Biomedical subjects

Gordon Baltuch

Publications and source records attributed to Gordon Baltuch.

4 recordsLinked to original sources

PubMed2006

Deep brain stimulation in neurologic disorders.

Deep brain stimulation (DBS) is an effective surgical therapy for well-selected patients with medically intractable Parkinson's disease (PD) and essential tremor (ET). The purpose of this review is to describe the success of DBS in these two disorders and its promising application in dystonia, Tourette Syndrome (TS) and epilepsy. In the last 10 years, numerous short- and intermediate-term outcome studies have demonstrated significant relief to patients with PD and ET. A few long-term follow-up studies have also reported sustained benefits. When successful, DBS greatly reduces most of parkinsonian motor symptoms and drug-induced dyskinesia, and it frequently improves patients' ability to perform activities of daily living with less encumbrance from motor fluctuations. Quality of life is enhanced and many patients are able to significantly reduce the amount of antiparkinsonian medications required to still get good pharmacological benefit. Overall, adverse effects associated with DBS tend to be transient, although device-related and other postoperative complications do occur. DBS should be considered the surgical procedure of choice for patients who meet strict criteria with medically intractable PD, ET and selected cases of dystonia.

Clinical Trials as Topic↗

PubMed2006

Long-term effects of bilateral subthalamic nucleus stimulation on health-related quality of life in advanced Parkinson's disease.

We evaluated the long-term effects of subthalamic nucleus (STN) stimulation on health-related quality of life (HRQL) in patients with advanced Parkinson's disease (PD). STN stimulation improves motor function and decreases medication requirements in patients with advanced PD. The impact of STN stimulation on HRQL is less well established, especially beyond 1 year after surgery. We report HRQL outcomes for 18 patients with advanced PD. Patients were evaluated with the Parkinson's Disease Questionnaire-39 (PDQ-39), the Medical Outcome Study Short Form (SF-36), and the EuroQol visual analogue scale (VAS) before surgery, 6 months postoperatively, and at a long-term follow-up visit (mean, 35.9 months; range, 18-57 months after surgery). Preoperative scores on HRQL measures were compared to results obtained at short- and long-term follow-up evaluations. The VAS and all domains of the PDQ-39 except for cognition, communication, and social support showed marked improvements at 6 months after surgery. At the long-term follow-up, there were sustained improvements in the VAS (63% improvement; P = 0.0009) and in several domains of the PDQ-39 [mobility: 20%, P = 0.01; activities of daily living (ADL): 29%, P = 0.005; emotional well-being: 26%, P = 0.02; stigma: 43%, P = 0.003; and bodily discomfort: 35%, P = 0.007]. At the long-term evaluation, only the vitality domain of the SF-36 was significantly improved from baseline (16%; P = 0.01). In this selected group of patients, many of the short-term gains in HRQL persist beyond 18 months after STN implantation. Benefits in nonmotor aspects of HRQL such as bodily discomfort and stigma appear to be among the most durable.

Adult↗

PubMed2004

High-frequency oscillations and seizure generation in neocortical epilepsy.

Neocortical seizures are often poorly localized, explosive and widespread at onset, making them poorly amenable to epilepsy surgery in the absence of associated focal brain lesions. We describe, for the first time in an unselected group of patients with neocortical epilepsy, the finding that high-frequency (60-100 Hz) epileptiform oscillations are highly localized in the seizure onset zone, both before and temporally removed from seizure onset. These findings were observed in all six patients with neocortical epilepsy out of 23 consecutive patients implanted with intracranial electrodes for pre-surgical evaluation during the study period. The majority of seizures (62%) in these patients were anticipated by an increase in high-frequency activity in the 20 min prior to neocortical seizure onset. Contrary to observations in normal brain, high-frequency activity was strongly modulated by behavioural state, and was maximal during slow-wave sleep, which may explain the propensity for neocortical onset seizures to begin during sleep. These findings point to an important role for neuromodulatory circuits, probably involving the thalamus, in mechanisms underlying seizure generation in neocortical epilepsy. These findings demonstrate that high-frequency epileptiform oscillations may prove clinically useful in localizing the seizure onset zone in neocortical epilepsy, for identifying periods of increased probability of seizure onset, and in elucidating mechanisms underlying neocortical ictogenesis. Confirmation that prolonged bursts of high-frequency activity may predict focal onset neocortical seizures will require prospective validation on continuous, prolonged recordings in a larger number of patients. Importantly, the results show that the dynamic range utilized in current clinical practice for localization of epileptogenic brain largely ignores fundamental oscillations that are signatures of an epileptogenic brain. It may prove that many currently available clinical EEG systems and EEG analysis methods utilize a dynamic range that discards clinically important information.

Analysis of Variance↗

PubMed2004

Electrical stimulation of the anterior nucleus of the thalamus for the treatment of intractable epilepsy.

PURPOSE: Animal studies and sporadic case reports in human subjects have suggested that intermittent electrical stimulation of the anterior nucleus of the thalamus reduces seizure activity. We embarked on an open-label pilot study to determine initial safety and tolerability of bilateral stimulation of the anterior nucleus of the thalamus (ANT), to determine a range of appropriate stimulation parameters, and to begin to gather pilot efficacy data. METHODS: We report an open-label pilot study of intermittent electrical stimulation of the anterior nucleus of the thalamus in five patients (three men, two women; age range, 24-47 years), with follow-up between 6 and 36 months. All patients had intractable partial epilepsy. Four of the five patients also had secondarily generalized seizures. Stimulation was delivered by bilateral implantable, programmable devices by using an intermittent, relatively high-frequency protocol. Stimulation parameters were 100 cycles per second with charge-balanced alternating current; pulse width, 90 ms; and voltages ranging between 1.0 and 10.0 V. Seizure counts were monitored and compared with preimplantation baseline. RESULTS: Four of the five patients showed clinically and statistically significant improvement with respect to the severity of their seizures, specifically with respect to the frequency of secondarily generalized tonic-clonic seizures and complex partial seizures associated with falls. One patient showed a statistically significant reduction in total seizure frequency. No adverse events could clearly be attributed to stimulation. None of the patients could determine whether the stimulator was on or off at these parameters. CONCLUSIONS: Electrical stimulation of the ANT appears to be well tolerated. Preliminary evidence suggests clinical improvement in seizure control in this small group of intractable patients. Further controlled study of deep brain stimulation of the anterior nucleus is warranted.

Adult↗