Amantadine and Modafinil as Neurostimulants During Post-stroke Care: A Systematic Review.

Amantadine and modafinil are neurostimulants that may improve cognitive and functional recovery post-stroke, but the existing study results vary, and no comprehensive review has been published. This systematic review describes amantadine and modafinil administration practices post-stroke, evaluates timing and impact on clinical effectiveness measures, and identifies the incidence of potential adverse drug effects. A librarian-assisted search of the MEDLINE (PubMed) and EMBASE databases identified all English-language publications with "amantadine" or "modafinil" in the title or abstract from inception through February 1, 2020. Publications meeting predefined Patient, Intervention, Comparator, Outcome (PICO) criteria were included: Patients (≥ 18 years of age post-stroke); Intervention (amantadine or modafinil administration); Comparison (pretreatment baseline or control group); Outcomes (cognitive or functional outcome). Amantadine and modafinil administration practices, cognitive and functional outcomes, and incidence of potential adverse drug effects were collected following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidance. Quantitative analyses were not performed due to heterogeneity in the clinical effectiveness measures; descriptive data are presented as number (percent) or median (interquartile range). Of 12,620 publications initially identified, 10 amantadine publications (n = 121 patients) and 12 modafinil publications (n = 120 patients) were included. Amantadine was initiated 39 (16, 385) days post-stroke, with most common initial doses of 100 mg once or twice daily (range 100-200 mg/day), and final daily dose of 200 (188, 200) mg/day. Modafinil was initiated 170 (17, 496) days post-stroke, with initial and final daily doses of 100 (100, 350) mg/day and 200 (100, 350) mg/day, respectively. The most common indication was consciousness disorders for amantadine (n = 3/10 publications; 30%) and fatigue for modafinil (n = 5/12; 42%). Forty unique clinical effectiveness measures (1.8 per study) with 141 domains (6.4 per study) were described across all studies. A positive response in at least one clinical effectiveness measure was reported in 70% of amantadine publications and 83% of modafinil publications. Only one publication each for amantadine (10%; n = 5 patients) and modafinil (8%; n = 21 patients) studied acutely hospitalized or ICU patients; both were randomized studies showing improvements in neurocognitive function for amantadine and fatigue for modafinil. Potential adverse drug effects were reported in approximately 50% of publications, most commonly visual hallucinations with amantadine (2% of patients) and dizziness (5% of patients) and dry eyes or mouth (5% of patients). Amantadine and modafinil may improve cognitive and functional recovery post-stroke, but higher-quality data are needed to confirm this conclusion, especially in the acute care setting.

Facial tremors in patients with and without parkinsonism.

Facial (lip and jaw) tremors can be an early sign of Parkinson's disease (PD), essential tremor and other parkinsonisms. Its response to acute dopaminergic therapy and further predictive clinical diagnosis has not been previously addressed. The aim of this study was to evaluate facial tremors response to acute dopaminergic therapy and further predictive value for clinical diagnosis. A retrospective review of medical records from patients with recent onset of facial tremor, with or without parkinsonism, submitted to acute levodopa challenge for clinical prediction of sustained long-term dopaminergic response was conducted. Twenty-eight out of 559 patients (5 %) had facial tremors, which responded to levodopa in 46 % of patients. Facial tremors response to acute levodopa challenge showed 92 % sensitivity and 93 % specificity to predict a final PD diagnosis. In PD patients, facial tremor magnitude of response to levodopa was not different from that of hand rest tremor (p = 0.8). Facial tremors, although infrequent, can be an early sign of PD. Positive response to acute levodopa challenge predicts long-term PD diagnosis.

Lesch-Nyhan syndrome and its variants: examining the behavioral and neurocognitive phenotype.

