surgical-training-for-implantation-neocortical-microelectrode-arrays

Surgical Training for the Implantation of Neocortical Microelectrode Arrays Using a Formaldehyde-fixed Human Cadaver Model

This protocol describes a procedure to assist surgeons in training for the implantation of microelectrode arrays into the neocortex of the human brain. ...

Geneva University Hospitals

The mechanism of ventricular dilation in normal-pressure hydrocephalus remains unclear. Numerical finite-element (FE) models of hydrocephalus have been developed to investigate the biomechanics of ventricular enlargement. However, previous linear poroelastic models have failed to reproduce the relatively larger dilation of the horns of the lateral ventricles. In this paper the authors instead elaborated on a nonlinear poroplastic FE model of the brain parenchyma and studied the influence of the introduction of these potentially more realistic mechanical behaviors on the prediction of the ventricular shape.

Nonlinear poroplastic model of ventricular dilation in hydrocephalus.

We report the case of a Menière's disease patient affected by normal pressure hydrocephalus (NPH) who presented a cerebrospinal fluid (CSF) pressure-dependent hearing impairment after shunting. This side-effect was not only reversible and reproducible but occurred at a high opening pressure when the valve setting was lowered by only 0.7 mmHg (10 mmH(2)O). This observation suggests that hearing in Menière's disease might be very sensitive to small reductions of intracranial pressure (ICP) and that these patients should be informed of this potential risk, which can compromise the efficacy of the shunt.

Extreme sensitivity of hearing to decreases of ICP in Menière's disease.

Corticotroph pituitary stone.

The neuropsychological results of temporal lobe epilepsy surgery are well reported in the literature. The aim of this study was to analyse the neuropsychological outcome in a consecutive series of patients with extra-temporal epilepsy.

Neuropsychological outcome after extra-temporal epilepsy surgery.

A 39-year old man came to our outpatient clinic with long history of unspecific symptoms and signs. Cerebral MRI showed herniation of the cerebellar tonsils of more than 1 cm below the foramen magnum and a triventricular hydrocephalus. A diagnosis of Chiari I malformation was retained. After an osteo-dural decompression of the posterior fossa, post-operative MRI revealed an aqueductal stenosis with triventricular hydrocephalus. An endoscopic-third- ventriculostomy showed an idiopathic stenosis of the right foramen of Monro. Residual symptoms and persistence of biventricular hydrocephalus justified a ventriculo-peritoneal shunt. Aqueductal and foramina of Monro stenosis can mimick a Chiari I malformation.

Hidden aqueductal stenosis associated to bilateral idiopathic foramina of Monro stenosis mimicking a Chiari I malformation? Case report.

It remains controversial whether interictal spikes are a surrogate of the seizure onset zone (SOZ). Electric source imaging (ESI) is an increasingly validated non-invasive approach for localising the epileptogenic focus in patients with drug-resistant epilepsy undergoing evaluation for surgery, using high-density scalp EEG and advanced source localisation algorithms that include the patient's own MRI. Here we investigate whether localisation of interictal spikes by ESI provides valuable information on the SOZ.

Electric source imaging of interictal activity accurately localises the seizure onset zone.

Idiopathic normal pressure hydrocephalus (iNPH) is very prevalent in aging, underdiagnosed, and represents a rare cause of reversible neurological condition. The clinical triad of iNPH - gait, cognitive and urinary symptoms - and its neuroradiological features (i.e. ventriculomegaly) are not specific and found a various neurodegenerative and/or vascular conditions. We present our iNPH standardized protocol at the Geneva University Hospitals involving a multispecialty team of behavioral neurologists, neurosurgeons, neuropsychologists, engineers, and physical therapists. Based on a pragmatic approach, the goal of this protocol is to improve the identification of older patients with iNPH from its mimics (i.e. vascular dementia or other parkinsonian syndromes).

Article	Year
Nonlinear poroplastic model of ventricular dilation in hydrocephalus. Journal of neurosurgery\| PubMed ID: 18590438	2008
Extreme sensitivity of hearing to decreases of ICP in Menière's disease. Acta neurochirurgica\| PubMed ID: 19224119	2009
Corticotroph pituitary stone. The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques\| PubMed ID: 22384503	2012
Neuropsychological outcome after extra-temporal epilepsy surgery. Acta neurochirurgica\| PubMed ID: 22581433	2012
Hidden aqueductal stenosis associated to bilateral idiopathic foramina of Monro stenosis mimicking a Chiari I malformation? Case report. Acta neurochirurgica\| PubMed ID: 22955871	2012
Electric source imaging of interictal activity accurately localises the seizure onset zone. Journal of neurology, neurosurgery, and psychiatry\| PubMed ID: 23899624	2014
A combined cognitive and gait quantification to identify normal pressure hydrocephalus from its mimics: The Geneva's protocol. Clinical neurology and neurosurgery\| PubMed ID: 28605723	2017

Shahan Momjian

Biography

JoVE Journal Publications

Other Publications