Flora Gossink

Diagnostic Accuracy of MRI and Additional [ 18F]FDG-PET for Behavioral Variant Frontotemporal Dementia in Patients with Late Onset Behavioral Changes

BACKGROUND Neuroimaging has a reasonable accuracy to differentiate behavioral variant frontotemporal dementia (bvFTD) from other neurodegenerative disorders, its value for the differentiation of bvFTD among subjects with acquired behavioral disturbances is unknown. OBJECTIVE To determine the diagnostic accuracy of MRI, additional [18F]FDG-PET, and their combination for bvFTD among subjects with late onset behavioral changes. METHODS Patients with late onset behavioral changes referred to a memory clinic or psychiatric services were included. At baseline, 111 patients had a brain MRI scan and 74 patients received an additional [18F]FDG-PET when the MRI was inconclusive. The consensus diagnosis after two-year-follow-up was used as the gold standard to calculate sensitivity and specificity for baseline neuroimaging. RESULTS 27 patients had probable/definite bvFTD and 84 patients had a non-bvFTD diagnosis (primary psychiatric diagnosis or other neurological disorders). MRI had a sensitivity of 70% (95% CI 52-85%) with a specificity of 93% (95% CI 86-97%). Additional [18F]FDG-PET had a sensitivity of 90% (95% CI 66-100%) with a specificity of 68% (95% CI 56-79%). The sensitivity of combined neuroimaging was 96% (95% CI 85-100%) with a specificity of 73% (95% CI 63-81%). In 66% of the genetic FTD cases, MRI lacked typical frontotemporal atrophy. 40% of cases with a false positive [18F]FDG-PET scan had a primary psychiatric diagnosis. CONCLUSION A good diagnostic accuracy was found for MRI and additional [18F]FDG-PET for bvFTD in patients with late onset behavioral changes. Caution with the interpretation of neuroimaging results should especially be taken in cases with a genetic background and in cases with a primary psychiatric differential diagnosis where [18F]FDG-PET is the only abnormal investigation.

Diagnostic Accuracy of the Frontotemporal Dementia Consensus Criteria in the Late-Onset Frontal Lobe Syndrome.

Background/Aims: We aimed to prospectively assess the diagnostic accuracy of the revised criteria for behavioural variant frontotemporal dementia (bvFTD) among subjects presenting with a frontal lobe syndrome in middle-late adulthood. Methods: Patients were included based on a predominant behavioural clinical presentation, a Frontal Behavioural Inventory (FBI) score of ≥11 and/or a Stereotypy Rating Inventory (SRI) score of ≥10. At baseline, the fulfilment of the international consensus criteria for behavioural variant FTD (FTDC) was systematically recorded. The 2-year follow-up consensus diagnosis was used as the gold standard to calculate sensitivity and specificity of the FTDC criteria for possible and probable bvFTD. Results: Two-year follow-up data were available for 116 patients (85%). Two-year follow-up consensus diagnoses consisted of probable/definite bvFTD (n = 27), other dementia (n = 30), psychiatric disorders (n = 46) and other neurological disorders (n = 13). Sensitivity for possible bvFTD was 85% (95% CI 70-95%) at a specificity of 27% (95% CI 19-37%). Sensitivity for probable bvFTD was 85% (95% CI 69-95%), whereas their specificity was 82% (95% CI 73-89%). Conclusions: We found a good diagnostic accuracy for FTDC probable bvFTD. However, the specificity for FTDC possible bvFTD was low. Our results reflect the symptomatic overlap between bvFTD, other neurological conditions and psychiatric disorders, and the relevance of adding neuroimaging to the diagnostic process.

Social Cognition Differentiates Behavioral Variant Frontotemporal Dementia From Other Neurodegenerative Diseases and Psychiatric Disorders

