[Radiosurgery as adjuvant treatment of a recurrent adult medulloblastoma. Ultra-early response]. / Radiocirugía como tratamiento complementario del meduloblastoma recidivadodel adulto: respuesta ultratemprana.

The role of radiosurgery after multimodality treatment of recurrent desmoplastic adult medulloblastoma is analyzed. The ultra-early clinical and pathological response of this tumor to adjunctive radiosurgery is stressed.

[Bone marrow stem cell transplantation in amyotrophic lateral sclerosis: technical aspects and preliminary results from a clinical trial]. / Terapia celular para la esclerosis lateral amiotrófica: aspectos técnicos y resultados preliminares del estudio CMN/ELA.

Patients with amyotrophic lateral sclerosis (ALS) experience progressive and irreversible paralysis as a result of the continued loss of motor neurons, which leads to death in less than five years. To date, there is no treatment that can change the progression of this disease. Bone marrow stem cells have shown neural regenerative and neural repairing properties. Specifically, our group showed in a murine model of the disease that these cells, when injected in the spinal cord, can rescue motor neurons through the secretion of GDNF. Based on these results, we designed a phase I/II clinical trial for the purpose of demonstrating the viability of the intraspinal injection of autologous bone marrow mononuclear cells in patients with bulbar onset ALS, with an evolution between 6 and 36 months, with a forced vital capacity (FVC) 50% and T90 29%. This article describes the technique for extracting 60 mL of bone marrow used for the intervention, processing it by density gradient, and the neurosurgical technique used for implanting it. After 6 months of follow-up, the few adverse events reported in the first seven patients included seem to show that the procedure is safe and viable. Most of these patients, including two with a rapid deterioration, have stabilized the progression of their FVC and the neurologic scales measured. The data obtained so for seem to justify the design of new trials more oriented toward the efficacy of the procedure.

[Usefulness of hyperbaric oxygen in the treatment of radionecrosis and symptomatic brain edema after LINAC radiosurgery]. / Eficacia del oxígeno hiperbárico en el tratamiento de la radionecrosis y el edemacerebral sintomáticos tras radiocirugía con acelerador lineal.

Radionecrosis with brain edema is a complication of radiosurgery. Three female patients harbouring a frontal pole, petrous and parasagital parietoocipital meningiomas respectively who had been treated with LINAC radiosurgery are presented. Those patients developed, between two and eight months later, a severe symptomatic radionecrosis with a huge brain edema resistant to the usual steroid therapy. Only after 40 sessions of hyperbaric oxygen, a good remission of the lesions was obtained. There are few cases reported in the literature with such a good outcome. Consequentely, this therapy must be taken into account to treat this type of radiosurgical complication before considering surgery.

Cavernomas in children with brain tumors: a late complication of radiotherapy.

BACKGROUND: Delayed complications of radiation therapy comprise cerebral atrophy, radionecrosis and induction of tumors. Recent reports indicate the possibility of the "de-novo" formation of intracranial cavernomas in patients submitted to radiation therapy to the brain. OBJECTIVES: To report three children, two with medulloblastomas and one with a pineal germinoma, treated with radiotherapy that developed intracerebral cavernous hemangiomas some years after treatment. With this work, we aim to draw attention to this occurrence in the neurosurgical community. RESULTS: The patients were two girls and one boy with ages comprised between 2.5 and 7 years (mean 5.2 years). The average interval from irradiation to the appearance of cavernoma was of 5.3 years (range 5-6 years). The lesions were found during the routine neuroimaging studies performed for the follow-up of their primary neoplasms. No patient showed signs or symptoms related to the cavernomas. However, the three children will need both clinical and neuroimaging surveillance to monitor the evolution of these incidentally discovered lesions. CONCLUSIONS: Intracranial cavernomas can occur years after cerebral radiation therapy. In spite of previous reports that show a high incidence of bleeding lesions, cavernomas may be found incidentally during the neuroimaging surveillance studies that are performed to children with brain tumors previously treated with radiotherapy. In these cases, a conservative attitude seems to be advisable, reserving surgery only for those lesions that grow or bleed.

[Brain abscess. Evaluation of prognostic factors: does the use of antibiotic prescribing protocols improve outcome?]. / Abscesos cerebrales: análisis de factores pronóstico e influencia del tratamiento antibiótico protocolizado en su evolución.

