Effects of Fluoxetine on Poststroke Dysphagia: A Clinical Retrospective Study

The effect of rasagiline on swallowing function in Parkinson's disease

Dysphagia, a potentially fatal symptom of Parkinson's disease, is characterized by frequent silent aspiration, a risk factor for aspiration pneumonia. The transdermal dopamine agonist rotigotine alleviates dysphagia in patients with Parkinson's disease and is more effective than oral levodopa, suggesting the importance of continuous dopaminergic stimulation during swallowing. Rasagiline is a monoamine oxidase B (MAOB) inhibitor that facilitates continuous dopaminergic stimulation. We hypothesized that MAOB inhibition by rasagiline would be effective in improving swallowing function in patients with early- and mid-to late-stage Parkinson's disease. To this end, we performed an analytical observational study to determine the effects of rasagiline (1 mg/day) on swallowing function using videofluoroscopic swallowing study. This open-label, evaluator-blinded study enrolled 32 patients with Parkinson's disease, among whom 19 were drug-naïve and 13 were receiving add-on therapy. Our results showed that rasagiline significantly improved all swallowing measures during the oral and pharyngeal phases, including oral transit time and pharyngeal transit time, in all enrolled patients. Similar results were found in drug-naïve and mid-to late-stage patients, with no intergroup differences. In conclusion, drugs capable of continuous dopaminergic stimulation may effectively improve swallowing function in patients with Parkinson's disease, with similar effects in early- and mid-to late-stage Parkinson's disease. This study has been the first to show that rasagiline significantly improves swallowing function in mid-to late-stage patients receiving add-on therapy.

Effect of transcutaneous auricular vagus nerve stimulation on post-stroke dysphagia

BACKGROUND AND PURPOSE

It has been proved that electrical vagus nerve stimulation can promote the recovery of motor function after stroke. There were no trials on the use of transcutaneous auricular electrical vagus nerve stimulation (ta-VNS) in patients with dysphagia after acute stroke. Our aim was to confirm whether ta-VNS can promote the recovery of swallowing function in these acute stroke patients with dysphagia.

METHODS

We conducted a sham-controlled, double-blinded, parallel pilot study in 40 acute stroke patients randomly assigned to receive ta-VNS or sham ta-VNS combined with conventional rehabilitation training. The intensity of ta-VNS treatment was adjusted according to the patient's tolerance, 30 min each time, twice a day, five times a week, with a total course of 3 weeks. In the sham group, the parameters were the same except energy output. Swallowing function was assessed with Modified Mann assessment of swallowing ability (MASA), functional communication measure swallowing test (FCM), and the Rosenbek leakage/aspiration scale (RAS) according to swallowing video fluoroscopic (SVF) before the intervention (baseline, T0), immediately after the intervention (T1) and 4 weeks after the intervention (T2).

RESULTS

After treatment, ta-VNS group statistically and clinically had larger change of MASA, FCM, and RAS scores compared with control group (P < 0.05) and this improvement continued at least 4 weeks after the end of treatment. There were no serious adverse events occurred during the whole intervention.

CONCLUSION

The transcutaneous auricular electrical vagus nerve stimulation is effective as a novel and noninvasive treatment strategy for patients with dysphagia after acute stroke.

TRIAL REGISTRATION

No: kelunshen No. 63 in 2020.

Acupuncture Reduces the Risk of Dysphagia in Stroke Patients: A Propensity Score-Matched Cohort Study

Background: Post-stroke dysphagia (PSD) affects the quality of life in stroke patients, impairs their rehabilitation ability, and causes other complications following stroke. Currently, there is currently some understanding of PSD risk factors, but its protective factors remain largely unknown. Objective: To analyze the effects of acupuncture (AP) on dysphagia in stroke patients and explore its potential as a preventive therapy. Methods: Patients with a diagnosis of stroke from 2010 to 2019 were selected and followed until 2020, utilizing factors such as age, gender, stroke location, stroke type, and baseline comorbidity. To compare the incidence of dysphagia, equal numbers of stroke patients treated with and without AP (n = 1,809) were matched by 1:1 propensity scoring. The Cox proportional hazards model and Kaplan-Meier method were used to assess the risk of dysphagia as an outcome measure. Results: The stroke patients treated with AP had a lower risk of dysphagia after adjusting for age, gender, stroke location, stroke type, and baseline comorbidity [adjusted hazard ratio (AHR) = 0.43, 95% confidence interval = 0.37-0.49] compared with those in the non-AP cohort. AP also decreased the risk of PSD among different gender groups. The risk ratios were AHR = 0.45 and AHR = 0.33 for males and females, respectively. AP also reduced the risk for PSD among different age groups. The risk ratios were AHR = 0.20, AHR = 0.37, AHR = 0.41, and AHR = 0.45 for the 18-39, 40-59, 60-79, and >80 years-old groups. Regarding stroke types (ischemic, hemorrhagic, and mixed type), patients treated with AP had a lower risk (AHR = 0.47, 0.28 and 0.17, respectively). With respect to stroke location, the risk of PSD in AP-treated patients was decreased regardless of location: brain stem (AHR = 0.41), diencephalon (AHR = 0.13), or multiple lesions (AHR = 0.40), the risk of PSD in AP-treated patients was decreased. For all baseline comorbidities, AP attenuated the risk of dysphagia. The cumulative incidence of dysphagia was remarkably lower in the AP group than in the non-AP group (log-rank test, P = 0.000). Limitations: First, this was a single-center clinical retrospective study. Second, we did not classify the severity of stroke and dysphagia. Third, all data were extracted manually. Lastly, the sample size was relatively small. Thus, future studies with larger sample sizes are warranted to verify our findings. Conclusion: Acupuncture treatment attenuates the risk of dysphagia in stroke patients. Future research should increase the sample size and elaborate further on the details of the AP protocol.

