Utilization of neuronavigation in the influence on the visual cortex with transcranial magnetic stimulation (TMS)

The topic of my thesis I chose because of my interest in the fields psychiatry and neurology, mainly new possibilities for treatment and diagnosis of diseases and to a great extent due to the possibility of being part of a research project doc. George Horacek Prague Psychiatric Cente

Utilization of neuronavigation in the influence on the visual cortex with transcranial magnetic stimulation (TMS)

The topic of my thesis I chose because of my interest in the fields psychiatry and neurology, mainly new possibilities for treatment and diagnosis of diseases and to a great extent due to the possibility of being part of a research project doc. George Horacek Prague Psychiatric Cente

The Role of Anterior Nuclei of the Thalamus: a Subcortical Gate in Memory Processing. An Intracerebral Recording Study.

<p>Abstract</p> <p>Objective</p> <p>To study the involvement of the posterior medial cortex (PMC), the anterior nuclei of the thalamus (ANT), and the hippocampus in the processes of encoding and recognition during visual and verbal (auditory) memory tasks.</p> <p>Methods</p> <p>We studied intracerebral recordings in epilepsy-surgery candidates using depth electrodes implanted in the retrosplenial cingulate, precuneus, cuneus, lingual gyrus, and hippocampus and in patients with pharmacoresistent epilepsy who underwent deep brain stimulation (DBS) of the ANT with depth electrodes implanted bilaterally in the ANT. We recorded the event-related potentials (ERPs) evoked by visual and verbal memory encoding-recognition tasks.</p> <p>Results</p> <p>In the hippocampus, ERPs were elicited in the encoding and recognition phases in both visual and verbal modalities. In the PMC and ANT, ERPs were recorded in both the encoding and recognition visual tasks; in the verbal modality, they were recorded in the recognition task, but not in the encoding task. In the visual and verbal recognition tasks, the ERPs (P300-like potentials) in the ANT preceded the P300-like potentials in the hippocampus.</p> <p>Conclusions</p> <p>The PMC and the ANT are modality dependent in memory processing. ERPs are elicited by memory recognition, but they are not elicited by verbal encoding memory processing in the PMC and ANT. The PMC appears to be involved in higher-order top-down cognitive activities as well as in more basic, rather bottom-up activities. The ANT is a structure in the memory pathway that processes memory information before the hippocampus. We suggest that the ANT has a specific role in memory processes, especially memory recognition, and that memory disturbance should be considered in patients with ANT-DBS and in patients with ANT and PMC lesions. ANT is well positioned to serve as a subcortical gate for memory processing in cortical structures.</p> <p>Key words: event-related potentials (ERPs), P300 like potentials, memory, posterior medial cortex (PMC), hippocampus, stereoelectroencephalography (SEEG), deep brain stimulation (DBS), anterior nuclei of the thalamus (ANT)</p

The Role of Anterior Nuclei of the Thalamus: A Subcortical Gate in Memory Processing: An Intracerebral Recording Study.

To study the involvement of the anterior nuclei of the thalamus (ANT) as compared to the involvement of the hippocampus in the processes of encoding and recognition during visual and verbal memory tasks.We studied intracerebral recordings in patients with pharmacoresistent epilepsy who underwent deep brain stimulation (DBS) of the ANT with depth electrodes implanted bilaterally in the ANT and compared the results with epilepsy surgery candidates with depth electrodes implanted bilaterally in the hippocampus. We recorded the event-related potentials (ERPs) elicited by the visual and verbal memory encoding and recognition tasks.P300-like potentials were recorded in the hippocampus by visual and verbal memory encoding and recognition tasks and in the ANT by the visual encoding and visual and verbal recognition tasks. No significant ERPs were recorded during the verbal encoding task in the ANT. In the visual and verbal recognition tasks, the P300-like potentials in the ANT preceded the P300-like potentials in the hippocampus.The ANT is a structure in the memory pathway that processes memory information before the hippocampus. We suggest that the ANT has a specific role in memory processes, especially memory recognition, and that memory disturbance should be considered in patients with ANT-DBS and in patients with ANT lesions. ANT is well positioned to serve as a subcortical gate for memory processing in cortical structures

Visual recognition task in the ANT: N 115- P 150- N 200- P 250 and N700 complex (the mean from all thalamic contacts from all patients in bipolar montage during the recognition task).

<p>Arrows mark fast and slow ERP components N115, P150, N200, P250, and N700. The black curve indicates a new stimulus (new picture); red indicates a repeated stimulus during the recognition phase (old picture). On axis <i>x</i> is time (in s). The statistical significance to baseline is highlighted by black and red horizontal lines.</p

The main characteristics of patients with ANT and hippocampal electrodes.

<p>*F:female</p><p>**M:male</p><p>***DNET:Dysembryoplastic neuroepithelial tumor</p><p>****MQ:memory quotient</p><p>*****IQ: intelligence quotient</p><p>******ANT: anterior nuclei of the thalamus.</p><p>The main characteristics of patients with ANT and hippocampal electrodes.</p

P300-like potentials in the hippocampus and the thalamus (the mean from all hippocampal and thalamic contacts from all patients in bipolar montage during the encoding and the recognition task).

<p>The black curve indicates a new stimulus (new picture/word: NP/NW); red indicates a repeated stimulus during the recognition phase (old picture/word: OP, OW). The arrow shows the beginning of the P300-like potential (red for the repeated stimulus, black for the new one.) Axis <i>x</i> is time (in s); axis <i>y</i> is amplitude in μV. The statistical significance to baseline is highlighted by black and red horizontal lines. The significant difference between tasks in the hippocampus is highlighted by a black rectangle. Simultaneously the difference between tasks is drawn—DIFF.</p

P300-like potentials: latency of P300-like potentials recorded from all contacts from the hippocampus versus all contacts from the ANT, mean and standard deviation.

<p>OP/ OW: old picture/ word, NP/NW: new picture/word.</p><p>Statistical significance of differences between Hippocampus and ANT is in column Diff. Statistical significance of differences between the old and new pictures/words is in line of Diff NP vs. OP or Diff NW vs. OW. Significance of differences</p><p>P<0.001 ***</p><p>P<0.01 **</p><p>P<0.05 *</p><p>NS: non-significant.</p><p>P300-like potentials: latency of P300-like potentials recorded from all contacts from the hippocampus versus all contacts from the ANT, mean and standard deviation.</p

Epilepsy, cognition, and neuropsychiatry (epilepsy, brain, and mind, part 2)

Epilepsy is, of course, not one disease but rather a huge number of disorders that can present with seizures. In common, they all reflect brain dysfunction. Moreover, they can affect the mind and, of course, behavior. While animals too may suffer from epilepsy, as far as we know, the electrical discharges are less likely to affect the mind and behavior, which is not surprising. While the epileptic seizures themselves are episodic, the mental and behavioral changes continue, in many cases, interictally. The episodic mental and behavioral manifestations are more dramatic, while the interictal ones are easier to study with anatomical and functional studies. The following extended summaries complement those presented in Part 1