these collateral vessels. The data suggest a multistep process of pathophysiological alterations in patients with sinus-vein thrombosis and may explain why these patients present with a wide variety of symptoms: minor neurological deficits or headache might indicate thrombosis of the superior sagittal sinus and/or its bridging veins.(ABSTRACT TRUNCATED AT 400 WORDS)

[Surgical accidents during repair of intracranial aneurysms]. / Incidents chirurgicaux au cours de la chirurgie des anévrysmes intra-craniens.

The need to discuss incidents encountered during cerebral aneurysm surgery--as well as techniques and results--is increasingly accepted. Single incidents, however, do not allow for general conclusions; we wish to present 5 cases, analysis of which, we believe, is likely to elucidate the trouble of diagnosis and intraoperative decision making.

Myxoma of the orbit: a clinicopathologic report.

A 27-year-old white man developed proptosis of his left eye over a period of 2 years. It was associated with vertical diplopia and displacement of the left globe down and laterally. Ultrasonography showed a cystic mass in the superior orbital region. Computed tomography (CT) demonstrated a solid, well-defined lesion behind the globe displacing the optic nerve medially. A transfrontal craniotomy revealed a nodular mass in the posterior and superior orbit, which extended anteriorly up to the globe. Histopathology, immunohistochemistry, and transmission electron microscopy proved the tumor to be a myxoma.

Brain oedema and intracranial pressure in superior sagittal sinus balloon occlusion. An experimental study in pigs.

About 2/3 of all patients with thrombosis of the superior sagittal sinus (SSS) develop signs of increased ICP and/or brain oedema (BE). The time of onset and the spectrum of symptoms in SSS thrombosis vary extremely. This variability might be caused by differences in pathomechanism like BE and rise of ICP, parameters studied in the present contribution. 10 domestic pigs received a standardized occlusion of the SSS with two different balloon types (spherical and cylindrical). They were monitored for several systemic and intracranial pressures. After 4 hours of occlusion the brains were examined for BE (Evans blue, water content). They were compared with those of 4 sham-operated control animals. 4 animals underwent cerebral angiography. Within 4 hours ICP rose to 60 mm Hg in the group with the spherical balloon. Normal ICP of 5-10 mm Hg was seen in the group with the cylindrical balloon and in the sham-operated controls. The water content of the white matter was elevated in both occlusion groups differing significantly from the control group. Haemorrhagic infarction of the frontal parts of the cerebrum occurred in animals with concomitant obliteration of bridging and cortical veins. We conclude from our experiments that SSS occlusion may initiate a multitude of possible pathomechanisms depending on the involvement of bridging veins, cortical veins and inner brain veins.

[Risks of premedication with benzodiazepines exemplified by a case of asphyxia caused by flunitrazepam]. / Risiken der Prämedikation mit Benzodiazepinen am Beispiel einer Asphyxie nach Flunitrazepam.

Oral premedication with benzodiazepines is well established in clinical anaesthesia. Appreciation of the specific pharmacodynamic profile of available drugs suggest individual prescription for certain groups of patients. We report a case of severe respiratory depression following oral premedication with flunitrazepam 1 mg in a patient with intracranial neoplasma. With respect to this complication and a review of the literature we suggest administration of short acting benzodiazepines with pronounced anxiolytic and moderate sedative properties (lormetazepam type) for neurosurgical patients.

Tissue elastance and fluid conduction in normotensive and hypertensive intracerebral mass haematomas.

This is an investigation into the prognostic factors of 117 patients with spontaneous normo- and hypertensive intracerebral haematomas, supported by animal experiments. Preserved tissue elastance and fluid conduction enables the drainage of intrinsic haematoma serum into the CSF spaces in normotensive patients, who showed an increased extension of a perifocal hypodensity in the CT. Arterial hypertension decreased the possibility of fluid resolution. Our experimental studies showed that in hypertensive cases the serum remained trapped in the haematoma, which explains the small hypodense area around the haematoma in most of the hypertensive cases. If as an exception in hypertensives of perifocal hypodensity develops then it acts as additional space-occupying factor. Corresponding observations were made in hypertensive animals which showed a reduced serum movement out of the haematoma, but an increased Evans-Blue content in the perifocal tissue. Both pathological mechanisms explain the poorer prognosis in patients with intracerebral haematomas associated with high arterial blood pressure.

Pathomechanism of brain oedema in experimental intracerebral mass haemorrhage.

