tDCS and Speech Therapy for Motor Speech Disorders Caused by FTLD Syndromes: a Feasibility Study

The investigators will test the feasibility of using transcranial direct current stimulation (tDCS) and speech therapy to treat participants with motor speech disorders caused by Frontotemporal Lobar Degeneration Pathology including nonfluent variant Primary Progressive Aphasia, Progressive Supranuclear Palsy, Corticobasal Syndrome, or behavioral variant Frontotemporal Dementia. The investigators will deliver transcranial direct current stimulation (tDCS) either in a clinic setting at the University of California San Francisco, or in patients' homes, via a consumer tDCS device and videoconferencing. Transcranial direct current stimulation (tDCS) is a neuromodulation technique that can enhance the benefits of speech therapy treatment. Participants will receive a dose of tDCS stimulation + speech therapy and a dose of sham tDCS + speech therapy in a randomized double blind crossover study performed either in the clinic or at home via videoconferencing. This study can be performed entirely remotely.

Nonfluent Aphasia, Progressive, Primary Progressive Nonfluent Aphasia, Primary Progressive Non Fluent Aphasia, Progressive Supranuclear Palsy, Corticobasal Degeneration, Behavioral Variant of Frontotemporal Dementia

Experimental: Neurostimulation of 2 milliamps anodal (active) tDCS stimulation for 20 mins during 1 hour speech therapy sessions, 3 times a week for 8 weeks, plus daily homework. Then a washout period of no treatment, followed by a 8 weeks of sham tDCS treatment during 1 hour speech therapy sessions, 3 times a week for 8 weeks, plus daily homework. Active comparator: Experimental: Sham tDCS stimulation for 20 mins during 1 hour speech therapy sessions, 3 times a week for 8 weeks, plus daily homework. Then a washout period of no treatment, followed by a 8 weeks of neurostimulation of 2 milliamps anodal (active) sham tDCS treatment during 1 hour speech therapy sessions, 3 times a week for 8 weeks.

Percent intelligible words, calculated by an SLP scoring each word spoken as intelligible or unintelligible, divided by total number of words spoken, during trained and untrained scripted speech.

Percent intelligible words, calculated by an SLP scoring each word spoken as intelligible or unintelligible, divided by total number of words spoken, during trained and untrained scripted speech.

Percent intelligible words, calculated by an SLP scoring each word spoken as intelligible or unintelligible, divided by total number of words spoken, during trained and untrained scripted speech.

Acceptability & ease of use of tDCS device from patient's homes. Measured via surveys designed by the investigators. Scores will range from 0 to 100. Higher scores will indicate better acceptability and ease of use.

Inclusion Criteria: Mini Mental Status Exam score > 10 diagnosis of nfvPPA via Gorno-Tempini 2011 criteria, or a diagnosis of FTLD syndrome including progressive supranuclear palsy, corticobasal syndrome or behavioral variant frontotemporal dementia PLUS a motor speech disorder (apraxia of speech and/or dysarthria) able to give consent right-handed native English speaker having a caregiver who is also able to sign and understand the caregiver's consent form. Exclusion Criteria: History of: stroke TBI brain cancer seizures craniotomy, skull surgery or fracture metallic implant in head pacemaker or cardioverter-defibrillator pregnancy.

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