SAT0143 A PHASE 1 STUDY IN HEALTHY VOLUNTEERS EXPLORING THE SAFETY, PHARMACOKINETICS AND PHARMACODYNAMICS OF ATI-450: A NOVEL ORAL MK2 INHIBITOR

Background:

ATI-450, is an investigational small molecule inhibitor of the MAPK-activated protein kinase 2 (MK2) signaling pathway. This pathway drives the expression of multiple cytokines including TNFα, IL-1α and β, and IL-6.

Objectives:

We evaluated the safety and tolerability of ATI-450 in healthy volunteers as well as pharmacokinetics (PK) and pharmacodynamics (PD). Here we present data from single and multiple ascending dose cohorts. The aim was to select a dose for evaluation in phase 2 in patients with rheumatoid arthritis.

Methods:

Safety, PK and PD were assessed in a randomized, observer-blind, placebo-controlled, phase 1 study in male and female healthy subjects aged 18-55 (n=77).

Safety and tolerability of ATI-450 was evaluated based on adverse events, clinical laboratory, vital signs, 12-lead ECG, Holter monitoring, and physical examination. Blood was drawn for PK analysis at 0.5, 1, 2, 4, 6, 8, 12 hours, 24, 36, and 48 hours post dose in the SAD cohort and on day 7 of the MAD cohort. PD of ATI-450 were explored by investigating the inhibition of a target biomarker, phospho-HSP27 (pHSP27) and proinflammatory cytokines, TNFα, IL1β, IL6 and IL8 inex-vivoLPS-stimulated blood samples collected 4 and 12 hours post dose on day 7 from subjects in the MAD cohorts.

Results:

ATI-450 was generally well tolerated. No serious adverse events or severe adverse events were reported, and no adverse events led to discontinuation of the study medication. The most common adverse events (reported by 2 or more subjects who received ATI-450) observed during the trial were dizziness, headache, upper respiratory tract infection, constipation, nausea, and abdominal pain. All adverse events were mild. A trend of a decrease in absolute neutrophil count (ANC) was observed without correlated clinical sequelae.

ATI-450 had dose proportional PK with a terminal half-life (t½) of 9-12 hours in the MAD cohort on day 7. A dose and concentration dependent inhibition ofex vivostimulated cytokines and target biomarker was observed. On day 7, patients in the 50mg BID dose (the dose with the highest degree of inhibition) recorded mean trough drug levels (12 hours post dose) that were 1.4, 2.5, 2.5 and 2.4 times greater than the IC80for TNFα, IL1β, IL8 and pHSP27 respectively. Mean Cmax drug levels (4 hours post dose) were 3.6, 6.4, 6.2 and 6.0 times greater than the IC80for TNFα, IL1β, IL8 and pHSP27 respectively. IL6 levels were inhibited by more than 50% for part of the dosing interval.

Conclusion:

Oral ATI-450 was generally well tolerated at all doses with dose proportional PK. The t½ suggests that once or twice daily oral dosing may be possible. At the 50mg BID dose, marked inhibition of TNFα, IL1β and IL8, IL6 and pHSP27 was observed. ATI-450 has the potential to be an oral, small molecule drug which can target multiple cytokines. Exploration of its benefit to risk profile in patients with rheumatoid arthritis is warranted.

Disclosure of Interests:

Judy Schnyder Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, Joe Monahan Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, Walter Smith Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, Heidi Hope Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, Deborah Kelly Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, David Burt Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, E Huff Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, A Kaul Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, A Hildebrand Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, B Burnette Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, N Klug Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, M Bangs Shareholder of: Aclaris Therapeutics, Employee of: Aclaris Therapeutics, David Gordon Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics

Nonconvulsive status epilepticus as a possible cause of coma in neurosurgical intensive care

Nonconvulsive status epilepticus (NCSE) can occur in comatose patients without clinical signs of seizure activity. We evaluated the occurrence of NCSE in patients who were admitted to our neurosurgical intensive care unit between 1998 and 2000. EEGs were obtained from 158 patients with head trauma, spontaneous bleeding or brain tumour. Patients with clinically apparent seizure activity or no electrophysiological signs of seizure activity were excluded from the study. Epileptiform activity was seen in 28 out of 158 patients. 11/28 of these patients had a Glasgow-Coma-Scale (GCS) Score below 9 and showed continuous epileptiform discharge without clinical signs of seizure activity (NCSE). The clinical status of 4 of these 11 NCSE patients improved after initiation of anticonvulsive medication. NCSE may be an under-recognised cause of coma in neurosurgical intensive medicine. EEG should be included in the routine evaluation of comatose patients, even if clinical seizure activity is not apparent.

The hour-glass model of corpus callosum injury

In this retrospective study, the authors analyze the frequency, anatomical distribution and the clinical outcome of 44 patients after severe head injury, with and without lesions of the corpus callosum (CC). 44 patients with severe head injury (GCS<9 on admission), who were admitted to the intensive care unit of the Department of Neurosurgery after trauma, underwent early MR-tomography (T1, T2 and FLAIR sequences) in addition to CCT performed on admission. CC lesions were found in about 1/3 of patients with severe head injury. Posterior (splenium) lesions of the CC were three times more common than anterior lesions. Patients with CC injury were much younger compared to patients without CC injury (25 versus 34 years). The Glasgow Outcome Scale (GOS) score after six months was poor (death, persistent vegetative state, severe disability, GOS>3) in all patients with CC injury when compared to patients without CC injury (GOS<4). CC lesions are an important parameter in the assessment of severe brain trauma, hinting at the mechanism of injury as well as the outcome of patients. If a patient does not awake after blunt head injury, MRT scans (including FLAIR sequences) are indicated. A CC lesion alone is not the cause of prolonged coma but indicates a severe diffuse injury resulting in functional deorganization of the brain. The mechanisms of CC injury are discussed and a new pathophysiological model, based on the hour-glass analogy, is presented.

Incidence and outcome of traumatic brain injury in an urban area in Western Europe over 10 years

INTRODUCTION

Valid epidemiological data on incidence and outcome of traumatic brain injury (TBI) show great variability. A study on incidence, severity and outcome of TBI was conducted in an urban area of one million inhabitants.

MATERIALS AND METHODS

130,000 prehospital emergencies were screened for TBI.

INCLUSION CRITERIA

Glasgow Coma Scale (GCS) score <or=8 and/or Abbreviated Injury Scale for head injuries (AIS(head)) score >or=2 with confirmed TBI via appropriate diagnostics.

RESULTS

Annual incidence was 7.3/100,000. Overall mortality rate was 45.8%: 182 (28%) were prehospital deaths, 116 (17.8%) patients died in hospital. Two hundred and fourteen of 352 (60.8%) surviving patients were sufficiently rehabilitated at discharge [Glasgow Outcome Scale (GOS) score = 1], but 138 patients (39.2%) survived with persisting deficits. GOS was associated with initial GCS and AIS(head).

CONCLUSION

The incidence of TBI was lower compared to the literature. The overall mortality was high, especially prehospital and early in-hospital mortality rates.

Severe inflammatory reaction of the optic system after endovascular treatment of a supraophthalmic aneurysm with bioactive coils

We report on a patient who, after a symptom-free interval, developed severe vision impairment and whose MR imaging demonstrated extensive edema in the central nervous tissue neighboring the treated aneurysm. To our knowledge, this is an unreported complication of endovascular treatment of aneurysms.

