Researchers recently identified the most common causes of rapidly progressive dementia, and under what conditions it could be reversed.

Rapidly progressive dementia occurs when impairments in activities of daily living are apparent after less than one year of the onset of dementia. A research group in India has recently published a paper in the PLoS ONE journal where they performed a case analysis on 187 patients that suffered from rapidly progressive dementia (RPD) between January 2008 to August 2016.

As part of this analysis, they reviewed the medical records of patients who presented with either:

A rapidly progressive dementia (as defined using the Diagnostic and Statistical manual of disorders-5 [DSM-V]) Young-onset cognitive decline with suspected secondary causes of dementia A fluctuating course of symptoms.

Detailed medical records containing clinical details such as patient information, MRI scans, CT scans, autoimmune disease tests, and results from infectious disease tests were used in tandem with statistical analysis to identify specific causes of dementia amongst patients.

The patients with rapidly progressive dementia were split into three groups:

Reversible (treatable) secondary dementia group (126 patients

Irreversible secondary dementias (14 patients)

Non-prion neurodegenerative and vascular dementias (47 patients)

Most Rapidly Progressive Dementia was Reversible

The results indicated that secondary reversible causes were the most common causes of rapidly progressive dementia. A number of secondary causes of dementia were found to be reversible in patients with younger onset of rapidly progressive dementia. Among those suffering from rapidly progressing dementia, infections were the strongest driver of dementia (39%). Of these, suspected subacute sclerosing panencephalitis (41%), neurosyphylis (17.9%), and progressive multifocal leukoencephalopathy (15.3%) were the most common infections. Following infections, immune-mediated dementias (18.1%) and neurodegenerative dementias were the next most common causes of reversible rapidly progressive dementias.

Interestingly, this study noted that neoplastic disorders (i.e. related to abnormal growth of tissue) and immune-mediated rapidly progressive dementia could be identified earlier (under six months), while neurodegenerative disorders were identified later (over six months).

Some limitations of this study include that a number of patients lacked a thorough neuropsychological assessment, and a number of tests for autoimmune diseases could not be performed on patients due to budgetary constraints.

This research shows that many seemingly irreversible diseases can, in fact, be treated if diagnosed early enough. The authors maintain that rapidly progressive dementia is a medical emergency that must be taken seriously. What were once considered degenerative conditions are now considered reversible conditions and diagnostic and treatment protocols should be adjusted accordingly. This is valuable information to take into account going forward when creating treatment regimens to combat these illnesses.

Written by Michael Healy, BSc, MSc

Reference: Anuja P, Venugopalan V, Darakhshan N, Awadh P, Wilson V, Manoj G, et al. (2018) Rapidly progressive dementia: An eight year (2008–2016) retrospective study. PLoS ONE 13(1): e0189832.