The prognosis of intracerebral haemorrhage is extremely poor when arterial hypertension is present. We investigated elastance of the brain tissue and brain hydraulic conductivity in normotensive (MAP approximately 110 mmHg) and hypertensive (MAP approximately 170 mmHg/angiotensin infusion) cats following a stereotactically produced intracerebral haemorrhage. For 12 hours after the onset of haemorrhage we registered the course of ICP, subsequently the water content of cortex, white matter and basal ganglia as well as the interstitial concentration of serum proteins in the corresponding regions were determined (Evans-Blue, immunofluorescence). Hypertension was associated with a slight increase in ICP and tissue water content but with a 3 fold more elevated content of interstitial serum proteins. Immunofluorescence analysis showed the oedema in the hypertensive group to be vasogenic in nature and in the normotensive cats to originate from the haematoma itself. The generally poor outcome of intracerebral mass haemorrhage in hypertensive subjects could be ascribed to the nature of the concomitant brain oedema, as described in this study.

'Anestheticography': on-line monitoring and documentation of inhalational anesthesia.

The safe practice of inhalational anesthesia requires control over the amount of volatile anesthetic delivered to the patient. With minimal fresh gas flow this is facilitated by continuous monitoring and recording of the agent's concentration ('Anestheticography'). Alterations brought about by routine clinical maneuvers become visible. We recorded the course of the inspiratory and expiratory concentration of volatile anesthetic (Isoflurane) by infrared absorption and a trend recorder. Changing the carrier gas composition during high flow from 75% to 25% nitrous oxide in oxygen resulted in a 10% increase of the inspiratory isoflurane concentration. Activating the oxygen bypass or exchanging the soda lime canisters was followed by a prolonged disturbance of concentrations, most pronounced with minimal flow. Initiating emergence by closing the vaporizer during minimal flow led to a slow decrease in concentration whilst at a flow of 61/min the inspiratory isoflurane concentration rapidly decreased to subanesthetic levels. Insertion of a charcoal filter into the inspiratory limb of the breathing circuit immediately dropped the inspiratory concentration to undetectable levels. 'Anestheticography' is a useful means of monitoring and documentation of inhalational anesthetic. With the use of a charcoal filter all advantages of minimal flow anesthesia can be realized throughout the entire anesthetic, including emergence.

Rare sacral space-occupying lesions, their surgical management and reconstructive measures involved.

Nine cases of space-occupying lesions of the sacral bone are presented. The problems of the clinical diagnosis, which in many cases comes too late, are discussed together with the indications for surgical treatment in this special group of tumours. The main clues are provided by the changes in the X-rays as well as the more modern imaging techniques (CT and MRI). The surgical technique aims at a most radical tumour removal with preservation of the sacral nerve roots, after which stabilisation of the sometimes weakened pelvic girdle may be necessary. The good prospects of complete removal of these tumours of the sacrum with satisfactory results seem to be very little known and justifies further dissemination of this information.

[Therapeutic concepts in neurologic damage following severe soft tissue and bone injuries of the distal lower leg and foot]. / Therapeutisches Konzept bei neurologischen Schäden nach schweren Weichteil- und Knochenverletzungen am distalen Unterschenkel und fuss.

In less than 1% of the cases nervous lesions after severe lower leg lesions demand surgical treatment: Neurosurgical Clinic: 28 reconstructive interventions on the lower leg, however, 362 on the forearm in 15 years; Clinic of Accident Surgery: 264 severest lower leg- and foot-injuries, among them only two nervous lesions. The n. peronaeus is more frequently affected than the n. tibialis. Even if continuity of the nerve is maintained, endoneural bleeding and internal ruptures can lead to extensive axonal lesions. The kind of nervous lesion (neurapraxia, axonotmesia, neurotmesia) should be clarified during the first three months, if possible, since it determines the prognosis as well as the kind of operative treatment during the first six months.

[Paranasal sinus reconstruction with bioactive bone cement--a 5-year animal experiment study]. / Stirnhöhlenrekonstruktion mit bioaktivem Knochenzement--5 Jahre tierexperimentelle Erfahrungen.

The newly developed bioactivated bone cement Palavital is composed of polymethylmethacrylate, glass fibers and bioactive glass ceramic. The superficially located glass ceramic particles offer the possibility of true bonding of the bone cement to the bony implantation bed. Reconstruction of the frontal sinuses and the skull was performed on 9 dogs. The follow up was 14 days to 5 years. The implants were checked by tomography and histology. All implants were tolerated without any inflammatory reaction. The bond between bone and implant was demonstrated. Palavital seems to be an improvement on bone cement on a polymethylmethacrylate base.