Processing of Music in Alzheimer Patients

Alzheimer's disease (AD) is the most common cause of dementia accounting for 60-70% of all dementias. In most cases the cause for AD is unknown. The progression of AD is characterized by an advancing decline in cognitive skills and symptoms like impaired learning, memory deficits, language impairment and behavioral disturbances in later stages. The symptoms of AD are caused by cerebral atrophy which is the consequence of multiple pathological processes, including the formation of neurofibrillary tangles at neurites and amyloid plaques in the walls of cerebral blood vessels. AD is a major public health issue and its significance increases as the population grows older.

Music is thought to have preceded the development of spoken language as a form of communication and it has been used for therapeutic purposes in many ways throughout history. In patients with AD, musical memory has been noticed to be well-preserved and constituting a relatively independent part of memory. Music-based neurological rehabilitation provides a mode of treatment, which is free of side effects and can be personalized for patients with dementia.

Aims of this study are to examine how AD affects the structure of various brain areas associated with music processing and to statistically correlate musical cognition with memory performance in patients with AD. Focus is on brain areas associated with musical pleasure like the striatum, superior temporal gyrus, inferior frontal gyrus and areas associated with long-term musical memory like the anterior cingulate gyrus and presupplementary motor area. Hippocampal atrophy serves as a reference of the stage of AD. Our working hypothesis is that musicality correlates with preserved cognitive skills and memory.

Voluntary participants who have been diagnosed with AD are recruited from Turku University Central Hospital. Their musicality is assessed with a short version of Montreal Battery of Evaluation of Amusia which contains listening tasks that test the patients' memory, rhythm recognition and pitch discrimination. In addition, patients are asked to fill an inquiry that maps their use of music and its significance in their daily lives. Voxel-Based Morphometry is applied on MRI images to evaluate atrophy in the hippocampus and entorhinal cortex, which correlate with clinical stages of AD, as well as on the brain areas relevant for processing of music.