Small keyhole transuncal foraminotomy for unilateral cervical radiculopathy

Interbody fusion after anterior discectomy may lead to acceleration of degenerative changes at adjacent levels. Although the posterior approach preserves the motion segment, decompression of the nerve root is indirect if "hard disc prolaps" is the main cause. Recently, a technique of microsurgical anterior cervical foraminotomy for the treatment of radiculopathy with preservation of the segment mobility was published. In this study, we present this technique with several modifications.Thirteen patients - 5 men and 8 women with an average age of 49 years - with unilateral radiculopathy resistant to conservative treatment underwent microsurgical anterior foraminotomy via a small keyhole transuncal approach. The base of the uncinate process (UP) was directly drilled in the trajectory to the intervertebral foramen without destroying the disc tissue. The vertebral artery between the transverse process was not exposed. Furthermore, the functional anatomy of the uncovertebral joint remained largely intact. All patients experienced complete relief of radiating pain. A cervical collar was not used. Mean follow-up time was 19 months. The mobility of the operated segment was preserved in each patient. No instability of the cervical spine was seen. The microsurgical anterior foraminotomy via a small keyhole transuncal approach is safe, minimally invasive, and represents an effective method to treat unilateral cervical radiculopathy caused by disc prolaps and/or uncovertebral osteophytes. Additionally, the segment mobility is preserved and prevents the acceleration of degenerative changes at adjacent levels.

F-wave amplitudes indicate evolving spinal autonomy during spontaneous recovery of hindlimb function in rat spinal cord contusion

STUDY DESIGN

Experimental rat model of spinal cord contusion.

OBJECTIVES

To reveal the extent of spinal autonomy contributing to recovery of hindlimb function.

SETTING

Experimental laboratory of a neurosurgical university department.

METHODS

F-wave amplitudes as a probe for spinal cord excitability were recorded from both sciatic nerves (lumbar segments L2-L5) before and after an experimental spinal cord contusion performed in the lower thoracic spinal cord. Additionally, transcranial electrically motor evoked potentials from the hindlimbs and cerebral somatosensory potentials evoked by sciatic nerve stimulation were recorded. Clinical evaluation of hindlimb function was done regularly for survival periods of 3 and 50 days, respectively. Electrophysiological testing was performed immediately prior and after lesioning of the cord and at the endpoint of survival periods.

RESULTS

Hindlimb function recovered from a mean Basso-Beattie-Bresnahan score of 5.6 on day 1 to 9.2 on day 3 (3-day-survivors) and from 7.7 to 17.2 on day 50 (50-day-survivors). This was accompanied by a significant increase of F-wave amplitudes on day 50 compared to baseline values, whereas amplitudes of somatosensory and motor-evoked potentials remained significantly depressed.

CONCLUSION

Recovery of hindlimb function may at least in part be attributed to evolving spinal autonomy, which can be assessed by F-wave amplitudes.

Spinal epidural abscess: prognostic factors and comparison of different surgical treatment strategies

BACKGROUND

Spinal epidural abscess (SEA) is a rare but potentially devastating disease requiring immediate surgical intervention and appropriate antibiotic treatment. The standard approach to decompress SEA is laminectomy. No report covers comprehensively the indications for the less invasive interlaminar approach, the usefulness of intra-operative ultrasonography and the suspected benefit of inserting a suction-irrigation drainage.

METHOD

A retrospective evaluation of the medical and radiological data was undertaken in 27 consecutive patients with SEA operated on during a period of 10 years by a dorsal approach. Factors influencing outcome were evaluated with special regard to different surgical strategies concerning the invasiveness of the operative approach, the use of intra-operative ultrasound and the use of different drainage systems.

FINDINGS

Outcome was mainly determined by the pre-operative neurological condition and the localization of the abscess. Recurrence rate was dependent on the longitudinal extent of the mass and the intra-operative finding of granulation tissue, but not on the administration of a postoperative suction-irrigation drainage. An interlaminar approach was equally matched to a decompression by laminectomy in lumbar SEA concerning the incidence of residual/recurrent abscess formation. In concomitant spondylodiscitis, laminectomy bore the risk of the formation of a postoperative kyphotic deformity. The use of intra-operative ultrasound allowed the visualization of hidden inflammatory masses and, thus, reduced the rate of residual abscess formation.

CONCLUSION

An interlaminar approach should be considered instead of laminectomy in lumbar SEA and in impending anterior column instability due to spondylitis. Intra-operative ultrasound is a beneficial aid for the determination of the extent of decompression during surgery and is practicable even through a narrow interlaminar bony window. The insertion of postoperative suction-irrigation drainage had no beneficial effect on outcome but bore the risk of epidural fluid congestion.

[Optimization of microsurgical operation technique to insert auditory brainstem implants, taking into account the results of a morphometric study]

STATE OF THE ART

The surgical placement of auditory brainstem implants to stimulate the cochlear nuclear region in patients with acquired bilateral retrocochlear deafness allows limited restitution of hearing. However, there have been few studies on the topographical relations in the target region, particularly the floor of the IVth ventricle.

TOPIC OF THE STUDY

Is it possible to obtain more precise anatomical data in order to improve the surgical approaches and techniques for the placement of auditory brainstem implants? AIMS. To obtain a more precise topo- anatomical orientation in the target region for microsurgical lateral and midline approaches or a stereotactic operative strategy.

METHODS AND RESULTS

Landmarks for the placement of an auditory brainstem implant via the IVth ventricle were examined and measured in a series of formalin-fixed human brainstems ( n=28). These data, and knowledge of their variability, allow a more precise surgical lateral approach. It is essential to precisely localise the target region, as it can only be partly discerned under the microscope during an operation. For this reason, to date its precise localisation has been determined only electrophysiologically.

CONCLUSION

Exact target localisation improves safety. From an anatomical point of view the midline approach gives the chance to enlarge the indication spectrum for an implant. The anatomical data obtained here could also be integrated into a stereotactic surgical strategy.

CT-guided percutaneous aspiration of Tarlov cyst as a useful diagnostic procedure prior to operative intervention

Tarlov or perineural cysts are lesions of the nerve root most often found in the sacral region. Several authors recommend surgical treatment of symptomatic Tarlov cysts. However, successful surgical treatment is dependent on appropriate patient selection. In this article, we report three cases of a sacral perineural cyst, causing sciatic pain, and emphasize the usefulness of CT-guided percutaneous aspiration as an important diagnostic and prognostic procedure prior to definitive operative treatment.

Visually evoked changes of blood flow velocity and pulsatility index in the posterior cerebral arteries: a transcranial Doppler study

OBJECTIVE

Transcranial Doppler sonography (TCD) can detect visual evoked blood flow responses non-invasively and continuously with high temporal resolution. While the mean flow velocity response to visual stimuli is well documented, the response of the pulsatile characteristics of the waveform is less well known.

METHOD

We examined the changes of blood flow velocity and pulsatility index (PI) in the posterior cerebral artery (PCA) in 50 healthy volunteers. TCD responses were measured in response to metabolic activation of the visual cortex by visual stimulation.

