Guidelines for Clinical Target Volume Definition for Perineural Spread of Major Salivary Gland Cancers.

AIMS: Postoperative radiotherapy is the standard of care for resected major salivary cancers that are at risk of locoregional recurrence. Of the various histological subtypes, perineural invasion is most common in adenoidcystic carcinomas of the three major salivary glands - parotid, submandibular and sublingual. The clinical target volume (CTV) for these cases must include the relevant cranial nerve pathways at risk. A contouring atlas was devised for delineation of the CTV of the nerves supplying the major salivary glands. MATERIALS AND METHODS: Using standard anatomy texts and e-anatomy sources the nerves supplying the major salivary glands were identified. Subsequently the pathways of the nerves were drawn on an archived patient's planning computed tomography scan. RESULTS: The innervation of the major salivary glands has been identified and studied. Both bone and soft tissue CTVs have been delineated. A full set of images and CTVs of all the relevant transverse computed tomography slices has been archived, a number of which are printed in this article. CONCLUSIONS: Variation in CTV delineation is a recognised problem in a variety of anatomic sites. Guidelines and atlases can standardise practice and may improve the safety and efficacy of therapy. An atlas has been generated to guide clinicians in delineating the CTVs for perineural spread in major salivary gland cancers.

Stereotactic radiosurgery for the treatment of brain metastases; results from a single institution experience.

BACKGROUND: Stereotactic radiosurgery is frequently used for the treatment of brain metastases. This study provides a retrospective evaluation of patients with secondary lesions of the brain treated with stereotactic radiosurgery (SRS) at our institution. AIMS: To provide outcome data from a single institutional experience with SRS and identify any significant prognostic factors in the cohort. METHODS: Sixty-seven patients received first time SRS to 86 intracranial metastases between 2007 and 2010. Sixteen patients were excluded from this study due to the absence of post-treatment neuroimaging, resulting in 51 patients with 64 treated lesions. Of these patients, 37 (72.5%) received SRS electively, while 14 (27.5%) received salvage SRS after brain metastasis progression following whole brain radiotherapy. RESULTS: Median survival for the entire group was 15 months from the date of radiosurgery. Patients without active extracranial disease had statistically significant survival time than those with active extracranial disease (P=0.03). 45 (70.3%) lesions achieved local tumour control in 34 patients (66.7%) with a mean follow-up period of 10.7 months (range 1.7-33.6 months, 95 % confidence interval 6.6-9.8 months). CONCLUSIONS: The results reported in this study equate to those reported in other series consolidating SRS as an effective treatment option with few serious complications. Developments in systemic disease control will see further improvements in overall survival.

Computer-assisted image-guided orbit surgery.

PURPOSE: Modern stereotaxy utilizes preoperative computed tomography (CT) and magnetic resonance imaging (MRI) to provide accurate localization information which can be very helpful in orbital surgery. The purpose of this report is to evaluate the usefulness of stereotactic surgery and application of this procedure in the orbit. METHODS: Interventional case series of three patients with orbital tumors. All patients had tumor resection with the utilization of two frameless stereotactic systems: Cygnus and Stealth Station. RESULTS: The applications of image-guided stereotactic surgery proved to be beneficial in three extensive orbital tumors, including optic nerve glioma, recurrent pleomorphic adenoma of lacrimal gland, and secondary orbital meningioma. CONCLUSIONS: The interactive nature of image guidance can be useful in orbital surgery to orient the surgeon to the exact location within the surgical field and to determine the tumor margins.

Intrathecal grafting of porcine chromaffin cells reduces formalin-evoked c-Fos expression in the rat spinal cord.

