The effect of deprenyl (selegiline) on cognition and emotion in parkinsonian patients undergoing long-term levodopa treatment

Insights into the management of Lewy body dementia: a scoping review

Lewy body dementia (LBD) is situated at the convergence of neurodegenerative disorders, posing an intricate and diverse clinical dilemma. The accumulation of abnormal protein in the brain, namely, the Lewy body causes disturbances in typical neural functioning, leading to a range of cognitive, motor, and mental symptoms that have a substantial influence on the overall well-being and quality of life of affected individuals. There is no definitive cure for the disease; however, several nonpharmacological and pharmacological modalities have been tried with questionable efficacies. The aim of this study is to figure out the role of different interventional strategies in the disease. Donepezil, rivastigmine, memantine, and galantamine were the commonly used drugs for LBD. Together with that, levodopa, antipsychotics, armodafinil, piracetam, and traditional medications like yokukansan were also used, when indicated. Talking about nonpharmacological measures, exercise, physical therapy, multicomponent therapy, occupational therapy, psychobehavioral modification, transcranial stimulation, and deep brain stimulation have been used with variable efficacies. Talking about recent advances in the treatment of LBD, various disease-modifying therapies like ambroxol, neflamapimod, irsenontrine, nilotinib, bosutinib, vodobatinib, clenbuterol, terazosin, elayta, fosgonimeton, and anle138b are emerging out. However, there drugs are still in the different phases of clinical trials and are not commonly used in clinical practice. With the different pharmacological and nonpharmacological modalities we have for treatment of LBD, all of them offer symptomatic relief only. Being a degenerative disease, definite cure of the disease can only be possible with regenerative measures.

Systematic review of pharmacological interventions for people with Lewy body dementia

OBJECTIVE

Lewy body dementia (LBD) is the second most common neurodegenerative dementia, and it causes earlier mortality and more morbidity than Alzheimer's disease. Reviewing current evidence on its pharmacological management is essential for developing evidence-based clinical guidelines, and for improving the quality of its clinical care. Hence, we systematically reviewed all studies that investigated the efficacy of any medication for managing various symptoms of LBD.

METHOD

We identified eligible studies by searching 15 databases comprehensively. We completed quality assessment, extracted relevant data, and performed GRADE assessment of available evidence. We conducted meta-analyses when appropriate (PROSPERO:CRD42020182166).

RESULTS

We screened 18,884 papers and included 135 studies. Our meta-analyses confirmed level-1 evidence for Donepezil's efficacy of managing cognitive symptoms of dementia with Lewy bodies (DLB) (SMD = 0.63; p < 0.001) and Parkinson's Disease Dementia (PDD) (SMD = 0.43; p < 0.01), and managing hallucinations in DLB (SMD=-0.52; p = 0.02). Rivastigmine and Memantine have level-2 evidence for managing cognitive and neuropsychiatric symptoms of DLB. Olanzapine and Yokukansan have similar evidence for managing DLB neuropsychiatric symptoms. Level-2 evidence support the efficacy of Rivastigmine and Galantamine for managing cognitive and neuropsychiatric symptoms of PDD.

CONCLUSION

We list evidence-based recommendations for the pharmacological management of DLB and PDD, and propose specific clinical guidelines for improving their clinical management.

Supplemental data for this article can be accessed online at https://doi.org/10.1080/13607863.2022.2032601 .

Monoamine-oxidase Type B Inhibitors and Cognitive Functions in Parkinson's Disease: Beyond the Primary Mechanism of Action

