Alfonso Lagares

Intracranial Hemangiopericytoma: Study of 12 Cases

Summary Most hemangiopericytomas (HPCs) are located in the musculoskeletal system and the skin, while the intracranial location is rare. They represent 2 to 4% in large series of meningeal tumours, thus accounting for less than 1% of all intracranial tumours. Many authors have argued about the true origin of this tumour. The current World Health Organization classification of Central Nervous System tumours distinguishes HPC as an entity of its own, and classified it into the group of “mesenchymal, non-meningothelial tumours”. Radical surgery is the treatment of choice, but must be completed with postoperative radiotherapy, which has proved to be the therapy most strongly related to the final prognosis. HPCs have a relentless tendency for local recurrence and metastases outside the central nervous system which can appear even many years after diagnosis and adequate treatment of the primary tumour. Twelve patients with intracranial HPC were treated at our Unit between 1978 and 1999. There were 10 women and 2 men. Ten tumours were supratentorial and most located at frontoparietal parasagittal level. The most common manner of presentation was a focal motor deficit. All tumours were hyperdense in the basal Computed Tomography scans and most enhanced homogeneously following intravenous contrast injection. In 50% of cases, tumour margins were irregular or lobulated. Seven tumours were studied with Magnetic Resonance Imaging, being six of them iso-intense with the cortical gray matter on T1-weighted and T2-weighted images. Twenty operations were performed in the 12 patients. In 10 cases radical excision could be achieved with no operative mortality. Total recurrence rate was 33.3%. Eight patients were treated with external radiotherapy at some time through the course of their disease. Eight out of the 12 patients in this series are disease-free (Glasgow Outcome Scale categories 1 and 2) after a mean follow up of 52 months.

Prognostic Factors on Hospital Admission after Spontaneous Subarachnoid Haemorrhage

Summary Background and Objective. Factors related to prognosis after subarachnoid haemorrhage (SAH) have been mainly extracted from surgical series, and only few authors have considered these factors in total management or population series. Though the level of consciousness is a major determinant of outcome after subarachnoid haemorrhage, there is not a consensus about which classification should be used to define it. The objective of this study was twofold. Firstly to find which factors recorded on hospital admission relate to outcome determining their relative importance in a non-selected series of patients suffering from aneurysmal SAH admitted to our centre, and secondly to assess the validity of the WFNS clinical scale for predicting the final result. Methods. A series of 294 patients consecutively admitted to Hospital 12 de Octubre Madrid between January 1990 and June 2000 with the diagnosis of aneurysmal SAH were retrospectively reviewed. All factors possibly related to prognosis were recorded on hospital admission. Outcome was measured by means of the Glasgow Outcome Scale measured one month after hospital discharge. Relationship between factors and outcome was evaluated by univariate and logistic regression multivariate analysis. Results. Although several factors appeared related to prognosis in the univariate analysis, only the age, the level of consciousness defined by the WFNS scale and the presence of global brain hypodensity on the initial CT scan had a significant prognostic influence in the logistic regression model. Global brain hypodensity was strongly related to mortality. Since a number of factors associated with poor outcome in the univariate analysis are related to age, their influence could be explained by the difficulty of recovery of the ageing brain. The WFNS grading scale failed to predict significant differences in outcome between some of its grades. Conclusions. Age and clinical grade on admission are the most important factors influencing the final outcome of patients suffering aneurysmal SAH. A reappraisal of the WFNS grading scale should be considered as no significant differences in outcome were found between some of its grades.

The Added Value of Apparent Diffusion Coefficient to Cerebral Blood Volume in the Preoperative Grading of Diffuse Gliomas