RESULTS

A specific, stimulus-related increase of the mean flow velocity (MFV) in the PCA was found. The intensity of the blood flow response was significantly influenced by the complexity of the stimulus. During complex visual stimulation we found a mean flow velocity (MFV) increase of 29.4 % from the baseline in the subjects. However, a stimulus-related decrease was observed in the pulsatility index (PI); although the mean PI with closed eyes during baseline measurement was 1.18 (SD 0.27), on average, it fell significantly to 0.95 (SD 0.23) with the alternating chessboard and 0.82 (SD 0.22) during the complex stimulus condition. The relative decrement of the pulsatility index with increasing complexity of the visual stimulus is highly significant, with values of -19.5 % and -30.5 % compared to the baseline.

CONCLUSION

These findings demonstrate the inverse correlation between MFV response and pulsatility index in the PCA. We assume that this decrease of the PI in the PCA may reflect the reduced regional vascular resistance in the visual cortex during visual stimulation.

[Diagnosis, treatment and progress after frontal lobe injury]

The comprehensive assessment of a frontal lobe injury is one of the most complex problems in diagnosis and treatment due to the variability of nature, extent and effect of various disorders of higher cerebral functions, i. e. impairment of the ability to act systematically, attention, motivation and emotionality. This brings about considerable differences in assessing and judging the effects of frontal lobe syndromes. Impairments of initiation, planning and carrying out of actions, of impulse control, attention, memory and self-perception often manifest in disorganised and dissocial behaviour which brings about serious effects in many fields of social adaptability. Deeper neurological insights in nature and effects of these deficiencies and improved diagnostical methods and concepts of intensive-care treatment as well as the improved understanding in the necessity of a longterm rehabilitation program have led to the development of specific strategies concerning the dealing with the patient, the counseling of the social environment, especially of the relatives, and the treatment of the patient's symptoms. In the course of acute and rehabilitative treatment the patient normally has to develop strategies of habituation and adaptation to his social environment, furthermore techniques of compensation as well as an improvement of personal resources including attention, memory and planning of actions. The ability of self-control ought to be improved by training of behavioural strategies leading to an increased independence. The success of treatment varies distinctly from individual to individual. As a rule, basic capabilities in the scope of higher brain functions as well as executive and behavioural abilities can be improved. However, a restitutio ad integrum of all dysfunctions is very rare.

Influence of TachoComb in comparison to local hemostyptic agents on epidural fibrosis in a rat laminectomy model

This animal experimental study was designed to examine the effects of TachoComb, a fixed combination of collagen with tissue adhesive, as an interposition membrane on the development of spinal epidural fibrosis in comparison to other hemostyptic materials. In 10 Wistar rats, four laminectomies were performed at lumbar and sacral vertebrae. Alternately, a piece of TachoComb, Spongostan, or Tabotamp was placed into each laminectomy site. One laminectomy site served as an empty control (n = 10). 8 weeks later, the animals were sacrificed, and the spinal column including surrounding muscle tissue was removed en bloc from each rat and fixed in formaldehyde. After decalcification and staining the specimens were graded by a neuropathologist in a blindfold test for severity of epidural fibrosis as "light-moderate" or "marked". Epidural scarring of variable density was seen in all laminectomy sites. Light epidural fibrosis, without any adhesion to dura, as only noted in cases after application of TachoComb (n = 4/10) and Spongostan (n = 1/10). All other slices showed marked epidural fibrosis with dura adherence regardless of the implanted material. Statistical analysis revealed significantly lower epidural fibrosis after application of TachoComb compared to all other groups (p < 0.05). In this series, TachoComb is more effective in reducing the epidural fibrosis than Spongostan, and Tabotamp. However, complete prevention of scar tissue formation was not achieved.

Intermediate and long-term outcome in traumatic brain injury is not influenced by additional multiple organ injury

BACKGROUND

This investigation aims at evaluating the influence of additional multiple organ injury in traumatic brain injury on the outcome in terms of the ability to perform the activities of daily life, of the need of care, and of job ability.

METHODS

62 victims (male to female ratio 4 : 1; age range 15-68 years) of traumatic brain injury were studied. Group 1 (n = 24) consisted of patients who suffered from traumatic brain injury with additional multiple organ injury, group 2 (n = 38) comprised patients with isolated brain injury. Outcome was assessed at 6 and 12 months after trauma by means of different rehabilitation scores.

RESULTS

After 6 as well as after 12 months, the majority of both groups were independent in the activities of daily living. Furthermore, no differences were observed concerning the need of care. Job ability was almost equal for both groups.

CONCLUSION

Additional multiple organ injury does not pertain to prognosis of traumatic brain injury.

Rehabilitation of hearing and communication functions in patients with NF2

Most patients with neurofibromatosis type 2 (NF2) lose hearing either spontaneously or after removal of their neurofibromas. The patient may benefit from conventional hearing aids if, due to modern microsurgery and intraoperative monitoring the integrity of the cochlea and the 8th nerve is preserved. With lost auditory function but preserved electrical stimulibility of the 8th nerve a cochlear implant may be appropriate. But if the patients have no remaining 8th nerve to stimulate, there is no benefit from cochlear implants. Until some years ago, vibrotactile aids, lip-reading, and sign language have been the only communication modes available to these patients. With auditory brain stem implants it is now possible to bypass both the cochlea and the 8th nerve and to stimulate the cochlear nucleus directly. Stimulation of the devices produces useful auditory sensations in almost all patients. Testing of perceptual performance indicated significant benefit from the device for communication purposes, including sound-only sentence recognition scores and the ability to converse on the telephone. Also lip-reading is significantly improved with brain stem implants. The successful work of an auditory brainstem program center depends very much on the close interdisciplinary collaboration between the Departments of Neurosurgery and ENT-surgery. In the future new developments like speech processing strategies and new designed electrodes accessing the complex tonotopic organization of the cochlear nucleus may further improve rehabilitation in these patients who would have been deaf some years ago.

Early rehabilitative concepts in therapy of the comatose brain injured patients

OBJECTIVES

To evaluate the changes of vegetative parameters and behavioural assessment in comatose patients after severe brain injury during the Multimodal-Early-Onset-Stimulation (MEOS) in early rehabilitation.

MATERIAL AND METHODS

We studied 16 predominantly male (3:1) patients, age mean 43.6 (16-77) years. Mean coma duration was 22.2 (8-41) days, therapy duration (MEOS) 9.8 (1-30) days. The initial GCS was 6.6 (3-9), KRS 5.3 (0-15). Including criteria for therapy: Severe head trauma, coma for at least 48 hours (GCS < 8), vegetative stability, normal intracranial pressure, abandon of mechanical ventilation, sedation and severe infections. MEOS was finished in achieving GCS > 9, follow-up investigations were made after 2 years.

RESULTS

We identified significant changes in two vegetative parameters (heart/respiratory frequencies), even in deep coma (GCS 3-4). Most significant changes were caused by tactile and acoustic stimulation. Standardized behavioural assessment turned out to be particularly advisable in cases of medium coma (GCS 5-7). Stimulation of tactile and acoustic senses resulted mainly in mimical, head and eye movements. Follow-up was possible in 14 patients: One remained in a vegetative state (GOS 2), two exhibited severe neurologic/neuropsychologic deficits, depending on care (GOS 3), six substained major functional deficits (GOS 4), at though they were able to perform the tasks of daily life on their own, three patients reached GOS 5. Two returned to their former jobs.