Symptoms of cognitive impairment are rather common since the early stage of Parkinson's disease (PD); they aggravate with disease progression and may lead to dementia in a significant proportion of cases. Worsening of cognitive symptoms in PD patients depends on the progression of subcortical dopaminergic damage as well as the involvement of other brain neurotransmitter systems in cortical and subcortical regions. Beyond the negative impact on disability and quality of life, the presence and severity of cognitive symptoms may limit adjustments of dopamine replacement therapy along the disease course. This review focuses on the consequences of the administration of monoamine-oxidase type Binhibitors (MAOB-I) on cognition in PD patients. Two drugs (selegiline and rasagiline) are available for the treatment of motor symptoms of PD as monotherapy or in combination with L-DOPA or dopamine agonists in stable and fluctuating patients; a further drug (safinamide) is usable in fluctuating subjects solely. The results of available studies indicate differential effects according to disease stage and drug features. In early, non-fluctuating patients, selegiline and rasagiline ameliorated prefrontal executive functions, similarly to other dopaminergic drugs. Benefit on some executive functions was maintained in more advanced, fluctuating patients, despite the tendency of worsening prefrontal inhibitory control activity. Interestingly, high-dose safinamide improved inhibitory control in fluctuating patients. The benefit of high-dose safinamide on prefrontal inhibitory control mechanisms may stem from its dual mechanism of action, allowing reduction of excessive glutamatergic transmission, in turn secondary to increased cortical dopaminergic input.

Identification of 5-(1-Methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl)thiophene-2-Carboxamides as Novel and Selective Monoamine Oxidase B Inhibitors Used to Improve Memory and Cognition

Initial work in Drosophila and mice demonstrated that the transcription factor cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) is a master control gene for memory formation. The relationship between CREB and memory has also been found to be true in other species, including aplysia and rats. It is thus well-established that CREB activation plays a central role in memory enhancement and that CREB is activated during memory formation. On the basis of these findings, a phenotypic high-throughput screening campaign utilizing a CRE-luciferase (CRE-Luci) SK-N-MC cell line was performed to identify compounds that enhance transcriptional activation of the CRE promoter with a suboptimal dose of forskolin. A number of small-molecule hits of unknown mechanisms of action were identified in the screening campaign, including HT-0411. Follow-up studies suggested that the CREB activation by HT-0411 is attributed to its specific and selective inhibition of monoamine oxidase B (MAO-B). Further, HT-0411 was shown to improve 24 h memory in rodents in a contextual fear conditioning model. This report describes the lead optimization of a series of 5-(1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl) thiophene-2-carboxamides that were identified as novel, potent, and selective inhibitors of MAO-B. Extensive SAR studies and in vivo behavioral evaluations of this and other related analogue series identified a number of potential clinical development candidates; ultimately, compound 8f was identified as a candidate molecule with high selectivity toward MAO-B (29-56 nM) over MAO-A (19% inhibition at a screening concentration of 50 μM), an excellent profile against a panel of other enzymes and receptors, good pharmacokinetic properties in rodents and dogs, and efficacy in multiple rodent memory models.

Effects of combined MAO-B inhibitors and levodopa vs. monotherapy in Parkinson's disease

Background: Prior studies report that monoamine oxidases inhibitors (MAO-I) when used as an adjunct to levodopa ameliorate motor symptoms in Parkinson’s disease (PD), but this was not tested in relation to cognitive or psychiatric measures.

Objective: Here, we tested the effects of MAO-I as an adjunct to levodopa, in comparison to levodopa or dopamine (DA) agonists alone, on various cognitive, affective and quality of life measures.

Methods: We studied three groups of subjects: healthy controls, PD patients on combined levodopa and MAO-I, and PD patients on levodopa or DA agonists only.

Results: We found that compared to monotherapy, combined MAO-I and levodopa seemed to improve cognition, including probabilistic learning, working memory and executive functions. There were no differences between the different medication regimes on deterministic learning, attention or memory recall. It was also found that MAO-I as an adjunct to levodopa improves affective measures such as depression, apathy, anxiety and quality of life. Interestingly, this enhancing effect of combined levodopa and MAO-I was more pronounced in PD patients with severe akinesia, compared to patients with severe tremor.

Conclusion: Our data are in agreement with (a) the Continuous Dopaminergic Stimulation (CDS) theory which states that continuous stimulation of the basal ganglia enhances motor, psychiatric and cognitive functions in PD patients; and/or (b) findings that MAO-I increase the bioavailability of monoamines that have beneficial effects on motor and behavioral dysfunction in PD.

Serum estrogen level, attention, memory and other cognitive functions in middle-aged women

OBJECTIVE

To evaluate the relationship between serum estradiol level and cognitive processing efficiency and memory.

