Vocal music enhances memory and language recovery after stroke: pooled results from two RCTs.

OBJECTIVE: Previous studies suggest that daily music listening can aid stroke recovery, but little is known about the stimulus-dependent and neural mechanisms driving this effect. Building on neuroimaging evidence that vocal music engages extensive and bilateral networks in the brain, we sought to determine if it would be more effective for enhancing cognitive and language recovery and neuroplasticity than instrumental music or speech after stroke. METHODS: Using data pooled from two single-blind randomized controlled trials in stroke patients (N = 83), we compared the effects of daily listening to self-selected vocal music, instrumental music, and audiobooks during the first 3 poststroke months. Outcome measures comprised neuropsychological tests of verbal memory (primary outcome), language, and attention and a mood questionnaire performed at acute, 3-month, and 6-month stages and structural and functional MRI at acute and 6-month stages. RESULTS: Listening to vocal music enhanced verbal memory recovery more than instrumental music or audiobooks and language recovery more than audiobooks, especially in aphasic patients. Voxel-based morphometry and resting-state and task-based fMRI results showed that vocal music listening selectively increased gray matter volume in left temporal areas and functional connectivity in the default mode network. INTERPRETATION: Vocal music listening is an effective and easily applicable tool to support cognitive recovery after stroke as well as to enhance early language recovery in aphasia. The rehabilitative effects of vocal music are driven by both structural and functional plasticity changes in temporoparietal networks crucial for emotional processing, language, and memory.

Cognitive and neural mechanisms underlying the mnemonic effect of songs after stroke.

Sung melody provides a mnemonic cue that can enhance the acquisition of novel verbal material in healthy subjects. Recent evidence suggests that also stroke patients, especially those with mild aphasia, can learn and recall novel narrative stories better when they are presented in sung than spoken format. Extending this finding, the present study explored the cognitive mechanisms underlying this effect by determining whether learning and recall of novel sung vs. spoken stories show a differential pattern of serial position effects (SPEs) and chunking effects in non-aphasic and aphasic stroke patients (N = 31) studied 6 months post-stroke. The structural neural correlates of these effects were also explored using voxel-based morphometry (VBM) and deterministic tractography (DT) analyses of structural MRI data. Non-aphasic patients showed more stable recall with reduced SPEs in the sung than spoken task, which was coupled with greater volume and integrity (indicated by fractional anisotropy, FA) of the left arcuate fasciculus. In contrast, compared to non-aphasic patients, the aphasic patients showed a larger recency effect (better recall of the last vs. middle part of the story) and enhanced chunking (larger units of correctly recalled consecutive items) in the sung than spoken task. In aphasics, the enhanced chunking and better recall on the middle verse in the sung vs. spoken task correlated also with better ability to perceive emotional prosody in speech. Neurally, the sung > spoken recency effect in aphasic patients was coupled with greater grey matter volume in a bilateral network of temporal, frontal, and parietal regions and also greater volume of the right inferior fronto-occipital fasciculus (IFOF). These results provide novel cognitive and neurobiological insight on how a repetitive sung melody can function as a verbal mnemonic aid after stroke.

Functional neural changes associated with acquired amusia across different stages of recovery after stroke.

Brain damage causing acquired amusia disrupts the functional music processing system, creating a unique opportunity to investigate the critical neural architectures of musical processing in the brain. In this longitudinal fMRI study of stroke patients (N = 41) with a 6-month follow-up, we used natural vocal music (sung with lyrics) and instrumental music stimuli to uncover brain activation and functional network connectivity changes associated with acquired amusia and its recovery. In the acute stage, amusic patients exhibited decreased activation in right superior temporal areas compared to non-amusic patients during instrumental music listening. During the follow-up, the activation deficits expanded to comprise a wide-spread bilateral frontal, temporal, and parietal network. The amusics showed less activation deficits to vocal music, suggesting preserved processing of singing in the amusic brain. Compared to non-recovered amusics, recovered amusics showed increased activation to instrumental music in bilateral frontoparietal areas at 3 months and in right middle and inferior frontal areas at 6 months. Amusia recovery was also associated with increased functional connectivity in right and left frontoparietal attention networks to instrumental music. Overall, our findings reveal the dynamic nature of deficient activation and connectivity patterns in acquired amusia and highlight the role of dorsal networks in amusia recovery.

Music-based interventions in neurological rehabilitation.

During the past ten years, an increasing number of controlled studies have assessed the potential rehabilitative effects of music-based interventions, such as music listening, singing, or playing an instrument, in several neurological diseases. Although the number of studies and extent of available evidence is greatest in stroke and dementia, there is also evidence for the effects of music-based interventions on supporting cognition, motor function, or emotional wellbeing in people with Parkinson's disease, epilepsy, or multiple sclerosis. Music-based interventions can affect divergent functions such as motor performance, speech, or cognition in these patient groups. However, the psychological effects and neurobiological mechanisms underlying the effects of music interventions are likely to share common neural systems for reward, arousal, affect regulation, learning, and activity-driven plasticity. Although further controlled studies are needed to establish the efficacy of music in neurological recovery, music-based interventions are emerging as promising rehabilitation strategies.

[Effectiveness of music in brain rehabilitation. A systematic review]. / Musiikin vaikuttavuus aivojen kuntoutuksessa.

There is no curative treatment for diseases causing brain injury. Music causes extensive activation of the brain, promoting the repair of neural systems. Addition of music listening to rehabilitation enhances the regulation or motor functions in Parkinson and stroke patients, accelerates the recovery of speech disorder and cognitive injuries after stroke, and decreases the behavioral disorders of dementia patients. Music enhances the ability to concentrate and decreases mental confusion. The effect of music can also be observed as structural and functional changes of the brain. The effect is based, among other things, on lessening of physiologic stress and depression and on activation of the dopaminergic mesolimbic system.