Delirium prior to dementia as a clinical phenotype of Lewy body disease: an autopsied case report

New Insights into Potential Biomarkers in Patients with Mild Cognitive Impairment Occurring in the Prodromal Stage of Dementia with Lewy Bodies

BACKGROUND

Prodromal dementia with Lewy bodies (DLB) can emerge with the onset of mild cognitive impairment (MCI). Standard biomarkers can help identify such patients to improve therapy and treatment strategies. Our review aims to describe the latest evidence on promising biomarkers in prodromal DLB with MCI onset (MCI-LB).

METHODS

We selected articles on different biomarkers in MCI-LB from PubMed and conducted a narrative review.

RESULTS

We identified potentially promising clinical biomarkers, e.g., (1) assessing autonomic symptoms specifically, (2) describing the cognitive profile in several subdomains including executive and visual functions, and (3) measuring the speed of speech. In addition, we describe the measurement of seeding amplification assays of alpha-synuclein in cerebrospinal fluid as a relevant biomarker for MCI-LB. Electroencephalographic markers, as in calculating the theta/beta ratio or intermittent delta activity, or analyzing peak frequency in electroencephalography-methods also potentially useful once they have been validated in large patient cohorts. The 18F fluorodesoxyglucose positron emission tomography (FDG-PET) technique is also discussed to investigate metabolic signatures, as well as a specific magnetic resonance imaging (MRI) technique such as for the volumetric region of interest analysis.

CONCLUSIONS

These biomarker results suggest that MCI-LB is a promising field for the use of biomarkers other than established ones to diagnose early prodromal DLB. Further large-scale studies are needed to better evaluate and subsequently use these promising biomarkers in prodromal DLB.

Challenges in diagnosis and management of delirium in Lewy body disease

BACKGROUND

Delirium is an acute onset and fluctuating impairment of cognition, attention and arousal, often precipitated by acute illness. Lewy body disease (LBD) is an umbrella term for a range of clinical conditions, including Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB). People living with LBD seem to be more susceptible to delirium than those with other subtypes of dementia.

AIM

To describe the challenges in clinical diagnosis and management of LBD.

METHODS

A systematic review of published literature on diagnosis and management of delirium in LBD.

RESULTS

Delirium is particularly challenging to diagnose in LBD as many of the clinical characteristics which define delirium such as inattention, fluctuating arousal, complex visual hallucinations and delusions, are also common to LBD. Distinguishing delirium from LBD can be very difficult clinically especially in the prodromal stages. Both under and over diagnosis of delirium, and under and over treatment of the symptoms have the potential to compromise the care and safety of people with a diagnosed or undiagnosed LBD. Clinicians are currently working with an extremely limited set of evidence-based management options for those with delirium in the context of a LBD diagnosis. For patients with LBD and their families this is an area of clinical practice that needs focused research.

Delirium Superimposed on Dementia in Perioperative Period and Intensive Care

Delirium is a life-threatening condition, the causes of which are still not fully understood. It may develop in patients with pre-existing dementia. Delirium superimposed on dementia (DSD) can go completely unnoticed with routine examination. It may happen in the perioperative period and in the critical care setting, especially in the ageing population. Difficulties in diagnosing and lack of specific pharmacological and non-pharmacological treatment make DSD a seriously growing problem. Patient-oriented, multidirectional preventive measures should be applied to reduce the risk of DSD. For this reason, anesthesiologists and intensive care specialists should be aware of this interesting condition in their everyday clinical practice.

Young-Onset Dementia with Lewy Bodies

Young-onset (< 65 years) dementia is a challenging clinical problem. A 61-year-old man visited our clinic because of a 2-year history of mild cognitive impairment of the executive disorder type. He was initially suspected of having young-onset Alzheimer's disease due to the lack of motor signs or hippocampal atrophy by conventional brain MRI. However, he proved to have anosmia, erectile dysfunction, hypersexuality, constipation, REM sleep behavior disorder, and emotional lability; imaging findings included positive brain perfusion SPECT, nigrosome MRI, DAT scan, and MIBG myocardial scintigraphy. All these clinical imaging features led to the correct diagnosis of young-onset dementia with Lewy bodies (YOD-DLB). It is hoped that this case report will help facilitate a future prospective study to diagnose and follow YOD-DLB patients with the aim of determining appropriate management and care.