Jacques Caemaert

Long-term amygdalohippocampal stimulation for refractory temporal lobe epilepsy.

Short‐term deep brain stimulation (DBS) recently has been shown to be efficacious in refractory temporal lobe epilepsy. We (1) evaluated long‐term DBS in medial temporal lobe structures in patients with normal magnetic resonance imaging (MRI) findings and (2) investigated the use of chronic DBS electrodes for the localization of the ictal onset zone before DBS. In three patients with complex partial seizures (CPSs), DBS electrodes were implanted in the amygdalohippocampal region to identify and subsequently stimulate the ictal onset zone. CPSs were compared before and after chronic DBS. Side effects were carefully monitored. DBS electrodes yielded high‐quality electroencephalogram recordings showing unilateral seizure onset in medial temporal lobe structures. For all patients, unilateral amygdalohippocampal stimulation was performed. After a mean follow‐up of 5 months (range, 3–6 months), all patients had a greater than 50% reduction in seizure frequency. In two patients, antiepileptic drugs could be tapered. None of the patients reported side effects. This open study demonstrates the feasibility of consecutive electroencephalographic recordings and DBS in medial temporal lobe structures using DBS electrodes. These results prompt further studies in a larger patient population to establish the efficacy and safety of chronic DBS as an alternative treatment for refractory temporal lobe epilepsy.

Deep Brain Stimulation in Patients with Refractory Temporal Lobe Epilepsy

Summary:u2002 Purpose: This pilot study prospectively evaluated the efficacy of long‐term deep brain stimulation (DBS) in medial temporal lobe (MTL) structures in patients with MTL epilepsy.

Endoscopic treatment of suprasellar arachnoid cysts

SummaryFour cases of large suprasellar arachnoid cysts in children are described. The authors propose a large fenestration into the lateral ventricles and into the basal cisterns as the treatment of choice. A specific multipurpose cerebral endoscope has been designed by the first author. The endoscopic technique with different instruments and with the use of a laser is illustrated. Results and complications are discussed.

Vagus nerve stimulation for refractory epilepsy

Left-sided vagus nerve stimulation (VNS) is a relatively new and efficacious neurophysiological treatment for patients with refractory epilepsy who were rejected for resective epilepsy surgery or who have had insufficient benefit from such a treatment. Animal experiments have shown that electrical stimulation of the vagus nerve can reduce the occurrence and duration of electrically and chemically induced seizures. The precise mechanism of action remains unclear. In 1988 the first vagus nerve stimulator was implanted in humans. Currently more than 7500 patients have been implanted world-wide. Randomized controlled clinical studies have shown a more than 50% reduction in seizure frequency in one third of the patients. Results on long-term treatment indicate that VNS remains effective over time and a trend towards improved seizure control with longer use of VNS was observed. VNS seems equally efficient in children. Hoarseness or voice change during stimulation are the most common side effects. VNS requires a substantial financial investment. Cost-efficacy studies have shown that these costs can easily be payed back by savings in epilepsy related direct medical costs in patients treated with VNS.

Direct Medical Costs of Refractory Epilepsy Incurred by Three Different Treatment Modalities: A Prospective Assessment

Summary: u2002Purpose: More than 20% of epilepsy patients have refractory seizures. Treatment options for these patients include continued polytherapy with/without novel antiepileptic drugs (AEDs), epilepsy surgery (ES), or vagus nerve stimulation (VNS). The purpose of this study was prospectively to compare epilepsy‐related direct medical costs (ERDMCs) incurred by these different treatment modalities.

Lateralized effects of subthalamic nucleus stimulation on different aspects of speech in Parkinson’s disease

In this report, we have analyzed the effects of left and right STN stimulation separately on different aspects of speech. Significant differences were found between left and right stimulation. It appears that selective left-sided stimulation has a profoundly negative effect on prosody, articulation and hence intelligibility. Right-sided stimulation does not display this side-effect. There is no significant difference in speech characteristics between bilateral stimulation on and off. We suggest that a balanced tuning of bilateral basal ganglia networks is necessary for speech, and that the left circuit is probably dominant.

Symptomatic Pineal Cysts: Clinical Manifestations and Management

Summary.u2003Between 1991 and 2000, seven patients presented with symptomatic pineal cysts at our hospital (6 females, 1 male). Average age was 22 years (range 4–33 years). Headache was present in 6 patients, who were subsequently operated on. A scotoma and a transient inferior visual field deficit were minor signs in two patients respectively. A Parinaud syndrome with vertical gaze paralysis was found in none. In one child, paroxysmal pupillary dilatations and contractions (`springing pupils) constituted the only signs and a conservative policy was adopted. Four patients presented with hydrocephalus and were treated by an endoscopic resection of their pineal cysts (one stereotactically, three free-hand). Two other patients presented with a prolonged history of symptoms and signs: headache alone in one, headache with discrete neurological deficits in the other. Ventricles in these two patients were not dilated and therefore an open cyst resection by infratentorial supracerebellar approach was performed. Average follow-up in the six “operated” patients was 29 months (range 12–108 months). All four patients treated by endoscopy, are symptom-free at follow-up, whereas the two who were approached by open surgery, are not. Clinical presentation, radiological evaluation and treatment modalities of pineal cysts are discussed and compared with experiences reported in the literature. It is concluded that pineal cysts in the presence of obstructive hydrocephalus are a clear indication for endoscopy with a rigid endoscope.

Spinal cord stimulation in chronic pain: evaluation of results, complications, and technical considerations in sixty-nine patients

Sixty-nine patients undergoing spinal cord stimulation (SCS) were studied for a period of up to 8 years. Indications, implantation techniques, and stimulation systems are presented in this article. Pain-suppressor effects of SCS are reviewed, assessing the clinical efficacy over time as well as complications with the stimulation device. Immediately following implantation, inadequate pain relief was noted in 20% of the patients. Decrease of the efficacy of pain alleveation occurs during the first 3 years after implantation. Most failures are noted in patients presenting with failed back surgery. This study also demonstrates that SCS systems should offer the capability of both monopolar and bipolar stimulation modes by the use of multipolar electrodes.

Diagnostic and therapeutic stereotactic cerebral endoscopy

SummaryModern neuro-imaging caused a renewed interest in endoscopic techniques. Several indications for stereotactic endoscopy are illustrated. A prototype of a new four channel endoscope is used. Lesions in the posterior part of the third ventricle and even the fourth ventricle are reachable for biopsy. Cystic intra-or paraventricular lesions can be approached stereotactically and treated. Continuous rinsing is mandatory to preserve a clear vision.

Endoscopic Diagnosis and Treatment of Para- and Intra-Ventricular Cystic Lesions

Different cystic lesions can be located in or around the ventricular system, eventually causing hydrocephalus. Twenty-one patients are described where endoscopic intervention, mainly large fenestration towards the ventricular cavity, has been performed. This treatment can sometimes replace open surgery or extracranial shunting. Most rewarding are the arachnoid and ependymal intra- and paraventricular cysts. With careful and adequate endoscopic technique this procedure is safe and much less invasive than other methods described.