Trial of N-Acetyl-l-Leucine in Niemann-Pick Disease Type C.

BACKGROUND: Niemann-Pick disease type C is a rare lysosomal storage disorder. We evaluated the safety and efficacy of N-acetyl-l-leucine (NALL), an agent that potentially ameliorates lysosomal and metabolic dysfunction, for the treatment of Niemann-Pick disease type C. METHODS: In this double-blind, placebo-controlled, crossover trial, we randomly assigned patients 4 years of age or older with genetically confirmed Niemann-Pick disease type C in a 1:1 ratio to receive NALL for 12 weeks, followed by placebo for 12 weeks, or to receive placebo for 12 weeks, followed by NALL for 12 weeks. NALL or matching placebo was administered orally two to three times per day, with patients 4 to 12 years of age receiving weight-based doses (2 to 4 g per day) and those 13 years of age or older receiving a dose of 4 g per day. The primary end point was the total score on the Scale for the Assessment and Rating of Ataxia (SARA; range, 0 to 40, with lower scores indicating better neurologic status). Secondary end points included scores on the Clinical Global Impression of Improvement, the Spinocerebellar Ataxia Functional Index, and the Modified Disability Rating Scale. Crossover data from the two 12-week periods in each group were included in the comparisons of NALL with placebo. RESULTS: A total of 60 patients 5 to 67 years of age were enrolled. The mean baseline SARA total scores used in the primary analysis were 15.88 before receipt of the first dose of NALL (60 patients) and 15.68 before receipt of the first dose of placebo (59 patients; 1 patient never received placebo). The mean (±SD) change from baseline in the SARA total score was -1.97±2.43 points after 12 weeks of receiving NALL and -0.60±2.39 points after 12 weeks of receiving placebo (least-squares mean difference, -1.28 points; 95% confidence interval, -1.91 to -0.65; P<0.001). The results for the secondary end points were generally supportive of the findings in the primary analysis, but these were not adjusted for multiple comparisons. The incidence of adverse events was similar with NALL and placebo, and no treatment-related serious adverse events occurred. CONCLUSIONS: Among patients with Niemann-Pick disease type C, treatment with NALL for 12 weeks led to better neurologic status than placebo. A longer period is needed to determine the long-term effects of this agent in patients with Niemann-Pick disease type C. (Funded by IntraBio; ClinicalTrials.gov number, NCT05163288; EudraCT number, 2021-005356-10.).

Selective perforant-pathway atrophy in Huntington disease: MRI analysis of hippocampal subfields.

INTRODUCTION: While individuals with Huntington disease (HD) show memory impairment that indicates hippocampal dysfunction, the available literature does not consistently identify structural evidence for involvement of the whole hippocampus but rather suggests that hippocampal atrophy may be confined to certain hippocampal subregions. METHODS: We processed T1-weighted MRI from IMAGE-HD study using FreeSurfer 7.0 and compared the volumes of the hippocampal subfields among 36 early motor symptomatic (symp-HD), 40 pre-symptomatic (pre-HD), and 36 healthy control individuals across three timepoints over 36 months. RESULTS: Mixed-model analyses revealed significantly lower subfield volumes in symp-HD, compared with pre-HD and control groups, in the subicular regions of the perforant-pathway: presubiculum, subiculum, dentate gyrus, tail, and right molecular layer. These adjoining subfields aggregated into a single principal component, which demonstrated an accelerated rate of atrophy in the symp-HD. Volumes between pre-HD and controls did not show any significant difference. In the combined HD groups, CAG repeat length and disease burden score were associated with presubiculum, molecular layer, tail, and perforant-pathway subfield volumes. Hippocampal left tail and perforant-pathway subfields were associated with motor onset in the pre-HD group. CONCLUSIONS: Hippocampal subfields atrophy in early symptomatic HD affects key regions of the perforant-pathway, which may implicate the distinctive memory impairment at this stage of illness. Their volumetric associations with genetic and clinical markers suggest the selective susceptibility of these subfields to mutant Huntingtin and disease progression.

Survival in Huntington's disease and other young-onset dementias.

