Biomedical subjects

Antonio De Salles

Publications and source records attributed to Antonio De Salles.

5 recordsLinked to original sources

PubMed2006

Stereotactic radiosurgery of the rete mirabile in swine: a longitudinal study of histopathological changes.

OBJECTIVE: Stereotactic radiosurgery is an established, effective treatment for brain arteriovenous malformations. The mechanisms of vessel occlusion in arteriovenous malformations has not been extensively evaluated. To better understand these mechanisms, we report histopathological changes in the swine rete mirabile after stereotactic radiosurgery. METHODS: Thirty-five swine were used, 15 as nonradiated controls and 20 as radiated. Two in the control group and five in the radiated group were sacrificed before the study endpoint. Tissue was obtained from 13 nonradiated (4 at 3 mo, 5 at 6 mo, 4 at 9 mo) and 15 radiated swine (2 at 3 mo, 3 at 6 mo, 10 at 9 mo) for histological, immunohistochemical, and morphometric analysis. RESULTS: Radiated vessels showed increasing intimal hyperplasia over the follow-up period. Histometrical analysis confirmed this with evidence of progressive luminal narrowing over the follow-up period. Immunohistochemical analysis showed intimal cells to be proliferating smooth muscle cells with surrounding extracellular collagen Type IV. Adventitial fibrosis composed of collagen Type IV was also seen with smooth muscle cells interspersed within the collagen matrix. The nonradiated animals showed no intimal hyperplasia or change in the appearance or size of the vessels over the same follow-up period. Adventitial fibrosis was minimal in the nonradiated animals. CONCLUSION: The vessels show an intimal response to radiation with progressive occlusion caused by migrating, proliferating smooth muscle cells, a likely source of the extracellular collagen in the intima. Cytokine mediated pathways likely produce these morphological changes. Future studies will be directed toward elucidating these underlying molecular mechanisms.

Animals↗

PubMed2004

Linear accelerator thalamotomy.

BACKGROUND: The capability of performing functional radiosurgery lesions in the brain using a dedicated linear accelerator (LINAC) have not yet been demonstrated. This study evaluates modern LINAC technology for the creation of a sharp, small and functionally eloquent lesion in the thalamus. METHODS: Three patients underwent thalamotomy using a dedicated linear accelerator to radiosurgery, 2 females and 1 male, ages were 52, 53, and 73 years. Two patients presented with unilateral poststroke central pain and 1 with unilateral upper extremity pain secondary to metastatic infiltration of the brachial plexus. Maximal doses varied from 150 to 200 Gy, delivered by a 5-mm diameter collimator and 5 to 8 noncoplanar arcs evenly distributed. RESULTS: All patients gained substantial relief of their pain. They were able to reduce their medications and improve their activity levels. The patient with end-stage metastatic disease died of his malignancy 2 weeks after the treatment. One patient presented with recurrence of the pain 4 months after the treatment. No clinical complications were noticed. CONCLUSIONS: A dedicated linear accelerator is able to perform a precise and circumscribed lesion in the thalamus for pain control. Moreover, it proved to be safe, because no complications were observed. For patients using chronic anticoagulant therapy or with severe disabilities caused by cardiac, pulmonary or malignant diseases, this technique represents an alternative of treatment to radiofrequency thalamotomy.

Aged↗

PubMed2003

The impact of thalamic stimulation on activities of daily living for essential tremor.

BACKGROUND: Deep Brain Stimulation (DBS) of the ventro-intermedius nucleus of the thalamus is the treatment of choice for drug-refractory essential tremor (ET). This study evaluated the effectiveness of thalamic stimulation in improving the patient's quality of life through activities of daily living. METHODS: Sixteen ET patients completed a health questionnaire, the "Tremor Activities of Daily Living Scale" (TADLS) measured by the patient, a 10-item subset of the TADLS measured by the clinician, and the Fahn-Tolosa-Marin tremor rating scale (TRS). Each patient was evaluated with the stimulator on and off with the average evaluation occurring 13 months after surgery. Additionally, improvements on the TADLS were compared to electrode positioning on the axial plane and stimulation parameters. RESULTS: There was a 44.0% improvement in the patient-rated TADLS, a 45.2% improvement in the clinician-rated TADLS, and a 33.9% improvement in the TRS. The average electrode location was 5.65 mm anterior to the posterior commissure (AC-PC), 13.4 mm lateral from the midline, and 2.0 mm below the AC-PC line. The average stimulation parameters were 2.74 Volts, 160 Hertz, and 119 microsec. There was no correlation between improvements on the TADLS, electrode location, and stimulation parameters. Of the 16 patients, 10 patients would repeat the surgery, two were unsure, and four would not repeat the surgery. CONCLUSIONS: Tremor is significantly controlled with DBS and activities of daily living are highly correlated with patient satisfaction. The degree of improvement in the four patients who would not repeat the surgery was outweighed by the negative factors associated with the surgery.

Activities of Daily Living↗

PubMed2003

Prospective study of stereotactic radiosurgery without whole brain radiotherapy in patients with four or less brain metastases: incidence of intracranial progression and salvage radiotherapy.

This prospective study was conducted to evaluate the treatment outcome after stereotactic radiosurgery (SRS) alone with special attention to its influence on intracranial freedom from progression (FFP), local control, time to whole brain radiotherapy (WBRT), and survival. Forty-one patients with brain metastases who met the inclusion criteria were enrolled in this prospective cohort and treated by SRS alone between January 1998 and September 2001. The overall local control rate was 76%. The one year actuarial intracranial FFP was 33%. Ten patients (24%) had relapse at treated site. Twenty-three patients (56%) had intracranial progression with a median time of 4.25 months (1-24.6). Salvage radiotherapy was given in 21 patients (51%). Only 12 (29%) patients required WBRT with the median time to WBRT after SRS of 4.85 months. Nine patients (22%) underwent additional SRS at the median time of 5 months after the first procedure. The median survival was 10 months. At the time of follow up, 16 patients (39%) were still alive with a range of 6-31 months. This prospective study suggests that the omission of WBRT in the initial treatment of patients with SRS for four or less brain metastases may allow up to 70% of patients to avoid WBRT.

Adult↗

PubMedDate not supplied

Analysis of probabilistic classification learning in patients with Parkinson's disease before and after pallidotomy surgery.

This study examined the characteristics of probabilistic classification learning, a form of implicit learning previously shown to be impaired in patients with basal ganglia dysfunction (e.g., Parkinson's disease). In this task, subjects learn to predict the weather using associations that are formed gradually across many trials, because of the probabilistic nature of the cue-outcome relationships. Patients with Parkinson's disease, both before and after pallidotomy, and age-matched control subjects, exhibited evidence of probabilistic classification learning across 100 training trials. However, pallidotomy appears to hinder the learning of associations most implicit in nature (i.e., weakly associated cues). Although subjects were most sensitive to single-cue associations when learning the task, there is evidence that cue combinations contribute significantly to probability learning. The utility of multiple dependent measures is discussed.

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