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J-G Villemure

Publications and source records attributed to J-G Villemure.

15 recordsLinked to original sources
PubMed2007

Third ventriculostomy vs ventriculoperitoneal shunt in pediatric obstructive hydrocephalus: results from a Swiss series and literature review.

INTRODUCTION: Few series compare endoscopic third ventriculostomies (ETV) and ventriculoperitoneal shunts (VPS). To avoid the complications after a shunt insertion, there is an increased tendency to perform a third ventriculostomy. We reviewed all pediatric patients operated in the French-speaking part of Switzerland for a newly diagnosed obstructive hydrocephalus since 1992 and compared the outcome of patients who benefited from ETV to the outcome of patients who benefited from VPS. There were 24 ETV and 31 VPS. DISCUSSION: At 5 years of follow-up, the failure rate of ETV was 26%, as compared to 42% for the VPS group. This trend is also found in the pediatric series published since 1990 (27 peer-reviewed articles analyzed). CONCLUSION: In accordance to this trend, although a statistical difference cannot be assessed, we believe that ETV should be the procedure of choice in pediatric obstructive hydrocephalus.

Adolescent↗
PubMed2006

Speech arrest with stimulation may not reliably predict language deficit after epilepsy surgery.

The authors present a patient in whom electrical cortical stimulation of the posterior temporal cortex induced speech arrest, comprehension deficits, and other language-related impairments. This area was ultimately resected because of persistence of a severe seizure disorder. No postoperative aphasia was observed despite the cortical stimulation results, and the patient is since seizure free. These findings question the well-established principle that corticography directly reflects local cortical functions in all patients.

Adult↗
PubMed2006

Electrophysiological characteristics of limbic and motor globus pallidus internus (GPI) neurons in two cases of Lesch-Nyhan syndrome.

OBJECTIVE: Lesch-Nyhan syndrome is a rare and debilitating condition characterized by dystonia and self-mutilating behavior. In order to shed light on the pathophysiology of dystonia, we report the pallidal electrophysiological activity recorded in two patients during deep brain stimulation surgery (DBS). METHODS: Microrecordings were performed on 162 neurons along four tracks aimed at the right and left anterior (limbic) and posterior (motor) globus pallidus internus (GPI). RESULTS: Regardless of the anesthetic agent used (propofol or sevoflurane), both patients showed similar neurons firing rates in the four regions studied, namely the limbic and motor portions of the globus pallidus externus (GPE) or GPI. In both patients, firing rates were similar in the GPE (12.2+/-1.8 Hz, N=38) and GPI (13.2+/-1.0 Hz, N=83) portions of the limbic track, while the motor GPE fired at a higher frequency (23.8+/-2.7 Hz, N=18) than the motor GPI (12.5+/-1.4 Hz, N=23). CONCLUSIONS: These results demonstrate that light propofol or sevoflurane anesthesia influences pallidal activity in a similar way. Electrophysiological recordings suggest that Lesch-Nyhan syndrome might be characterized by analogous firing frequencies in the limbic GPE and GPI while motor GPE would tend to fire at higher rate than the motor GPI. It is therefore tempting to suggest that the symptoms that are observed in Lesch-Nyhan syndrome might result from motor GPI inhibition. SIGNIFICANCE: This observation may confirm the Albin and Delong's model of the basal nuclei in hypokinetic and hyperkinetic disorders.

Child↗
PubMed2005

Early surgery for brainstem cavernomas.

BACKGROUND: The purpose was to review our experience with the surgical management of brainstem cavernomas (BSCs) and especially the impact of the surgical timing on the clinical outcome. METHOD: We retrospectively reviewed 22 patients harboring a BSC, who underwent 23 procedures. FINDINGS: Surgery was carried out during the early stage after the last haemorrhage, with a mean delay of 21.6 days (range 4-90 days). Sixteen procedures were performed after a first bleeding event while seven after multiple bleedings. Complete resection was achieved in 19 patients (86.4%). Early after surgery, 12 patients (52.2%) improved neurologically, 5 (21.7%) were stable and 6 (26.1%) worsened. New postoperative deficits were noted after 9 procedures (39.1%). Statistically significant factors for postoperative aggravation were: late surgery (P = 0.046) and multiple bleedings (P = 0.043). No patient operated on within the first 19 days after bleeding did worsen (n = 11), as opposed to 6 out of 12 who did when operated on later. After a mean follow-up of 44.9 months, 20 patients (90.9%) were improved, 1 patient (4.6%) was worse and 1 patient was lost to follow-up (4.6%), after reoperation for rebleeding of a previously completely resected cavernoma. Late morbidity was reduced to 8.6%. The mean Glasgow Outcome Scale (GOS) at the end of the follow-up period was 4.24, compared to a mean preoperative GOS of 3.22 (P<0.001). Complete neurological recovery of motor deficits, sensory disturbances, cranial nerves (CNs), internuclear ophtalmoplegia and cerebellar dysfunction were respectively 41.7%, 38.5%, 52.6%, 60.0% and 58.3%. Among the most affected CNs: CN 3, CN 5 and CN 7 were more prone to completely recover, respectively in 60.0%, 70.0% and 69.2%. CONCLUSIONS: Surgical removal of BSCs is feasible in experienced hands with acceptable morbidity and good outcome. Early surgery and single bleeding were associated with better surgical results.

