Prevalence and outcomes of rapidly progressive dementia: a retrospective cohort study in a neurologic unit in China

Abstract

Background: Rapidly progressive dementia (RPD) is a syndrome originating from various diseases. Recent advances have allowed a better understanding of its categories and spectrum; however, it remains challenging to make an accurate differential diagnosis and prognosis prediction.

Methods: This study was a retrospective evaluation of all participants admitted to the neurology department of a single center in China from January 2015 to December 2019. The screened patients met the RPD criteria and their characteristics were collected to explore a diagnostic pattern of RPD. In addition, outcomes of RPD were evaluated with the Glasgow Outcome Scale (GOS), activities of daily living scale (ADL), and simplified Mini-Mental State Examination (MMSE), and different prognostic analysis methods were performed to determine the prognostic factors of RPD.

Results: A total of 149 RPD patients among 15,731 inpatients were identified with an average MMSE value of 13.0 ± 4.6 at baseline. Etiological epidemiology revealed infectious, neurodegenerative and toxic/metabolic diseases as the three largest groups, accounting for 26.2%, 20.8% and 16.8% of all cases, respectively. In particular, prevalence rates of Creutzfeldt-Jakob disease (13.4%), Alzheimer's disease (11.4%), carbon monoxide poisoning (8.1%), neurosyphilis (5.4%) and dementia with Lewy bodies (5.4%) were highest in this series. A recommended diagnostic framework for RPD etiology was thus established. Follow-up evaluations showed a negative correlation between age and GOS scores (r=-0.421, P < 0.001), as well as age and simplified MMSE scores (r_s =- 0.393, P < 0.001), and a positive correlation between age and ADL scores (r_s =0.503, P < 0.001), and significantly different GOS, ADL and simplified MMSE scores across various etiologies (P = 0.003; F = 9.463, P < 0.001; F = 6.117, P < 0.001).

Conclusion: Infectious, neurodegenerative and toxic-metabolic entities were the most common RPD categories, and establishing a practical approach to RPD etiology would allow better disease management.

Keywords: Alzheimer’s disease; Carbon monoxide poisoning; Dementia with Lewy bodies; Neurosyphilis; Rapidly progressive dementia.

Fig. 1

Enrollment, evaluation and follow-up of patients with RPD in a single center

Fig. 2

Selected brain MRI images in participants with rapidly progressive dementia. The descriptive text of each image is shown with definitions of disease name, age, sex, disease course, and MRI data. (A) Creutzfeldt–Jakob disease: 72 years, female, 20 days. DWI image indicating the bilateral frontal and parietal cortex hyperintensities. (B) Neurosyphilis: 61 years, male, 2 months. T2WI demonstrating wide brain atrophy. (C) Tuberculous meningoencephalitis: 55 years, male, 1 month, T2WI demonstrating ventricular enlargement, paraventricular hyperintensities and increased vascular shadow. (D) Alzheimer’s disease: 75 years, male, 1 year, T2WI demonstrating wide brain atrophy and ventricular enlargement. (E & F) Neuronal intranuclear inclusion disease: 78 years, male, 2 months, T2WI demonstrating diffuse white matter hyperintensities and brain atrophy, and DWI images indicating hyperintensities involving corticomedullary junction in the frontal and parietal lobes. (G & H): CO poisoning: 61 years, female, 1 month, DWI and ADC images indicating diffuse sub-cortical hyperintensities. (I & J) Polyvinyl alcohol poisoning: 35 years, male, 1 month, T2WI images showing diffuse subcortical and globus pallidus hyperintensities. (K & L) Dichloroethane poisoning: 34 years, female, 10 days, T2WI showing diffuse subcortical and dentate nucleus hyperintensities. (M) Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episode: 52 years, female, half a month. T2WI showing hyperintensity and local swelling on the bilateral temporal lobes. (N & O) Autoimmune encephalitis associated with LGI1 receptor: 47 years, male, 20 days, FLAIR showing hyperintensities on the bilateral hippocampus (N), and lesions disappeared after treatment at 6-month follow-up (O). (P & Q) Sjogren’s syndrome with central nervous system involvement: 45 years, male, 2 months, T2WI showing bilateral basal ganglia (caudate nucleus, globus pallidus and anterior thalamus) symmetrical hyperintensities (P), and enhanced sequence showing significantly enhanced lesions in patches (Q). (R) Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy: 62 years, male, 2 years, T2WI images showing hyperintensity on the pole of the bilateral temporal lobes

Fig. 3

Recommended diagnostic framework of RPD etiology