DISCUSSION AND CONCLUSION

The present results indicate that stimulation therapy should be based on a close observation of patterns of behaviour, and, at least in deep coma stages, involve the registration of vegetative parameters. It may be sensitive to identify parameters predicting a favourable or unfavourable outcome. Preliminary data seem to support the hypothesis that the absence of any response to external stimuli is indicative of an unfavourable outcome.

Functional and psychosocial outcome one year after severe traumatic brain injury and early-onset rehabilitation therapy

This study evaluates the impact of early-onset continuous rehabilitation treatment on the 1-year outcome of patients after severe traumatic brain injury. Immediately after recovery from mechanical ventilation, a total of 48 patients underwent a complex early rehabilitation treatment until they were discharged from hospital and local ambulant care was deemed sufficient. The follow-up examination took place 12 months after trauma. Data reveal that at 1 year 91.6% of the patients were completely or restrictedly independent of care and capable of carrying out activities of daily living, although they frequently were still suffering from marked behavioural and also from certain sensorimotor deficits. Only 45.8% of the patients were obviously able to work without restrictions or had returned to work. In those subjects who were not or only very restrictedly able to work, behavioural and speech deficits were significantly more frequent. Behavioural and speech deficits seem to represent the major cause that hinders professional reintegration. Rehabilitation therapy therefore should be specifically directed to improve these deficits.

Relevance of magnetic resonance imaging for ventricular endoscopy

OBJECTIVE

Endoscopic procedures may represent an alternative to microsurgery or shunt operations in intra- or paraventricular pathologies. However, the operative results mainly depend on the selection of suitable patients. In the present study of 30 patients with occlusive hydrocephalus, the relevance of differentiated magnetic resonance (MR) imaging for evaluation of the pathophysiological and anatomic prerequisites was investigated.

PATIENTS AND METHODS

Apart from conventional axial T(2) -weighted turbo spin echo (TSE) sequences (TR/TE 2126/100 ms) and T(1) -weighted spin echo (SE) sequences (TR/TE 450/15 ms) with and without the administration of Gd-DTPA, the MR protocol included sagittal and coronal thin-sliced T(2) -weighted TSE sequences, cardiac-triggered (TR/TE > 2700/120 ms, slice thickness 3.0 mm) or in volume technique (TR/TE 4000/180 ms, slice thickness 1.4 mm). For the visualization of CSF flow, a sagittal and axial phase-contrast-multi-heart-phase (PCMHP) measurement with 16 phases per cardiac cycle and flow sensitivity in the cranio-caudal direction (TR/TE 18/9.5 ms and 14/9.5 ms) was performed.

RESULTS

The combination of imaging and flow sequences provided most information about the extent and the etiology of hydrocephalus. An obstruction of CSF pathways could be detected by the absence of flow voids in T(2) -weighted TSE sequences or of flow signals in PCMHP sequences. The size of the foramen of Monro and of the third ventricle could be evaluated in thin-sliced T(2) -weighted TSE sequences, for the foramen of Monro in coronal and sagittal and for the third ventricle in coronal and axial slice direction, respectively. The basal structures of the third ventricle, including its floor, the infundibular recess, the mamillary bodies, and the basilar artery, could be best identified in sagittal thin-sliced T(2) -weighted TSE scans, cardiac-triggered or in volume technique.

CONCLUSION

In occlusive hydrocephalus, a differentiated MR protocol with thin-sliced T(2) -weighted TSE sequences and phase-contrast sequences allows a very precise estimation of the pathophysiological and the anatomic prerequisites for endoscopic procedures. Furthermore, MR imaging can be used for the follow-up documentation of ventriculo-cisternostomies, -cytostomies, or openings of other membranes.

Does wave VI of BAEP pertain to the prognosis of coma?

OBJECTIVES

The significance of brainstem auditory evoked potential (BAEP) wave VI for the outcome of comatose patients was assessed and compared to the prognostic impact of median nerve evoked somatosensory potential (MSEP) recording.

PATIENTS AND METHODS

One hundred sixteen patients in a comatose state due to traumatic brain injury (n = 57) and to intracerebral hemorrhage or tumours (n = 59) were investigated prospectively. Outcome was assessed 3 months after the onset of coma using Glasgow Outcome Score (GOS). Standard BAEP and MSEP recordings were obtained within 24 h after coma onset. The frequency of findings was correlated with outcome by means of non-parametric statistical analysis. Additionally, 27 healthy volunteers were studied to confirm the constant presence of wave VI in normal BAEP.

RESULTS

In healthy controls, wave VI was present in 53/54 ears stimulated. Outcome correlation analysis revealed a significantly (p < 0.01) higher frequency of abnormal wave VI in patients with unfavourable outcome (GOS 1-3) irrespective of the underlying pathology. Similarly, abnormal MSEP findings were significantly more frequent in this outcome group. Diagnostic sensitivity for an unfavourable outcome was low for both parameters, whereas specificity and positive predictive value of abnormal wave VI as well as of abnormal MSEP were equally high.

CONCLUSION

Abnormal BAEP wave VI bears prognostic information in comatose patients.

Recording nasal muscle F waves and electromyographic activity of the facial muscles: a comparison of two methods used for intraoperative monitoring of facial nerve function

OBJECT

A comparison of two electrophysiological methods used to assess facial nerve function intraoperatively was conducted in 33 patients with tumors of the cerebellopontine angle.

METHODS

All 33 patients had presented with normal facial nerve function preoperatively. After general anesthesia had been induced by a mixture of midazolam and fentanyl, continual online EMG recordings from the orbicularis oculi and oris muscles were alternated with nasal muscle F-wave recordings. Facial nerve outcomes, assessed using a modified House-Brackmann scale, varied among good (48%), moderate (18%), and poor (33%). Analysis of electromyographic (EMG) data resulted in a significant correlation between the finding of only transient manipulation-evoked activity and a good outcome, whereas in cases in which there was poor outcome, an increase in the amplitude or duration of ongoing activity was detected. A permanent loss of nasal muscle F waves specifically appeared to indicate a severe dysfunction of the facial nerve that was linked to a poor outcome. All patients with latency and/or amplitude changes or even a transient loss of the F wave achieved good or moderate facial nerve outcomes. A transient loss of the F wave, however, was detected significantly more frequently in patients with moderate outcomes. None of these patients exhibited normal facial function (House-Brackmann Grade I) postoperatively.

CONCLUSIONS

Online EMG monitoring can provide some information on imminent or even present damage to the facial nerve intraoperatively. The diagnostic sensitivity, specificity, and positive predictive values of a permanent F-wave loss, however, are much higher than those of EMG monitoring. Additionally, this loss of the F wave is supposed to be transient if the surgical procedure is stopped until the F wave recovers. Therefore, F-wave monitoring serves to alert the surgeon that the facial nerve is about to receive a lesion.