PURPOSE OF REVIEW: Lesch-Nyhan Syndrome (LNS) is a metabolic disorder involving mutations in the HGPRT1 gene that result in hyperuricemia, intellectual disability, a dystonic movement disorder, and compulsive self-injury with self-mutilation. The aim of this review is to summarize recent research that documents the extended behavioral, neurologic, and neurocognitive phenotype in classic LNS, to describe milder variants of HGprt deficiency that do not self-injure and have less severe neurological and cognitive deficits, and to provide an update on treatment for associated psychiatric and behavioral disorders. RECENT FINDINGS: Psychiatric management utilizes combined behavioral and pharmacological treatment in conjunction with protective equipment and dental management to avert self-injury. Pharmacological management focuses on stabilization of mood and anxiety management. S-adenosylmethionine (SAMe), a physiological intermediate in methylation and transsulfuration, has shown beneficial effects in carefully selected patients who can tolerate the drug. Deep brain stimulation is shown in several case reports and series to reduce or eliminate self-injury and aggression, and in some cases, modify dystonia. SUMMARY: This review highlights progress in our understanding of the behavioral and neurocognitive phenotype of Lesch-Nyhan syndrome (HGprt deficiency) and its variants, describes psychiatric and behavioral management, and discusses prospects for new therapies.

Alzheimer's disease: psychopathology, medical management and dental implications.

BACKGROUND: The authors review the clinical features, epidemiology, pathophysiology, medical management, dental findings and dental treatment of patients with Alzheimer's disease (AD). STUDIES REVIEWED: The authors conducted MEDLINE searches for 2000 through 2005 using the terms "Alzheimer's disease," "geriatric," "epidemiology," "pathophysiology," "treatment" and "dentistry." Reports selected for further review included those published in English in peer-reviewed journals. The authors gave preference to articles reporting randomized, controlled trials. RESULTS: AD is a progressive and fatal neurodegenerative disorder characterized by cognitive dysfunctions, particularly in learning and memory, and the emergence of behavioral abnormalities. Deficiencies in the cells responsible for storage and processing of information underlie the cognitive, functional and behavioral changes seen in patients with the disorder. CLINICAL IMPLICATIONS: As the elderly population grows, increasing numbers of Americans with AD will require dental treatment. The prevalence of dental disease likely will be extensive, because of diminished salivary flow and patients' inability to perform appropriate oral hygiene techniques. Preventive dental education for the caregiver and use of saliva substitutes and anticaries agents by the patient are indicated.

Aspiration and infection in the elderly : epidemiology, diagnosis and management.

Aspiration of the oropharyngeal or gastric contents by elderly persons often leads to lower respiratory tract infections, such as aspiration pneumonia or pneumonitis. The existence of dysphagia and aspiration in elderly patients are important factors in the occurrence of aspiration pneumonia, but are not sufficient to cause aspiration pneumonia in the absence of other risk factors. Salivary flow and swallowing can eliminate Gram-negative bacilli from the oropharynx in healthy persons. However, elderly persons may have diminished production of saliva as a result of medications and oral/dental disease, leading to poor oral hygiene and oropharyngeal colonisation with pathogenic organisms. When dysphagic patients aspirate pathogenic bacteria while swallowing food or liquids, they must also have decreased defences, such as impaired immunity or pulmonary clearance, in order to develop aspiration pneumonia.Elderly patients with cerebrovascular disease often have dysphagia that leads to an increased incidence of aspiration. It was previously reported that patients with silent cerebral infarction affecting the basal ganglia were more likely to experience subclinical aspiration and an increased incidence of pneumonia. Basal ganglia infarction leads to the impairment of dopamine metabolism and, as a consequence, a decrease of substance P in the glossopharyngeal nerve and sensory vagal nerves. Therefore, dysphagia and a decreased cough reflex may be induced by the impairment of dopamine metabolism in some elderly patients with cerebrovascular disease, suggesting that pharmaceutical agents which modulate dopamine metabolism may be able to improve swallowing and the cough reflex in patients with basal ganglia infarction. The main strategy for controlling aspiration and aspiration-related pulmonary infection in the elderly is to prevent aspiration of pathogenic bacteria along with the oropharyngeal or gastric contents. Because aspiration pneumonia in the elderly is related to certain risk factors, including dysphagia and aspiration, effective preventive measures involve various approaches, such as pharmacological therapy, swallowing training, dietary management, oral hygiene and positioning.

A proposed mechanism for diurnal/nocturnal bruxism: hypersensitivity of presynaptic dopamine receptors in the frontal lobe.

