Impact of our Research

We have developed several scales and instruments for medical professionals to use in order to better grade the types and severity of a patient’s symptoms. These scales include the Progressive Aphasia Severity Scale, the Social Impairment Rating Scale, and the Neuropsychological Assessment Rating. All of these scales are modeled after the widely-used Clinical Dementia Rating (CDR) scale, with a range of 0 to 3, 0 indicating normal function, 0.5 indicating questionable or very mild impairment, and 1, 2, or 3 indicating mild, moderate, or severe impairment.

The Progressive Aphasia Severity Scale (PASS) is a scale with a focus on measuring the types and severity of language impairments and areas of preserved function in 10 different subdomains of speech and language. More than 100 clinicians and researchers from more than 20 countries around the world are using the scale, and it has been or is being translated into 4 other languages.

We also developed a scale to measure social symptoms of FTD, called the Social Impairment Rating Scale (SIRS). This scale allows specific types of social behavioral impairments to be graded using the scale above. We hope will ultimately be useful in treatment trials to demonstrate therapies can help these key symptoms.

For both of these scales, we have identified brain regions measured by MRI where shrinkage is associated with symptoms and are using these as MRI markers of the brain changes associated with symptoms, again with the ultimate goal we hope of being able to measure stabilization of shrinkage with treatments of the future.

We developed the Neuropsychological Assessment Rating (NAR) scale because we believe it is helpful for neuropsychologists to be able to use their clinical judgment to rate the types and severity of a patient’s areas of weakness or strength on a battery of neuropsychological tests regardless of exactly what tests are used. That is most neuropsychological testing measures a set of domains of cognitive functions, including attention, executive function, language, memory, visual and spatial skills. For tests with normative data, each patient is compared to others of similar age, gender, educational level, etc to generate scores. If a patient is tested twice using different tests, or if two patients are being compared to each other after having been tested using different tests, it may be challenging to use those test scores to compare them to each other. The NAR allows the neuropsychologist to interpret the test results and rate the patient’s impairments on a standard scale regardless of the specific tests that were used. We hope this will facilitate a variety of types of research and enable test performance to be contextualized by the neuropsychologist’s clinical judgment.

• Gallée J, Cordella C, Fedorenko E, Hochberg D, Touroutoglou A, Quimby M, Dickerson BC. Breakdowns in Informativeness of Naturalistic Speech Production in Primary Progressive Aphasia. Brain Sci. 2021 Jan 20;11(2):130. doi: 10.3390/brainsci11020130. PMID: 33498260; PMCID: PMC7909266.
• Putcha D, Dickerson BC, Brickhouse M, Johnson KA, Sperling RA, Papp KV. Word retrieval across the biomarker-confirmed Alzheimer’s disease syndromic spectrum. Neuropsychologia. 2020 Feb 10:107391. doi:10.1016/j.neuropsychologia.2020.107391. [Epub ahead of print] PubMed PMID:32057937.
• Putcha D, McGinnis SM, Brickhouse M, Wong B, Sherman JC, Dickerson BC. Executive dysfunction contributes to verbal encoding and retrieval deficits in posterior cortical atrophy. Cortex. 2018 May 10;106:36-46.
• Bickart KC, Brickhouse M, Negreira A, Sapolsky D, Barrett LF, Dickerson BC. Atrophy in distinct corticolimbic networks in frontotemporal dementia relates to social impairments measured using the Social Impairment Rating Scale. J Neurol Neurosurg Psychiatry 2014;85:438-448.
• Sapolsky D, Domoto-Reilly K, & Dickerson BC. Use of the Progressive Aphasia Severity Scale (PASS) in monitoring speech and language status in PPA. Aphasiology. 2014; 28(8-9): 993-1003.
• Domoto-Reilly K, Sapolsky D, Brickhouse M, Dickerson BC; for the Alzheimer’s Disease Neuroimaging Initiative. Naming impairment in Alzheimer’s disease is associated with left anterior temporal lobe atrophy. Neuroimage. 2012 Oct 15;63(1):348-55.
• Sapolsky D, Domoto-Reilly K, Negreira A, Brickhouse M, McGinnis S, Dickerson BC. Monitoring progression of primary progressive aphasia: Current approaches and future directions. Neurodegenerative Disease Management 2011 1(1): 43-55.
• Wolk DA, Dickerson BC, Alzheimer’s Disease Neuroimaging Initiative. Fractionating verbal episodic memory in Alzheimer’s disease. Neuroimage 2011;54:1530-1539
• Dickerson BC, Sperling RA, Hyman BT, Albert MS, Blacker D. Clinical prediction of AD dementia across the spectrum of mild cognitive impairment. Archives of General Psychiatry. 2007;64(12):1443-1450.