High cervical spinal cord stimulation (CSCS) increases regional cerebral blood flow after induced subarachnoid haemorrhage in rats

The effects of high cervical spinal cord stimulation (cSCS) on regional cerebral blood flow (rCBF) were investigated after experimentally induced subarachnoid haemorrhage (SAH) in rats by the means of (99m)Tc-HMPAO. The experiments were carried out on a total of 24 Wistar rats, divided in three groups [group I: control without SAH, group II: SAH, group III: SAH and cSCS]. (99m)Tc-HMPAO was administered intravenously (group II/group III) 48 hours after induction of SAH. In group III, (99m)Tc-HMPAO was given after 3 hours of cSCS. All animals were sacrificed 30 minutes after application on (99m)Tc-HMPAO. Radioactivities were determined in blood, cerebrum and cerebellum. The ratio cerebrum/blood and cerebellum/blood was calculated to ascertain "extraction rate" in the sample differentially. The following mean values were calculated for the cerebellum/blood ratio: Group I: 1.06, SD: 0.21; Group II: 0.66, SD: 0.21; Group III: 1.00, SD: 0.37. Comparing the mean values a highly significant difference could be found between group II and III (p = 0.007) and between group I and II (p = 0.0019), respectively. Calculations of the cerebrum/blood ratio revealed similar results. After SAH cSCS enhances cerebral and cerebellar blood flow in rats. Possibly, cSCD constitutes a new therapeutic approach in the treatment of disturbed regional cerebral blood flow after SAH.

Age related signal decrease in functional magnetic resonance imaging during motor stimulation in humans

Right handed healthy volunteers underwent functional magnetic resonance imaging (fMRI) examinations on a 1.5 Tesla MRI-scanner (Gyroscan ACS NT; Philips, Best, NL). Blood oxygen level dependent (BOLD) images were obtained using a three dimensional multi-shot echo planar imaging sequence employing a shifted echo technique (Principles of echo shifting with a train of observations). Finger tapping of the right hand was used as a task for motor stimulation. A total of 86 subjects was included into statistical analysis. Absolute and relative signal differences and cluster sizes of activation for the left motor cortex were obtained. In addition, Z-score, pooled Z-score and cross correlation activation maps were calculated and matched with high resolution anatomic images. A significant decrease with age could be detected for absolute and relative signal intensity differences for the whole group and for the male subgroup. Correlation analysis for the female subgroup also bore negative albeit non-significant correlation coefficients. An age-related decline of BOLD-contrast can be assumed to explain signal decrease. This age-related effect should be considered in clinical fMRI applications.

Functional magnetic resonance imaging of human pontine auditory pathway

The purpose of this study is to visualize brainstem auditory pathways by functional magnetic resonance imaging (fMRI). Eighteen healthy volunteers (age 28 to 42 years) with normal hearing function underwent fMRI examination on a 1.5 Tesla imaging system (Philips, Best, The Netherlands) with periodic click stimulation. Blood oxygen level dependent images were obtained using a three-dimensional EPI sequence with shifted echo technique (principles of echo shifting with a train of observations). Control scans without click stimulation were obtained in the identical setting. Cross correlation activation maps were calculated using a postprocessing tool (Philips). They were matched with anatomic slices of identical orientation and thickness. Five of 18 subjects were excluded because of motion artifacts. In 4/13 significant activation was observed at the root entry zone of the ipsilateral acoustic nerve corresponding to the cochlear nuclei. In 11/13 subjects, significant activation was found in the same slice contralaterally close to the floor of the 4th ventricle, corresponding to the expected region of the superior olivary nucleus. Activation of the rostral parts of the auditory pathway (inferior colliculus, medial geniculate body) was not found. In the absence of the stimulus no activation occurred in these structures. It was concluded that activation of the brainstem auditory pathways by click stimuli can be visualized by fMRI.

Polyamine metabolism in brain tumours: diagnostic relevance of quantitative biochemistry

OBJECTIVE

Activation of polyamine metabolism is closely associated with cellular proliferation. The purpose was to investigate whether the content of the polyamines putrescine, spermidine, and spermine, and the activity of the first metabolic key enzyme of polyamine metabolism, ornithine decarboxylase (ODC), represent biochemical markers of malignancy in brain tumours.

METHODS

The concentration of putrescine, spermidine, and spermine, and the activity of ODC were biochemically quantified in tissue samples obtained during open microsurgery of 670 patients with brain tumours. Biochemical analysis and histopathological classification were carried out in serial tumour samples.

RESULTS

The activity of ODC was very low in peritumoral non-neoplastic brain tissue (0.9 (SD 0.6) nmol/g/h). It was significantly higher in gliomas and it significantly increased with a higher grade of malignancy (grade I 2.7 (2.8) nmol/g/h, grade II 3.1 (4.0) nmol/g/h, grade III 5.7 (5.6) nmol/g/h, grade IV 10.6 (11.7) nmol/g/h). High enzyme activity was also found in medulloblastomas (25.5 (15.1) nmol/g/h), malignant lymphomas (52.1 (42.1) nmol/g/h), and metastases from carcinoma (14.9 (22.1) nmol/g/h). Lowest values were measured in epidermoid cysts (0.5 (0.2) nmol/g/h), craniopharyngiomas (1.2 (0.9) nmol/g/h), angioblastomas (1.6 (1.7) nmol/g/h), and neurinomas (2.0 (1.8) nmol/g/h). By contrast with ODC activity, polyamine concentrations did not correlate with the grade of malignancy. Correlation of regional biochemical and histomorphological data in rapidly growing neoplasms showed high enzyme activity in solid tumour parts and low activity in necrotic areas.

CONCLUSIONS

Novel data relating ODC activation and polyamine concentrations to neuropathology is presented indicating that high ODC activity represents a biochemical marker of malignancy in brain tumours. This information is important for clinical and therapeutic investigations.

A normative study on human facial F waves

F waves from the nasalis muscle were obtained bilaterally after transcutaneous constant-current stimulation of the facial nerve in 37 of 42 (88%) healthy volunteers examined. F waves were of varying shape and latency. Standard parameters (latencies, amplitudes, ratios, chronodispersion) of F-wave analysis were assessed. Of these, minimum and mean F-wave latencies, the F ratio, and F-wave and peripheral conduction times (PCT) were approximately normally distributed, with a low standard deviation. Latencies and conduction times exhibited a significantly positive correlation with body height, as has been demonstrated for the F-wave latencies in limb muscles. Side and sex differences were present but without statistical significance. Chronodispersion and chronodispersion range, F-wave amplitudes, and F-wave frequencies were broadly scattered. It is concluded that F-wave latencies and conduction times are best suited to define a range of reference values. Moreover, facial F waves bear characteristics similar to those described for F waves recorded from limb muscles.

ODC mRNA as a prognostic factor for predicting recurrence in meningiomas

In proliferating neoplastic cells, activity of the enzyme ornithine decarboxylase (ODC) increases. Among other brain tumors, ODC activation could also be observed in meningiomas. In the present study, we have investigated ODC gene expression in primary and recurrent meningiomas at the transcriptional level. ODC mRNA (messenger ribonucleic acid), ODC activity, number of mitoses, and Ki-67 index as a marker for nuclear proliferation were quantified in three different groups of meningiomas: tumors without recurrence in a 8.4 years median follow-up period, tumors with recurrence within a median follow-up of 3.0 years, and their corresponding recurrent tumors. ODC mRNA level was significantly higher in meningiomas with later recurrence as compared to meningiomas without recurrence (p < or = 0.01), whereas it declined in the recurrences of the second group (p < or = 0.001). In contrast, ODC activity showed no difference between the two groups of primary tumors, but a significant increase of enzyme activity could be observed in the recurrences as compared to the correponding primary tumors (p < or = 0.001). Likewise, an increase of the Ki-67 index could be detected in the recurrent group (p < or = 0.001). These results suggest that ODC mRNA may represent a prognostic factor for predicting recurrence in meningiomas.