OBJECTIVES: To compare survival and risk factors associated with mortality in common young-onset dementias (YOD) including Huntington's disease. METHODS: This retrospective cohort study included inpatients from an Australian specialist neuropsychiatry service, over 20 years. Dementia diagnoses were based on consensus criteria and Huntington's disease (HD) was confirmed genetically. Mortality and cause of death were determined using linkage to the Australian Institute of Health and Welfare National Death Index. RESULTS: There were 386 individuals with YOD included. The dementia types included frontotemporal dementia (FTD) (24.5%), HD (21.2%) and Alzheimer's disease (AD) (20.5%). 63% (n = 243) individuals had died. The longest median survival was for those who had HD, 18.8 years from symptom onset and with a reduced mortality risk compared to AD and FTD (hazard ratio 0.5). Overall, people with YOD had significantly increased mortality, of 5-8 times, compared to the general population. Females with a YOD had higher standardised mortality ratio compared to males (9.3 vs. 4.9) overall. The most frequent cause of death in those with HD was reported as HD, with other causes of death in the other YOD-subtypes related to dementia and mental/behavioural disorders. DISCUSSION: This is the first Australian study to investigate survival and risk factors of mortality in people with YOD. YOD has a significant risk of death compared to the general population. Our findings provide useful clinical information for people affected by YOD as well as future planning and service provision.

The Diagnostic Challenge of Young-Onset Dementia Syndromes and Primary Psychiatric Diseases: Results From a Retrospective 20-Year Cross-Sectional Study.

OBJECTIVE: Distinguishing a dementia syndrome from a primary psychiatric disease in younger patients can be challenging and may lead to diagnostic change over time. The investigators aimed to examine diagnostic stability in a cohort of patients with younger-onset neurocognitive disorders. METHODS: A retrospective review of records was conducted for patients who were admitted to an inpatient neuropsychiatry service unit between 2000 and 2019, who were followed up for at least 12 months, and who received a diagnosis of young-onset dementia at any time point. Initial diagnosis included Alzheimer's disease-type dementia (N=30), frontotemporal dementia (FTD) syndromes (N=44), vascular dementia (N=7), mild cognitive impairment (N=10), primary psychiatric diseases (N=6), and other conditions, such as Lewy body dementia (N=30). RESULTS: Among 127 patients, 49 (39%) had a change in their initial diagnoses during the follow-up period. Behavioral variant FTD (bvFTD) was the least stable diagnosis, followed by dementia not otherwise specified and mild cognitive impairment. Compared with patients with a stable diagnosis, those who changed exhibited a higher cognitive score at baseline, a longer follow-up period, greater delay to final diagnosis, and no family history of dementia. Patients whose diagnosis changed from a neurodegenerative to a psychiatric diagnosis were more likely to have a long psychiatric history, while those whose diagnosis changed from a psychiatric to a neurodegenerative one had a recent manifestation of psychiatric symptoms. CONCLUSIONS: Misdiagnosis of younger patients with neurocognitive disorders is not uncommon, especially in cases of bvFTD. Late-onset psychiatric symptoms may be the harbinger to a neurodegenerative disease. Close follow-up and monitoring of these patients are necessary.

Mortality in dementia is predicted by older age of onset and cognitive presentation.

OBJECTIVES: Survival information in dementia is important for future planning and service provision. There have been limited Australian data investigating survival duration and risk factors associated with mortality in younger-onset dementia. METHODS: This was a cross-sectional retrospective study investigating survival in inpatients with a diagnosis of dementia admitted to a tertiary neuropsychiatry service from 1991 to 2014. The Australian Institute of Health and Welfare National Death Index was used to obtain mortality information. RESULTS: A total of 468 inpatients were identified, of which 75% had symptom onset at ⩽65 years of age (defined as younger-onset dementia). Dementia was categorised into four subtypes, Alzheimer's dementia, frontotemporal dementia, vascular dementia and other dementias; 72% of the patients had died. Overall median survival duration was 10.6 years with no significant differences in duration within the dementia subtypes (p = 0.174). Survival in older-onset dementia (symptom onset at >65 years of age) was about half of that in younger-onset dementia (median survival 6.3 years compared to 12.7 years, respectively). Independent predictors of mortality were having older-onset dementia (hazard ratio: 3.2) and having initial presenting symptoms being cognitive in nature (hazard ratio: 1.5). Females with an older-onset dementia had longer survival compared to males with an older-onset dementia, and this was reversed for younger-onset dementia. Older-onset dementia and younger-onset dementia conferred 3 and 6 times, respectively, increased risk of death compared to the general population. CONCLUSION: This is the largest Australian study to date investigating survival and risk factors to mortality in dementia. We report important clinical information to patients with dementia and their families about prognosis which will assist with future planning. Our findings suggest that for both older-onset dementia and younger-onset dementia, 'new onset' psychiatric symptoms precede the cognitive symptoms of a neurodegenerative process. This, and sex differences in survival depending on the age of onset of the dementia warrant further investigation.