Adolescent↗
PubMed2005

[Current treatment of Parkinson's disease: problems and controversies].

Treating patients with Parkinson's disease is not an easy task for the physician who is facing a disease well responsive to symptomatic therapy, yet escaping any curative approaches. In spite of the large therapeutic armamentarium available, many issues remained unsolved, as indications of a particular therapeutic agent are only loosely defined and evolving according to various parameters such as disease progression and severity, the profile of potentially serious adverse effects, the physician's level of expertise and patient's expectations. The growing experience acquired with subthalamic nucleus deep brain stimulation has shown that indications for such a surgery have to be cautiously examined. After initial therapeutic enthusiasm, we are now at a time of problems and controversies.

Antiparkinson Agents↗
PubMed2005

[Current epilepsy treatment in adults].

The prevalence of epilepsy is about 1%. Only two thirds of these patients respond satisfactorily to an antiepileptic drug (AED) treatment. New AED did not clearly improve this overall efficacy, but often show a better tolerability as compared to old AED. This may allow a more targeted choice, especially in some delicate clinical situations, such as for the treatment of women in childbearing age, or patients receiving other drugs with possible pharmacokinetic interactions. Invasive approaches should be considered early in the course of treatment-resistant epilepsy, and may offer a complete seizure remission in selected cases. On the background of recent acquisitions from the literature, the pros and cons of different treatment options are presented. This is followed by the discussion of some clinical relevant situations.

Adult↗
PubMed2005

Pathogenesis, diagnosis and treatment of Rasmussen encephalitis: a European consensus statement.

Rasmussen encephalitis (RE) is a rare but severe immune-mediated brain disorder leading to unilateral hemispheric atrophy, associated progressive neurological dysfunction and intractable seizures. Recent data on the pathogenesis of the disease, its clinical and paraclinical presentation, and therapeutic approaches are summarized. Based on these data, we propose formal diagnostic criteria and a therapeutic pathway for the management of RE patients.

Adolescent↗
PubMed2004

Suicide after successful deep brain stimulation for movement disorders.

The authors observed a high rate of suicide (6/140 patients, 4.3%) in a large cohort of patients with movement disorders treated with deep brain stimulation (DBS). Apparent risk factors included a previous history of severe depression and multiple successive DBS surgeries, whereas there was no relationship with the underlying condition, DBS target, electrical parameters, or modifications of treatment. Paradoxically, all patients experienced an excellent motor outcome following the procedure. The authors propose that patients at high risk for suicide should be excluded from DBS surgery.

Adult↗
PubMed2004

Subthalamic nucleus deep brain stimulation in Parkinson disease patients over age 70 years.

The effects of subthalamic nucleus deep brain stimulation were studied in 52 consecutive patients (13 over age 70, 15 under age 60, 24 age 60 to 70). All groups had improvement of motor fluctuations and dyskinesia. Patients over age 70 had worsening of Unified Parkinson's Disease Rating Scale motor scores on medication, despite less medication reduction. Their activities of daily living and axial subscores worsened, particularly in those with preoperative gait difficulties.

Age Factors↗
PubMed2003

Magnetic resonance artifact induced by the electrode Activa 3389: an in vitro and in vivo study.

BACKGROUND: The electrode Activa 3389 is widely implanted for deep brain stimulation (DBS) and MRI is often used to control the position of the electrode. However, induced distorsion artifacts may result in imprecise localization and may lead to misinterpretations of the clinical effects and mechanisms of DBS. METHODS: In vitro 3D MR study: the proximal and distal contacts of one electrode were spotted by two localizers. The maximal artifact height (MAH) and width (MAW: measured on distal contact), and the distances between the artifact and the localizers (proximal, distal and lateral) were measured on 2 transverse and sagittal MR sequences with 90 degrees rotation of frequency-encoded gradient and phase direction. In vivo 3D MR study: coronal and sagittal reconstructions along the main axis of the electrode were performed on 10 postoperative MR (20 electrodes) to measure MAH and MAW. A Student t test was used to compare in vitro and in vivo measurements. FINDINGS: In vitro study: A MAH of 10.35 mm (+/-0.23) and MAW of 3.6 mm (+/-0.2) were found. We measured symmetrical extensions of the artifact over the distal contact. In vivo study: A MAH of 10.36 mm (+/-0.44) and MAW of 3.56 mm (+/-0.30) were obtained. No significant different artifact dimensions were measured between in vitro and in vivo studies (p<0.0001). INTERPRETATION: Precise 3D localization of the electrode in implanted patients is provided by MR identification of the limits of the distal contact artifact. The position of the other contacts is deduced given the size of the contacts and the intercontact distance.

