Repetitive transcranial magnetic stimulation (rTMS) is a well known non-invasive brain stimulation procedure which is capable of inducing the expression of the hippocampal BDNF that has been already shown to exert significant neuroprotective and pro-cognitive effects in AD. However, it is nearly impossible directly to evaluate the BDNF expression in humans after rTMS application. Here we summarized the underlying mechanisms of the neuroprotective and procognitive effect of BDNF that can be induced through a region-specific rTMS approach. Additionally, we have also evaluated the role of Magnetic Resonance Spectroscopy in monitoring the BDNF response after rTMS application in Alzheimer's Disease. We have provided strong evidence that rTMS exerts significant neuroprotective and pro-cognitive effects through the expression of hippocampal BDNF. Furthermore, Magnetic Resonance Spectroscopy might play a critical role in monitoring the BDNF response after rTMS application in AD patients. Such a sophisticated approach might be able to enlighten us on the time-dependent cognitive and neuroprotective correlates of the rtMS application in AD patients.

The therapeutic approaches currently applied in Alzheimer's disease (AD) and similar neurodegenerative diseases are essentially based on pharmacological strategies. However, despite intensive research, the effectiveness of these treatments is limited to transient symptomatic effects, and they are still far from exhibiting a true therapeutic effect capable of altering prognosis. The lack of success of such pharmacotherapy-based protocols may be derived from the cases in the majority of trials being too advanced to benefit significantly in therapeutic terms at the clinical level. For neurodegenerative diseases, mild cognitive impairment (MCI) may be an early stage of the disease continuum, including Alzheimer's. Noninvasive brain stimulation (NIBS) techniques have been developed to modulate plasticity in the human cortex in the last few decades. NIBS techniques have made it possible to obtain unique findings concerning brain functions, and design novel approaches to treat various neurological and psychiatric conditions. In addition, its synaptic and cellular neurobiological effects, NIBS is an attractive treatment option in the early phases of neurodegenerative diseases, such as MCI, with its beneficial modifying effects on cellular neuroplasticity. However, there is still insufficient evidence about the potential positive clinical effects of NIBS on MCI. Furthermore, the huge variability of the clinical effects of NIBS limits its use. In this article, we reviewed the combinatory approach of NIBS with various neuroimaging and electrophysiological methods. Such methodologies may provide a new horizon to the path for personalized treatment, including a more individualized pathophysiology approach which might even define new specific targets for specific symptoms of neurodegenerations.

Charles Bonnet Syndrome (CBS) has been defined as complex visual hallucinations (CVH) due to visual loss. The underlying mechanism of CBS is not clear and the underlying pathophysiology of the visual hallucinations in CBS patients and pure visually impaired patients is still not clear. In our study, we have scanned three with eye disease and CBS (VH+) and three patients with eye disease without CBS (VH-) using FDG-PET. Our results showed underactivity in the pons and overactivity in primary right left visual cortex and inferior parietal cortex in VH- patients and underactivity in left Broca, left inf frontal primary visual cortex and anterior and posterior cingulate cortex in VH+ patients relative to the normative 18F-FDG PET data that was taken from the database consisting of 50 age-matched healthy adults without neuropsychiatric disorders. From this distributed pattern of activity changes, we conclude that the generation of visual hallucination in CBS is associated with bottom-up and top-down mechanism rather than the generally accepted visual deafferentation-related hyperexcitability theory.

AIM:To investigate the surgical value of MER recordings and improve surgical technique by demonstrating the consistency between preoperative radiological STN volume and intraoperative neurophysiological STN length. MATERIAL and METHODS:Sixty-one patients with PD were enrolled. The volumes of the STN were measured using magnetic resonance images 3-dimensional volume reconstructions of stereotactic magnetic resonance images. MER were performed in all patient and the maximal electrophysiologic length of the STN was recorded each patient. In the postoperative period, the permanent electrode was modeled and reconstructed in 3D, and the longest distance traveled in the STN was calculated. RESULTS:A total of 61 patients who underwent surgery between 2012-2022 were included in the study. Thirty-six (59%) of the patients were male, and 25 (41%) were female. A total of 122 STNs were performed with 166 electrodes. The most common end alignment used was center with 86. STN length averaged 4.9 mm (0-10.5 mm). The mean STN volume was 0.11 cm 3 . The STN Volume of men were significantly higher than women. The STN Length, Volume, and the target MER length showed a positive correlation significantly. CONCLUSION:With radiological advances, it is possible to better visualize the target points and define the boundaries better, and direct methods can be used more in making targeting plans. MER records obtained during surgery and STN dimensions in presurgical planning show compatibility, and it is seen that there may be differences between the right and left sides because of brain shifting. Although radiology is increasingly providing better support, electrophysiological recordings provides real-time information on the electrodes' locations and give the opportunity to surgical team choosing alternative target.

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