The central role of the Thalamus in psychosis, lessons from neurodegenerative diseases and psychedelics.

The PD-DLB psychosis complex found in Parkinson's disease (PD) and Dementia with Lewy Bodies (DLB) includes hallucinations, Somatic Symptom/Functional Disorders, and delusions. These disorders exhibit similar presentation patterns and progression. Mechanisms at the root of these symptoms also share similarities with processes promoting altered states of consciousness found in Rapid Eye Movement sleep, psychiatric disorders, or the intake of psychedelic compounds. We propose that these mechanisms find a crucial driver and trigger in the dysregulated activity of high-order thalamic nuclei set in motion by ThalamoCortical Dysrhythmia (TCD). TCD generates the loss of finely tuned cortico-cortical modulations promoted by the thalamus and unleashes the aberrant activity of the Default Mode Network (DMN). TCD moves in parallel with altered thalamic filtering of external and internal information. The process produces an input overload to the cortex, thereby exacerbating DMN decoupling from task-positive networks. These phenomena alter the brain metastability, creating dreamlike, dissociative, or altered states of consciousness. In support of this hypothesis, mind-altering psychedelic drugs also modulate thalamic-cortical pathways. Understanding the pathophysiological background of these conditions provides a conceptual bridge between neurology and psychiatry, thereby helping to generate a promising and converging area of investigation and therapeutic efforts.

A Case Report of Treatment-Resistant Agitation in Dementia With Lewy Bodies: Medical Marijuana as an Alternative to Antipsychotics.

Palliative care teams are often consulted to assist in treating persistent dementia-related behavioral issues. Delta-9-tetrahydrocannabinol (THC) offers an alternative to traditional antipsychotic drugs in the long-term management of dementia with behavioral change. We present the case of an 85-year-old man with dementia with Lewy bodies with worsening aggression refractory to antipsychotic management. Multiple regimens of antipsychotics failed both in the outpatient and inpatient settings. After exhausting other options and in the setting of worsening agitation, a tincture of THC was prescribed. After starting THC tincture, the patient's behavior rapidly improved, and he was discharged home to the care of his spouse. The challenges of prescribing and obtaining THC are discussed.

Synergistic neuroprotection by coffee components eicosanoyl-5-hydroxytryptamide and caffeine in models of Parkinson's disease and DLB.

Hyperphosphorylated α-synuclein in Lewy bodies and Lewy neurites is a characteristic neuropathological feature of Parkinson's disease (PD) and Dementia with Lewy bodies (DLB). The catalytic subunit of the specific phosphatase, protein phosphatase 2A (PP2A) that dephosphorylates α-synuclein, is hypomethylated in these brains, thereby impeding the assembly of the active trimeric holoenzyme and reducing phosphatase activity. This phosphatase deficiency contributes to the accumulation of hyperphosphorylated α-synuclein, which tends to fibrillize more than unmodified α-synuclein. Eicosanoyl-5-hydroxytryptamide (EHT), a fatty acid derivative of serotonin found in coffee, inhibits the PP2A methylesterase so as to maintain PP2A in a highly active methylated state and mitigates the phenotype of α-synuclein transgenic (SynTg) mice. Considering epidemiologic and experimental evidence suggesting protective effects of caffeine in PD, we sought, in the present study, to test whether there is synergy between EHT and caffeine in models of α-synucleinopathy. Coadministration of these two compounds orally for 6 mo at doses that were individually ineffective in SynTg mice and in a striatal α-synuclein preformed fibril inoculation model resulted in reduced accumulation of phosphorylated α-synuclein, preserved neuronal integrity and function, diminished neuroinflammation, and improved behavioral performance. These indices were associated with increased levels of methylated PP2A in brain tissue. A similar profile of greater PP2A methylation and cytoprotection was found in SH-SY5Y cells cotreated with EHT and caffeine, but not with each compound alone. These findings suggest that these two components of coffee have synergistic effects in protecting the brain against α-synuclein-mediated toxicity through maintenance of PP2A in an active state.

Natural Phytochemicals in the Treatment and Prevention of Dementia: An Overview.

The word dementia describes a class of heterogeneous diseases which etiopathogenetic mechanisms are not well understood. There are different types of dementia, among which, Alzheimer's disease (AD), vascular dementia (VaD), dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD) are the more common. Currently approved pharmacological treatments for most forms of dementia seem to act only on symptoms without having profound disease-modifying effects. Thus, alternative strategies capable of preventing the progressive loss of specific neuronal populations are urgently required. In particular, the attention of researchers has been focused on phytochemical compounds that have shown antioxidative, anti-amyloidogenic, anti-inflammatory and anti-apoptotic properties and that could represent important resources in the discovery of drug candidates against dementia. In this review, we summarize the neuroprotective effects of the main phytochemicals belonging to the polyphenol, isothiocyanate, alkaloid and cannabinoid families in the prevention and treatment of the most common kinds of dementia. We believe that natural phytochemicals may represent a promising sources of alternative medicine, at least in association with therapies approved to date for dementia.

