Nesrin Helvaci Yilmaz

The Brain Protective Effect of rTMS (Repetitive Transcranial Magnetic Stimulation) in Depression: A Mini-Review in Animal Studies.

There are rapidly replicating human data suggesting the therapeutic and neurorestorative role of repetitive transcranial magnetic stimulation (rTMS) in clinical depression. However there are only limited experimental studies in the literature and the neurobiological mechanisms of the technique are still unclear. Studies have suggested that modulating of either excitatory or inhibitory neural circuitry may be responsible for the mechanism of action of rTMS while it is still unclear whether rTMS exerts a neuroprotective effect. In the light of these findings, we aimed to review the neuroprotective effect of rTMS in animal models of depression. We have shown that rTMS may exert significant neuroprotective effect through acting on the oxidative injury, stress hormones, dopamine and serotonin levels, Brain Derived Neurotrophic Factor expression, neuroinflamation and hippocampal cell proliferation.

Therapeutic Effects Of Rivastigmine And Alfa-Lipoic Acid Combination In The Charles Bonnet Syndrome: Electroencephalography Correlates.

BACKGROUND Charles Bonnet Syndrome (CBS) is a rare clinical condition which is characterized by complex hallucinations in visually impaired patients. The pathophysiology of this disorder remains largely unknown, and there is still no proven treatment for this disease. In our study, we aimed to investigate the neural activity through Electroencephalography (EEG) power and evaluate the effect of rivastigmine in combination with alpha-lipoic acid on hallucination in two CBS patients with diabetic retinopathy. METHODS EEG data was recorded with standard routine EEG protocols for both patients in our electrophysiological research laboratory (REMER Clinical Electrophysiology and Neuromodulation Research and Application Laboratory) with Brain Vision Recorder (Brainproduct, Munich, Germany). All spectral analyses were processed by BrainVision Analyzer 2 (Brainproduct, Munich, Germany, 2.0.4 Version) in 128 Hz sample rates and the EEG recording and analysis was performed before the administration of rivastigmine (4.5 mg/daily and five patch daily for the first and second patients, respectively) in combination with alpha-lipoic acid (600 mg/daily) for both patients while they were not hallucinated during the time period recordings. Based on our measurement protocol, we have compared the patients in the study group with the three control subjects who were found to be normal except of visual disturbances secondary to significant diabetic retinopathy. RESULTS Highest theta power values were found in right occipital and left temporo-parietal regions for first and second CBS patients, respectively. Additionally, power spectra were lower in two cases as compared to their control groups in the alpha band for all electrodes. We have also shown that acid rivastigmine in combination with alpha-lipoic exerted significant anti-hallucinatory efficiency. CONCLUSION Our present findings could support the hypothesis that increased activation of specific areas in the source monitoring system plays an important role in the pathogenesis of CBS. In addition, rivastigmine in combination with alpha-lipoic acid could be a new valuable option for CBS patients.

Cognitive Impairment in Parkinson’s Disease Is Reflected with Gradual Decrease of EEG Delta Responses during Auditory Discrimination

Parkinson’s disease (PD) is a neurodegenerative disease that is characterized by loss of dopaminergic neurons in the substantia nigra. Mild Cognitive impairment (MCI) and dementia may come along with the disease. New indicators are necessary for detecting patients that are likely to develop dementia. Electroencephalogram (EEG) Delta responses are one of the essential electrophysiological indicators that could show the cognitive decline. Many research in literature showed an increase of delta responses with the increased cognitive load. Furthermore, delta responses were decreased in MCI and Alzheimer disease in comparison to healthy controls during cognitive paradigms. There was no previous study that analyzed the delta responses in PD patients with cognitive deficits. The present study aims to fulfill this important gap. 32 patients with Parkinson’s disease (12 of them were without any cognitive deficits, 10 of them were PD with MCI, and 10 of them were PD with dementia) and 16 healthy subjects were included in the study. Auditory simple stimuli and Auditory Oddball Paradigms were applied. The maximum amplitudes of each subject’s delta response (0.5–3.5 Hz) in 0–600 ms were measured for each electrode and for each stimulation. There was a significant stimulation × group effect [F(df = 6,88) = 3,21; p < 0.015; ηp2 = 0.180], which showed that the difference between groups was specific to the stimulation. Patients with Parkinson’s disease (including PD without cognitive deficit, PD with MCI, and PD with dementia) had reduced delta responses than healthy controls upon presentation of target stimulation (p < 0.05, for all comparisons). On the other hand, this was not the case for non-target and simple auditory stimulation. Furthermore, delta responses gradually decrease according to the cognitive impairment in patients with PD. Conclusion: The results of the present study showed that cognitive decline in PD could be represented with decreased event related delta responses during cognitive stimulations. Furthermore, the present study once more strengthens the hypothesis that decrease of delta oscillatory responses could be the candidate of a general electrophysiological indicator for cognitive impairment.

Anti-Ri-associated paraneoplastic neurological syndrome: Initial symptom of breast cancer with HER2 overexpression and treatment by dual HER2 blockade

Paraneoplastic neurological syndrome is associated with anti-Ri antibodies, which are typically present with opsoclonus–myoclonus–ataxia. Human epidermal growth factor receptor 2 (HER2) overexpression is present in 15%–25% of breast cancer and is associated with poor prognosis. There are a few reports of paraneoplastic neurological syndrome associated with HER2-positive breast cancer in the literature, of which most are anti-Yo-associated paraneoplastic neurological syndrome. We present herein the case of a female patient with HER2-positive breast cancer who had atypical anti-Ri antibody associated with opsoclonus–myoclonus paraneoplastic neurological syndrome. Following the diagnosis of paraneoplastic syndrome, chemotherapy with dual HER2 blockade and immunomodulating treatment including intravenous immunoglobulin and oral prednisolone were administered. Although the patient was negative for serum anti-Ri antibodies, there was partial clinical improvement and her neurological deficit persisted. To our knowledge, this is the first case report of female patient with HER2-positive breast cancer who had atypical anti-Ri antibody associated with opsoclonus–myoclonus paraneoplastic neurological syndrome and treated with dual HER2 blockade.