A prospective PMS study to validate the sensitivity for change of the D-scale in advanced stages of dementia using the NMDA-antagonist memantine

A Systematic Review of Nonpharmacological Interventions for Moderate to Severe Dementia: A Study Protocol for a Systematic Review and Meta-Analysis

The study is designed as a systematic review on nonpharmacological interventions for patients with moderate to severe dementia. This review will be conducted in accordance with the Cochrane Handbook for Systematic Reviews of Interventions. The following databases will be searched: Cochrane CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, KoreaMED, KMbase, and KISS. The primary outcome will include the effect of the interventions on activities of daily living and behavioral and psychological symptoms of dementia. The literature search will be conducted based on search strategies designed for each database. The reviewers will independently assess the identified studies and extract the data. The risk of bias will be assessed and a meta-analysis will be conducted in accordance with the methodology for meta-analysis described in the Cochrane handbook. This systematic review will provide clinicians and policy makers with reliable evidence for developing and implementing nonpharmacological interventions for moderate to severe patients with dementia.

Domain-specific improvement of cognition on memantine in patients with Alzheimer's disease treated with rivastigmine

OBJECTIVE

Cholinergic therapy is used in mild-to-moderate Alzheimer's disease (AD) and antiglutamatergic therapy in moderate-to-severe AD. Global scales, as commonly used in clinical trials, blur specifics of disease progression and drug effects. The objective was to assess combination therapy of rivastigmine plus memantine by specific neuropsychological tests in patients with mild-to-moderate AD.

METHODS

12-week-short multicenter open-label pilot study. Ninety patients with mild-to-moderate AD already on stable medication with rivastigmine (3-6 mg b.i.d.) additionally received memantine for 12 weeks. Subscales of the Alzheimer's Disease Assessment Scale (ADAS-cog), the Mini-Mental State Examination (MMSE) and additional neuropsychological tests (e.g. span tasks, semantic fluency) were assessed.

RESULTS

The scores in the ADAS-cog memory subscale, the MMSE score, and digit span and semantic fluency significantly improved on combination therapy.

CONCLUSION

Memory improvement was correlated with ADAS-cog memory score at baseline and inversely with age at onset of treatment. The data suggest that improvement on combination therapy results from an improvement of attention/executive function with secondary memory improvement, which will need to be confirmed in a subsequent double-blind study on a larger number of patients.

Adding memantine to rivastigmine therapy in patients with mild-to-moderate alzheimer's disease: results of a 12-week, open-label pilot study

OBJECTIVE

At present, inhibition of cholines-terase is the treatment of choice for subjects with mild-to-moderate Alzheimer's disease (AD). Memantine, a noncompetitive antagonist at N-methyl-d-aspartate receptors, is currently used to treat subjects with moderate-to-severe AD. The goal of this multicenter, open-label pilot study was to investigate whether combination therapy with memantine added to rivastigmine is safe and beneficial in subjects with mild-to-moderate AD.

METHOD

Patients with a DSM-IV diagnosis of dementia of the Alzheimer's type (N = 95), who were treated with rivastigmine (6-12 mg/day) for a maximum duration of 24 weeks prior to baseline, received memantine (5-20 mg/day) in combination with rivastigmine for 12 weeks. The primary efficacy variable was the change in the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) total score at the end of 12 weeks compared with baseline. The study was conducted between September 15, 2003, and May 27, 2004.

RESULTS

There was a statistically significant difference between baseline and week 12 for the ADAS-cog total score, showing a positive effect of combination therapy. Combination therapy did not evidence any unexpected safety concerns and was well-tolerated by most patients.

CONCLUSION

Memantine in combination with rivastigmine appears to be safe and beneficial in patients with mild-to-moderate AD. Our results need to be confirmed in a large, long-term, randomized, double-blind, placebo-controlled clinical trial.

Divergent effects of Abeta1-42 on ionotropic glutamate receptor-mediated responses in CA1 neurons in vivo

