Study proves effectiveness of intensive voice therapy in Parkinson’s disease

They said their findings, published in the British Medical Journal, highlighted the need to optimise the use of speech therapy resources for people with Parkinson’s disease.

“This randomized trial provides insights that can guide clinical decisions”

Authors of the study

The study authors emphasized that slurred or slow speech – known as dysarthria – is a common feature of Parkinson’s disease that can have a significant impact on communication.

They said that while both NHS speech and language therapy and Lee Silverman’s US-developed voice treatment (LSVT LOUD) are available in the UK, the evidence on their effectiveness has so far been inconclusive.

Therefore, the researchers wanted to investigate the clinical effectiveness of these two speech therapy approaches compared to no therapy for dysarthria in Parkinson’s patients.

Their results are based on 388 people with Parkinson’s disease and dysarthria who were randomly assigned to one of three groups from September 2016 to March 2020.

Of the participants, 130 were assigned to the LSVT LOUD program, 129 to NHS speech and language therapy, and 129 to no speech and language therapy.

LSVT LOUD consisted of four 50-minute sessions per week over a four-week period, plus home practice activities.

NHS Speech and Language Therapy sessions were scheduled by the local therapist according to the patient’s needs, on average one session per week for a period of six to eight weeks.

All participants reported their Voice Impairment Index score after three months – a measure of the impact of communication difficulties on a scale of 0 to 120, with a low score being positive.

After three months, voice impairment scores were eight points lower for patients who received LSVT LOUD than for those who received no therapy and almost ten points lower than for those who received NHS therapy.

There was no difference in voice impairment scores between NHS speech and language therapy and no speech and language therapy, the researchers found.

Voice impairment outcomes at six and 12 months were similar, the study authors said, and quality of life related to communication also showed a significant benefit in patients who received LSVT LOUD.

Approximately 93 adverse events, mainly voice strain, were reported in the LSVT-LOUD group, 46 in the NHS therapy group and none in the other group. No serious adverse events were recorded.

The study authors said: “LSVT LOUD was more effective than no speech and language therapy or NHS speech and language therapy in reducing participant-reported impact of voice problems.”

“This randomized trial provides evidence to guide clinical decisions and highlights the need to optimize the use of resources for speech and language therapy in patients with Parkinson’s disease.”

The study, funded by the National Institute for Health and Care Research, was led by researchers at the University of Nottingham.