METHODS

Sixty-three healthy women aged 45-65 years were recruited through a newspaper announcement. The subjects were divided into two subgroups (low-estrogen group, n = 37 and high-estrogen group, n = 26) according to their serum follicle stimulating hormone (FSH) and estradiol levels. In the high-estrogen group, estrogen was either endogenous or supplied by estrogen replacement therapy. Automatic and controlled cognitive processing and attentional resources were measured using CogniSpeed software, together with conventional tests of cognitive performance: similarities, digit span, digit symbol, block design, object naming and recall, paired word associates (PWA) recall, Benton visual retention and paced auditory serial addition test (PASAT). The Beck depression inventory was also assessed.

RESULTS

Cognitive reaction speeds were similar in both groups. Women with low estrogen levels made more errors in the vigilance test (sustained attention, p = 0.040). There were no differences in short-term or long-term memory, or verbal, visual or working memory between the study groups. Older women were slower in the ten-choice reaction time (10-CRT) test (r = 0.25, p = 0.047) and made more errors in the test of suppressing attention (Stroop incongruence test; r = 0.34, p = 0.007) and in the sustaining attention test (vigilance test; r = 0.47, p < 0.001). Depression scores did not correlate with cognitive variables.

CONCLUSIONS

Cognitive performance was well preserved in healthy middle-aged women. Cognitive speed, accuracy, attentional resources and memory did not show impairment with decline of serum estrogen level in this age group.

Memory and learning strategies in patients with Parkinson's disease

Parkinson's disease patients (PD) do not differ from control subjects (CS) when they have to execute a problem solving task in which external cues for solving the problem are given. However, when PD have to solve a problem by means of an internally generated strategy, they show a serious decrease in performance. We hypothesised that this distinction may also apply to the way PD and CS organize recall. In order to test our hypothesis the California Verbal Learning Test (CVLT) was administered to 59 PD and 30 CS. The test consists of five learning trials using a 16-word target list, composed of four items from each of four semantic categories. The fact that the word list was built on this implicit organization was not divulged in advance. The sequence in which the words were read is fixed; each subsequent word belongs to a category being different from the category to which the preceding word belongs. The organization in recall according to the semantic categories is considered to be the result of an unprompted, internally generated strategy. Recall according to the sequence in which the words are read by the experimenter, is viewed as an externally offered strategy. The results prove to be in line with our hypothesis: unlike CS who appeared to rely mainly and increasingly on an internally generated semantic organization, PD showed evidence of gradually adhering more to the externally imposed serial sequence.

Neuropsychological correlates of L-deprenyl therapy in idiopathic parkinsonism

1. Monoaminergic neurotransmitter systems are known to play an important role in neuropsychological functions and they are impaired in dementia of DAT and PD. 2. L-deprenyl is a monoamine-enhancing drug which at low doses selectively inhibits MAO-B, an enzyme whose brain activity has been reported to increase in normal aging and neurodegenerative dementing disorders. 3. The authors studied the effects of L-deprenyl, 10 mg/day, on several cognitive domains in idiopathic parkinsonians without dementia. Ten out-patients, treated with levodopa plus DDI, were tested before receiving L-deprenyl and retested six months after they had been treated with the drug. A control group of ten parkinsonian out-patients treated with only levodopa plus DDI, matched for age, educational level, severity and duration of extrapyramidal disease, was tested by the same neuropsychological battery and retested after a comparable time interval. 4. Statistically significant changes were noted in the verbal and visuospatial learning performances of PD patients treated with the combination of L-deprenyl and levodopa.

Effect of advanced brain atrophy and vitamin deficiency on cognitive functions in non-demented subjects

The relationship between the cognitive functions, structural changes of the brain and vitamin levels was evaluated in 36 non-demented subjects with advanced brain atrophy, and 57 age- and sex-matched healthy controls. In the control subjects ageing was associated with mild decline of cognitive skills, but the cognitive changes were not linked to the structural changes of the brain. In contrast, advanced brain atrophy and vitamin deficiency was related to the decline of complex cognitive functions in the atrophy group. Our results indicate that there are limits of normal age-related changes of the brain structure, and advanced brain atrophy on CT scans increase the probability of mild deficits of the cognitive skills.