Aggregated Abeta1-42 is hypothesized to be the central cause of Alzheimer's disease. However, early changes in synaptic activity may be detected in the disease long before a significant cell loss is manifested. Despite the fact that Abeta1-42 interference with long-term potentiation (LTP) and the field excitatory postsynaptic potential (fEPSP) is well documented, the exact mechanism of these events remains to be clarified. Here we studied the effects of iontophoretically applied Abeta1-42 on the neuronal firing evoked in vivo on the CA1 hippocampal neurons of Wistar rats by different agonists of the ionotropic glutamate receptors: N-methyl-d-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and kainic acid (KA). NMDA elicited firing enhanced in all of the measured cells; in contrast, the AMPA-mediated responses decreased significantly after Abeta1-42 ejection. The changes in KA-evoked responses to Abeta1-42 revealed two types of cells. In the first type, the KA-mediated firing remained at the control level, while in the second type, Abeta1-42 attenuated the KA-evoked responses. A protective pentapeptide, Leu-Pro-Tyr-Phe-Asp-amide, was used to verify the specificity of these beta-amyloid-elicited effects. The pentapeptide protected against the modulatory effects of Abeta1-42 on the NMDA and AMPA responses. In conclusion, we have shown that Abeta1-42 exerts divergent effects on the activity of the ionotropic glutamate receptors in vivo. These results suggest that the LTP disruption and fEPSP attenuation seen after Abeta1-42 application are in part due to the altered function of these receptors.

Dementia of Alzheimer's disease and other neurodegenerative disorders--memantine, a new hope

Alzheimer's disease is the fourth largest cause of death for people over 65 years of age. Dementia of Alzheimer's type is the commonest form of dementia, the other two forms being vascular dementia and mixed dementia. At present, the therapy of Alzheimer's disease is aimed at improving both, cognitive and behavioural symptoms and thereby, quality of life for the patients. Since the discovery of Alzheimer's disease by Alois Alzheimer, many pathological mechanisms have been proposed which led to the testing of various new treatments. Until recently the available drugs for the treatment of Alzheimer's disease are cholinesterase inhibitors, which have limited success because these drugs improve cognitive functions only in mild dementia and cannot stop the process of neurodegeneration. Moreover, drugs of this category show gastrointestinal side effects. As the cells of central and peripheral nervous system cannot regenerate, newer strategies are aimed at preserving the surviving neurons by preventing their degeneration. NMDA-receptor-mediated glutamate excitotoxicity plays a major role in Abeta-induced neuronal death. Hence, it was thought that NMDA receptors could be a promising target for preventing the progression of Alzheimer's disease. All the compounds synthesized initially in this category showed toxicity mainly because of their high affinity for NMDA receptors. Memantine (1-amino adamantane derivative), NMDA-receptor antagonist was reported to be effective therapeutically in Alzheimer's disease. It was available in Germany as well as European Union and has been approved for moderate to severe dementia in United States of America recently. It is an uncompetitive, moderate affinity antagonist of NMDA receptors that inhibits the pathological functions of NMDA receptors while physiological processes in learning and memory are unaffected. Memantine is also reported to have beneficial effects in other CNS disorders viz., Parkinson's disease (PD), stroke, epilepsy, CNS trauma, amyotrophic lateral sclerosis (ALS), drug dependence and chronic pain. Mechanisms of neuroprotection, preclinical and clinical evidence for effectiveness of memantine have been provided. Pharmacology and pharmacokinetics of memantine and other NMDA-receptor antagonists in comparison with currently approved drugs for dementia treatment have been discussed. The focus is on 'glutamate excitotoxicity' and glutamate receptors as drug target. Various other novel strategies for the treatment of dementia of neurodegenerative disorders have also been discussed.

Pharmacotherapy of dementia with Lewy bodies

The syndrome of dementia with Lewy bodies (DLB) is characterised by the clinical triad of fluctuating cognitive impairment, recurrent visual hallucinations and spontaneous motor features of Parkinsonism. In an attempt to define DLB as a distinct clinical syndrome separate from Alzheimer's disease (AD) and Parkinson's disease (PD) with dementia, a consensus workshop in 1995 established a new set of diagnostic criteria. Dementia that precedes or accompanies the onset of spontaneous (i.e., not neuroleptic-induced) Parkinsonism is termed DLB. In addition, fluctuations in alertness, cognition and function and visual hallucinations are emphasised and included as core features of DLB. The degree to which an individual patient exhibits cognitive impairment, behavioural problems and Parkinsonian features is variable. Therefore, treatment must be individualised. Although there are no officially approved drugs for DLB, limited experience from clinical trials, as well as past experience with the treatment of AD and PD patients, provide some basis for making drug choices. The cholinergic deficit seen in DLB makes cholinesterase inhibitor drugs the mainstay of treatment for cognitive impairment. This class of drugs has also shown therapeutic benefit in reducing hallucinations and other neuropsychiatric symptoms of the disease. Because of their relatively greater therapeutic window, cholinesterase inhibitors are also used as first-line therapy for the treatment of psychosis in DLB. Patients with DLB are extremely sensitive to the extrapyramidal side effects of neuroleptic medications. Thus, only atypical antipsychotic agents such as quetiapine, should be considered as alternative treatment for psychosis. Anxiety and depression are best treated with selective serotonin re-uptake inhibitors, whereas REM sleep behaviour disorder may be treated with low dose clonazepam. Parkinsonism responds to dopaminergic agents; however, precipitation or aggravation of hallucinosis may occur. Levodopa is preferred over dopamine agonists due to its lower propensity to cause hallucinations and somnolence. As the diagnostic criteria for DLB become more refined and validated by postmortem studies, it is hoped that rigorous, well-designed trials will be performed, aimed at alleviating the primary target symptoms of dementia, psychosis and Parkinsonism.

