Impact of brain atrophy on tDCS and HD-tDCS current flow: a modeling study in three variants of primary progressive aphasia.

BACKGROUND: During transcranial direct current stimulation (tDCS), the amount and distribution of current that reaches the brain depends on individual anatomy. Many progressive neurodegenerative diseases are associated with cortical atrophy, but the importance of individual brain atrophy during tDCS in patients with progressive atrophy, including primary progressive aphasia (PPA), remains unclear. OBJECTIVE: In the present study, we addressed the question whether brain anatomy in patients with distinct cortical atrophy patterns would impact brain current intensity and distribution during tDCS over the left IFG. METHOD: We developed state-of-the-art, gyri-precise models of three subjects, each representing a variant of primary progressive aphasia: non-fluent variant PPA (nfvPPA), semantic variant PPA (svPPA), and logopenic variant PPA (lvPPA). We considered two exemplary montages over the left inferior frontal gyrus (IFG): a conventional pad montage (anode over F7, cathode over the right cheek) and a 4 × 1 high-definition tDCS montage. We further considered whether local anatomical features, specifically distance of the cortex to skull, can directly predict local electric field intensity. RESULTS: We found that the differences in brain current flow across the three PPA variants fall within the distribution of anatomically typical adults. While clustering of electric fields was often around individual gyri or sulci, the minimal distance from the gyri/sulci to skull was not correlated with electric field intensity. CONCLUSION: Limited to the conditions and assumptions considered here, this argues against a specific need to adjust the tDCS montage for these patients any more than might be considered useful in anatomically typical adults. Therefore, local atrophy does not, in isolation, reliably predict local electric field. Rather, our results are consistent with holistic head anatomy influencing brain current flow, with tDCS producing diffuse and individualized brain current flow patterns and HD-tDCS producing targeted brain current flow across individuals.

A preliminary study of a health related quality of life assessment of priority symptoms in advanced lymphoma: the National Comprehensive Cancer Network-Functional Assessment of Cancer Therapy - Lymphoma Symptom Index.

Despite the recent advances in cancer therapeutics for lymphoma (Lym), a continuum of disease, treatment and psychological challenges, adversely impacting health-related quality of life, remain for the clinical management of the patient with Lym. In response, this study presents the development and validation of the National Comprehensive Cancer Network-Functional Assessment of Cancer Therapy (NCCN-FACT) Lymphoma Symptom Index-18 (FLymSI-18). Patients with advanced Lym (n = 50) rated the significance of 40 symptoms, and hematologist-oncologists (n = 10) rated these symptoms according to importance and disease-related or treatment-related origin. Patient symptom priorities were unified with clinician priorities for symptom measurement in Lym for instrument development. Reliability estimates indicate that FLymSI-18 has acceptable internal consistency (α = 0.87), content validity and concurrent validity as indicated by moderate to strong correlations with the FACIT (Functional Assessment of Chronic Illness Therapy). Overall, the FLymSI-18 provides evidence for its reliability and validity as a brief assessment of the most important symptoms associated with advanced Lym in the clinical trial research environment.

General population norms for the Functional Assessment of Cancer Therapy-Kidney Symptom Index (FKSI).

BACKGROUND: Metastatic renal cell cancer is associated with poor long-term survival and has no cure. Traditional clinical endpoints are best supplemented by patient-reported outcomes designed to assess symptoms and function. Normative data was obtained on the National Comprehensive Cancer Network-Functional Assessment of Cancer Therapy-Kidney Symptom Index (NFKSI) to aid in score interpretation and planning of future trials. METHODS: General population data were obtained from 2000 respondents, who completed the 19-item NFKSI-19, as well the SF-36 (Short Form 36-item instrument) and the PROMIS-29 (29-item Patient Reported Outcomes Measurement Information System), both general health status measures. Basic demographic and self-reported comorbidity data were also collected. RESULTS: The sample was 50% female, 85.7% caucasian, with an equal distribution across age bands from 18 years to 75 years and older. Most respondents (62.8%) had more than a high school education and reported an Eastern Cooperative Oncology Group performance status of normal activity without symptoms (63.4%). Score distributions on the NFKSI-19, its subscales, and individual items are summarized. CONCLUSIONS: The NFKSI-19 and its subscales now have scores for the general US population, allowing comparability to generic questionnaires such as the SF-36 and PROMIS-29. These data can be used to guide treatment expectations and plan future comparative effectiveness research using the scales.