There are many reports in the literature concerning nocturnal bruxism, however, diurnal (non-sleep)/nocturnal bruxism is rarely mentioned. We report three patients with diurnal/nocturnal bruxism. They differed from the usual features of nocturnal bruxism in hypoperfusion of the left frontal lobe, a poor response to l-dopa or bromocriptine therapy and a favourable response to metoclopramide. Hypersensitive presynaptic dopamine receptors may be the underlying pathology responsible for this type of bruxism. Regional differences in dopamine receptor pharmacology may explain the perplexing relationship of bruxism to both hyper- and hypo-dopaminergic states.

MK 458, a selective and potent D2 receptor agonist in advanced Parkinson's disease.

MK 458 is a potent and selective D2 receptor agonist. MK 458 consists of (+)-4-propyl-9-hydroxynaphthoxazine (PHNO) in a hydroxypropyl-methylcellulose-lactose matrix. MK 458, mean dose 8.1 mg (range 2.5 to 13.5 mg), was administered to 14 patients with advanced Parkinson's disease (PD) who were no longer satisfactorily responding to levodopa. The duration of the study was 4 weeks with a titration to maximum dose in 2 weeks. The addition of MK 458 resulted in a mean reduction in levodopa of 41% (range 0 to 81%). This degree of levodopa reduction was not seen in previous studies with other DA agonists. While the reduction in signs of PD was comparable to those on levodopa, MK 458 did not induce dyskinesias or dystonias. It is postulated that MK 458 may be able to replace levodopa as the primary treatment for PD.

Respiratory muscle performance and the Perception of dyspnea in Parkinson's disease.

BACKGROUND: Pulmonary and respiratory muscle function impairment are common in patients with Parkinson's disease (PD). However, dyspnea is not a frequent complaint among these patients, although it is well documented that the intensity of dyspnea is related to the activity and the strength of the respiratory muscles. PATIENTS AND METHODS: We studied pulmonary function, respiratory muscle strength and endurance and the perception of dyspnea (POD) in 20 patients with PD (stage II and III Hoehn and Yahr scale) before and after their first daily L-dopa dose. Respiratory muscle strength was assessed by measuring the maximal inspiratory and expiratory mouth pressures (PImax and PEmax), at residual volume (RV) and total lung capacity (TLC) respectively. The POD was measured while the subject breathed against progressive load and dyspnea was rated using a visual analog scale. RESULTS: Respiratory muscle strength and endurance were decreased and the POD was increased during the off medication period compared to normal subjects. There was a nonsignificant trend to an increase in Plmax, PEmax and endurance after L-dopa intake. The POD of PD patients decreased (p<0.05) following medication, although, it remained increased (p<0.01) as compared to the normal subjects. Even if patients had spirometry data showing a mild restrictive pattern, before medication, both forced vital capacity (FVC) and forced expiratory volume (FEV)1 remained almost identical after L-dopa intake. CONCLUSIONS: Patients with PD have higher POD, compared to normal subjects and this increased perception is attenuated when the patients are on dopaminergic medication. The change in the POD is not related to changes in respiratory muscle performance or pulmonary functions. A central effect or a correction of uncoordinated respiratory movements by L-dopa may contribute to the decrease in POD following L-dopa treatment.

Levodopa/benserazide microsphere (LBM) prevents L-dopa induced dyskinesia by inactivation of the DR1/PKA/P-tau pathway in 6-OHDA-lesioned Parkinson's rats.

L-3, 4-dihydroxyphenylalanine (L-dopa) is the gold standard for symptomatic treatment of Parkinson's disease (PD), but long-term therapy is associated with the emergence of L-dopa-induced dyskinesia (LID). In the present study, L-dopa and benserazide were loaded by poly (lactic-co-glycolic acid) microspheres (LBM), which can release levodopa and benserazide in a sustained manner in order to continuous stimulate dopaminergic receptors. We investigated the role of striatal DR1/PKA/P-tau signal transduction in the molecular event underlying LID in the 6-OHDA-lesioned rat model of PD. We found that animals rendered dyskinetic by L-dopa treatment, administration of LBM prevented the severity of AIM score, as well as improvement in motor function. Moreover, we also showed L-dopa elicits profound alterations in the activity of three LID molecular markers, namely DR1/PKA/P-tau (ser396). These modifications are totally prevented by LBM treatment, a similar way to achieve continuous dopaminergic delivery (CDD). In conclusion, our experiments provided evidence that intermittent administration of L-dopa, but not continuous delivery, and DR1/PKA/p-tau (ser396) activation played a critical role in the molecular and behavioural induction of LID in 6-OHDA-lesioned rats. In addition, LBM treatment prevented the development of LID by inhibiting the expression of DR1/PKA/p-tau, as well as PPEB mRNA in dyskintic rats.

