The Clinical Utility of the Neuropsychological Exam in Early Identification of Corticobasal Syndrome

Alyssa Nett, Clarus Health Alliance, Norwich, United States
Caleb Peck, Clarus Health Alliance, Norwich, United States


Corticobasal degeneration (CBD) is a rare neurodegenerative movement disorder that is insidious and progressive in nature, with death occurring six to eight years following onset. Corticobasal syndrome (CBS) is the most common clinical presentation of CBD, and typically presents with asymmetric motor symptoms and cognitive decline. While CBS is the most common presentation, multiple and evolving phenotypes of CBD can make differential diagnosis based on clinical signs more challenging. In this study, we present the case of a woman referred by neurology to assist in differential diagnosis. Based on neuropsychological exam, we identified CBS as the most likely cause – a conclusion that was not shared by her referral. Follow-up neuroimaging studies confirmed the presence of CBS and possible CBD.

Participants and Methods:

Ms. X is a 58-year-old right-handed married White female with a medical history of hypothyroidism, asthma, arthritis, long-standing syncope, long-standing muscle spasms, and prior sports-related orthopedic injuries. Surgical history was unremarkable. She was referred for comprehensive outpatient neuropsychological evaluation by neurology. Presenting symptoms included worsening balance over the past six months (with falls), reduced right-hand dexterity, reduced energy, and pain related to prior injuries. Cognitive concerns included worsening word-finding issues, delayed response latency, reduced arithmetic, poor task monitoring, and declines in memory.

Computerized tomography (CT) of the brain and spine, and magnetic resonance imaging (MRI) of the brain were completed prior to the neuropsychological exam but were unavailable. Referring neurologist reported “no evidence of acute vascular events or tumors” on initial review of scans.

Cognitive findings revealed deficits localizing predominantly to the language dominant (left) hemisphere, including reduced performances on tasks of auditory working memory, sustained attention, verbal processing speed, verbal fluency, vocabulary, learning/recall of rote and contextualized verbal material, dominant fine motor dexterity, and frontal-executive skills of verbal abstraction, planning/organization, and motor sequencing/self-monitoring of the dominant hand. There was strong lateralization on motor tasks.


Ms. X’s neuropsychological profile raised concern for the early signs of a progressive asymmetric neurodegenerative condition (i.e., clinically presenting like corticobasal syndrome), which was communicated a week later during feedback with the referring neurologist, Ms. X, and her spouse. Initially, the neurologist disagreed with the diagnosis; later review of the MRI revealed “mild-moderate left cortical atrophy (frontoparietal), with minimum enlargement of the left ventricle.” Ms. X then underwent single-photon emission computerized tomography (SPECT) and positron emission tomography (PET) imaging. SPECT/PET imaging revealed asymmetric hypoperfusion and hypometabolism within the left hemisphere, consistent with the neuropsychological profile and confirming CBS and possible CBD.


Neuropsychological profile and clinical presentation were consistent with CBS, which was later confirmed by SPECT/PET imaging. This case expands upon the limited CBS literature by illustrating the clinical utility of neuropsychology in early identification of CBS, highlighting the importance of multidisciplinary collaboration with difficult cases. Additional details from the neurology consult, timeline of diagnosis, and implications of outcome are discussed.

Category: Movement and Movement Disorders

Keyword 1: movement disorders
Keyword 2: neuropsychological assessment
Keyword 3: neuroimaging: functional