Lewis-Sumner syndrome: contribution of diffusion tensor imaging in its differential diagnosis.

Lewis-Sumner syndrome (LSS) is an atypical variant of chronic inflammatory demyelinating polyneuropathy characterized by an asymmetric sensory-motor neuropathy with multifocal distribution. The diagnosis is typically clinical and electrophysiological but in some cases might be challenging causing a significant therapeutic delay. Diffusion tensor imaging (DTI) has been progressively used for the in vivo assessment of peripheral nerves integrity.

Time stability and connectivity analysis with an intracortical 96-channel microelectrode array inserted in human visual cortex.

Microstimulation via electrodes that penetrate the visual cortex creates visual perceptions called phosphenes. Besides providing electrical stimulation to induce perceptions, each electrode can be used to record the brain signals from the cortex region under the electrode which contains brain state information. Since the future visual prosthesis interfaces will be implanted chronically in the visual cortex of blind people, it is important to study the long-term stability of the signals acquired from the electrodes.

Visual percepts evoked with an intracortical 96-channel microelectrode array inserted in human occipital cortex.

BACKGROUNDA long-held goal of vision therapy is to transfer information directly to the visual cortex of blind individuals, thereby restoring a rudimentary form of sight. However, no clinically available cortical visual prosthesis yet exists.METHODSWe implanted an intracortical microelectrode array consisting of 96 electrodes in the visual cortex of a 57-year-old person with complete blindness for a 6-month period.

Toward Long-Term Communication With the Brain in the Blind by Intracortical Stimulation: Challenges and Future Prospects.

The restoration of a useful visual sense in a profoundly blind person by direct electrical stimulation of the visual cortex has been a subject of study for many years. However, the field of cortically based sight restoration has made few advances in the last few decades, and many problems remain. In this context, the scientific and technological problems associated with safe and effective communication with the brain are very complex, and there are still many unresolved issues delaying its development.

When Playing Is a Problem: An Atypical Case of Alien Hand Syndrome in a Professional Pianist.

Alien hand syndrome (AHS) is a neurological illness characterized by limb movements which are carried out without being aware of it. Many patients describe these movements as aggressive and some perceive a strong feeling of estrangement and go so far as to deny ownership. The sense of body ownership is the perception that parts of one's body pertain to oneself, despite it is moving or not and if movement is intentional or unintentional.

Is diffusion tensor imaging useful in the assessment of the sciatic nerve and its pathologies? Our clinical experience.

Objective: To evaluate the usefulness of diffusion tensor imaging (DTI) in the clinical setting as a complementary tool to conventional MRI in the study and assessment of the sciatic nerve and its pathologies.

Methods: 17 patients diagnosed with different types of sciatic neuropathy and 10 healthy controls underwent a conventional MRI and a DTI study in a 3-T MR scanner (Achieva(®) 3-T X-Series; Philips Healthcare, Netherlands).

Results: In the control group, we were able to track and visualize the common sciatic nerve and its main branches from hip to foot.

Hearing colors: an example of brain plasticity.

Sensory substitution devices (SSDs) are providing new ways for improving or replacing sensory abilities that have been lost due to disease or injury, and at the same time offer unprecedented opportunities to address how the nervous system could lead to an augmentation of its capacities. In this work we have evaluated a color-blind subject using a new visual-to-auditory SSD device called "Eyeborg", that allows colors to be perceived as sounds. We used a combination of neuroimaging techniques including Functional Magnetic Resonance Imaging (fMRI), Diffusion Tensor Imaging (DTI) and proton Magnetic Resonance Spectroscopy ((1)H-MRS) to study potential brain plasticity in this subject.

Acute human brain responses to intracortical microelectrode arrays: challenges and future prospects.

The emerging field of neuroprosthetics is focused on the development of new therapeutic interventions that will be able to restore some lost neural function by selective electrical stimulation or by harnessing activity recorded from populations of neurons. As more and more patients benefit from these approaches, the interest in neural interfaces has grown significantly and a new generation of penetrating microelectrode arrays are providing unprecedented access to the neurons of the central nervous system (CNS). These microelectrodes have active tip dimensions that are similar in size to neurons and because they penetrate the nervous system, they provide selective access to these cells (within a few microns).

[Effect of lacosamide on the quality of life of patients with epilepsy].

Introduction: Epilepsy causes psychiatric disorders in 20-40% of patients impacting negatively on their quality of life. Lacosamide is a new antiepileptic as adjunctive therapy in partial seizures with or without generalization.

Aim: We conducted a study to assess the impact of lacosamide as to the quality of life of epileptic patients.

Proton magnetic resonance spectroscopy (1H-MRS) reveals the presence of elevated myo-inositol in the occipital cortex of blind subjects.

This paper is addressed to investigate whether proton magnetic resonance spectroscopy ((1)H-MRS) may provide the means to investigate changes associated to alterations of neural activity and sensory experience in the blind. We examined the relationships between different brain metabolite levels in 10 blind volunteers and 10 sighted subjects matched for age and gender. Adjusted levels of N-acetylaspartate (NAA), creatine (Cr), choline (Cho), glutamate/glutamine (Glx) and myo-inositol (mIno) in the occipital cortex region were quantified in the water-suppressed spectrum using the AMARES estimation algorithms.

An atypical presentation of visual hallucinatory experiences following prolonged blindness.

We report a patient with long-standing blindness experiencing both simple and complex visual hallucinations secondary to a cortical arteriovenous malformation (AVM). The hallucinations were located in the right visual field corresponding to the contra-lateral site of cortical damage. This case contributes to our understanding of neurophysiological mechanisms underlying visual hallucinations and ongoing research investigating the phenomenology of hallucinations with respect to the cause and localization of neural damage.