Chromaffin cells from the adrenal gland secrete a combination of neuroactive compounds including catecholamines, opioid peptides, and growth factors that have strong analgesic effects, especially when administered intrathecally. Preclinical studies of intrathecal implantation with xenogeneic bovine chromaffin cells in rats have provided conflicting data with regard to analgesic effects, and recent concern over risk of prion transmission has precluded their use in human clinical trials. We previously developed a new, safer source of adult adrenal chromaffin cells of porcine origin and demonstrated an in vivo antinociceptive effect in the formalin test, a rodent model of tonic pain. The goal of the present study was to confirm porcine chromaffin cell analgesic effects at the molecular level by evaluating neural activity as reflected by spinal cord c-Fos protein expression. To this end, the expression of c-Fos in response to intraplantar formalin injection was evaluated in animals following intrathecal grafting of 10(6) porcine or bovine chromaffin cells. For the two species, adrenal chromaffin cells significantly reduced the tonic phases of the formalin response. Similarly, c-Fos-like immunoreactive neurons were markedly reduced in the dorsal horns of animals that had received injections of xenogeneic chromaffin cells. This reduction was observed in both the superficial (I-II) and deep (V-VI) lamina of the dorsal horn. The present study demonstrates that both xenogeneic porcine and bovine chromaffin cells transplanted into the spinal subarachnoid space of the rat can suppress formalin-evoked c-Fos expression equally, in parallel with suppression of nociceptive behaviors in the tonic phase of the test. These findings confirm previous reports that adrenal chromaffin cells may produce antinociception by inhibiting activation of nociceptive neurons in the spinal dorsal horn. Taken together these results support the concept that porcine chromaffin cells may offer an alternative xenogeneic cell source for transplants delivering pain-reducing neuroactive substances.

[What is the role of neuropsychological testing in the investigation and management of pharmacologically intractable partial epilepsy?]. / Quelle est la place du bilan neuropsychologique dans la prise en charge des patients souffrant d'une épilepsie partielle pharmaco-résistante?

Neuropsychological testing is an integral part of investigation and management of pharmacologically intractable epilepsy. Patients often complain of cognitive difficulties, in particular memory disturbances. A review of the literature demonstrates that correlations between subjective memory difficulties and objective memory deficits are often poor with mood correlating more consistently with subjective complaints. Nevertheless, objective memory difficulties are often found, especially in patients with temporal lobe epilepsy. Many factors can contribute to cognitive difficulties in patients with pharmacoresistant partial epilepsy. These include brain pathology that may be the cause or the consequence of chronic seizures (or both), physiological brain dysfunction due to epileptic activity and effects of antiepileptic medications. We review some of the abundant relevant literature. Neuropsychological evaluation is routinely used in pre-surgical evaluations of patients and cognitive dysfunction has some degree of correlation with lateralization and localization of epileptic activity, thus helping to determine a surgical strategy. The goal of seizure control is tempered with an assessment of the potential cognitive loss resulting from resective surgery. A number of studies have addressed postoperative neuropsychological findings and it is universally recognized that patients who have high levels of cognitive functioning in the areas targeted for resection (for instance verbal memory in dominant temporal lobe) show the greatest functional loss following surgery. More selective surgery probably results in some level of preservation of cognitive function.

[What is the current role of a Wada test in the pre-surgical work-up of pharmacologically intractable epilepsy in adults?]. / Quelle est la place du test de Wada dans le bilan préchirurgical des épilepsies pharmaco-résistantes chez l'adulte?

Juhn Wada developed a test while in Montreal designed to definitively confirm hemispheric lateralization of speech in candidates for surgical treatment of epilepsy. By unilateral intra-carotid administration of a bolus of a general anesthetic, classically sodium amobarbital, function can be tested in the non-injected hemisphere, while the injected side is dysfunctional. The test has been expanded to test memory functions in the hemisphere (temporal lobe) contralateral to expected surgery (memory reserve) in the hope of contra-indicating surgery that may result in global amnestic syndromes (patient HM). Conversely, risk of material-specific memory loss following surgery can be assessed by testing memory in the hemisphere/temporal lobe to be operated ("functional adequacy"). Memory dysfunction, when concordant with EEG seizure onset and chosen side of temporal lobe surgery has also been shown to correlate with favourable post-operative seizure outcome. Nevertheless, the test remains invasive, requiring an angiogramme. Non-invasive alternatives such as fMRI and PET and their reported reliability compared to a Wada test are discussed. A world-wide shortage of amobarbital has led to the use of some other anesthetic agents. Overall, the indications for the test and the manner in which it is performed vary greatly from one institution to the next. It is used almost systematically in some institutions and very rarely in others. Future perspectives are discussed.