BACKGROUND: the aim of this study was to evaluate prognostic factors in brain abscess (AB) and influence of management with antibiotic prescribing protocols (APP). PATIENTS AND METHODS: observational study of a cohort of non-paediatric patients with BA admitted at a 944-bed hospital (1976-2005). Data collection from clinical records has been done according to a standard protocol. We analysed epidemiological, clinical, radiological, microbiological and laboratory data associated with mortality. From 1976 to 1983 (Period I), antibiotic treatment was not done according to any internal APP; from 1983 (Period II), antibiotic management was done according to a APP designed by infectious diseases specialists and neurosurgeons. Predictors of mortality were identified by univariate analysis. The influence of the use of APP in outcome was assessed. RESULTS: 104 patients with BA were included (mean age 45 years; range 12-86); presumed primary pathogenic mechanism of BA was identified in 89%; microbiologic diagnosis was made in 76%. Overall mortality was 16.3%. Factors statistically associated with higher mortality were: age > 40 years, ultimately fatal underlying disease, acute severe clinical condition at the onset of BA, altered mental status and inadequate empirical treatment; 33 patients were treated in Period I and 71 in Period II; no statistically significant differences were found between epidemiological, clinical, radiological or microbiological characteristics of the groups except for mean age (> 40 years in 36% and 62% respectively in Period I and II). Rates of resolution of BA were 60 vs. 77.4% (p < 0.05); relapses 21 vs. 7% (p < 0.05) and mortality 18 vs. 15.4% (p > 0.05), in Period I and II respectively. CONCLUSIONS: main prognostic factors associated with mortality in patients with BA are age, rapidly fatal underlying disease, acute severe clinical condition at the onset of BA, altered mental status and inadequate empirical treatment. Empiric treatment according to APP was associated with greater resolution and lower relapse rates.

"Benign" shaken baby syndrome. Case report.

The authors report an infant with clinical and neuroimaging findings of shaken baby syndrome. The pitfalls encountered in the assessment on the cause of the bilateral frontal and interhemispheric subdural hematomas in this child are also briefly discussed. We have called this condition "benign" shaken baby syndrome and emphasize that not always acute subdural hematomas are of non-accidental nature.

[Postoperative delirium in patient neurosurgical: evaluation by means of the Abbreviated Mental Test]. / Delirio postoperatorio en pacientes neuroquirúrgicos: evaluación mediante el Test Mental Abreviado.

OBJECTIVES: To assess the incidence and characteristics of postoperative changes in the higher cerebral functions after elective intracranial surgery under general anesthesia. PATIENTS AND METHODS: This is a prospective study of 60 patients, aged 18-81 years, submitted to neurosurgical operations, allocated into two groups of 30 patients each: intracranial surgery group, patients submitted to craniotomy, and extracranial surgery group or control group, patients submitted to spinal procedures. All patients were given the Abbreviated Mental Test (AMT) on the day before to the operation, and then 2 and 24 hours after the end of the procedure. All individuals were managed with the same anesthetic technique. RESULTS: No differences in regard to demographics, duration of the operation, ASA physical state, and habits were found between the two groups. No differences in the pre-surgical and post-surgical AMT mean score were encountered between patients submitted to intracranial 9.87 +/- 0.35 or to spinal surgeries 9.80 +/- 0.41. Similarly, there were no significant differences between the two groups in the results of the AMT performed at 2 and 24 hours after the end of the surgeries. Only two subjects undergoing spinal procedures had a score of < or = 8 in the AMT performed 2-hours after the operation, while none showed a decrease in the 24-hour test score. CONCLUSIONS: Patients submitted to intracranial surgery did not show any changes in cognitive or attention functions during the first postoperative 24 hours as assessed by the AMT.

[Syndromes of overdrainage of ventricular shunting in childhood hydrocephalus]. / Síndromes de hiperdrenaje de las válvulas en hidrocefalia infantil.

Overdrainage in ventricular shunting constitutes a difficult to prevent and to treat complication. The authors reviewed a retrospective series of 512 children submitted to a ventricular shunting procedure aimed at analysing factors influencing this type of complication. The causes for the hydrocephalus were congenital (n=172), post-myelomeningocele (n=123), posthemorrhagic (n=103), tumoral (n=64), postmeningitis (n=40) and posttraumatic (n=10). Eighty-eight children (17.8%) evolved with a complication related to the excessive function of the valve. The authors investigated the relationship between hydrocephalus' etiology and type of overdrainage syndromes. The most frequent complication was ventricular catheter block (n=50), followed by symptomatic slit ventricle syndrome (SVS) (n=19), subdural hematoma (n=10) and trapped fourth ventricle (n=9). There were no statistical differences regarding complications for each etiologic subset of hydrocephalus. SVS occurred in 19 children (3.71%), a low rate according to the current literature. Posthemorrhagic and postinfectious hydrocephalus grouped together showed a higher rate of SVS (p=0.005), a feature that we attributed to the cerebral destruction caused by these two conditions. Treatment of SVS was complex and required diverse procedures, applied in an escalated way, which included five decompressive craniectomies. The authors suggest avoiding, as much as possible, the use of ventricular shunts, and recommend the alternative use of new technology valves and neuroendoscopic procedures.