Risk factors to mortality and causes of death in frontotemporal dementia: An Australian perspective.

OBJECTIVES: Frontotemporal dementia (FTD) is a common cause of dementia in younger people. There is less information known about risk factors to mortality such as the type of symptom onset and cause of death in this group. METHOD: This was a retrospective file review of inpatients with FTD admitted to a tertiary neuropsychiatry unit located in Australia from 1992 to 2014. Mortality information including linkage of names and causes of death were obtained from the Australian Institute Health and Welfare National Death Index. RESULTS: One hundred inpatients were diagnosed with FTD, including behavioural-variant, language-variant FTDs and FTD-motor neuron disease (FTD-MND). Mean age was 52.8 years (SD = 10, range 31-76 years). Sixty-seven of them had died at linkage. Median survival of the sample was 10.5 years and FTD-MND had the shortest survival, 3.5 years. Increasing age of onset and FTD-MND were found to be significant predictors of association for mortality. Compared to the general population, having a FTD had an 8× increased risk of death. Females had double the standardised mortality ratio compared to males. DISCUSSION: This study provides important prognostic information for people diagnosed with FTD living in Australia. It highlights the importance of obtaining a definitive diagnosis as early as possible for future planning. More investigation into the relationship of symptom onset type and sex differences in FTD is required.

A 10 year retrospective cohort study of inpatients with younger-onset dementia.

OBJECTIVES: Younger-onset dementia (YOD) refers to a dementia where symptom onset occurs when the patient is less than 65 years of age. YOD is far less common than late-onset dementia (occurring when patients are over 65 years old) and more challenging to diagnose due to its heterogeneous presentation. There have been relatively few studies describing demographic and diagnostic characteristics of patients with YOD in the community, particularly with follow-up information. METHODS: A retrospective cohort study was performed of inpatients admitted to a tertiary neuropsychiatry service, located in metropolitan Victoria, Australia, from 2009 to 2019. Inpatients with a YOD diagnosis were identified and data regarding diagnosis, demographics and investigations were obtained. RESULTS: There were 849 individual inpatients who were admitted to the service in the 10-year period and received comprehensive assessment. There were 306 individuals who received a YOD diagnosis, using contemporaneous diagnostic criteria (frequency 36%). The most common diagnoses were Alzheimer's disease (24.2%), frontotemporal dementia (23.1%), Huntington's disease (16.7%) and vascular dementia (7.8%). More than half of these inpatients were followed up and 6.5% had a diagnostic change when reviewed. CONCLUSIONS: This study reports on the largest cohort of YOD to date, with diagnostic breakdown similar to previous retrospective file reviews. The neuropsychiatry service is funded to follow-up its patients, thus allowing re-assessment and continuity of care. While there are limitations in this study such as the lack of neuropathological outcomes, the findings emphasise the strengths of follow-up and appropriate service provision for these patients.

Bringing psychiatrists into the picture: Automated measurement of regional MRI brain volume in patients with suspected dementia.