Multimodal electrophysiological examinations in patients suffering from various tumors of the pineal region

Multimodal electrophysiological examinations: blink-, glabella- and masseter-reflexes, as well as brain stem acoustic, somatosensory and visual evoked potentials were examined in thirteen patients with clear consciousness suffering from extra-axial, chronic, expanding processes in the tectal region. According to the data, the authors came to the conclusion that several modalities were often required to make a correct diagnosis or to the localization of the space occupying processes. Functional disturbances of the whole of the lower brain stem, but especially of the mesencephalon and of the lower pons were found in cases of expanding processes surrounding the tectum.

Histological study of lumbar intervertebral disc herniation in adolescents

Herniated intervertebral discs are rare in children and adolescents constituting approximately 1-5% of all patients undergoing surgery for lumbar and lumbosacral intervertebral disc herniation. Preceding traumata and congenital anomalities have been reported as important factors for the pathogenesis of intervertebral disc prolapses in young patients. The present histological study is based upon 15 patients with lumbar disc herniation within an age range from 14 to 19 years. Only in one case, was adequate trauma reported. All patients exhibited degenerative changes of the disc, similiar to those observed in adults. These changes were marked in 11 patients (73%). Thus, as known from adults, also in isolated traumatic disc herniation of adolescence, pre-existing degeneration of the disc has to be considered. If such changes are present, trauma has the significance of only transitory deterioration of the previous disc degeneration.

Effects of electrical stimulation of the Gasserian ganglion on regional cerebral blood flow after induced subarachnoid hemorrhage in pigs evaluated by 99mTc-HMPAO-SPECT

It could be demonstrated that cervical spinal cord stimulation increases cerebral blood flow. The effects of electrical stimulation of the trigeminal ganglion in the acute phase of SAH in pigs were investigated. The experiments were carried out on 11 domestic pigs divided in two groups (group I: SAH [n = 5]; group II: SAH and trigeminal stimulation [n = 6]). In all animals a native SPECT was performed. The Gasserian ganglion was exposed for inserting the stimulation electrode. SAH was induced by injecting 10 ml autologous blood through a catheter placed in the suprasellar cistern. 30 minutes after SAH-induction electrical stimulation was started for two hours in group II (2.8-4.5 V, 50 Hz, 300 microseconds). 99mTc-HMPAO (400-540 MBq) was injected intravenously 110 minutes later. In group I 99mTc-HMPAO was applied after the same time interval. 80 minutes later SPECT was performed. Data were processed to calculate the uptake of radioactivity (%/kg tissue weight). The mean values were calculated for the different groups: native animal examination (%/kg tissue weight): 0.6343; group I: 0.468; group II: 0.6533. Comparing the mean values a highly significant difference between group I and group II (p < 0.01) and between native examination and group I (p < 0.01) could be found. No statistical significance could be detected on comparing the left/right-ratio in any ROI. The electrical stimulation of the Gasserian ganglion leads to a significantly increased uptake of 99mTc-HMPAO after induced SAH. Maybe the stimulation of the Gasserian ganglion constitutes a new therapeutic modality treating disturbed rCBF after SAH.

Surgery of intrinsic cerebral neoplasms in eloquent areas under local anesthesia

28 patients with a mean age of 43.6 years were operated on for a cerebral neoplasm situated in close proximity to an eloquent area (24 speech area, 4 motor cortex) from 1996 to 1999. Preoperatively, all patients had undergone a detailed neuropsychological examination. In 10 patients aphasic disturbances could be detected. All patients underwent preoperative PET studies (methionine and (15)O-labeled water with activation during speech or finger tapping). These were performed and co-registered with MRI data to demonstrate the topographical relationship between motor or language function and the tumor borders. Anesthesia was induced with i.v. administration of propofol (150-250 mg/h). Craniotomy was performed under local infiltration anesthesia. After opening of the dura, sedation was stopped and operation was continued with the patient being alert and co-operative. With close clinical observation during electrical cortex stimulation, a speech arrest could be triggered or avoided. The motor cortex was identified by recording the phase reversal of the contralateral SEP of the median nerve and by direct cortical stimulation. As soon as aphasic or motor disturbances appeared, the tumor removal was continued with the goal of avoiding these specific regions. In 27 patients, preexisting neuropsychological and neurological deficits did not worsen. Only one patient was left postoperatively with a major permanent aphasic deficit that was present preoperatively to a minor degree. The use of local anesthesia in craniotomy for surgery of intrinsic cerebral neoplasms in eloquent areas allows for a continuous and repetitive monitoring of speech and motor function during the removal of even those tumors that were previously considered inoperable.

Prognostic significance of preoperative electrophysiologic investigation for facial nerve outcome in acoustic neuroma surgery

The prognostic significance of transcranial magnetic stimulation and nasal muscle F-wave recording to predict postoperative facial nerve function was assessed in 24 patients with unilateral acoustic neuromas (mean diameter, 31 mm) and clinically intact facial nerve function. Latency of F waves and response to cortical magnetic stimulation, as well as F ratios, central motor conduction time, and the ratio of response latency to cortical and cisternal magnetic stimulation were significantly increased. Outcome analysis revealed no significant correlation between preoperative electrophysiologic changes and postoperative facial nerve function. However, a significant correlation with tumor diameter was detected. Thus, acoustic neuroma size seems to be the best predictor of facial nerve function after surgery.

[The sacral perineural system--are there radiological criteria for an indication for surgery? First results and literature survey]

PURPOSE

To establish recommendations for diagnostic imaging of cystic lesions of the sacral region and to evaluate for potential predictors of therapeutic outcome.

METHODS

Conventional imaging of the lumbar spine, conventional CT, myelography, post myelo-CT and MRI were performed in 7 symptomatic [corrected] patients. All patients underwent operative decompression and histological examination. The radiographic examinations were reevaluated retrospectively and correlated with the postoperative outcome.

RESULTS

In one patient the differential diagnosis of a neurinoma could not be excluded with CT and CT-myelography alone. In all 7 patients MRI provided a definite diagnosis and a precise presentation of the cyst extension. A complete postoperative remission of symptoms was noticed in 4, a partial remission in three cases. The correlation of cyst extension, cyst shape, and the communication with the subarachnoid space did not provide predictive information concerning operative outcome.

CONCLUSION

MR can be used as the sole imaging tool for demonstration of cystic lesions. Relevant disadvantages in comparison to myelography and myelo-CT were not evident. No imaging modality could predict the value of surgical intervention.