The new generation of monoamine oxidase inhibitors

Irreversible and unspecific inhibitors of MAO were the first modern antidepressants, but after an initial success they fell into discredit due to adverse side effects. In the past two decades interest in MAO inhibitors has been renewed because of progress in basic research, a milestone being the finding that there are two subtypes of MAO, MAO-A and MAO-B. These are distinct proteins with high amino acid homology, coded by separate genes both located on the short arm of the human chromosome X. The enzyme subforms show different substrate specificities in vitro and different distributions within the central nervous system and in peripheral organs. In the central nervous system of man MAO-A seems to be mainly involved in the metabolism of 5 HT and noradrenaline, whereas 2-phenylethylamine and probably dopamine are predominantly deaminated by MAO-B. In the intestinal tract tyramine is mainly metabolized by MAO-A. These characteristics indicate distinct physiological functions of the two MAO-subforms. Several irreversible and reversible non-hydrazine inhibitors with relative selectivities for one of the MAO-subforms have been developed. They belong to various chemical classes with different modes of enzyme inhibition. These range from covalent mechanism based interaction (e.g. by propargyl- and allylamine derivatives) to pseudosubstrate inhibition (e.g. by 2-aminoethyl-carboxamides) and non-covalent interaction (e.g. by brofaromine, toloxatone and possibly moclobemide). The most important pharmacological effects of the new types of MAO inhibitors are those observed in neuropsychiatric disorders. The inhibitors of MAO-A show a favorable action in various forms of mental depression. The drugs seem to have about the same activity as other types of antidepressants, including tricyclic and related compounds as well as classical MAO inhibitors. The onset of action of the MAO-A inhibitors is claimed to be relatively fast. Other possible indications of these drugs include disorders with cognitive impairment, e.g. dementia of the Alzheimer type. In subjects with Parkinson's disease the MAO-B inhibitor L-deprenyl exerts a L-dopa-sparing effect, prolongs L-dopa action and seems to have a favorable influence regarding on-off disabilities. The action is in general transitory (months to several years). In addition L-deprenyl has been shown to delay the necessity for L-dopa treatment in patients with early parkinsonism. Whether the drug influence the progression of the disease is still a matter of debate. L-deprenyl also appears to have some antidepressant effect (especially in higher doses) and to exert a beneficial influence in other disorders, e.g. dementia of the Alzheimer type.(ABSTRACT TRUNCATED AT 400 WORDS)

Quality of life and cognitive performance after carotid endarterectomy during long-term follow-up

The quality of life and the cognitive performance of patients with extracranial carotid stenosis were investigated 8-11 years after treatment in 18 non-operatively treated patients and 44 patients treated with carotid endarterectomy. The cognitive performance was compared with data on a normal control group. Cognitive performance was assessed with neuropsychological tests and the quality of life by personal interview based on a questionnaire. Most of the carotid stenosis patients recovered well both subjectively and cognitively regardless of the type of treatment. Only the subgroup operated twice was subjectively worse compared to the other groups. Even 10 years later the cognitive performance of carotid stenosis patients was remarkably close to normal.

Selegiline and cognitive function in Parkinson's disease

Eighteen patients with Parkinson's disease were treated with placebo for 4 weeks and with the MAO-B inhibitor selegiline for 8 weeks without levodopa in a randomized double-blind clinical study. The maximum dose of selegiline was 30 mg/day and the patients' cognitive functions were evaluated before treatment and at week 12 when they were either on 30 mg selegiline or placebo. A series of neuropsychological tests were used to study general cognitive reasoning, memory, visuospatial abilities, attention, cognitive flexibility, motor functions and depression. Specific cognitive effects were not observed. Slight improvement occurred mainly in learning (easy word associations) which may reflect a limited, nonspecific arousal effect.

Selegiline hydrochloride and cognition

Selegiline HCl, 10 mg per day has been reported to improve attention and episodic memory in Parkinson's disease and early Alzheimer's disease. Selegiline also improves motor reaction times in Parkinson's and subjective feelings of increased vitality, euphoria and energy. At doses of between 10 and 40 mg a day it has also been shown to improve depression particularly when psychomotor retardation is prominent and anxiety minimal.

