Recovery of Dementia Syndrome following Treatment of Brain Inflammation

Abstract

Aim/background: This research aims to prevent progression from mild cognitive impairment (MCI) to Alzheimer's disease. A Japanese study of leprosy patients revealed that the incidence of dementia in leprosy patients was lower than that in patients taking dapsone who had never been treated. But a similar study the following year refuted the finding of less dementia in leprosy patients taking dapsone. According to conflicting reports, Mycobacterium leprae was a factor in reducing the incidence of Alzheimer's disease. Thus, we formed a hypothesis that if dapsone is administered to patients without leprosy but with MCI and the prophylactic effect of dementia syndrome is observed over a long period of time, we can determine whether dapsone can prevent the progression of MCI to dementia syndrome. If dementia does not occur after treating inflammation in brain cells while dementia develops after a certain long-term period (usually within 2-3 years), brain cell inflammation can be demonstrated as the cause of dementia.

Methods: This is a prospective cohort research. We report on an elderly patient diagnosed with MCI from February 2008 to January 2019. The patient took dapsone 100 mg once a day from 2010 to 2015 for the treatment of MCI. Since 2016, the production of dapsone has ceased in Korea. In June 2018, the patient was diagnosed with Alzheimer's disease. The patient took Aricept for the treatment of Alzheimer's disease but complained of serious side effects. And dapsone was re-administered to the patient from November 2018.

Results: The patient recovered to MCI and improved her daily life owing to the treatment with dapsone. The drug controls the inflammatory response in the brain, irrespective of whether proteins are deposited in neurons.

Conclusions: This finding means that dementia syndrome is an inflammatory disease. This research suggests that diagnostic criteria for Alzheimer's disease should be based on the presence or absence of inflammation in neurons. Because inflammation in neurons can occur in middle age due to various causes, we can treat inflammation in neurons and prevent and treat dementia syndrome, including Alzheimer's disease.

Keywords: Activities of daily living; Alzheimer's disease; Brain cell inflammation; Dapsone; Dementia syndrome; Diaminodiphenyl sulfone; Magnetic resonance imaging; Mild cognitive impairment; Neuropsychological assessment.

Fig. 1

Scope of Alzheimer's disease and dementia syndrome [1]. Alzheimer's disease belongs to dementia syndrome with cognitive impairment, but it is a degenerative brain disease in which the amyloid beta protein or tau protein is deposited in brain cells even in the absence of cognitive impairment [1]. In this study, we suggest that the diagnosis criteria and treatment plan of Alzheimer's disease should be changed. Whether inflammatory reactions are persistent is important when diagnosing and treating Alzheimer's disease.

Fig. 2

Structure and result of prospective cohort. Japanese Sanatorium Study: In the 1990s, a Japanese epidemiological survey study of leprosy patients aged 65 years or older revealed the incidence of dementia in leprosy patients [2]. A neuropathological case series of leprosy patients detected the absence of senile plaques [4]. But a similar study the following year showed no difference in the discovery of senile plaques between the patient and control groups [5]. Seoul study: a patient diagnosed with MCI through MRI and mental neurological examination in 2008 continued to take dapsone regularly until 2016 and lived a normal routine (online suppl. 4, 5, 6). However, after discontinuation, the patient was diagnosed with Alzheimer's disease in 2018, but lives with MCI as of November 2019 after taking dapsone (online suppl. 1, 2).