Titanium clamps for refixation of bone fragments in the repair of depressed skull fractures: technical note

The rigid fixation of bone fragments in the repair of depressed skull fractures can be a problem, especially if not all fragments are replaceable. Usually, in these cases mini- or microplates are used. The Craniofix titanium clamp (Aesculap, Germany) was developed for the fixation of bone flaps after osteoplastic craniotomy. It consists of a screw holding together two 10-mm diameter metallic disks with concaved teeth pressing bone flap and cranium between the two disks. We used this system for the operative treatment of two patients with depressed skull fracture. A rigid fixation of the bone fragments was achieved in both cases. The postoperative three-dimensional CT scan showed a good fragment alignment. From the report of two cases we show that this system is a useful tool in the fixation of bone fragments in the repair of depressed skull fractures.

Multiple interstitial substances measured by microdialysis in patients with subarachnoid hemorrhage

OBJECTIVE

Intracerebral microdialysis is a tool to monitor metabolic disturbances in the brains of patients with severe head injuries or subarachnoid hemorrhage (SAH). In the search for putative indicators of primary and secondary brain damage, we measured multiple metabolites in the dialysates of patients with SAH, to elucidate their significance for the outcomes of the patients as well as their temporal profiles of liberation after the insult.

METHODS

Microdialysis probes were placed, with a ventriculostomy catheter for drainage of cerebrospinal fluid, into a frontal lobe of 10 patients with aneurysmal SAH, for 4.6 +/- 0.5 days. Amino acids, metabolites of glycolysis, purines, catecholamines, and nitric oxide oxidation byproducts were measured by high-performance liquid chromatography. Spearman's correlation coefficient and Student's t test were used to compare the levels of the metabolites with the outcomes of the patients, as assessed using the Glasgow Outcome Scale, 3 months after the ictus.

RESULTS

For patients with unfavorable outcomes (Glasgow Outcome Scale scores of 1-3), which were primarily associated with the development of large infarctions, dialysate levels of excitatory amino acids increased up to 30-fold, those of lactate up to 10-fold, and those of nitrite up to 5-fold, compared with normal levels observed for patients with favorable outcomes (Glasgow Outcome Scale scores of 4 or 5). When average peak concentrations in the dialysates of patients with favorable and unfavorable outcomes were compared, significantly higher levels of excitatory amino acids, taurine, lactate, and nitrite, but not of purines and catecholamines, were observed for those with poor outcomes (P < 0.05). With respect to the temporal profiles of the average metabolite concentrations, the significantly increased levels of amino acids observed for patients with poor outcomes followed a biphasic course, with maximal concentrations on the first and second days or the seventh day after the insult (P < 0.01).

CONCLUSION

These data confirm the usefulness of excitatory amino acids and lactate as major parameters for neurochemical monitoring for patients threatened by acute cerebral disorders. Other substances, such as taurine and nitrite, were also demonstrated to be potentially predictive. Release of these substances into the extracellular fluid of the brain might be particularly relevant for the development of secondary brain damage after SAH, e.g., infarction or brain swelling.

Management of vein of Galen malformations. A review based on five neurosurgically treated cases and literature reports

The high morbidity and mortality associated with the management of vein of Galen aneurysmal malformations (VGAM) continues to pose a tremendous challenge to the neurosurgeon as well as to the attending interventional radiologist. Since 1985, five patients with VGAM have been referred to the neurosurgical unit of the University of Cologne, two neonates, one infant and two adults. Four patients underwent direct operation and two patients received a shunt. The treatment was performed without mortality. A review of the literature reflects no substantial difference between neurosurgical treatment during the last 15 years (mortality 10%) and endovascular treatment (best series mortality 6%).

Augmentative treatment of chronic deafferentation pain syndromes after peripheral nerve lesions

Deafferentation pain syndromes developing after peripheral nerve lesions are difficult to treat. According to the follow-up (mean: 39.5 months) of 6 patients suffering from causalgic pain we will present our method of augmentative therapy in chronic neuropathic pain caused by peripheral nerve lesions, i.e., peripheral nerve stimulation (PNS), spinal cord stimulation (SCS) and chronic intrathecal opioid infusion. None of the patients showed intraoperative or follow-up complications. Evaluated by visual analogue scales all patients reported a good to excellent pain relief (75-100%). (1) Regarding the favourable long-term results of PNS, this method should be considered in cases of mononeuropathic pain syndromes. (2) Neuropathic pain syndromes which are not assignable to a singular nerve lesion, can often be managed effectively by SCS. (3) In contrast to the widespread opinion, deafferentation pain syndromes of central or peripheral origin can be treated satisfactorily by intrathecal opiate administration.

Assessment of facial nerve function in acoustic tumor disease by nasal muscle F waves and transcranial magnetic stimulation

Standard transcranial magnetic stimulation and nasal muscle F-wave recordings were used to assess proximal facial nerve function in 27 patients with unilateral acoustic tumors (mean diameter, 29 mm) and clinically intact facial nerve function. Latency measurements for F waves and cortical magnetic stimulation were abnormal. Moreover, F ratios, central motor conduction time, and the ratio of response latency to cortical and cisternal magnetic stimulation were significantly increased. Amplitudes were unchanged. Correlation analysis with tumor diameter as dependent variable yielded maximum r values for F-wave latencies (0.57) and F ratios (0.41), whereas for magnetic stimulation, a significant correlation could be found (0.4) only for cortical stimulation. Nasal muscle F-wave recording can reveal clinically inapparent facial nerve dysfunction. Its efficacy in predicting tumor diameter seems to be superior to that of standard magnetic stimulation.

Comparison of a new automatically controlled electrocoagulator (Valleylab NS 2000-INSTANT RESPONSE technology) with a high-frequency coagulator

Bipolar electrocoagulation is one of the most important procedures in modern neurosurgery. However, there are still many practical problems, especially tissue adherence to the tips of the coagulating forceps and the difficulty removing carbonized clots from the tips. Both make the process less accurate and more time-consuming. To prevent formation of coagulum, recently, irrigation with a saline solution and coating of the forceps tips with a special metal have been tried. In this work, we compare a new bipolar electrocoagulator with automatic output control in relation to tissue impedance (Auto Suture - Valleylab NS 2000 with INSTANT RESPONSE technology) with a high-frequency coagulator (Erbotom ICC 350, Erbe). The femoral arteries and nerves of Wistar rats, weighing on average 360 g, were prepared and coagulation was carried out with variable power settings during a constant time (3 seconds). Sections were stained with haematoxylin-eosin, van Gieson and Luxol-Fast-Blue for histological examination. Coagulation with Erbotom ICC 350 resulted in tissue sticking to the tips of the forceps in all cases, regardless of the power chosen. With the new electrocoagulator, tissue adherence to the forceps tips was not seen. With the new system, effective coagulation was also achieved at comparably lower power settings.

Comparative use of magnetic resonance imaging and electrophysiologic investigation for the prognosis of head injury

BACKGROUND

To compare magnetic resonance imaging (MRI) and electrophysiologic investigation as prognostic methods in acute head injury.