Mémantine (Ebixa®) : une nouvelle stratégie thérapeutique dans le traitement des formes modérément sévères à sévères de la maladie d’Alzheimer

Alzheimer's disease has definitively emerged from its ghetto and has been identified as a (priority) public health concern in view of the increasing age of the population. Considerable advances have been made in this disease over the last 15 Years, with progress in the following fields: knowledge of the underlying aetiopathogenetic, genetic and biochemical mechanisms; semiological, clinical and paraclinical approaches; creation of early diagnostic centres and multidisciplinary care networks; therapy available to patients or currently under development. The four existing acetylcholinesterase inhibitors having confirmed symptomatic action in patients with mild to moderate Alzheimer's disease have now been joined by memantine (Ebixa), a non-competitive agonist of N-methyl-D-aspartate (NMDA) receptors. One pathogenic mechanism of Alzheimer's disease appears to be hyperactivity of the glutaminergic neurons. Various preclinical studies have shown that memantine (Ebixa) inhibits glutaminergic hyperactivity in Alzheimer's disease through modulation of NMDA receptors. Since the early 1990s, several controlled clinical trials in patients with moderate to severe Alzheimer's disease (3<MMSE< or =14) have demonstrated the efficacy of memantine on cognitive criteria (cognitive evaluation of severe dementia) (Severe Impairment Battery--SIB), functional criteria (Functional Assessment Stage--FAST) and global clinical criteria (Clinician's Interview-Based Impression of Change--CIBIC-Plus). The data from these studies together with clinical experience of memantine in Germany since 1982 confirm the safety of use and good tolerability profile of this medication at the recommended dosages (10 to 30 mg/day). Treatment with memantine reduces the global costs of the disease by lightening the burden on helpers and delaying institutionalisation of patients. These different studies have resulted in approval of memantine in this particular indication by the European Medicines Agency. The efficacy of memantine in mild to moderate Alzheimer's disease is currently being assessed. The preliminary results also appear to militate in favour of the efficacy of the drug in certain forms of vascular dementia. Finally, the good safety profile of combined use of this drug with antiacetylcholinesterases opens up a realistic perspective of bitherapy in Alzheimer's disease.

The neuropharmacological basis for the use of memantine in the treatment of Alzheimer's disease

Memantine has been demonstrated to be safe and effective in the symptomatic treatment of Alzheimer's disease (AD). While the neurobiological basis for the therapeutic activity of memantine is not fully understood, the drug is not a cholinesterase inhibitor and, therefore, acts differently from current AD therapies. Memantine can interact with a variety of ligand-gated ion channels. However, NMDA receptors appear to be a key target of memantine at therapeutic concentrations. Memantine is an uncompetitive (channel blocking) NMDA receptor antagonist. Like other NMDA receptor antagonists, memantine at high concentrations can inhibit mechanisms of synaptic plasticity that are believed to underlie learning and memory. However, at lower, clinically relevant concentrations memantine can under some circumstances promote synaptic plasticity and preserve or enhance memory in animal models of AD. In addition, memantine can protect against the excitotoxic destruction of cholinergic neurons. Blockade of NMDA receptors by memantine could theoretically confer disease-modifying activity in AD by inhibiting the "weak" NMDA receptor-dependent excitotoxicity that has been hypothesized to play a role in the progressive neuronal loss that underlies the evolving dementia. Moreover, recent in vitro studies suggest that memantine abrogates beta-amyloid (Abeta) toxicity and possibly inhibits Abeta production. Considerable attention has focused on the investigation of theories to explain the better tolerability of memantine over other NMDA receptor antagonists, particularly those that act by a similar channel blocking mechanism such as dissociative anesthetic-like agents (phencyclidine, ketamine, MK-801). A variety of channel-level factors could be relevant, including fast channel-blocking kinetics and strong voltage-dependence (allowing rapid relief of block during synaptic activity), as well as reduced trapping (permitting egress from closed channels). These factors may allow memantine to block channel activity induced by low, tonic levels of glutamate--an action that might contribute to symptomatic improvement and could theoretically protect against weak excitotoxicity--while sparing synaptic responses required for normal behavioral functioning, cognition and memory.