Intrathecal xenogeneic chromaffin cell grafts reduce nociceptive behavior in a rodent tonic pain model.

Adrenal medullary chromaffin cells synthetize and secrete a combination of pain-reducing neuroactive compounds including catecholamines and opioid peptides. Previous reports have shown that implantation of chromaffin cells into the spinal subarachnoid space can reduce both acute and chronic pain in several animal models. We recently demonstrated that human chromaffin cell grafts in the cerebrospinal fluid (CSF) could alleviate intractable cancer pain after failure of systemic opiates. However, wider application of this approach was limited by the limited availability of allogeneic donor material. Alternatively, chromaffin cells from xenogeneic sources such as bovine adrenal medulla were successful in the experimental treatment of pain, but recent concern over risk of prion transmission precluded use of bovine grafts in human clinical trials. The objective of the present study was to investigate the possibility of developing a new xenogeneic porcine source of therapeutic chromaffin cells because this strategy is currently considered the safest for transplantation in man. In the present study, we report the isolation and the characterization of primary porcine chromaffin cells (PCC) compared to bovine cells. We show, for the first time, that these cells grafted in the rat subarachnoid space can attenuate pain-related behaviors as assessed by the formalin test, a model of tonic pain. Moreover, in addition to behavioral studies, immunohistochemical analysis revealed robust survival of chromaffin cells 35 days after transplantation. Taken together, these results support the concept that porcine chromaffin cells may offer an alternative xenogeneic cell source for transplants delivering pain-reducing neuroactive substances.

Frontal sinus osteoma associated with cerebral abscess formation: a case report.

BACKGROUND: Osteomas of the paranasal sinuses rarely lead to intracranial manifestations. We present an unusual case of a frontal sinus osteoma leading to intracerebral abscess formation. CASE DESCRIPTION: A 51-year-old Hispanic man presented with increasing frontal headaches, new onset seizure, lethargy, global dysphasia, and unilateral hemiparesis. CSF studies demonstrated mild pleocytosis. Neuroradiological studies revealed an opacity filling the left frontal sinus, as well as a ring-enhancing mass with surrounding edema in the left frontal lobe. The patient was surgically treated with a left frontal osteoplastic craniotomy and removal of the abscess and bony mass. Intraoperative cultures were positive for Streptococcus pneumoniae. Pathology revealed bony tumor consistent with osteoma. The patient's neurological status improved to baseline after surgery. CONCLUSION: The frontal sinus osteoma was associated with rapid development of a frontal lobe abscess, requiring emergent surgical debridement. Although rare, intracerebral manifestations should be considered and expected as a cause of new neurological deficits in the presence of paranasal sinus osteoma.

Primary myxoma of the temporal bone in a 17-year-old boy: case report.

OBJECTIVE AND IMPORTANCE: Only two cases of primary intracranial myxomas have been described previously in the literature: one patient had a primary intracranial myxoma in the pituitary fossa, and the other patient's myxoma was located in the posterior fossa. CLINICAL PRESENTATION: A rare case of primary myxoma of the temporal bone in a 17-year-old boy is described. The patient presented with a history of progressive left-sided hearing loss and increasing headaches of a few months' duration. INTERVENTION: An initial draining procedure in the left ear revealed extant mucous material, and further investigation showed a large calcified lesion involving the petrous and temporal bones and filling the middle fossa. At surgery, a large mucoid-appearing tumor was removed. The tumor pathology revealed a primary myxoma with bone and meningeal involvement. No clinical or histopathological evidence that it was a metastatic lesion was found. CONCLUSION: The features of myxomas on computed tomographic and magnetic resonance imaging, the histopathology, and surgical considerations are discussed.

Delayed epidural hematoma: presentation in a pediatric patient.