OBJECTIVE Although deficits in social cognition are established as core features in behavioral variant frontotemporal dementia (bvFTD), it remains unresolved if impaired social cognition distinguishes bvFTD from the broad differential diagnoses in clinical practice. Our aim was to study whether social cognition discriminates bvFTD from other neurodegenerative diseases and psychiatric disorders in patients presenting with late-onset frontal symptoms. Next, we studied the association of social cognition with frontal symptoms and cognitive functioning. METHODS In this longitudinal multicenter study, besides clinical rating scales for frontal symptoms, social cognition was determined by Ekman 60 Faces test and Faux Pas in addition to neuropsychological tests for other cognitive domains in patients with probable and definite bvFTD (N = 22), other neurodegenerative diseases (N = 24), and psychiatric disorders (N = 33). Median symptom duration was 2.8 years, and patients were prospectively followed over 2 years. RESULTS Total scores from Ekman 60 Faces test were significantly lower in bvFTD than in other neurodegenerative diseases and psychiatric disorders. Ekman 60 Faces test explained 91.2% of the variance of psychiatric disorders and other neurodegenerative diseases versus bvFTD (χ2 = 11.02, df = 1, p = 0.001) and was associated with all other cognitive domains. Faux Pas and the other cognitive domains did not differ between these diagnostic groups. CONCLUSION In this clinical sample Ekman 60 Faces test distinguished bvFTD successfully from other neurodegenerative diseases and psychiatric disorders. Although associated with social cognition, other cognitive domains were not discriminative. This study provides arguments to add the Ekman 60 Faces test to the neuropsychological examination in the diagnostic procedure of bvFTD.

Psychosis in behavioral variant frontotemporal dementia

Background Dementia is generally characterized by cognitive impairment that can be accompanied by psychotic symptoms; for example, visual hallucinations are a core feature of dementia with Lewy bodies, and delusions are often seen in Alzheimer’s disease. However, for behavioral variant of frontotemporal dementia (bvFTD), studies on the broad spectrum of psychotic symptoms are still lacking. The aim of this study was to systematically and prospectively subtype the wide spectrum of psychotic symptoms in probable and definite bvFTD. Methods In this study, a commonly used and validated clinical scale that quantifies the broad spectrum of psychotic symptoms (Positive and Negative Symptom Scale) was used in patients with probable and definite bvFTD (n=22) and with a primary psychiatric disorder (n=35) in a late-onset frontal lobe cohort. Median symptom duration was 2.8 years, and the patients were prospectively followed for 2 years. Results In total, 22.7% of bvFTD patients suffered from delusions, hallucinatory behavior, and suspiciousness, although the majority of the patients exhibited negative psychotic symptoms such as social and emotional withdrawal and blunted affect (95.5%) and formal thought disorders (81.8%). “Difficulty in abstract thinking” and “stereotypical thinking” (formal thought disorders) differentiated bvFTD from psychiatric disorders. The combined predictors difficulty in abstract thinking, stereotypical thinking, “anxiety”, “guilt feelings,” and “tension” explained 75.4% of variance in the diagnosis of bvFTD versus psychiatric diagnoses (P<0.001). Conclusion Delusions, hallucinatory behavior, and suspiciousness were present in one-fifth of bvFTD patients, whereas negative psychotic symptoms such as social and emotional withdrawal, blunted affect, and formal thought disorders were more frequently present. This suggests that negative psychotic symptoms and formal thought disorders have an important role in the psychiatric misdiagnosis in bvFTD; misdiagnosis in bvFTD might be reduced by systematically exploring the broad spectrum of psychiatric symptoms.

Cerebrospinal fluid biomarker examination as a tool to discriminate behavioral variant frontotemporal dementia from primary psychiatric disorders

To prospectively determine the diagnostic value of cerebrospinal fluid (CSF) levels total‐tau (tau) to amyloid‐β1–42 ratio (Aβ1–42) ratio (tau/Aβ1–42 ratio), phosphorylated‐tau (p‐tau) to tau ratio (p‐tau/tau ratio), neurofilament light chain (NfL) and YKL40 in the late‐onset frontal lobe syndrome, in particular for the differential diagnosis of behavioral variant frontotemporal dementia (bvFTD) versus primary psychiatric disorders (PSY).

Formal Psychiatric Disorders are not Overrepresented in Behavioral Variant Frontotemporal Dementia