Selegiline in de novo parkinsonian patients: the French selegiline multicenter trial (FSMT)

The French selegiline multicenter trial was conducted in 1990 to test the possibility to improve disability of de novo parkinsonian patients (P.P.) during the first three months of treatment with selegiline (S) (10 mg/day) monotherapy. 93 P.P. were included in this double-blind, randomized, placebo controlled, clinical trial, in which 13 centers participated. Both parallel groups were followed up from inclusion (D0) to D30, D60 and D90. Drug efficacy was judged with Hoehn and Yahr (HY), Hamilton Depression Rating Scale (HDRS), Unified Parkinson's Disease Rating Scale (UPDRS), Schwab and England scores, decision to introduce levodopa and selfassessment. Biological and clinical parameters (cardio- vascular, weight, side-effects reports) were assessed for tolerability. 84 P.P. (38 P, 46 S) were evaluable for efficacy at D90. When considering the main parameters, S appears superior to placebo: HY scores (p less than 0.001), global UPDRS scores (p less than 0.001) and UPDRS subscores: mental (p less than 0.001), daily living activities (p less than 0.01), motor activities (p less than 0.01). Depressive scores (HDRS) are significantly improved only at D90 (p = 0.005). Levodopa therapy was introduced in 45% of the cases in S groups versus 18.4% in P group. Global impression of efficacy was largely in favor of S; failure was noted in half of the cases in P group and only in 1/5th of the cases in S group. Side-effects were rare and minor. S 10 mg/day monotherapy is statistically superior to placebo in improving de novo P.P. during the first three months treatment. Motor symptoms rapidly improve; mood is only modified after 3 months. S appears to be well tolerated. S may be considered as a good candidate for the initial treatment of P.P.

Neuropsychological aspects of Parkinson's disease

The neuropsychological effects of Parkinson's disease have gained wide recognition in recent literature. Effects have been documented in almost all areas of cognitive functioning, including general intellectual functioning, visual-spatial functioning, executive functions, attention and memory functions, language functions, and affective processes. Visual-spatial functions, memory functions, and executive functions have received particular interest. This review of the literature is an attempt to tie together the large number of studies in these cognitive areas and to present a suggestion for a comprehensive neuropsychological battery tailored to the patient with Parkinson's disease. Throughout the review, factors relevant to Parkinson's disease, e.g., dementia, motor symptoms, and hemiparkinsonism, are considered.

Selegiline in the treatment of Parkinson's disease

Selegiline is a selective, irreversible inhibitor of monoamine oxidase type B (MAO-B). It also inhibits the reuptake of catecholamines into the presynaptic nerve and enhances the synthesis of dopamine by blocking the presynaptic dopamine autoreceptors. Thanks to these properties it potentiates and prolongs the duration of action of levodopa. Several clinical trials have shown its efficacy as an adjuvant to levodopa therapy. Improvement in parkinsonian disability and reduction of fluctuations in disability can be achieved by adding selegiline to the prevailing levodopa therapy. End-of-dose type fluctuations, in particular, react favourably to selegiline. Side-effects of the therapy can be managed by reducing the dose of levodopa. According to preliminary studies selegiline may also have some benefit as monotherapy in de novo parkinsonian patients. High doses of selegiline have been found to have some antidepressant efficacy, especially in patients with nonendogenous depression. It may also have an effect on bradyphrenia and some symptoms of cognitive dysfunction and dementia. In animal models selegiline has been shown to prevent parkinsonism caused by MPTP and also to increase the life span of rats. Whether selegiline slows down the progression of Parkinson's disease needs further examination.

Senile dementia of the Alzheimer type treated with aniracetam: a new nootropic agent

Forty-four patients with senile dementia of the Alzheimer type were randomly allocated into double-blind treatment with either aniracetam (RO 13-5057) 1 g or placebo daily for 3 months. Neurological examinations were made before and after treatment and psychometric tests were performed before and after 1 month's and after 3 month's treatment. Treatment was interrupted due to occurrence of confusion in four cases in the aniracetam group and in one case in the placebo group. During treatment, an improvement was seen in several cognitive tests, especially those associated with memory, but this improvement occurred in the placebo as well as in the aniracetam-treated group. In clinical evaluation no difference was seen in efficacy between the two treatment groups.