Epidural hematomas remain at the pinnacle of neurosurgical emergencies, representing approximately 3% to 8% of all serious head injuries. Mortality from this entity is usually prevented once the diagnosis is clear. Although readily recognized on non-contrast head CT, the occasional patient may go on to develop a clinically significant hematoma after an initial negative CT. This phenomenon is appropriately termed delayed epidural hematoma. We present a case in which a 3-year-old boy developed a large epidural hematoma, which was not evident until the second CT, several hours after the injury. We feel that maintaining a high clinical suspicion, coupled with a low threshold for CT scanning, is the key to morbidity prevention in this illness.

Chronic motor cortex stimulation for phantom limb pain: correlations between pain relief and functional imaging studies.

Chronic motor cortex stimulation (CMCS) has provided satisfactory control of pain in patients with central or trigeminal neuropathic pain. We used this technique in 3 patients with intractable phantom limb pain after upper limb amputation. Functional magnetic resonance imaging (fMRI) correlated to anatomical MRI permitted frameless image guidance for electrode placement. Pain control was obtained for all the patients initially and the relief was stable in 2 of the 3 patients at 2 year follow-up. CMCS can be used to relieve phantom limb pain. fMRI data are useful in assisting the neurosurgeon in electrode placement for this indication.

Peri-insular hemispherotomy: surgical principles and anatomy.

THE NATURE OF functional hemispherectomy continues to be misunderstood despite its 20-year history. Recently, we introduced the concept of peri-insular hemispherotomy, a functional hemispherectomy with minimal brain removal (9, 21). To avoid additional confusion, a detailed neuroanatomic account of this operation, which has been performed in 11 patients, is presented. The name of the operative variant presented derives from the central importance of the exposure of the insula as the first surgical landmark. Incising along the circular sulcus that surrounds the insula not only allows access to the dilated ventricular system but also disrupts the entire internal capsule. A parasagittal callosotomy is performed from within the lateral ventricle by incising the medial ventricular roof. Projections through the anterior commissure are disrupted at the time of radical amygdalar resection. The posterior hippocampus need not be radically removed, because its posterior transsection disconnects it. Overall, peri-insular hemispherotomy can be viewed as a radical hemispheric tractotomy, resulting in a completely disconnected hemisphere. Advantages include shorter operative times, a less stormy postoperative course, and better anatomic preservation of the operated hemisphere, thus presumably reducing long-term complications.

Automated EEG monitoring in defining a chronic epilepsy model.

There has been a recent surge of interest in chronic animal models of epilepsy. Proper assessment of these models requires documentation of spontaneous seizures by EEG, observation, or both in each individual animal to confirm the presumed epileptic condition. We used the same automatic seizure detection system as that currently used for patients in our institution and many others. Electrodes were implanted in 43 rats before intraamygdalar administration of kainic acid (KA). Animals were monitored intermittently for 3 months. Nine of the rats were protected by anticonvulsants [pentobarbital (PB) and diazepam (DZP)] at the time of KA injection. Between 1 and 3 months after KA injection, spontaneous seizures were detected in 20 of the 34 unprotected animals (59%). Surprisingly, spontaneous seizures were also detected during the same period in 2 of the 9 protected animals that were intended to serve as nonepileptic controls. Although the absence of confirmed spontaneous seizures in the remaining animals cannot exclude their occurrence, it indicates that, if present, they are at least rare. On the other hand, definitive proof of epilepsy is invaluable in the attempt to interpret pathologic data from experimental brains.

Cerebrovasculr response to CO2 in edematous brain during either fentanyl or isoflurane anesthesia.