While psychiatric misdiagnosis is well-known in behavioral variant frontotemporal dementia (bvFTD), a systematic evaluation of standardized criteria for psychiatric disorders in bvFTD is still missing. Our aim was to define frequency and character of DSM-IV psychiatric disorders among patients with probable and definite bvFTD compared to possible bvFTD, other neurodegenerative diseases, and psychiatric diagnoses, using MINI-International Neuropsychiatric Interview. We additionally compared psychiatric prodromes between these groups. Subjects were participants of the late-onset frontal lobe (LOF) study, a longitudinal multicenter study. In each patient, after baseline diagnostic procedure, a neurologist and geriatric psychiatrist made a joint clinical diagnosis. Independently, a structured diagnostic interview according to DSM-IV and ICD-10 criteria (MINI-Plus) was performed by a trained professional blinded to clinical diagnosis. Out of 91 patients, 23 with probable and definite bvFTD, 3 with possible bvFTD, 25 with a non bvFTD neurodegenerative disease, and 40 with a clinical psychiatric diagnosis were included. Overall frequency of formal current and past psychiatric disorders in probable and definite bvFTD (21.7% current, 8.7% past) did not differ from other neurodegenerative diseases (12.0% current, 16.0% past) or possible bvFTD (66.7% current, 66.7% past), but was less than in patients with a clinical psychiatric diagnosis (57.5% current, 62.5% past; p <  0.01). In probable and definite bvFTD unipolar mood disorders were most common. Formally diagnosed psychiatric disorders are not overrepresented in probable bvFTD, suggesting that psychiatric misdiagnosis in bvFTD can be reduced by strictly applying diagnostic criteria. In suspected bvFTD close collaboration between neurologists and psychiatrists will advance diagnostics and subsequent treatment.

The Diagnostic Challenge of the Late-Onset Frontal Lobe Syndrome: Clinical Predictors for Primary Psychiatric Disorders Versus Behavioral Variant Frontotemporal Dementia

OBJECTIVE Primary psychiatric disorders (PsD) can present with symptomatology identical to that of behavioral variant frontotemporal dementia (bvFTD). To date, clinical guidelines do not provide a solution for this diagnostic challenge. The aim of our study was to prospectively determine which demographic, clinical, neuropsychological, neuroimaging, and cerebrospinal fluid biomarkers are important in distinguishing PsD from bvFTD. METHODS Patients with late-onset behavioral disturbances (aged 45-75 years, 73% male) were included based on their scores on the Frontal Behavioral Inventory and the Stereotypy Rating Inventory and followed for 2 years from April 2011 to June 2015. Odds ratios (ORs) were calculated with backward stepwise logistic regression analyses to investigate the association between baseline clinical and demographic variables and the 2-year follow-up diagnosis of PsD (n = 46) (DSM-IV) versus probable/definite bvFTD (n = 27) (International Behavioral Variant FTD Criteria Consortium criteria). We separately measured the association between additional investigations and the 2-year follow-up diagnosis. Finally, we combined the selected variables to measure the predictive value of both clinical and additional investigations in a single model. RESULTS Male gender (OR = 5.9; 95% CI, 1.3-26.0), less stereotypy (OR = 0.08; 95% CI, 0.02-0.34), and more depressive symptoms (OR = 1.13; 95% CI, 1.04-1.24) explained 49% of the variance predicting PsD versus bvFTD (χ²₃ = 29.4, P < .001) and correctly classified 82.1% of the cases. Neuroimaging (OR = 0.02; 95% CI, 0.002-0.123) explained 55% of the variance (χ²₁ = 37.5, P < .001) and, in combination with clinical variables, 66.1% of the variance (χ²₃ = 44.06, P < .001). CONCLUSIONS The present study demonstrated that PsD can be distinguished from probable/definite bvFTD with a thorough clinical evaluation by a psychiatrist and neurologist along with use of validated questionnaires for depression and stereotypy; these measures are even more effective in combination with neuroimaging.

An intervention programme for caregivers of dementia patients with frontal behavioural changes: an explorative study with controlled effect on sense of competence: Support for dementia caregivers

Caregivers of dementia patients experience high levels of burden; this is especially true of caregivers of dementia patients with behavioural problems. As intervention studies for these caregivers are still lacking, we conducted an explorative pilot study into the efficacy of a support programme.

Disease trajectories in behavioural variant frontotemporal dementia, primary psychiatric and other neurodegenerative disorders presenting with behavioural change

