Similar autobiographical memory impairment in long-term secondary progressive multiple sclerosis and Alzheimer's disease.

BACKGROUND

Memory disturbance is a common symptom of multiple sclerosis (MS), but little is known about autobiographical memory deficits in the long-term course of different MS subtypes. Inflammatory activity and demyelination is pronounced in relapsing-remitting multiple sclerosis (RRMS) whereas, similar to Alzheimer's disease, neurodegeneration affecting autobiographical memory-associated areas is seen in secondary progressive multiple sclerosis (SPMS).

OBJECTIVE

In light of distinct disease mechanisms, we evaluated autobiographical memory in different MS subtypes and hypothesized similarities between elderly patients with SPMS and Alzheimer's disease.

METHODS

We used the Autobiographical Memory Interview to assess episodic and semantic autobiographical memory in 112 education- and gender-matched participants, including healthy controls and patients with RRMS, SPMS, amnesic mild cognitive impairment (aMCI) and early Alzheimer's dementia (AD).

RESULTS

Patients with SPMS, AD, and aMCI, but not with RRMS, exhibited a pattern of episodic autobiographical memory impairment that followed Ribot's Law; older memories were better preserved than more recent memories. In contrast to aMCI and AD, neither SPMS nor RRMS was associated with semantic autobiographical memory impairment.

CONCLUSION

Our neuropsychological findings suggest that episodic autobiographical memory is affected in long-term patients with SPMS, possibly due to neurodegenerative processes in functional relevant brain regions.