Is it worth doing both DWI and perfusion imaging in gliomas? These authors sought to study if ADC and rCBV improved diagnostic accuracy in the preoperative grading of gliomas by assessing 162 patients who later underwent surgery. rCBV was significantly different between grade II and IV and between grade III and IV gliomas, but not between grades II and III. ADC values were significantly different for all 3 grades. Conclusion: ADC measurements were better than rCBV values for distinguishing the grades of gliomas, and the combination of minimum ADC and maximum rCBV improved the diagnostic accuracy of glioma grading. BACKGROUND AND PURPOSE: In cerebral gliomas, rCBV correlates with tumor grade and histologic findings of vascular proliferation. Moreover, ADC assesses water diffusivity and is inversely correlated with tumor grade. In the present work, we have studied whether combined rCBV and ADC values improve the diagnostic accuracy of MR imaging in the preoperative grading of gliomas. MATERIALS AND METHODS: One hundred sixty-two patients with histopathologically confirmed diffuse gliomas underwent DWI and DSC. Mean rCBV and ADC values were compared among the tumor groups with the Student t test or ANOVA. ROC analysis was used to determine rCBV and ADC threshold values for glioma grading. RESULTS: rCBV had significantly different values between grade II and IV gliomas and between grade III and IV tumors, but there were no significant differences between grade II and III gliomas (P > .05). Grade II and III tumors also did not differ when astrocytomas, oligodendrogliomas, and oligoastrocytomas were considered separately. ADC values were significantly different for all 3 grades. The ADC threshold value of 1.185 × 10−3 mm2/s and the rCBV cutoff value of 1.74 could be used with high sensitivity in the characterization of high-grade gliomas. The area under the ROC curve for the maximum rCBV and minimum ADC was 0.72 and 0.75, respectively. The combination of rCBV and ADC values increased the area under the ROC curve to 0.83. CONCLUSIONS: ADC measurements are better than rCBV values for distinguishing the grades of gliomas. The combination of minimum ADC and maximum rCBV improves the diagnostic accuracy of glioma grading.

Ganglioglioma of the Brainstem REPORT OF THREE CASES AND REVIEW OF THE LITERATURE

BACKGROUND Brainstem gangliogliomas are rare low-grade tumors that usually have a long clinical history. However, they may cause sudden death. There are only 31 cases of brainstem ganglioglioma reported in the literature, and only one has been studied with magnetic resonance (MR). We present three new cases of brainstem ganglion cell tumor studied with computed tomography (CT) (3 cases) and MR (2 cases) and discuss the clinical presentation, diagnostic imaging and treatment of these tumors. CASE DESCRIPTION Age at presentation ranged from 19 to 59 years old. Two patients were female and 1 male. Duration of symptoms before diagnosis ranged from 1 year to nearly 14 years. Presenting complaints included syncope spells, cranial nerve deficits, headache, and gait instability. Imaging studies revealed well-circumscribed lesions involving the brainstem; the lesion was cystic in one case and calcified in one. They were iso- or hyperdense on CT scan, isodense on T1-weighted and hyperdense on T2-weighted MRI and frequently showed contrast enhancement. All tumors were operated through a posterior fossa craniectomy. Using microsurgical techniques only partial resection could be achieved, as there was no sharp delineation from the surrounding tissue in any case. Two of our patients had increased neurological deficits after surgery. Radiotherapy was not given. Follow-up of tumoral remnants has not shown clear tumor growth after 1, 3.5, and 10 years. CONCLUSIONS Imaging characteristics of brainstem gangliogliomas do not seem to differ from those in other locations and are not specific. Radical surgery is rarely if ever possible, nor is it advisable because of the risk of functional deterioration. However, because of their benign histology, partial resection seems to carry a similar prognosis as tumors in other locations that are amenable to complete resection.

Neuron numbers in the sensory trigeminal nuclei of the rat: A GABA- and glycine-immunocytochemical and stereological analysis

The volume, total neuron number, and number of GABA‐ and glycine‐expressing neurons in the sensory trigeminal nuclei of the adult rat were estimated by stereological methods. The mean volume is 1.38 ± 0.13 mm3 (mean ± SD) for the principal nucleus (Vp), 1.59 ± 0.06 for the n. oralis (Vo), 2.63 ± 0.34 for the n. interpolaris (Vip), and 3.73 ± 0.11 for the n. caudalis (Vc). The total neuron numbers are 31,900 ± 2,200 (Vp), 21,100 ± 3,300 (Vo), 61,600 ± 8,300 (Vip), and 159,100 ± 25,300 (Vc). Immunoreactive (‐ir) neurons were classified as strongly stained or weakly stained, depending on qualitative criteria, cross‐checked by a densitometric analysis. GABA‐ir cells are most abundant in Vc, in an increasing rostrocaudal gradient within the nucleus. Lower densities are found in Vip and Vp. The mean total number of strongly labeled GABA‐ir neurons ranges between 1,800 in Vp to 7,800 in Vip and 22,900 in Vc, and varies notably between subjects. Glycine‐ir neurons are more numerous and display more homogeneous densities in all nuclei. Strongly labeled Gly‐ir cells predominate in all nuclei, their total number ranging between 9,400 in Vp to 24,300 in Vip and 34,200 in Vc. A substantial fraction of immunolabeled neurons in all nuclei coexpress GABA and glycine. In general, all neurons strongly immunoreactive for GABA are small, while weakly GABA‐ir cells which coexpress Gly are larger. In Vc, one‐third of all neurons are immunoreactive: 16.6% of them are single‐labeled for GABA and 31.6% are single‐labeled for glycine. The remaining 51.8% express GABA and glycine in different combinations, with those showing strong double labeling accounting for 22.6%. J. Comp. Neurol. 493:538–553, 2005.

