Matheus Schmidt Soares

Ultrastructural study of the filum terminale and its elastic fibers.

OBJECTIVE:The filum terminale (FT) is a fibrovascular band involved in the pathophysiology of tethered cord syndrome (TCS). Its morphological and ultrastructural properties remain largely unknown even though they are thought to play a role in the generation of TCS in adult patients with normal level conus medullaris. MATERIALS AND METHODS:Twenty fresh adult human cadavers had their fila measured and removed. Transversal and longitudinal sections of the proximal, middle, and distal thirds of FT were submitted to light microscopy analysis with four different techniques. Five fila were selected for longitudinal and transversal scanning electron microscopy analysis. RESULTS:The bulk of the FT is composed of 5- to 20-&mgr;m thick longitudinal bundles of Type 1 collagen separated by 3- to 10-&mgr;m intervals, although capillaries and other elements may be present. A delicate (0.05–1.5 &mgr;m) meshwork of predominantly Type 3 collagen transversal fibers connects these bundles. Abundant longitudinally oriented elastic and elaunin fibers are found inside collagen bundles. A complex tridimensional structure is evidenced on electron microscopy. CONCLUSION:The longitudinal arrangement of collagen bundles and the impressive amount of elastic and elaunin fibers should elicit considerable elastic properties to the FT. An altered elasticity mechanism has been proposed for TCS; further studies are needed with TCS patients to define whether the collagen structure, Type 1/Type 3 proportion, or elastic fiber content are altered, which could lead to new histopathological definitions of TCS, helping neurosurgeons in the difficult management of TCS patients with normal level conus medullaris.

Morbidity following sural nerve harvesting: A prospective study

OBJECTIVE To evaluate donor site morbidity following sural nerve harvesting, with special attention to the recovery of sensory loss. METHODS We prospectively followed 38 subjects who underwent sural nerve harvest, including two with bilateral nerve excision. Symptoms related to sural nerve excision were evaluated and demarcation of the area with reduced touch sensation was quantified. Assessments were performed periodically up to 1 year after surgery and the results of different sensory evaluations were compared. RESULTS A significant reduction of sensory deficit was identified between consecutive evaluations (p<0.05). Decreases of 26.85%, 20.69% and 24.29% were observed 3, 6 and 12 months after surgery, respectively. Shock-like pain (7.5%), stabbing pain (7.5%), and numbness (5%) were the most frequently reported symptoms. All symptoms were brief and resolved spontaneously 3-6 months after surgery. CONCLUSION Sural nerve harvest can be performed with acceptable morbidity. When present, symptoms resolve between the third and sixth month after surgery and a significant reduction of sensory loss in the area innervated by the sural nerve was observed during the first year of follow-up.

Psychosurgery for schizophrenia: history and perspectives

Following the early studies of Moniz and Lima, psychosurgery had considerable scientific credibility until the advent of modern antipsychotics in the mid 1950s. Thereafter, psychosurgery was almost abandoned in large medical centers as a common treatment for schizophrenia, although is still used for some affective and anxiety disorders. We reviewed relevant papers cited in the Medline/Index Medicus, Cochrane, and Scielo databases from 1930 to 2012. In our review of the literature, we show from recent studies that there are still many patients with schizophrenia who have serious deficits even after being treated with current noninvasive therapies. The value of psychosurgery remains controversial. There are no data available to support the use of stereotactic procedures for schizophrenia. Well designed controlled trials are needed to establish the effectiveness of psychosurgery in patients with schizophrenia.

Experimental model of intracranial hypertension with continuous multiparametric monitoring in swine

OBJECTIVE Intracranial hypertension (IH) develops in approximately 50% of all patients with severe traumatic brain injury (TBI). Therefore, it is very important to identify a suitable animal model to study and understand the pathophysiology of refractory IH to develop effective treatments. METHODS We describe a new experimental porcine model designed to simulate expansive brain hematoma causing IH. Under anesthesia, IH was simulated with a balloon insufflation. The IH variables were measured with intracranial pressure (ICP) parenchymal monitoring, epidural, cerebral oximetry, and transcranial Doppler (TCD). RESULTS None of the animals died during the experiment. The ICP epidural showed a slower rise compared with parenchymal ICP. We found a correlation between ICP and cerebral oximetry. CONCLUSION The model described here seems useful to understand some of the pathophysiological characteristics of acute IH.