Differential Expression of BDNF and BIM in Streptozotocin-induced Diabetic Rat Retina After Fluoxetine Injection

BACKGROUND

Chronic diabetic retinopathy (DR) is a diabetic complication that causes blindness. Brain-derived neurotrophic factor (BDNF) expression is induced by fluoxetine. We observed the effects of fluoxetine on a streptozotocin (STZ)-induced diabetic rat model in this study.

MATERIALS AND METHODS

Rats were divided into three groups: Control, diabetic (65 mg/kg STZ injection), and diabetic with fluoxetine injection (20 mg/kg/week, six times). Western blotting was performed using anti-BDNF and anti-hexaribonucleotide-binding protein-3. Expression of BCL2 apoptosis regulator-like protein 11 (BIM) was analysed using a reverse transcription-polymerase chain reaction.

RESULTS

BDNF levels were significantly higher in the diabetic group treated with fluoxetine than in the untreated diabetic group. BIM expression was higher in the diabetic group than in the control group. BIM gene expression was lower in fluoxetine-treated diabetic group than in the untreated diabetic group.

CONCLUSION

Fluoxetine had an anti-apoptotic effect with upregulation of BDNF expression in retina of rats with STZ-induced diabetes.

Fluoxetine for motor recovery after acute intracerebral hemorrhage, the FMRICH trial

OBJECTIVES

Acute intracerebral hemorrhage (ICH) is a very common cause of disability. Previous evidence suggests that fluoxetine and other selective serotonin reuptake inhibitors improve, the recovery of motor function in patients with cerebral infarct. The purpose of this study was to investigate whether fluoxetine also improves motor recovery in patients with ICH.

PATIENTS AND METHODS

This is a double blind, placebo controlled, multicenter randomized trial, patients recruited from three centers were assigned to receive 20 mg/day of fluoxetine or matching placebo for three months from within ten days after onset of symptoms. Primary outcome was change in Fugl-Meyer Motor Scale from baseline to day 90.

RESULTS

Thirty patients (50 % women) were recruited to the fluoxetine (n = 14) or placebo (n = 16) groups. Median age was 55 years, the cause of the ICH was hypertension in 93.3 %, median volume of the hematomas was 22mm³. Basal ganglia hematoma was present in 67 % and, lobar location in 20 % of the patients. Improvement in FMMS at day 90 was significatively higher in the treatment group (median score 23) than in the placebo group, (median score 48), p = 0.001. No serious adverse events occurred.

CONCLUSION

In addition to standard treatment, early prescription of fluoxetine was safe and helped to increase motor recovery 90 days after ICH. This finding adds to the evidence regarding its beneficial effect upon stroke related disability. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01737541.

Selective serotonin reuptake inhibitors for functional recovery after stroke: similarities with the critical period and the role of experience-dependent plasticity

There has been a growing interest in the potential for plasticity-inducing pharmacological interventions to enhance post-stroke recovery. One group of drugs that continues to garner a great deal of attention in this regard is a class of antidepressants called the selective serotonin reuptake inhibitors. Here we propose a model for the mechanism by which these drugs may enhance plasticity after ischemic brain injury. First, we review the research in animal models demonstrating how selective serotonin reuptake inhibitors reopen the critical period for ocular dominance plasticity in adulthood. We then compare this period of heightened plasticity to the cellular and biochemical milieu of perilesional tissue after an ischemic event in the adult brain. We argue that selective serotonin reuptake inhibitors administered acutely after an ischemic stroke alter excitatory-inhibitory balance in perilesional tissue and reinstate a type of plasticity reminiscent of the critical period in development. Finally, we discuss opportunities for future research in this area in both the preclinical and clinical realms.

Mice Lacking Brain-Derived Serotonin Have Altered Swallowing Function

The intricate sensorimotor neural circuits that control swallowing are heavily reliant on serotonin (5-hydroxytryptamine [5-HT]); however, the impact of 5-HT deficiency on swallow function remains largely unexplored. We investigated this using mice deficient in tryptophan-hydroxylase-2 (TPH2), the enzyme catalyzing the rate-limiting step in 5-HT synthesis. Videofluoroscopy was utilized to characterize the swallowing function of TPH2 knockout (TPH2^-/-) mice as compared with littermate controls (TPH2^+/+). Results showed that 5-HT deficiency altered all 3 stages of swallowing. As compared with controls, TPH2^-/- mice had significantly slower lick and swallow rates and faster esophageal transit times. Future studies with this model are necessary to determine if 5-HT replacement may rescue abnormal swallowing function. If so, supplemental 5-HT therapy may have vast applications for a large population of patients with a variety of neurologic disorders resulting in life-diminishing dysphagia, particularly amyotrophic lateral sclerosis and Parkinson's disease, for which 5-HT deficiency is implicated in the disease pathogenesis.