Correction to: Cognitive profiles discriminate between genetic variants of behavioral frontotemporal dementia.

The original version of this article unfortunately contained a mistake.

Cognitive profiles discriminate between genetic variants of behavioral frontotemporal dementia.

INTRODUCTION: Trials to test disease-modifying treatments for frontotemporal dementia are eagerly awaited and sensitive instruments to assess potential treatment effects are increasingly urgent, yet lacking thus far. We aimed to identify gene-specific instruments assessing clinical onset and disease progression by comparing cognitive functioning between bvFTD patients across genetic mutations. METHODS: We examined differences in 7 cognitive domains between bvFTD patients with GRN (n = 20), MAPT (n = 29) or C9orf72 (n = 31) mutations, and non-carriers (n = 24), and described longitudinal (M = 22.6 months, SD = 16.6) data in a subsample (n = 27). RESULTS: Patients showed overall cognitive impairment, except memory recall, working memory and visuoconstruction. GRN patients performed lower on executive function (mean difference - 2.1; 95%CI - 4.1 to - 0.5) compared to MAPT and lower on attention compared to MAPT (mean difference - 2.5; 95%CI - 4.7 to - 0.3) and C9orf72 (mean difference - 2.4; 95%CI - 4.5 to - 0.3). Only MAPT patients were impaired on delayed recall (mean difference - 1.4; 95%CI - 2.1 to - 0.7). GRN patients declined rapidly on attention and memory, MAPT declined in confrontation naming, whereas C9orf72 patients were globally impaired but remained relatively stable over time on all cognitive domains. DISCUSSION: This study shows gene-specific cognitive profiles in bvFTD, which underlines the value of neuropsychological tests as outcome measures in upcoming trials for genetic bvFTD.

Familial aggregation of parkinsonism in progressive supranuclear palsy.

BACKGROUND: Progressive supranuclear palsy (PSP) is a progressive neurodegenerative disorder characterized by aggregates of the microtubule-associated protein tau (MAPT). A nonsignificant trend for positive family history has been observed in two case-control studies and several pedigrees with familial clustering of parkinsonism have been described. Occasionally, mutations in MAPT are found in patients with a clinical phenotype similar to PSP. In this case-control study, we compared the occurrence of dementia and parkinsonism among first-degree relatives of patients with PSP with an age- and sex-matched control group. METHODS: Family history of dementia and parkinsonism was collected from all first-degree relatives of patients with PSP who fulfilled the international National Institute of Neurological Disorders and Stroke criteria for PSP. Age- and sex-matched controls were selected from the Rotterdam Study. Genetic testing and pathologic examination was performed in a subset of familial PSP cases. RESULTS: Fifty-seven (33%) of the 172 patients with PSP had at least one first-degree relative who had dementia or parkinsonism compared to 131 (25%) of the control subjects (odds ratio [OR] 1.5, 95% confidence interval [CI] 1.01-2.13). In patients with PSP, more first-degree relatives with parkinsonism were observed compared to controls, with an OR 3.9 (95% CI 1.99-7.61). Twelve patients with PSP (7%) fulfilled the criteria for an autosomal dominant mode of transmission. The intrafamilial phenotype within these pedigrees varied among PSP, dementia, tremor, and parkinsonism. Genetic studies revealed one patient with a P301L mutation in MAPT. Pathologic examination of five familial cases confirmed the clinical diagnosis of PSP, with predominant four repeat tau pathology in affected brain areas. CONCLUSION: This study demonstrates familial aggregation of parkinsonism in progressive supranuclear palsy.

Distinct genetic forms of frontotemporal dementia.

