Identifying bvFTD Within the Wide Spectrum of Late Onset Frontal Lobe Syndrome: A Clinical Approach.
OBJECTIVE
The behavioral variant of frontotemporal dementia (bvFTD) can be difficult to diagnose because of the extensive differential diagnosis, including many other diseases presenting with a frontal lobe syndrome. We aimed to identify the diagnostic spectrum causing a late onset frontal lobe syndrome and examine the quality of commonly used instruments to distinguish between bvFTD and non-bvFTD patients, within this syndrome.


METHODS
A total of 137 patients fulfilling the criteria of late onset frontal lobe syndrome, aged 45 to 75 years, were included in a prospective observational study. Diagnoses were made after clinical and neuropsychological examination, and neuroimaging and cerebral spinal fluid results were taken into account. Baseline characteristics and the scores on the Mini-Mental State Exam (MMSE), frontal assessment battery (FAB), Frontal Behavioral Inventory (FBI), and Stereotypy Rating Inventory (SRI) were compared between the bvFTD and the non-bvFTD group.


RESULTS
Fifty-five (40%) of the patients received a bvFTD diagnosis (33% probable and 7% possible bvFTD). Fifty-one patients (37%) had a psychiatric disorder, including 20 with major depressive disorder. Thirty-one patients received an alternative neurological, including neurodegenerative, diagnosis. MMSE and FAB scores were unspecific for a particular diagnosis. A score above 12 on the positive FBI subscale or a score above 5 on the SRI were indicative of a bvFTD diagnosis.


CONCLUSIONS
A broad spectrum of both neurological and psychiatric disorders underlies late onset frontal lobe syndrome, of which bvFTD was the most prevalent diagnosis in our cohort. The commonly used MMSE and the FAB could not successfully distinguish between bvFTD and non-bvFTD, but this could be achieved with the more specific FBI and SRI.
Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, the Netherlands. Electronic address: w.krudop@vumc.nl.
Welmoed A
WA
Krudop
Department of Old Age Psychiatry, GGZInGeest, Amsterdam, the Netherlands.
Cora J
CJ
Kerssens
Department of Old Age Psychiatry, GGZInGeest, Amsterdam, the Netherlands.
Annemiek
A
Dols
Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, the Netherlands.
Niels D
ND
Prins
Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, the Netherlands.
Christiane
C
Möller
Department of Old Age Psychiatry, GGZInGeest, Amsterdam, the Netherlands.
Sigfried
S
Schouws
Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, the Netherlands; Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, the Netherlands.
Wiesje M
WM
van der Flier
Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, the Netherlands.
Philip
P
Scheltens
Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, the Netherlands; Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, the Netherlands.
Sietske
S
Sikkes
Department of Old Age Psychiatry, GGZInGeest, Amsterdam, the Netherlands.
Max L
ML
Stek
Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, the Netherlands.
Yolande A L
YA
Pijnenburg
D000368:Aged; D002555:Cerebrospinal Fluid; D003865:Major Depressive Disorder / Q000150:complications*; D042241:Early Diagnosis; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D057180:Frontotemporal Dementia / Q000175:diagnosis*; D006801:Humans; D000067562:Late Onset Disorders / Q000175:diagnosis*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D059906:Neuroimaging; D009483:Neuropsychological Tests; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D012372:ROC Curve
bvFTD; early diagnosis; frontal lobe syndrome; neurodegenerative disorders; psychiatry