Differentiating between visual hallucination-free dementia with Lewy bodies and corticobasal syndrome on the basis of neuropsychology and perfusion single-photon emission computed tomography

Michael R Misch; Sara Mitchell; Philip L Francis; Kayla Sherborn; Katayoun Meradje; Alicia A McNeely; Kie Honjo; Jiali Zhao; Christopher Jm Scott; Curtis B Caldwell; Lisa Ehrlich; Prathiba Shammi; Bradley J MacIntosh; Juan M Bilbao; Anthony E Lang; Sandra E Black; Mario Masellis

doi:10.1186/s13195-014-0071-4

Differentiating between visual hallucination-free dementia with Lewy bodies and corticobasal syndrome on the basis of neuropsychology and perfusion single-photon emission computed tomography

Alzheimers Res Ther. 2014 Dec 5;6(9):71. doi: 10.1186/s13195-014-0071-4. eCollection 2014.

Authors

Michael R Misch¹, Sara Mitchell¹, Philip L Francis¹, Kayla Sherborn¹, Katayoun Meradje¹, Alicia A McNeely¹, Kie Honjo¹, Jiali Zhao¹, Christopher Jm Scott¹, Curtis B Caldwell², Lisa Ehrlich³, Prathiba Shammi⁴, Bradley J MacIntosh², Juan M Bilbao⁵, Anthony E Lang⁶, Sandra E Black⁷, Mario Masellis⁸

Affiliations

¹ L.C. Campbell Cognitive Neurology Clinic, Sunnybrook Health Sciences Centre, Room A4 42, 2075 Bayview Avenue, Toronto, ON M4N 3M5 Canada.
² Department of Medical Biophysics, Sunnybrook Health Sciences Centre, University of Toronto, Room A4 42, 2075 Bayview Avenue, Toronto, ON M4N 3M5 Canada.
³ Department of Nuclear Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Room A4 42, 2075 Bayview Avenue, Toronto, ON M4N 3M5 Canada.
⁴ Neuropsychology Clinic, Sunnybrook Health Sciences Centre, Room A4 42, 2075 Bayview Avenue, Toronto, ON M4N 3M5 Canada.
⁵ Department of Pathology, Sunnybrook Health Sciences Centre, University of Toronto, Room A4 42, 2075 Bayview Avenue, Toronto, ON M4N 3M5 Canada.
⁶ Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, University Health Network, Toronto, Canada.
⁷ L.C. Campbell Cognitive Neurology Clinic, Sunnybrook Health Sciences Centre, Room A4 42, 2075 Bayview Avenue, Toronto, ON M4N 3M5 Canada ; Department of Medicine (Neurology), Brain Sciences Research Program, Sunnybrook Health Sciences, Centre University of Toronto, Room A4 42, 2075 Bayview Avenue, Toronto, ON M4N 3M5 Canada.
⁸ L.C. Campbell Cognitive Neurology Clinic, Sunnybrook Health Sciences Centre, Room A4 42, 2075 Bayview Avenue, Toronto, ON M4N 3M5 Canada ; Department of Medicine (Neurology), Brain Sciences Research Program, Sunnybrook Health Sciences, Centre University of Toronto, Room A4 42, 2075 Bayview Avenue, Toronto, ON M4N 3M5 Canada ; Cognition & Movement Disorders Clinic, Sunnybrook Health Sciences Centre, Room A4 42, 2075 Bayview Avenue, Toronto, ON M4N 3M5 Canada ; Neurogenetics Section, Centre for Addiction and Mental Health, University of Toronto, Room A4 42, 2075 Bayview Avenue, Toronto, ON M4N 3M5 Canada.

Abstract

Introduction: Dementia with Lewy bodies (DLB) and Corticobasal Syndrome (CBS) are atypical parkinsonian disorders with fronto-subcortical and posterior cognitive dysfunction as common features. While visual hallucinations are a good predictor of Lewy body pathology and are rare in CBS, they are not exhibited in all cases of DLB. Given the clinical overlap between these disorders, neuropsychological and imaging markers may aid in distinguishing these entities.

Methods: Prospectively recruited case-control cohorts of CBS (n =31) and visual hallucination-free DLB (n =30), completed neuropsychological and neuropsychiatric measures as well as brain perfusion single-photon emission computed tomography and structural magnetic resonance imaging (MRI). Perfusion data were available for forty-two controls. Behavioural, perfusion, and cortical volume and thickness measures were compared between the groups to identify features that serve to differentiate them.

Results: The Lewy body with no hallucinations group performed more poorly on measures of episodic memory compared to the corticobasal group, including the delayed and cued recall portions of the California Verbal Learning Test (F (1, 42) =23.1, P <0.001 and F (1, 42) =14.0, P =0.001 respectively) and the delayed visual reproduction of the Wechsler Memory Scale-Revised (F (1, 36) =9.7, P =0.004). The Lewy body group also demonstrated reduced perfusion in the left occipital pole compared to the corticobasal group (F (1,57) =7.4, P =0.009). At autopsy, the Lewy body cases all demonstrated mixed dementia with Lewy bodies, Alzheimer's disease and small vessel arteriosclerosis, while the corticobasal cases demonstrated classical corticobasal degeneration in five, dementia with agyrophilic grains + corticobasal degeneration + cerebral amyloid angiopathy in one, Progressive Supranuclear Palsy in two, and Frontotemporal Lobar Degeneration-Ubiquitin/TAR DNA-binding protein 43 proteinopathy in one. MRI measures were not significantly different between the patient groups.

Conclusions: Reduced perfusion in the left occipital region and worse episodic memory performance may help to distinguish between DLB cases who have never manifested with visual hallucinations and CBS at earlier stages of the disease. Development of reliable neuropsychological and imaging markers that improve diagnostic accuracy will become increasingly important as disease modifying therapies become available.