[Tension pneumocephalus after intracranial surgery in the supine position]. / Neumoencéfalo a tensión tras cirugía intracraneal en posición supina.

Tension pneumocephalus is a rare and severe complication appearing after posterior fossa procedures in the sitting position. This complication may endanger the patient's life and require immediate treatment. However, tension pneumocephalus after neurosurgical procedure in the supine position have been scarcely reported. We report such a complication occurring in a 14-year-old girl submitted to a frontotemporal craniotomy for removal of an astrocytome performed with the patient supine. We discuss ethiopathogenesis and management of this complication.

The effects of taxol, methylprednisolone, and 4-aminopyridine in compressive spinal cord injury: a qualitative experimental study.

BACKGROUND: Taxol is a diterpene alkaloid that stimulates tubulin production in cells. It may be effective in preserving the cytoskeleton of spinal cord axons after injury. METHODS: Thirty-nine rats were submitted to spinal cord compression. The animals were divided into three groups that received taxol (18.75 mg/m2), methylprednisolone (30 mg/kg), or 4-aminopyridine (1 mg/kg). Taxol was administered as one dose immediately after injury and two additional doses on days 14 and 21. Methylprednisolone was given as a single injection immediately postinjury. Four-aminopyridine was administered on days 25, 26, and 27. A group of nine injured animals served as a control without any treatment. Evoked potentials were recorded before, during, and 4 weeks postinjury. Behavioral tests were measured to evaluate recovery of motor function. RESULTS: The taxol and methylprednisolone-treated animals demonstrated a significant improvement in comparison with the control group. No functional improvement was found at 1 mg/kg treatment of 4-aminopyridine in rats. CONCLUSIONS: We conclude that taxol and methylprednisolone given shortly after the compression injury improve functional outcome after an incomplete spinal cord injury.

Radiofrequency as a lesioning model in experimental spinal cord injury.

Many models have been developed to study spinal cord injury (SCI), such as cryogenic lesioning, hot water injury, scalpel lesioning, compressive trauma using clips, electromechanical devices, extradural cuffs, and weight-drop techniques. In this study, the radiofrequency (RF) lesion was used for inducing an experimental SCI in cats. The neuropathology was correlated with the MRI. In this model, 4 cats were injured at the thoracic spinal cord (T11-T12) with a lesion of 65 degrees C for 1 min using a micromanipulated penetrating RF electrode. The MRI of the lesions after 2, 3, 5, and 6 weeks post-injury as well as the correlative histological changes were obtained. The RF-induced lesion was discrete with little spreading across the spinal cord. There was a good correlation between the histopathology findings and the MRI. We conclude that experimental RF lesioning of the spinal cord can produce a consistent lesion with predictable histopathological changes in experimental animals. A 65 degree C injury for 1 min induced a clinical picture of an incomplete SCI. The RF lesioning should be considered as a new model to study SCI, particularly those with a penetrating component.

Neurophysiological evidence of spared upper motor neurons after spinal cord injury.

Fourteen cats were subjected to a moderate (100 gm-cm; n = 7) or a severe (600 gm-cm; n = 7) spinal cord injury at the C4-C5 level using a weight drop technique. Somatosensory evoked potentials (SSEPs) were recorded after stimulation of the median nerve in the forearm. The SSEPs were measured in each animal before and after the injury. Motor evoked potentials (MEPs) were recorded from forearm extensor muscles after transcranial magnetic stimulation of the motor cortex. The SSEPs and The MEPs were measured in each animal before and after the injury under ketamine-based anesthesia. After the moderate injury (n = 7), 83% of the animals (6/7) maintained the SSEPs and 100% (7/7) maintained the MEPs. Postoperatively, only one animal who lost the SSEPs post-injury became tetraplegic. The remainder were neurologically intact. In the severely injured animals (n = 7), 5/7 of animals lost SSEPs and subsequently became tetraplegic. The MEPS were maintained in 3/5 (60%) of these tetraplegic animals. Two of seven animals (40%) in this group did not lose SSEPs or MEPs and recovered with no clinical deficit. Our data show a good correlation between the presence of SSEPs and functional recovery in the injured groups. The presence of MEPs in 3/5 (60%) of the tetraplegic animals may imply the existence of functionally active motor fibers after severe spinal trauma.