METHODS

Fifty-seven patients suffering moderate to mild (Glasgow Coma Scale score > 8) or severe (Glasgow Coma Scale score < 8) head injury were included. Both groups were analyzed as a total and separately for outcome as assessed by Glasgow Outcome Score. Two outcome groups were separated (Glasgow Outcome Score 1-3: unfavorable vs. Glasgow Outcome Score 4-5: favorable). MRI scans (T1-, T2-, T2*-sequences; transverse, coronal, and sagittal slices) were obtained 1 to 39 days after trauma (mean, 14 days). Electrophysiologic investigations consisted of median nerve-evoked somatosensory responses to assess corticosubcortical function and brain stem auditory-evoked potentials and brain stem reflexes for brain stem function. Recordings were performed 24 to 72 hours after trauma and repeated every 3 to 5 days.

RESULTS

Evaluation of all patients revealed a prognostic significance of MRI lesions within the corpus callosum, the basal ganglia, the hippocampus, the midbrain, and the pons. In the severe head injury subgroup, significance was limited to lesions within the corpus callosum, the basal ganglia, and the midbrain. Among the electrophysiologic findings, dysfunction of the corticosubcortical region as well as of the midbrain were linked to an unfavorable outcome. In severe head injury, prognostic significance was restricted to bilateral corticosubcortical dysfunction. A statistical test for diagnostic convergence of both methods indicated a distinct convergence only for lesions of the midbrain and the pons.

CONCLUSION

MRI scans performed early after head injury provide several indicators for unfavorable outcome. Electrophysiologic investigations add to this prognostic evidence. Both methods have comparably high specificity. However, because of the higher density of prognostic information obtained, MRI seems superior to electrophysiologic testing.

Operative treatment of tentorial herniation in herpes encephalitis

Herpes simplex virus is the most common cause of acute viral encephalitis in children. Due to the variety of possible clinical manifestations the diagnosis is often overlooked in the early stages of the disease. Anti-viral therapy with acyclovir should be started whenever HSE is suspected. When there is further deterioration under virostatic therapy, a brain biopsy should be performed to verify the diagnosis. But even when the adequate medical therapy is established, massive brain edema and brain shift resulting in tentorial herniation can develop. Up to now the reported mortality of these patients is still around 30%. Here we report on a child with severe necrotizing herpes simplex encephalitis who developed severe tentorial herniation due to a right-sided mass lesion. The patient's status markedly improved after decompressive anterior temporal lobe resection. To our knowledge a similar case has not yet been reported in the literature. We suggest that anterior temporal lobe resection and decompressive craniotomy is of benefit in selected cases with tentorial herniation because both decompression and reduction of infectious material can be achieved.

The incidence and outcome of severe brain trauma - Design and first results of an epidemiological study in an urban area

Epidemiological data on the incidence, the prehospital and hospital care and the outcome of traumatic brain injury in Germany are scarce. It is therefore difficult to estimate the importance of this injury with respect to magnitude as well as effectiveness and efficiency of therapeutic concepts. We therefore planned a study that was supposed to provide population based epidemiological data in the field of severe brain trauma from the site of the accident until discharge from hospital.All 90.000 prehospital emergencies that were cared for by emergency physicians in Cologne from January 1990 until December 1996 were screened for identification of severe brain trauma. Their clinical course was reviewed using standard records and patients were included if they had their accident within the city of Cologne and fullfilled the final inclusion criteria of GCS ≤ 8 or AISHead ≥ 3. 650 eligible patients were identified of whom 530 had complete datasets (follow-up 80 %). Univariate statistical analysis was performed for all relevant variables. The main study endpoints were incidence and outcome of severe brain trauma.The annual incidence of severe brain trauma in Cologne (1 mio. inhabitants) was 93. The average age was 39 years and 71 % of the patients were male. The average prehospital GCS was 6.8, the average prehospital Trauma Score was 8.3 points. 49 % of the study population suffered from multiple injuries. The overall mortality rate was 46,6 %. 60 % of deaths occurred within the prehospital setting.The incidence of severe brain trauma in Cologne in this study was significantly lower compared to what could be expected from the literature. The overall mortality was high, especially the high prehospital death rate is striking.

Nasal muscle F-wave for peri- and intraoperative diagnosis of facial nerve function

A new method for recording F-waves from facial muscles in order to assess the function of the intracranial and intracanalicular portion of the facial nerve peri- and intraoperatively has been developed: Direct (M) and F-responses were obtained from the nasal muscle after stimulation of the zygomatic branch of the facial nerve of healthy volunteers. We examined a number of patients with likely or obvious dysfunction of the facial nerve, mostly suffering from cerebellopontine angle (CPA) tumors. F-wave findings were compared to blink reflex and transcranial magnetoelectric evoked potential recordings, the latter obtained from the nasal muscle. The F-wave turned out to be a sensitive parameter for the diagnosis of facial nerve dysfunction. The feasibility of intraoperative nasal muscle F-wave recording and its prognostic value are demonstrated. The nasal muscle F-wave is considered to be a valid parameter for the diagnosis of clinically imperceptible facial nerve lesions, especially of its intracranial portion.

Pressor and depressor responses in thermocoagulation of the trigeminal ganglion

We have undertaken a retrospective analysis in 126 patients with trigeminal neuralgia on which a free-hand percutaneous thermocoagulation of the Gasserian ganglion was performed in our department. We focused on the occurrence of intraoperative vagal reactions, i.e. significant bradycardia and changes in blood pressure during the course of the procedure. Operative and anaesthetic records of patients who underwent the procedure were evaluated and correlated with clinical data from the patient's history. We observed the occurrence of vagal reactions i.e. significant bradycardia (< 50/min) or syncope in 20% of patients (p < 0.0002) during or immediately after penetration of the foramen ovale. No correlation between the operated side and the occurrence of vagal reactions was found. A significant rise in blood pressure levels (about 180 mmHg systolic) was observed in 36% of patients during thermocoagulation. We concluded that painful stimuli arising from lesioning in the course of the trigeminal nerve reach the mid-brain and may irritate the dorsal nucleus of the vagus nerve resulting in significant bradycardia or cardiac synode. To prevent haemodynamic deterioration i.v. atropine (0.5-2 mg) should be available when advancing the needle, while anti-hypertensive medication (Esmolol) may be needed during coagulation.

Acute nontraumatic spinal epidural hematomas. An important differential diagnosis in spinal emergencies

STUDY DESIGN

The clinical data of five patients with spontaneous spinal epidural hematoma (SSEH) were reviewed.

OBJECTIVES

To assess the clinical outcome of patients with SSEH after surgical decompression.

SUMMARY OF BACKGROUND DATA

The outcome in SSEH is essentially determined by the timing of the operation. Therefore, early and precise diagnosis is necessary.

METHODS

A retrospective analysis of five patients with SSEH was performed. The clinical data were stratified according to the Frankel Score. Special interest was given to the relevance of rapid and exact diagnosis and immediate therapeutic intervention.

RESULTS

Diagnosis of SSEH was established preoperatively by means of computed tomography (one case) or magnetic resonance imaging (three patients) and intraoperatively in one case. Lumbar myelography had been false negative in one patient, computed tomography false-negative in two patients. Surgical decompression was performed in four patients within 24 hours after the onset of symptoms. Favorable postoperative functional results were found only in one patient whose symptoms had been present for less than 12 hours and in the case of an incomplete cauda equina syndrome.

CONCLUSIONS

The results of the current series demonstrate both the superiority of magnetic resonance imaging for diagnosis of SSEH as well as the necessity of early decompressive surgery in cases of sensorimotor paralysis after SSEH.