Emerging trends in the pharmacotherapy of chronic pain

The pharmacotherapy for pain is dominated by conventional analgesics such as the opioids and the non-steroidal anti-inflammatory drugs. Recent advances in the understanding of the mechanisms of pain in general and chronic pain in particular, opened the field of analgesic therapy to newer pharmacological targets, which are aimed at improved efficacy and enhanced tolerability over conventional antipain treatments. Many novel targets are still in preclinical development, but some have made it into human trials and have shown promise. Newer anticonvulsants, new generation cyclooxygenase inhibitors, better tolerated glutamate modulators and balanced serotonin/noradrenaline re-uptake inhibitors are some targets that have shown promise in the clinic. These and other compounds that are in advanced phases of development for chronic pain are reviewed in this paper. It is hoped that the decade of pain control and research will lead us to an arsenal of effective and safe analgesics that will conquer the problem of chronic pain.

Current pharmacologic options for patients with Alzheimer's disease

BACKGROUND: The aim of the current study was to provide general practitioners with an overview of the available treatment options for Alzheimer's disease (AD). Since general practitioners provide the majority of medical care for AD patients, they should be well versed in treatment options that can improve function and slow the progression of symptoms. DESIGN: Biomedical literature related to acetylcholinesterase inhibitors (AChEIs) was surveyed. In the United States, there are four AChEIs approved for the treatment of AD: tacrine, donepezil, rivastigmine, and galantamine. There are other agents under investigation, but at present, AChEIs are the only approved drug category for AD treatment. MEASUREMENTS AND MAIN RESULTS: AD is becoming a major public health concern and underdiagnosis is a significant problem (with only about half of AD patients being diagnosed and only half of those diagnosed actually being treated). Clinical trials have demonstrated that patients with AD who do not receive active treatment decline at more rapid rates than those who do. CONCLUSIONS: Given that untreated AD patients show decline in three major areas (cognition, behavior, and functional ability), if drug treatment is able to improve performance, maintain baseline performance over the long term, or allow for a slower rate of decline in performance, each of these outcomes should be viewed a treatment success.

Amantadine to improve neurorecovery in traumatic brain injury-associated diffuse axonal injury: a pilot double-blind randomized trial

BACKGROUND

Traumatic brain injury (TBI) caused by a high-speed transportation accident results in a mechanism of injury commonly described as diffuse axonal injury (DAI), which is associated with a reduction in dopamine turnover in the brain. Because of its affect on both dopamine and N-methyl-D-aspartate (NMDA) channels, amantadine has been the subject of considerable interest and clinical use in acute TBI.

PARTICIPANTS

In this study, 35 subjects, who had a TBI in a transportation accident and were initially seen with a Glasgow Coma Scale score of 10 or less within the first 24 hours after admission, were randomly assigned to a double-blind, placebo-controlled, crossover design trial.

MAIN OUTCOME MEASURES

Amantadine, 200 mg, or placebo was each administered for 6 weeks (12 weeks total) to patients who were recruited consecutively.

RESULTS

There was an improvement in the Mini-Mental Status (MMSE) scores of 14.3 points (P =.0185), Disability Rating Scale (DRS) score of 9.8 points (P =.0022), Glasgow Outcome Scale (GOS) score of 0.8 points (P =.0077), and in the FIM Cognitive score (FIM-cog) of 15.1 points (P =.0033) in the group that received amantadine during the first 6 weeks (group 1), but there was no improvement in the second 6 weeks on placebo (P >.05). In group 2 (active drug second 6 weeks), there was an improvement in the MMSE of 10.5 points, in the DRS of 9.4 points (P =.0006), in the GOS of 0.5 points (P =.0231), and in the FIM-cog of 11.3 points (P =.0030, Wilcoxon signed rank) spontaneously in the first 6 weeks on placebo (P =.0015). However, group 2 gained a statistically significant additional 6.3 points of recovery in the MMSE (P =.0409), 3.8 points in the DRS (P =.0099), 0.5 points in the GOS (P =.4008), and 5.2 points in the FIM-cog (P =.0173, Wilcoxon signed rank) between the sixth week and the twelfth week of treatment on the active drug.