Covert dyskinesia associated with aripiprazole: a case report and review of the literature.

The atypical antipsychotic agents are felt by many to have a lower risk of inducing the development of dyskinetic movements than the conventional antipsychotic agents agents such as haloperidol and fluphenazine. However, that does not mean that treatment with the atypical antipsychotic agents carries no risk of developing dyskinesias. To the contrary, all of the atypical antipsychotic agents, including aripiprazole, have been associated with the induction of dyskinetic movements. We will present the case of a patient who developed a covert dyskinesia that manifested shortly after the discontinuation of aripiprazole. We will review the use of aripiprazole and the adverse effects most commonly associated with its use. We will also discuss the risk factors associated with the development of tardive dyskinesia and review the different clinical variations (withdrawal dyskinesia, covert dyskinesia, tardive diskinesia) of medication-induced dyskinesias.

The effect of L-dopa on the healing of a rat mandibular defect.

PURPOSE: This study was designed to evaluate the effect of L-dopa on healing of a surgically created bony defect in the adult male rat. MATERIALS AND METHODS: Thirty-six animals underwent surgery to create a 4-mm circular defect in the left mandibular angle. They were then randomly divided into two equal groups, one receiving 0.2 g/kg/day of L-dopa for 10 days by orogastric gavage, the other group acting as a control. Six experimental and six control animals were killed at 2 weeks, and five experimental and six control animals were killed at 4 and 6 weeks postoperation. Healing was classified as complete, partial, or incomplete based on gross and radiographic observations. RESULTS: Gross observation of the experimental mandibles showed five completely healed defects (31.25%), five partially healed defects (31.25%), and six defects with no healing (37.5%). Control mandibles showed three defects with partial healing (16.67%) and 15 with no healing (83.33%). Radiographs were taken of randomly chosen mandibles in each control and experimental group. Of the six experimental mandibles, one showed no healing, three showed partial healing, and two showed complete healing of the defect. The six control mandibles showed three defects with no bone formation and three with partial healing. CONCLUSIONS: The data from this study indicate that L-dopa had a promoting effect on the bony healing of defects in the rat mandible.

Differential time and related appearance of signs, indicating improvement in the state of consciousness in vegetative state traumatic brain injury (VS-TBI) patients after initiation of dopamine treatment.

OBJECTIVE: The goal of the study was to look for the response of treatment with increasing doses of dopaminergic medication on the recovery of vegetative state patients post-TBI. DESIGN: A prospective study of eight patients aged 25-50 years in vegetative state (VS) of mean duration of 104 days following traumatic brain injury (TBI) was performed by investigating changes of their state of consciousness while they were treated with levodopa/carbidopa. RESULTS: Initial improvement was observed in all patients within a mean of 13 days after onset of treatment. Seven patients recovered consciousness after a mean time of 31 days of treatment. The remaining patient showed only slight improvement to minimally conscious state. The sequence of symptoms leading to recovery was the same in all patients; the first to appear was moving a limb on a request, which appeared at a mean time of 13 days. Gradual increase of dose leads to the appearance of better-organized responses like reacting to more than one command, than opening the mouth and appearance of a reciprocal contact. The only side effect was visual hallucinations in one patient, which disappeared after decreasing the dosage. CONCLUSIONS: Clinical awareness to the structured order of responses and to the effect of dosage can help clinicians in early assessment of response to dopaminergic treatment in VS patients.

Influence of Parkinson's disease on oral health.

Thirty patients with Parkinson's disease were investigated with regard to their oral health. They had significantly more teeth and less caries than a control group of corresponding age. However, the salivary secretion rate was significantly lower with advancing parkinsonian symptoms. It is concluded that not only motor impairment but also autonomic dysfunction, as an expression of a more advanced neuron degeneration, could be of importance when the possibility of maintaining a good oral health in parkinsonian patients is considered.