Artifacts↗
PubMed2003

How do parkinsonian signs return after discontinuation of subthalamic DBS?

OBJECTIVE: To study the reappearance of the clinical signs of PD when subthalamic nucleus (STN) deep brain stimulation (DBS) was turned off. METHOD: The authors studied 35 patients treated with STN DBS 6.7 +/- 3.3 months (mean +/- SD) after implantation. All were clinically improved. Twenty-four had not required any antiparkinsonian medication for many months and 11 were in "practically defined off" conditions when studied. Unified Parkinson's Disease Rating Scale (UPDRS) motor scores were assessed at baseline and 5, 15, 30, 60, 90, 120, 150, 180, and 240 minutes after switching off STN DBS. RESULTS: A sequential pattern of return of parkinsonian signs was observed, with a fast worsening of tremor within minutes, followed by a smoother, slower worsening of bradykinesia and rigidity over half an hour to an hour, and finally a slow and steady worsening of axial signs over 3 to 4 hours. Ninety percent of the UPDRS motor score worsening was reached after 2 hours. When switching STN DBS "on" again, all motor UPDRS subscores improved with a similar pattern, but faster than their rate of worsening, especially for axial signs. CONCLUSIONS: STN DBS may act by different mechanisms on the four major parkinsonian signs. At least 3 hours off STN DBS is needed to estimate the clinical effect of stimulation.

Disease Progression↗
PubMed2003

Non-obstructive hydrocephalus associated with intracranial schwannomas: hyperproteinorrhachia as an etiopathological factor?

BACKGROUND: This series illustrates the association of communicating hydrocephalus with intracranial non-obstructive schwannomas. This association has commonly been observed, however it has only been reported once previously. Moreover, in all the patients we present, hyperproteinorrhachia was a common denominator. This finding may therefore be the underlying mechanism for hydrocephalus. METHOD AND FINDINGS: Seven patients presenting with intracranial schwannomas along with non-obstructive hydrocephalus and hyperproteinorrhachia are reported. Six had a vestibular schwannoma and presented with a unilateral deafness and various degrees of gait disturbance, urinary incontinence and neuropsychological impairment. Due to their advanced ages, these patients underwent a ventriculo-peritoneal shunt, and their symptoms related to hydrocephalus resolved. One patient that suffered from hemifacial dysesthesia and memory deficits presented with a non-obstructive trigeminal schwannoma. In this case the tumour was removed and the hydrocephalus was consequently reversed, and the CSF protein content normalized. INTERPRETATION: The constant finding of hyperproteinorrhachia in all these patients suggests that a high CSF protein content may be the underlying cause of hydrocephalus through a speculative mechanism of decreased CSF resorption.

Adult↗
PubMed2002

Effect on mood of subthalamic DBS for Parkinson's disease: a consecutive series of 24 patients.

A series of 24 consecutive PD patients were prospectively studied prior to and within 6 months postoperatively for mood, motor, and cognitive status to investigate the effects on mood of subthalamic deep brain stimulation (DBS) in PD. In six patients (25%), mood state worsened significantly, and three were transiently suicidal despite clear motor improvement. Caregivers and patients should be educated about the potential impact of this neurosurgical procedure on mood.

Adult↗
PubMed2002

Subthalamic DBS replaces levodopa in Parkinson's disease: two-year follow-up.

BACKGROUND: Subthalamic nucleus (STN) deep brain stimulation (DBS) of patients with PD allows reduction of antiparkinsonian medication but has only a mild direct effect on dyskinesia. Since antiparkinsonian medication has short- and long-term effects that may prevent an estimate of the maximal possible impact of STN DBS, such medication was used at the lowest possible dosage after DBS implantation. OBJECTIVE: To study the maximal and long-term effects of STN DBS using the lowest dose of medication. METHODS: Twenty consecutive patients with PD with motor fluctuations and dyskinesia underwent bilateral implantation under stereotactic guidance, microrecording, and clinical control. All medications were stopped before implantation and reintroduced, at the lowest dosage needed, only if the postoperative motor score did not reach the baseline level. Unified PD Rating Scale (UPDRS) motor (subscale III) scores were measured at baseline and after 3, 6, 12, and 24 months. RESULTS: After 21 plus minus 8 months, the UPDRS III "off-medication" score was decreased by 45% and was similar to the preoperative UPDRS III "on" score. Overall, medication was reduced by 79%, being completely withdrawn in 10 patients. Fluctuations and dyskinesia showed an overall reduction of >90%, disappearing completely in patients without medication. These improvements were maintained for 2 years. CONCLUSIONS: These results show that STN DBS could replace levodopa and allowed all antiparkinsonian medication to be discontinued in 50% of patients with PD. Fluctuations and dyskinesia disappeared completely in these patients but persisted in those still on medication. These improvements were maintained for 2 years.

Aged↗