More advanced MRI techniques, including diffusion tensor imaging, magnetization transfer ratio imaging, and postprocessing techniques such as quantitative volumetric analysis, may be useful in the evaluation of the microstructural makeup of the brain parenchyma, including the integrity of gray matter, white matter, and their connecting neural pathways. Nuclear medicine studies can be used to evaluate for abnormal patterns of glucose metabolism, buildup of abnormal particles or proteins within neurons, dysfunction or loss of specific categories of neurons, or individual neurochemical deficits. Discussion of Procedures by Variant Variant 1: Rapidly progressive dementia; suspected Creutzfeldt-Jakob disease. Initial imaging. Rapidly progressive dementias (RPDs) are a group of conditions that result in onset of dementia over weeks or months. Although prion diseases, such as Creutzfeldt-Jakob disease (CJD), are the prototypical example of RPD, the differential diagnosis of RPD is robust, including both reversible and irreversible causes. For instance, a study out of the Memory and Aging Center at the University of California, San Francisco, showed that the diagnostic breakdown of RPDs in their patient population was 62% prion disease (all forms), 15% other neurodegenerative diseases, 8% autoimmune, 4% infectious, 2% psychiatric, 2% cancer, 2% toxic-metabolic, 2% vascular, and 4% of undetermined etiology, often representing leukoencephalopathies [1]. Importantly, 17% of their patients had potentially treatable etiologies (50% autoimmune, 13% infectious, 13% psychiatric, 13% cancer, and 10% toxic- metabolic). aMassachusetts General Hospital, Boston, Massachusetts. bResearch Author, Massachusetts General Hospital, Boston, cUT Southwestern Medical Center, Dallas, Texas. Massachusetts. dPanel Chair, Montefiore Medical Center, Bronx, New York. eUC San Diego Health, San Diego, California.
Movement Disorders and Neurodegenerative Diseases. More advanced MRI techniques, including diffusion tensor imaging, magnetization transfer ratio imaging, and postprocessing techniques such as quantitative volumetric analysis, may be useful in the evaluation of the microstructural makeup of the brain parenchyma, including the integrity of gray matter, white matter, and their connecting neural pathways. Nuclear medicine studies can be used to evaluate for abnormal patterns of glucose metabolism, buildup of abnormal particles or proteins within neurons, dysfunction or loss of specific categories of neurons, or individual neurochemical deficits. Discussion of Procedures by Variant Variant 1: Rapidly progressive dementia; suspected Creutzfeldt-Jakob disease. Initial imaging. Rapidly progressive dementias (RPDs) are a group of conditions that result in onset of dementia over weeks or months. Although prion diseases, such as Creutzfeldt-Jakob disease (CJD), are the prototypical example of RPD, the differential diagnosis of RPD is robust, including both reversible and irreversible causes. For instance, a study out of the Memory and Aging Center at the University of California, San Francisco, showed that the diagnostic breakdown of RPDs in their patient population was 62% prion disease (all forms), 15% other neurodegenerative diseases, 8% autoimmune, 4% infectious, 2% psychiatric, 2% cancer, 2% toxic-metabolic, 2% vascular, and 4% of undetermined etiology, often representing leukoencephalopathies [1]. Importantly, 17% of their patients had potentially treatable etiologies (50% autoimmune, 13% infectious, 13% psychiatric, 13% cancer, and 10% toxic- metabolic). aMassachusetts General Hospital, Boston, Massachusetts. bResearch Author, Massachusetts General Hospital, Boston, cUT Southwestern Medical Center, Dallas, Texas. Massachusetts. dPanel Chair, Montefiore Medical Center, Bronx, New York. eUC San Diego Health, San Diego, California.