The value of sequential computed tomography scanning in anticoagulated patients suffering from minor head injury.

BACKGROUND Since 1999, the Italian guidelines have been used at our department for the management of patients with mild head injury (MHI). According to these guidelines, a computed tomography (CT) scan should be obtained in all patients with coagulopathy and these should routinely undergo strict observation during the first 24 hours after injury; in addition they should have a control CT scan before discharge. With the increased use of anticoagulant therapy in the elderly population, admitting patients in such treatment with a MHI to the emergency rooms has become very common. The aim of our study was to evaluate the need of performing a control CT scan in patients on anticoagulation treatment who showed neither intracranial pathology on the first CT-scan nor neurologic worsening during the observation period. METHODS We prospectively analyzed the course of all patients on anticoagulation treatment consecutively admitted to our unit between October 2005 and December 2006 who suffered from a MHI and showed a normal initial CT scan. All patients underwent strict observation during the first 24 hours after admission and had a control CT scan performed before discharge. RESULTS One hundred thirty-seven patients were included in this study. Only two patients (1.4%) showed hemorrhagic changes. However, neither of them developed concomitant neurologic worsening nor needed admitting or surgery. CONCLUSION According with our data, patients on anticoagulation treatment suffering from MHI could be managed with strict neurologic observation without routinely performing a control CT scan that can be reserved for the rare patients showing new clinical symptoms.

Severe Traumatic Head Injury: Prognostic Value of Brain Stem Injuries Detected at MRI

Because traumatic brain stem injuries are thought to imply a poor prognosis, these authors studied 188 patients with TBI and correlated their imaging findings with outcomes at 6 months. Brain stem lesions were found in 51 instances and 66% of these patients had a poor outcome, with those who had bilateral, posteriorly located, and hemorrhagic lesions having the worst outcome. Nonhemorrhagic brain stem lesions had the best outcome in this group of patients. BACKGROUND AND PURPOSE: Traumatic brain injuries represent an important cause of death for young people. The main objectives of this work are to correlate brain stem injuries detected at MR imaging with outcome at 6 months in patients with severe TBI, and to determine which MR imaging findings could be related to a worse prognosis. MATERIALS AND METHODS: One hundred and eight patients with severe TBI were studied by MR imaging in the first 30 days after trauma. Brain stem injury was categorized as anterior or posterior, hemorrhagic or nonhemorrhagic, and unilateral or bilateral. Outcome measures were GOSE and Barthel Index 6 months postinjury. The relationship between MR imaging findings of brain stem injuries, outcome, and disability was explored by univariate analysis. Prognostic capability of MR imaging findings was also explored by calculation of sensitivity, specificity, and area under the ROC curve for poor and good outcome. RESULTS: Brain stem lesions were detected in 51 patients, of whom 66% showed a poor outcome, as expressed by the GOSE scale. Bilateral involvement was strongly associated with poor outcome (P < .05). Posterior location showed the best discriminatory capability in terms of outcome (OR 6.8, P < .05) and disability (OR 4.8, P < .01). The addition of nonhemorrhagic and anterior lesions or unilateral injuries showed the highest odds and best discriminatory capacity for good outcome. CONCLUSIONS: The prognosis worsens in direct relationship to the extent of traumatic injury. Posterior and bilateral brain stem injuries detected at MR imaging are poor prognostic signs. Nonhemorrhagic injuries showed the highest positive predictive value for good outcome.