Intramedullary spinal teratoma: a rare condition with a good outcome

Departament of Neurology, University of São Paulo Medical School, São Paulo SP, Brazil (FMUSP): Resident, Division of Child Neurology, FMUSP; Resident, Division of Neurosurgery, FMUSP; Associated Physician, Division of Child Neurology, FMUSP; Full Professor, Division of Child Neurology, FMUSP; Chief of Pediatric Neurosurgery Unit, Division of Neurosurgery, FMUSP; Full Professor, Division of Neurosurgery, FMUSP.

Evaluation of the Maintained Effect of 3% Hypertonic Saline Solution in an Animal Model of Intracranial Hypertension

Background Current clinical treatment methods for refractory intracranial hypertension include elevation of the decubitus, ventilation adjustment, and use of hypertonic solutions such as hypertonic saline and mannitol solutions. Previous studies have shown that hypertonic solutions are particularly effective. Although several concentrations of saline solution have been proposed, a 3% solution is the most widely used. The aim of this study was to evaluate the maintained efficacy of a 3% hypertonic saline solution in an experimental model of intracranial hypertension. Material/Methods A porcine model of reversible intracranial hypertension was created by inserting a balloon catheter into the brain parenchyma, which was inflated and deflated to simulate intracranial hypertension and its surgical correction. The experiment included 3 groups of animals (A, B, and C) with different balloon inflation volumes. In group B, balloons were inflated 2 times to simulate reexpansion. A 20 mL/kg bolus of 3% saline solution was infused using a pump 90 minutes after the start of balloon inflation, and the effects of intracranial pressure were evaluated 60 minutes after infusion. Results No increases outside of the normal range were observed in mean serum sodium concentrations (p=0.09). In addition, we identified no differences within each group in serum sodium levels measured during hypertonic saline infusion (p=0.21). No significant reductions in intracranial pressure were observed in any of the 3 groups. Conclusions Bolus infusion of 3% hypertonic saline solution with the aid of a pump does not significantly reduce intracranial pressure in an animal model of intracranial hypertension.

Occlusion of the anterior cerebral artery after head trauma

Intracranial arterial occlusion is rarely encountered in association with head injury. Only six cases of traumatic occlusion of the anterior cerebral artery (ACA) have previously been reported. In this paper, the authors describe a case of a posttraumatic occlusion of ACA. A 35-year-old male presented to the emergency room with severe head injury. Computed tomography (CT) scan displayed diffuse brain swelling with multiple skull fractures. Follow up CT scan showed extensive cerebral infarction in the territory of ACA. The patient underwent CT angiography that demonstrated occlusion of the ACA by a fracture of the anterior fossa. He died after 3 d. ACA traumatic occlusion is a rare condition, with poor prognosis. In this case, fracture was responsible for dissection and direct obstruction of the artery.

Classification and management of mild head trauma

Mild head trauma had been defined in patients with direct impact or deceleration effect admitted with a Glasgow Coma Scale score of 13–15. It is one of the most frequent causes of morbidity in emergency medicine. Although common, several controversies persist about its clinical management. In this paper, we describe the Brazilian guidelines for mild head trauma, based on a critical review of the relevant literature.

Delayed unilateral traumatic brain swelling in a child

Traumatic brain injury is a leading cause of morbidity and death in the pediatric population. In this study, we report a delayed unilateral traumatic brain swelling in a child with initial favorable evolution and sudden neurological deterioration after 4 days; highlighting clinical, physiopathological and radiological aspects of delayed unilateral brain swelling.