Sharif Digital Repository

Parkinson’s disease (PD) is a progressive debilitating neurological disorder that causes motor and cognitive impairment. Administration of dopaminergic medication (Levodopa) has been reported to be effective in attenuating the excessive pathological synchronization in basal ganglia. However, long term levodopa therapy has its pitfalls. High frequency deep brain stimulation (DBS) has been suggested as an effective alternative for reducing motor symptoms in PD. In this method, distinct brain regions involved in the pathophysiology of the disease are stimulated electrically at high frequencies (i.e. at 130 Hz). While several studies have been carried out on the effects of DBS and its clinical... 

Parkinson's disease is a degenerative disorder of the central nervous system. The motor symptoms of Parkinson's disease result from the death of dopamine-generating cells in the substantia nigra. The cause of this cell death is unknown. Early in the course of the disease, the most obvious symptoms are movement-related. Some of the symptoms are: shaking, rigidity, slowness of movement and difficulty with walking and gait. Modern treatments are effective at managing the early motor symptoms of the disease, mainly through the use of levodopa and dopamine agonists. As the disease progresses these drugs eventually become ineffective and produce a complication called dyskinesia, marked by... 

Recent studies of brain activities indicate that Phase-Amplitude Coupling (PAC) between several regions of the brain, are meaningfully related to Parkinson’s Disease. In this research, we have studied PAC as a statistical measure in Parkinsonian patients’ brains while Deep Brain Stimulation treatment with different stimulation frequencies are being applied. In order to do so, we have investigated patients’ brain signals, and estimated PAC between regions of interest; afterwards, by using the estimated PAC values, we have found significant effects of the treatments on parkinsonian brains; furthermore, two treatments that are using 130 Hz and 340 Hz stimuli signals are compared. In this...