Origin of muscle action potentials evoked by transcranial magnetic stimulation in cats.

We studied the effects of transcranial magnetic stimulation on ipsilateral and contralateral forelimb extensor muscles in anesthetized cats. A magnetic stimulator, operating at 100% intensity, was used through a circular coil, which was placed tangentially over the midline scalp. Bilateral activation of extensor muscles was readily obtained in all animals. The onset latencies were 7.3 +/- 1.1 and 7.07 +/- 0.8 msec for the contralateral and ipsilateral muscles, respectively. The amplitude of muscle response was unstable in magnitude, nevertheless, it did not show any significant difference between the two sides. The latency of response for ipsilateral and contralateral muscles was similar, which suggests simultaneous activation of motor pathways servicing forelimb muscles. Lesioning or ablation of the motor cortex and decerebration at mid-colliculi level did not abolish the evoked responses elicited at high intensity magnetic stimulation. Stereotactic electrical stimulation of the vestibular nuclei complex was performed, and satisfactory ipsilateral motor responses were obtained. Subsequently, a stereotactic radiofrequency lesion was made at the vestibular nuclei complex, with morphological confirmation. After this lesion, the motor evoked potentials (MEPs) were significantly diminished in amplitude. This finding strongly suggests that the generator of the MEPs resides in the brainstem, mainly at the vestibular nuclei complex.

Effect of 4-aminopyridine in acute spinal cord injury.

BACKGROUND: The demyelination process has been proven to be an important factor contributing to long-term sensory and motor impairments after spinal cord injury (SCI). The loss of myelin promotes exposure of K+ channels in internodal region of the damaged myelinated axons leading to K+ efflux into the neurons with subsequent blockage of action potentials. The potassium channel blocker 4-aminopyridine (4-AP) has been effective in restoring some sensory and motor impairment in incomplete SCI patients. The effect of this compound given immediately after an acute injury is not known. The objective of this study was to determine if blockage of K+ ions efflux immediately after an acute SCI would improve neuronal conduction in this model of injury. METHODS: Cortical somatosensory evoked potentials (SSEPs) were recorded before and after a weight-induced compression injury of 120 grams, and were monitored up to 5 hours postinjury. A randomized treatment was initiated with administration of either vehicle or 4-AP. All 4-AP treatments were given as intravenous bolus injections of 1.0, 0.5, and 0.3 mg/kg at 1, 2, and 3 hours after the trauma. RESULTS: The SSEPs were abolished immediately after the injury in all control and treated animals. Both groups showed spontaneous recovery of the SSEPs at the rate of 44.5% for the 4-AP treated and nontreated groups at the second hour postinjury. This recovery rate remained the same for both groups at the end of the experiments. CONCLUSIONS: Based on the recovery of the SSEPs, our data indicate that early administration of 4-AP lacks any beneficial effect on axonal function during acute stage of spinal cord injury.

The child with a mass on its head: diagnostic and surgical strategies.

A series of 65 pediatric patients with scalp or calvarial masses is reported on. The majority of children presented with a disfiguring or painful mass on the head. Clinical findings suggested the correct diagnosis in 39/65 cases, skull radiographs in 46/65, and CT in 49/65. Taking the combined results of clinical and radiological studies, 54/65 of the lesions were accurately diagnosed. Tumor excision was curative in 43 of 48 patients who were operated on. Most scalp and calvarial neoplasms were benign; only 5/65 children harboured a malignant lesion. There was no mortality related to surgery in the series. Surgical intervention seems to be indicated in most cases, both for diagnosis and for treatment.

Bilateral brain abscesses complicating the use of Crutchfield tongs.

The case of a 4-year-old girl who developed bilateral brain abscesses complicating skull traction is reported. Crutchfield tongs were used to reduce a fracture dislocation at C2-3. Presenting symptoms consisted of headaches and focal seizures. Surgical treatment and antibiotics using serial CT led to a satisfactory outcome. This is the first reported case of this complication in a child. The current literature is reviewed.

Intracranial tumor biopsy--CT-guided stereotactic surgery.

A modification of Gildenberg's technique for brain tumor biopsy is described. Marking the light beam of the gantry on the scalp with a pencil, when the lesion appears on the screen, no ScoutView is necessary. With radiopaque marks on the drawn lines, the levels of the slice are transferred to a lateral conventional X-ray, for calculation of the 'Z' coordinate. 'X' and 'Y' coordinates are determined on the CT scanner.