ABSTRACT
Excessive theta (θ) frequency oscillation and synchronization in the basal ganglia (BG) has been reported in elderly parkinsonian patients and animal models of levodopa (L-dopa)-induced dyskinesia (LID), particularly the θ oscillation recorded during periods when L-dopa is withdrawn (the off L-dopa state). To gain insight into processes underlying this activity, we explored the relationship between primary motor cortex (M1) oscillatory activity and BG output in LID. We recorded local field potentials in the substantia nigra pars reticulata (SNr) and M1 of awake, inattentive resting rats before and after L-dopa priming in Sham control, Parkinson disease model, and LID model groups. We found that chronic L-dopa increased θ synchronization and information flow between the SNr and M1 in off L-dopa state LID rats, with a SNr-to-M1 flow directionality. Compared with the on state, θ oscillational activity (θ synchronization and information flow) during the off state were more closely associated with abnormal involuntary movements. Our findings indicate that θ oscillation in M1 may be consequent to abnormal synchronous discharges in the BG and support the notion that M1 θ oscillation may participate in the induction of dyskinesia.
ABSTRACT
Objective:To explore the selection of surgical methods for different sites of symptomatic Rathke's cleft cyst (RCC) and the clinical efficacies of these patients.Methods:Forty-seven patients with symptomatic RCC, admitted to our hospital from January 2016 to December 2019, were chosen in our study; 21 patients with intrasellar symptomatic RCC accepted surgery via unilateral nasal approach at the right side, 19 patients with intra-suprasellar symptomatic RCC accepted surgery via bilateral nasal approach, 3 patients with suprasellar symptomatic RCC accepted endonasal transsphenoidal surgery under endoscope, and 4 patients with suprasellar symptomatic RCC accepted craniotomy via pterion approach. The clinical efficacies and complications of patients accepted different surgical methods were compared. All patients were followed up for 3-36 months to observe the recurrence.Results:The postoperative symptoms of the patients were effectively improved, including headache relief ratio of 27/31, vision loss improvement ratio of 5/5, high prolactin relief ratio of 11/13, pituitary function improvement ratio of 9/18. Complications occurred in 6 patients, presenting as diabetes insipidus. Four patients recurred during follow-up.Conclusion:Intrasellar and intra-suprasellar symptomatic RCC accepted surgery via endoscopic transnasal transsphenoidal approach are safe and effective; selection of surgical methods for suprasellar symptomatic RCC should be determined according to the sizes and growth directions of cysts.
ABSTRACT
Objective To investigate the mechanism of improvement of gait behavior in PD rat models by low frequency electrical stimulation of pedunculopontine tegmental nucleus (PPTN) by optogenetics method. Methods (1) Twenty-four healthy adult male SD rats were randomly divided into a sham-operated group 1, a lesion group 1 and a photoactivation group (n=8); normal saline was injected into the right medial frontal tract (MFB) of the sham-operated group 1; 6-hydroxydopamine (6-OHDA) was injected into the lesion group 1 and photoactivation group to induce PD models; two weeks after modeling, injection of adeno-associated virus hsynapsin-ChR2-mcherry into the right PPTN of the three groups was performed, and the photoactivation group received blue-ray stimulation by implanting optical fibers into the PPTN at the same time. (2) Twenty-four healthy adult male SD rats were randomly divided into a sham-operated group 2, a lesion group 2 and a photoinhibition group (n=8);normal saline was injected into right MFB of the sham-operated group 2; 6-OHDA was injected into the lesion group 2 and photoinhibition group to induce PD models; two weeks after modeling, injection of adeno-associated virus hsynapsin-NpHR-mcherry into the right PPTN of the three groups was performed, and the photoinhibition group received yellow-ray stimulation by implanting optical fibers into the PPTN at the same time. (3) Three weeks after injection of adeno-associated virus, Catwalk gait analysis was used to assess the behavioral ability of rats in each group. Results (1) As compared with the sham-operated group 1, lesion group 1 had significantly increased front claw spacing and back front claw spacing, and significantly decreased stride length and pressure of damaged lateral and contralateral limbs, and significantly decreased swing speed of contralateral limb (P<0.05); as compared with those in the lesion group 1, the front claw spacing and back claw spacing were significantly shortened, and stride length and pressure of damaged lateral and contralateral limbs were statistically increased in the photoactivation group (P<0.05). (2) As compared with the sham-operated group 2, lesion group 2 had significantly increased front claw spacing and back front claw spacing, significantly decreased stride length of damaged lateral limb, and significantly decreased pressure and swing speed of damaged lateral and contralateral limbs (P<0.05); no significant differences were noted on the front claw spacing and back front claw spacing, pressure and swing speed of damaged lateral and contralateral limbs between lesion group 2 and photoinhibition group (P>0.05). Conclusion The mechanism of low frequency electrical stimulation of PPTN improving gait behavior of PD rat models is related to activation of PPTN neurons.
ABSTRACT
Deep brain stimulation (DBS) has been widely used in the treatment of a variety of functional neurological diseases.The high-frequency electrical stimulation of subthalamic nucleus can improve tremor,bradykinesia,and rigidity of patients with Parkinson's disease,however,the effects of DBS on gait and balance disorders don't get very good improvement.Recently,clinical studies have found that low frequency pedunculopontine nucleus stimulation can relieve these axial symptoms.Hence we will summarize the clinical researches on the low-frequency deep brain stimulation of pedunculopontine nucleus.