Biomedical subjects

C Dunoyer

Publications and source records attributed to C Dunoyer.

5 recordsLinked to original sources

PubMed2000

Epilepsy surgery in children with tuberous sclerosis complex: presurgical evaluation and outcome.

PURPOSE: Children with tuberous sclerosis complex (TSC) benefit from excisional surgery if seizures can be localized to a single tuber. We evaluated the role of noninvasive studies to localize the epileptogenic tuber/region (ET/R) and the outcome of focal resection. METHODS: We identified 21 children with TSC, ages 3 months to 15 years (mean 4.8 years). All had video-(electroencephalogram) EEG and magnetic resonance imaging (MRI) scans, and 18 also had ictal single photon emission-computed tomography (SPECT) studies. An ET/R was localized in 17 patients. Thirteen patients underwent resection guided by intraoperative electrocorticography (n = 7) or subdural monitoring (n = 6). RESULTS: Interictal EEG revealed a principal spike focus (PSF) that corresponded to the ET/R in 14 children. In seven, PSFs occurred in rhythmic runs. PSFs were not observed remote from the ET/R. Focal polymorphic slowing and attenuation occurred in the region of the PSF in 11 patients. Sixteen patients demonstrated an ictal focus corresponding to the ET/R. Ictal SPECT revealed focal hyperperfusion correlating with the ET/R in 10 patients. Although the MRIs in all children revealed multiple tubers, the ET/R corresponded to a large discrete tuber in 8 patients and a calcified tuber in 13 patients. Patchy calcified tubers were also seen elsewhere in six patients. At a mean follow-up of 26 months, 9 of the 13 children who underwent surgery were seizure-free, one had greater than 75% reduction in seizures, two were unchanged, and one was lost to follow-up. New seizures developed in one child from a contralateral tuber. CONCLUSIONS: Surgical resection of an ET/R alleviates seizures in most children with TSC and intractable epilepsy. The scalp EEG and MRI help define the ET/R and improve case selection when ictal SPECT is nonlocalizing.

Adolescent↗

PubMed2000

Intravenous valproate dosing in neonates.

The loading dosage of intravenous valproate required to achieve a desired serum concentration in neonates is not known. Two neonates with seizures received loading doses of intravenous valproate over 30 minutes. Serum valproate concentrations were measured 45 minutes and 3 hours after initiation of the infusion. Both neonates had received phenobarbital and phenytoin before the loading infusions. In the first patient, a loading dose of intravenous valproate of 10 mg/kg increased the 45-minute postinfusion serum valproate concentration to 41 microg/mL with a 3-hour postinfusion serum valproate concentration of 33 microg/mL. In the second patient, a loading dose of 25 mg/kg increased the 45-minute postinfusion serum valproic acid concentration to 100 microg/mL with a 3-hour postinfusion serum valproic acid concentration of 78 microg/mL. We found that each 1 mg/kg of intravenous valproate increased the 45-minute and 3-hour postinfusion serum valproic acid concentrations by approximately 4 microg/mL and 3 microg/mL, respectively. We suggest that these figures be used to calculate the desirable loading dose of intravenous valproate in neonates until larger studies are conducted. The volume of distribution and the serum clearance of valproate were approximately 0.245 L/kg and 25 mL/h/kg, respectively.

Anticonvulsants↗

PubMed1998

[Epilepsy centers: classification and basic requirements].

Over the last two decades the surgical treatment of epilepsies has become a commonly used and effective method for the treatment of intractable epilepsy. However, because of its wide use in various types of centers throughout the world the methodology involved varies significantly throughout the centers. With this article we propose the bases from which a multidisciplinary team of numerous centers can eventually develop an effective and acceptable international protocol for the surgical treatment of the epilepsies and the classifications of the centers.

Epilepsy↗

PubMedDate not supplied

[Epilepsy treatment by vagal stimulation].

INTRODUCTION: Vagal nerve stimulation is the latest therapeutic modality for the treatment of epilepsy. It consists of a lead implanted in the left vagal nerve which is connected to a subcutaneous stimulator implanted in the left axillary or pectorial region. DEVELOPMENT: The stimulator is programmed to intermittently stimulate the vagal nerve throughout the day and a magnet also allows the patient to control the stimulation from the outside. This treatment has been used in patients with intractable partial seizures who are not candidates for epilepsy surgery. The results reported have varied but in general the procedure appears promising with at least 50% of the implanted having over 50% improvement in their seizure frequency and many having complete control without significant side effects. CONCLUSION: Further review of the results are still needed to fully determine the true value of this treatment and to identify the subgroups of patients which will benefit the most.

Electric Stimulation↗

PubMedDate not supplied

[New techniques used to monitor cerebral function in the newborn].

INTRODUCTION: Continuous display four channels EEG monitoring and near infrared spectroscopy (NIRS) are relatively new and valuable techniques used for continuous brain monitoring in the neonatal period. Supporting the value of continuous display four channels EEG monitoring in the evaluation of neonates with paroxysmal motor events is a study recently conducted at Miami Children s Hospital. DEVELOPMENT: In this study 30 events were captures in 88 hours of simultaneous continuous display four channels EEG monitoring and continuous video EEG telemetry recording in five patients. Fourteen of the events were consider epileptic and 16 were considered non epileptic after evaluation of the continuous display four channels EEG monitoring printed epochs. RESULTS: The continuous video EEG telemetry confirmed the diagnosis for all the events. Several studies attest to the usefulness of NIRS in neonates and in older children with pathologies similar to those seeing in neonates. CONCLUSIONS: 1. NIRS is the best method to monitor regional cerebral oxygen saturation; 2. Regional cerebral oxygen saturation values are primarily those of the venous circulation in the subcortical white matter below the sensor; 3. Values of regional oxygen saturation should be considered not independently but only relative as a change over time; 4. Decreased regional cerebral oxygen saturation may be a sign of impending or established hypoxemia or hypotension, increased cerebral metabolic demands, or a cerebral oxygenation or perfusion problem that involve only brain, and 5. NIRS should be used in conjunction with arterial oxygen saturation and pressure monitoring (to detect hypoxemia and hypotension), with EEG to detect increased cerebral metabolic demands (electroencephalographic seizures) and with anterior cerebral artery Doppler ultrasound to detect perfusion (decreased flow velocity) and oxygenation (constant flow velocity) problems that involve only the brain.

Cerebrovascular Circulation↗