Cerebral blood flow response to changes in PaCO2 was studied in the edematous cerebral cortex of 19 patients with malignant supratentorial tumors using laser Doppler flowmetry technology. General anesthesia for craniotomy was induced with thiopental, 3-5 mg/kg i.v., and N2O, 60% in O2. In random sequence, 8 patients were assigned to receive fentanyl, 6 +/- 1.6 (SEM). mug/kg i.v.; the other 11 received isoflurane, 0.56% end-tidal + 0.07 (SEM). After a craniotomy bone flap was turned and the dura was opened, laser flowmetry probes were placed over surgically undisturbed cortex that was known to be edematous from preoperative CT and MRI scans. Flow index measurements were first made at hypocarbia (PaCO2 = 24.2 +/- 0.9 and 21.5 +/- 2.1 mm Hg for the fentanyl and isoflurane groups, respectively). Minute ventilation was then decreased and cortical flow index was remeasured with PaCO2 = 34.2 +/- 0.6 and 33.0 +/- 0.8 mm Hg for the fentanyl and isoflurane groups, respectively. Hypocarbia during fentanyl-supplemented N2O-O2 anesthesia resulted in a cortical flow index that was 70 +/- 8% of the flow index at near normocarbia (p <0.05). During isoflurane N2O-O2 anesthesia, however, there was a wide variety of responses to hypocarbia, including three patients whose flow indices increased markedly. The mean flow index during hypocarbia was significantly (p <0.05) lower during fentanyl-N2O anesthesia than it was during isoflurane-N2O anesthesia. There was no predictable relationship between the type of brain tumor and the CBF response to hypocapnia during isoflurane-N2O anesthesia. It is concluded that, in edematous brain, cerebral cortical blood flow response to hypocarbia is more likely to be preserved during fentanyl-supplemented N2O-O2 anesthesia than it is during isoflurane-supplemented N2O-O2 anesthesia. In neuropathologic states where hyperventilation is thought to be necessary to reduce cerebral blood flow and decrease brain bulk, isoflurane may be less satisfactory than fentanyl as a supplement to N2O-O2 anesthesia.

Sufentanil, alfentanil, and fentanyl: impact on cerebrospinal fluid pressure in patients with brain tumors.

In order to evaluate the safety of the new synthetic opioids, alfentanil and sufentanil, in neurosurgical patients, we administered sufentanil 1 microg/kg i.v., alfentanil 50 microg/kg i.v. followed by an infusion of 1 microg/kg/min, or fentanyl 5 microg/kg i.v. to 30 patients with supratentorial tumors anesthetized with nitrous oxide (N2O), 60% in O2. Lumbar cerebrospinal fluid pressure (CSFP) and mean arterial pressure (MAP) responses were recorded for 10 min thereafter, while ventilation was held constant [mean PaCO2 = 36.1 +/- 1.0 mm Hg (SEM)]. There was no change in CSFP after fentanyl. In contrast, both sufentanil and alfentanil caused increases in CSFP, equal to 89 +/- 31 % SE (p < 0.05) and 22 +/- 5% (p < 0.05), respectively. MAP decreased after administration of each opioid. Peak decreases in cerebral perfusion pressure (MAP - CSFP) were 14 +/- 3% after fentanyl, 25 +/- 5% after sufentanil, and 37 +/- 3% after alfentanil. It is concluded that because sufentanil increased CSFP in patients who have brain tumors, it also may be contraindicated in other neurosurgical patients at risk for intracranial hypertension. Alfentanil may share this propensity, since CSFP increased despite a profound reduction in MAP. Among the three opioids evaluated, only fentanyl appears to be appropriate for supplementing N2O-2 anesthesia in patients who have compromised intracranial compliance.

Consequences of antenatal diagnosis for pediatric surgery.

Based on an increase from 6000 ultrasound examinations done at the First University Gynecological Hospital of Munich in 1969 to more than 13,000 in 1982, and on an increased rate of antenatally diagnosed malformation, the accuracy of antenatal ultrasound diagnosis was investigated. It turned out that correct diagnosis could be made in over 80% of cases. However, this was incomplete in approximately 40% of the cases, since associated malformations of the gastrico-intestinal tract, congenital heart disease, myelomeningocele in correctly diagnosed hydrocephalus, and others were not recognized. False-positive results were found in 17.5% of cases, false-negative ones in 12.7%. Because of the uncertainty of antenatal diagnosis and ignorance of many physiological parameters, intrauterine surgical treatment cannot be advocated at present. Intrauterine measures are still confined to punctures, administration of drugs, and diagnostic procedures. Further consequences such as termination of pregnancy, psychological aspects, and possible development of intrauterine therapy are discussed.