Behavioural variant frontotemporal dementia (bvFTD) is characterized by behavioural and social cognitive disturbances, while various psychiatric and neurodegenerative disorders may have similar clinical symptoms. Since neurodegenerative disorders are eventually progressive, whereas primary psychiatric disorders are not, this study aimed to investigate whether the change in clinical symptoms over time differed between groups and which biomarkers predicted rate of decline. Disease trajectories (median follow-up = 3 years) of frontal and stereotyped behaviour, general and frontal cognitive functioning, and social cognition were examined in bvFTD (n = 34), other neurodegenerative (n = 28) and primary psychiatric disorders (n = 43), all presenting with late-onset frontal lobe syndrome (45-75 years), using linear mixed models. To gain more insight in underlying pathological processes driving disease progression, we studied the association of baseline cerebrospinal fluid (CSF) (neurofilament light (NfL) and YKL-40 levels, phosphotau181 to total tau ratio) and neuroimaging markers with disease trajectories. Frontal behavioural symptoms (e.g., disinhibition, apathy) worsened over time in bvFTD, whereas they improved in psychiatric disorders and remained stable in other neurodegenerative disorders. General and frontal cognitive decline was observed in bvFTD and other neurodegenerative disorders, but not in psychiatric disorders. None of the groups showed change in stereotypy and social cognition. For all diagnostic groups, higher CSF NfL levels were associated with faster frontal cognitive decline. A modest association was observed between caudate volume and stereotyped behaviour. Tracking frontal behavioural symptoms and cognition has potential to distinguish bvFTD from other disorders. CSF NfL levels seem to be associated with decline in frontal cognitive functioning.

Neuropsychiatry in Clinical Practice: The Challenge Of Diagnosing Behavioral Variant Frontotemporal Dementia

The behavioral variant of Frontotemporal dementia (bvFTD) is an insidious neurodegenerative disease associated with progressive degeneration of the frontal lobes, anterior temporal lobes, or both [1]. Alterations in social cognition represent the core symptoms of bvFTD resulting in emotional disengagement and socially inappropriate responses or activities [2,3]. As is apparent in revised consortium criteria, additional neuropsychiatric symptoms including apathy and stereotypical and impulsive behavior are prominent in the clinical presentation [4]. Consequently, both neurodegenerative diseases and primary psychiatric disorders are crucial in the challenging differential diagnosis. The differentiation between bvFTD and Alzheimer’s disease (AD) has become easier by the use of biomarkers that are able to identify underlying AD pathology, such as the amyloid-β (Aβ) and tau [1,5]. However, to distinguish bvFTD from psychiatric disorders can still be difficult, particularly since biomarkers for bvFTD are less robust [6]. Previous studies indicated that as a result of symptomatic overlap between bvFTD and psychiatric disorders, bvFTD patients are clinically often mistaken for psychiatric patients and vice versa [7-10]. The current clinical criteria for bvFTD require that “if behavioral disturbance is better accounted for by a psychiatric diagnosis, a diagnosis of bvFTD has to be excluded” [4]. Despite clinical overlap, bvFTD patients do not often fulfill formal criteria for a psychiatric diagnosis, suggesting that it is valuable to apply formal criteria for psychiatric disorders [11]. Careful clinical phenotyping of overlapping symptoms can help to distinguish bvFTD from psychiatric disorders in clinical practice (Figure 1) [12,13]. Figure 1 Overlap and differentiation between bvFTD and psychiatric disorders in clinical practice. The value of different symptom rating scales and clinical tools has been proven useful in clinical practice in case of suspected bvFTD when a psychiatric disorder is also probable (Figure 2) [11,14,15]. Figure 2 Clinical hallmarks and supportive measuring instruments in the differential diagnosis bvFTD and psychiatric disorders. According to current criteria, the diagnostic certainty of bvFTD increases when Frontotemporal abnormalities are found on neuroimaging. In a large cohort of patients with late-onset behavioral changes, MRI had a sensitivity of 70% and a specificity of 93% for a bvFTD diagnosis [4]. The additional [18F]FDG-PET, when the MRI was inconclusive, had a sensitivity of 90% at the cost of a lower specificity (68%) [16]. [18F]FDG-PET is mainly useful when Frontotemporal hypo-metabolism is absent to exclude bvFTD diagnosis. The interpretation of neuroimaging results should especially be taken with caution in cases with a psychiatric differential diagnosis where [18F]FDG-PET is the only abnormal investigation and in cases with a genetic background where both MRI and [18F]FDG-PET can show a specific abnormalities [16-18]. Genetic screening especially for C9orf72 repeat expansion is emphasized [19,20]. particularly in cases with a remarkable (prolonged) disease course. In clinical practice, bvFTD has a broad differential diagnosis including both neurodegenerative diseases and primary psychiatric disorders. The current criteria for bvFTD have clearly improved diagnostics but differentiating bvFTD from psychiatric disorders remains difficult. The challenge for the next decade is finding specific biomarkers for bvFTD on the one hand, and optimizing the neuropsychiatric diagnosis of bvFTD on the other hand. To this end, patient care for suspected bvFTD patients would be largely improved in a setting where neurologists and psychiatrists work hand in hand, ideally applying a consensus set of clinical rating scales next to their clinical expertise.