CONCLUSIONS

There was a consistent trend toward a more rapid functional improvement regardless of when a patient with DAI-associated TBI was started on amantadine in the first 3 months after injury.

Efficacy and safety of memantine in patients with mild to moderate vascular dementia: a randomized, placebo-controlled trial (MMM 300)

BACKGROUND AND PURPOSE

Based on the hypothesis of glutamate-induced neurotoxicity (excitotoxicity) in cerebral ischemia, this study examined the efficacy and tolerability of memantine, an uncompetitive N-methyl-D-aspartate antagonist, in the treatment of mild to moderate vascular dementia.

METHODS

In this multicenter, 28-week trial carried out in France, 321 patients received 10 mg/d memantine or placebo twice a day; 288 patients were valid for intent-to-treat analysis. Patients had to meet the criteria for probable vascular dementia and have a Mini-Mental State (MMSE) score between 12 and 20 at inclusion. The 2 primary end points were the cognitive subscale of the Alzheimers Disease Assessment Scale (ADAS-cog) and the global Clinician's Interview Based Impression of Change (CIBIC-plus).

RESULTS

After 28 weeks, the mean ADAS-cog scores were significantly improved relative to placebo. In the intention-to-treat population, the memantine group mean score had gained an average of 0.4 points, whereas the placebo group mean score had declined by 1.6 points, ie, a difference of 2.0 points (95% confidence interval, 0.49 to 3.60). The response rate for CIBIC-plus, defined as improved or stable, was 60% with memantine compared with 52% with placebo (P=0.227, intention to treat). Among the secondary efficacy parameters, which were analyzed in the per-protocol subset, MMSE was significantly improved with memantine compared with deterioration with placebo (P=0.003). The Gottfries-Brane-Steen Scale intellectual function subscore and the Nurses' Observation Scale for Geriatric Patients disturbing behavior dimension also showed differences in favor of memantine (P=0.04 and P=0.07, respectively). Memantine was well tolerated with a frequency of adverse events comparable to placebo.

CONCLUSIONS

In patients with mild to moderate vascular dementia, memantine 20 mg/d improved cognition consistently across different cognitive scales, with at least no deterioration in global functioning and behavior. It was devoid of concerning side effects.

Neuroprotective potential of ionotropic glutamate receptor antagonists

From the therapeutic point of view, the real challenge is not only to improve the symptoms, but to interfere with the pathomechanism of the disease. That is why a considerable interest has recently been devoted to developing glutamate receptor antagonists (mainly of the NMDA type) for acute and chronic neurodegeneration. Developing such a treatment that slows down the progression of the disease is extremely time and cost consuming. At present there is consensus that competitive NMDA receptor antagonists will not find therapeutic applications, in contrast to agents acting at the glycine(B) site, or channel blockers. Recently, at least seven glycine(B) antagonists (e.g. ACEA 1021, GV-150526, GV-196771A, ZD-9379, MRZ 2/576) and over 10 NMDA channel blockers (e.g. Remacemide, ARL-15896AR, HU-211, ADCI, CNS-5161, Neramexane-MRZ 2/579) have been under development, most of them as neuroprotective agents for acute (stroke, trauma) or chronic insult (e.g. Huntington's or Alzheimer's disease). Several substances selective for NR2B NMDA receptor subtypes such as eliprodil, CP-101606 and Ro-25-6981 have been claimed to have a good neuroprotective profile. This presentation is an attempt to critically review preclinical and scarce clinical experience in the development of new NMDA receptor antagonists as neuroprotective agents according to the following scheme: rational, preclinical findings in animal models and finally clinical experience if available. The general impression is that NMDA receptor antagonists may find use in chronic type of neurodegeneration while AMPA antagonists seem to show better promise in acute insult.

Neurotoxicity as a mechanism for neurodegenerative disorders: basic and clinical aspects

This three day meeting focused on chronic neurodegenerative diseases such as Parkinson's disease (PD), Alzheimer's disease (AD), and amylotrophic lateral sclerosis (ALS). It attracted 69 participants from 10 countries with dominance of Chile and USA. Neurodegeneration and its prevention increasingly gain in importance as the number of people affected increases year-by-year. The meeting addressed various basic aspects having pragmatic implications such as: oxidative stress, inflammatory reaction, glial activation, role of glutamatergic system and apoptosis using a plethora of in vitro and in vivo methods.