BACKGROUND: Frontotemporal dementia (FTD) is the second most common type of presenile dementia and can be distinguished into various clinical variants. The identification of MAPT and GRN defects and the discovery of the TDP-43 protein in FTD have led to the classification of pathologic and genetic subtypes. In addition to these genetic subtypes, there exist familial forms of FTD with unknown genetic defects. METHODS: We investigated the frequency, demographic, and clinical data of patients with FTD with a positive family history in our prospective cohort of 364 patients. Genetic analysis of genes associated with FTD was performed on all patients with a positive family history. Immunohistochemical studies were carried out with a panel of antibodies (tau, ubiquitin, TDP-43) in brains collected at autopsy. RESULTS: In the total cohort of 364 patients, 27% had a positive family history suggestive for an autosomal mode of inheritance, including MAPT (11%) and GRN (6%) mutations. We identified a new Gln300X GRN mutation in a patient with a sporadic FTD. The mean age at onset in GRN patients (61.8 +/- 9.9 years) was higher than MAPT patients (52.4 +/- 5.9 years). In the remaining 10% of patients with suggestive autosomal dominant inheritance, the genetic defect has yet to be identified. Neuropathologically, this group can be distinguished into familial FTLD+MND and familial FTLD-U with hippocampal sclerosis. CONCLUSION: Future genetic studies need to identify genetic defects in at least two distinct familial forms of frontotemporal dementia (FTD) with unknown genetic defects: frontotemporal lobe degeneration with ubiquitin-positive inclusions with hippocampal sclerosis and frontotemporal lobe degeneration with motor neuron disease.

Frontal presentation in progressive supranuclear palsy.

BACKGROUND: Progressive supranuclear palsy (PSP) is a progressive hypokinetic rigid disorder with supranuclear gaze palsy and frequent falls. Although clinical consensus criteria are available, an atypical presentation may lead to clinical misdiagnosis in the initial phase. In the present study we investigated the clinical presentation of PSP and its relationship to initial clinical diagnosis and survival. METHODS: We ascertained patients with PSP in a prospective cohort by nationwide referral from neurologists and nursing home physicians. All patients underwent a structural interview and clinical examination before entering the study. Medical records were reviewed for the presence of symptoms during the first 2 years. RESULTS: A total of 152 patients ascertained between 2002 and 2005 fulfilled the international consensus criteria for PSP. Categorical principal component analysis of clinical symptoms within the first 2 years showed apart from a cluster of typical PSP symptoms, the clustering of cognitive dysfunction and behavioral changes. Further analysis showed that 20% of patients had a predominant frontal presentation with less than two other PSP symptoms. Survival analysis showed that this subgroup had a similar prognosis to that of the total group of patients with PSP. CONCLUSIONS: There exists a subgroup of patients with progressive supranuclear palsy (PSP) with a predominant frontal presentation, who progressed into typical PSP over the course of the disease.

[Progressive supranuclear palsy; an unusual form of parkinsonism]. / Progressieve supranucleaire verlamming; een bijzondere vorm van parkinsonisme.

Progressive supranuclear palsy is a neurodegenerative disorder accompanied by parkinsonism, disturbances of eye movements, pseudobulbar palsy and often cognitive decline. Onset of disease is usually between 50-70 years of age and mean survival is 5-8 years. The prevalence of PSP has been estimated at around 5 per 100,000, although exact figures for the population of the Netherlands are not yet available. International consensus criteria differentiate between possible, probable and definite PSP; the latter requiring neuropathological confirmation. An extensive differential diagnosis may be made early in the course of the disease, but at a later stage development of the characteristic symptoms will make diagnosis easier. Imaging techniques can lend support to the clinical diagnosis to a limited extent, although they lack sufficient specificity to confirm it. PSP is a 'tauopathy' characterized by aggregates of abnormal tau protein in the basal ganglia and brainstem. Some mutations in the tau gene can cause a clinical and pathological picture similar to that of PSP, although most patients with sporadic and familial PSP do not have tau mutations. Various studies have found a strong association between PSP and a specific tau haplotype (H1 haplotype), but its role in the pathophysiological mechanism of PSP is still unclear and needs further research.

Medical and environmental risk factors for sporadic frontotemporal dementia: a retrospective case-control study.

A retrospective case-control study was carried out on 80 patients with sporadic frontotemporal dementia and 124 age, sex, and surrogate informant matched controls with respect to various medical and environmental risk factors. Head trauma was associated with an odds ratio of 3.3 (95% confidence interval (CI), 1.3 to 8.1). Although recall bias may play a role, the frontal lobes are known to be especially vulnerable to even mild head trauma. Thyroid disease was associated with a 2.5 times increased risk of frontotemporal dementia (95% CI, 0.9 to 7.9), which was not statistically significant (p = 0.09) owing to limited power. As altered thyroid hormone status has been observed before in frontotemporal dementia, future studies will be important to confirm this observation.