Primary Sensory Neuron Addition in the Adult Rat Trigeminal Ganglion: Evidence for Neural Crest Glio-Neuronal Precursor Maturation

It is debated whether primary sensory neurons of the dorsal root ganglia increase the number in adult animals and, if so, whether the increase is attributable to postnatal neurogenesis or maturation of dormant, postmitotic precursors. Similar studies are lacking in the trigeminal ganglion (TG). Here we demonstrate by stereological methods that the number of neurons in the TG of adult male rats nearly doubles between the third and eighth months of age. The increase is mainly attributable to the addition of small, B-type neurons, with a smaller contribution of large, A-neurons. We looked for possible proliferative or maturation mechanisms that could explain this dramatic postnatal expansion in neuron number, using bromodeoxyuridine (BrdU) labeling, immunocytochemistry for neural precursor cell antigens, retrograde tracing identification of peripherally projecting neurons, and in vitro isolation of precursor cells from adult TG explant cultures. Cell proliferation identified months after an extended BrdU administration was sparse and essentially corresponded to glial cells. No BrdU-labeled cell took up the peripherally injected tracer, and only a negligible number coexpressed BrdU and the pan-neuronal tracer neuron-specific enolase. In contrast, a population of cells not recognizable as mature neurons in the TG and neighboring nerve expressed neuronal precursor antigens, and neural crest glioneuronal precursor cells were successfully isolated from adult TG explants. Our data suggest that a protracted maturation process persists in the TG that can be responsible for the neuronal addition found in the adult rat.

A comparison of different grading scales for predicting outcome after subarachnoid haemorrhage.

SummaryBackground. Most scales used to assess prognosis after subarachnoid haemorrhage (SAH) are based on the level of consciousness of the patient. Based on information from a logistic regression model, Ogilvy et al. developed a new grading scheme (Massachussetts General Hospital (MGH) Scale) which applied a simple scoring method to each prognostic factor considered relevant such as level of consciousness, age, quantity of blood in the first CT scan and size of the aneurysm. The purpose of this study is to introduce a modified version of the MGH scale, built up using factors applicable to every patient suffering SAH, and compare this new scale to the World Federation of Neurological Surgeons scale (WFNS), the Glasgow Coma Scale (GCS) scale for SAH and the MGH scale.Method. A series of 442 patients consecutively admitted to Hospital 12 de Octubre between January 1990 and September 2001 with the diagnosis of spontaneous SAH were retrospectively reviewed. Outcome was assessed by means of the Glasgow Outcome Scale measured six months after hospital discharge. Differences between grades of the WFNS, the GCS scale for SAH, the MGH scale and the new scale were computed by χ2 statistics. ROC curves were plotted for the different scales and their areas compared.Findings. Both WFNS and GCS scales fail to present significant differences between most of their grades, while the proposed scale shows a constant inter-grade significant difference in predicting outcome. The proposed scale presents a significantly higher prognostic efficacy in the whole series of patients suffering spontaneous SAH, patients with idiopathic subarachnoid haemorrhage (ISAH) and patients with confirmed aneurysmal SAH. The MGH scale is not applicable to some groups of patients suffering SAH.Interpretation. Grading scales including additional factors to the level of consciousness show higher prognostic efficacy. The proposed modification of the MGH scale makes it applicable to every patient suffering SAH without losing its prediction capability.

Lhermitte-Duclos disease and Cowden disease: clinical and genetic study in five patients with Lhermitte-Duclos disease and literature review

SummaryBackground. Lhermitte-Duclos Disease (LDD) is an infrequent cerebellar disorder characterized by focal or diffuse enlargement of cerebellar folia presenting as a slowly growing mass in the posterior fossa. Over the past decade its association with Cowden disease (CD) has been recognized with increasing frequency. This latter disease is a genetic condition leading to the presence of multiple hamartomas and neoplasias which affect mainly the skin, thyroid, breast and genito-urinary and gastro-intestinal tracts. It has even been hypothesized that LDD and CD constitute a single entity. This work is aimed to analyse to what extent this association was present in patients treated for LDD at our institution. Method. We reviewed the medical records of five patients and performed clinical studies for CD manifestations, among them, genetic investigation for PTEN mutations. The International Cowden Consortium Criteria were applied for the diagnosis of CD. Findings. Four of the five patients treated for LDD were also diagnosed of CD. The genetic study found PTEN mutations in two of them. Interpretation. LDD has been found to be closely related to CD in this series, in accordance with previous literature. However, the absence of CD diagnosis in one of the patients led us to suggest that, despite the strong association between these two diseases, LDD can also appear as an isolated condition.