High-frequency repetitive transcranial magnetic stimulation to the left dorsolateral prefrontal cortex of patients with Parkinson’s disease and treatment-resistant depression: a pilot study

ABSTRACT

An increasing amount of evidence is showing the therapeutic effects of rTMS on PD-related non-motor functions neuroanatomically linked to the DLPFC. This presents an ongoing need to apply an optimal combination of stimulation parameters to clinically heterogeneous patient populations, including those with neuropsychiatric problems and other comorbidities along with the neurodegenerative process. In this prospective pilot study, six patients with PD and treatment-resistant depression were thoroughly assessed and carefully monitored before, during, and after each stimulation procedure. The results can provide the basis for developing an extended rTMS protocol that is both effective and safe.

KEYWORDS:

• Repetitive transcranial magnetic stimulation
• Parkinson’s disease
• dorsolateral prefrontal cortex
• treatment-resistant depression

Acknowledgments

The authors would like to thank dr Inna Rubanovits and RN Regina Palatu from the Neurology Center of East Tallinn Central Hospital for clinical assistance, Marika Tammaru from the Research Department and Mari-Liis Rehepapp from the Quality Departmant of East Tallinn Central Hospital for assistance on statistical analysis as well as Jaan Tulviste, Renate Rutiku, Kadi Tulver, Carolina Murd, Inga Karton, Jaan Aru and Professor Talis Bachmann from the Cognitive Psychology Lab of the University of Tartu for their assistance on various aspects during different stages of the study.

Authors’ contributions

René Randver: project conception, study design, review of literature, neuropsychological assessment, administering rTMS, data analysis, first manuscript draft, and subsequent revisions. Toomas Toomsoo: screening and recruitment of patients, neurological examinations. Külli Davel: technical assistance and clinical monitoring during the administration of rTMS.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported in part by the Estonian Research Council grant IUT20-40 (sub-grant TSVPH14140I, awarded to Talis Bachmann) and the project ASTRA PER ASPERA (financed by the EU Regional Development Fund and administered by the University of Tartu). The principal investigator (R.R.) received no additional renumeration apart from the doctoral stipend (in the early stages of the study) as well as regular monthly wages (in later stages).