Effect of ferulic acid and Angelica archangelica extract on behavioral and psychological symptoms of dementia in frontotemporal lobar degeneration and dementia with Lewy bodies.

AIM: The behavioral and psychological symptoms of dementia place a heavy burden on caregivers. Antipsychotic drugs, though used to reduce the symptoms, frequently decrease patients' activities of daily living and reduce their quality of life. Recently, it was suggested that ferulic acid is an effective treatment for behavioral and psychological symptoms. We have also reported several patients with dementia with Lewy bodies showing good responses to ferulic acid and Angelica archangelica extract (Feru-guard). The present study investigated the efficacy of Feru-guard in the treatment of behavioral and psychological symptoms in frontotemporal lobar degeneration and dementia with Lewy bodies. METHODS: We designed a prospective, open-label trial of daily Feru-guard (3.0 g/day) lasting 4 weeks in 20 patients with frontotemporal lobar degeneration or dementia with Lewy bodies. Behavioral and psychological symptoms of dementia were assessed at baseline and 4 weeks after the start of treatment, using the Neuropsychiatric Inventory. The Neuropsychiatric Inventory scores were analyzed using the Wilcoxon rank sum test. RESULTS: Treatment with Feru-guard led to decreased scores on the Neuropsychiatric Inventory in 19 of 20 patients and significantly decreased the score overall. The treatment also led to significantly reduced subscale scores on the Neuropsychiatric Inventory ("delusions", "hallucinations", "agitation/aggression", "anxiety", "apathy/indifference", "irritability/lability" and "aberrant behavior"). There were no adverse effects or significant changes in physical findings or laboratory data. CONCLUSION: Feru-guard may be effective and valuable for treating the behavioral and psychological symptoms of dementia in frontotemporal lobar degeneration and dementia with Lewy bodies.

Clinical practice with anti-dementia drugs: a consensus statement from British Association for Psychopharmacology.

The British Association for Psychopharmacology (BAP) coordinated a meeting of experts to review the evidence on the drug treatment for dementia. The level of evidence (types) was rated using a standard system: Types 1a and 1b (evidence from meta-analysis of randomised controlled trials or at least one controlled trial respectively); types 2a and 2b (one well-designed study or one other type of quasi experimental study respectively); type 3 (non-experimental descriptive studies); and type 4 (expert opinion). There is type 1a evidence for cholinesterase inhibitors (donepezil, rivastigmine and galantamine) for mild to moderate Alzheimer's disease; memantine for moderate to severe Alzheimer's disease; and for the use of bright light therapy and aromatherapy. There is type 1a evidence of no effect of anti inflammatory drugs or statins. There is conflicting evidence regarding oestrogens, with type 2a evidence of a protective effect of oestrogens but 1b evidence of a harmful effect. Type 1a evidence for any effect of B12 and folate will be forthcoming when current trials report. There is type 1b evidence for gingko biloba in producing a modest benefit of cognitive function; cholinesterase inhibitors for the treatment of people with Lewy body disease (particularly neuropsychiatric symptoms); cholinesterase inhibitors and memantine in treatment cognitive impairment associated with vascular dementia; and the effect of metal collating agents (although these should not be prescribed until more data on safety and efficacy are available). There is type 1b evidence to show that neither cholinesterase inhibitors nor vitamin E reduce the risk of developing Alzheimer's disease in people with mild cognitive impairment; and there is no evidence that there is any intervention that can prevent the onset of dementia. There is type 1b evidence for the beneficial effects of adding memantine to cholinesterase inhibitors, and type 2b evidence of positive switching outcomes from one cholinesterase inhibitor to another. There is type 2a evidence for a positive effect of reminiscence therapy, and type 2a evidence that cognitive training does not work. There is type 3 evidence to support the use of psychological interventions in dementia. There is type 2 evidence that a clinical diagnosis of dementia can be made accurately and that brain imaging increases that accuracy. Although the consensus statement dealt largely with medication, the role of dementia care in secondary services (geriatric medicine and old age psychiatry) and primary care, along with health economics, was discussed. There is ample evidence that there are effective treatments for people with dementia, and Alzheimer's disease in particular. Patients, their carers, and clinicians deserve to be optimistic in a field which often attracts therapeutic nihilism.

Fluctuations in cognition and alertness in Parkinson's disease and dementia.

Fluctuations in cognition and alertness (FC/FA) are key manifestations of dementia with Lewy bodies (DLB) and also have been recognized recently in patients with Parkinson's disease (PD) with dementia, a condition that shares important clinical, genetic, and neuropathologic characteristics with DLB. A comprehensive assessment of potential episodes of FC/FA is required for adequate clinical management, and several interesting clinical instruments are being developed for that purpose. FC/FA should be differentiated from episodes of excessive daytime sleepiness (EDS). Such diagnostic differentiation appears to be necessary, particularly in the light of the different therapeutic approaches to FA and EDS. Based on the deficit in cholinergic transmission observed in DLB patients, cholinesterase inhibitors, such as rivastigmine, may have a beneficial effect on FC/FA. Other therapies, such as melatonin or modafinil, require further investigation.