OBJECTIVE: The volumes of various brain regions can be rapidly quantified using automated magnetic resonance imaging tools. While these appear to be useful at face value, their formal clinical utility is not yet understood, particularly for non-neuroradiologists and in patients presenting with suspected dementia. This study investigated the utility of an automated normative morphometry tool on determinations of brain atrophy by psychiatrists and radiologists in a tertiary hospital. METHODS: Consecutive magnetic resonance scans (n = 110) of patients referred with suspected neurodegenerative disorders were obtained retrospectively and rated by two neuroradiologists, two general radiologists and four psychiatrists over two sessions. First, conventional magnetic resonance sequences were shown. Then, morphometry colour-coded maps, which segmented T1-weighted magnetisation prepared rapid gradient echo images into brain regions and visualised these regions in colour according to their volumetric standard deviation from a normative population, were added to the second reading which occurred ⩾6 weeks later. Presence and laterality of atrophy in frontal, parietal and temporal lobes and hippocampal regions were measured using a digital checklist. The primary outcome of inter-rater agreement on atrophy was measured with Fleiss' Kappa (κ). We also evaluated the accuracy of the atrophy ratings for differentiating post hoc diagnosis of subjective cognitive impairment, mild cognitive impairment and dementia. RESULTS: Agreement among all raters was fair in frontal lobe and moderate in other regions with conventional method (κ = 0.362-0.555). With morphometry, higher agreement was seen in all regions (κ = 0.551-0.654), reaching significant improvement in the frontal and temporal lobes. No significant improvement was seen within the various disciplines, except in frontal lobes rated by psychiatrists. Accuracy of atrophy ratings on determining post hoc diagnosis was significantly improved for distinguishing subjective cognitive impairment versus dementia. CONCLUSION: In routine clinical assessment, automated normative morphometry complements the determination of regional atrophy and improves inter-rater agreement regardless of neuroradiology experience.

Differential involvement of hippocampal subfields in Niemann-Pick type C disease: a case-control study.

Hippocampal brain regions are strongly implicated in Niemann Pick type C disease (NPC), but little is known regarding distinct subregions of the hippocampal complex and whether these are equally or differentially affected. To address this gap, we compared volumes of five hippocampal subfields between NPC and healthy individuals using MRI. To this end, 9 adult-onset NPC cases and 9 age- and gender-matched controls underwent a 3 T T1-weighted MRI scan. Gray matter volumes of the cornu ammonis (CA1, CA2 and CA3), dentate gyrus (DG), subiculum, entorhinal cortex and hippocampal-amygdalar transition area were calculated by integrating MRI-based image intensities with microscopically defined cytoarchitectonic probabilities. Compared to healthy controls, NPC patients showed smaller volumes of the CA1-3 and DG regions bilaterally, with the greatest difference localized to the left DG (Cohen's d = 1.993, p = 0.008). No significant associations were shown between hippocampal subfield volumes and key clinical features of NPC, including disease duration, symptom severity and psychosis. The pattern of hippocampal subregional atrophy in NPC differs from those seen in other dementias, which may indicate unique cytoarchitectural vulnerabilities in this earlier-onset disorder. Future MRI studies of hippocampal subfields may clarify its potential as a biomarker of neurodegeneration in NPC.

Understanding MRI in clinical psychiatry: perspectives from neuroimaging psychiatry registrars.

OBJECTIVE: Based on the experiences of neuroimaging psychiatry registrars, we describe several reflections on improving the understanding and integration of magnetic resonance imaging in clinical psychiatry. CONCLUSION: Better integration of magnetic resonance imaging into clinical psychiatry can be highly productive when our investments are focused on understanding the gaps in clinical knowledge and the systemic barriers involving the patient and relevant clinicians.

Huntington's disease: Neuropsychiatric manifestations of Huntington's disease.

OBJECTIVES: Huntington's disease (HD) is a profoundly incapacitating, and ultimately fatal, neurodegenerative disease. HD is presently incurable, so the current goal is to allow affected individuals to live as well as possible with the illness, to maximise functional independence and quality of life for the person with HD, their carers and family members. This clinical update review focuses on the common neuropsychiatric manifestations in HD, and outlines and evaluates the various neuropsychiatric facets of HD, including the aetiology, symptoms and diagnosis. CONCLUSIONS: Neuropsychiatric symptoms can precede the classic motor clinical symptoms of HD (prodromal HD) by decades, and cause significant functional impairment. HD provides key insights and understanding into the organic psychiatric disorders, including contemporary clinical insights into the process of neurodegeneration and manifestation of neuropsychiatric symptoms.

Assessment of the reliability, responsiveness, and meaningfulness of the scale for the assessment and rating of ataxia (SARA) for lysosomal storage disorders.

OBJECTIVE: To evaluate the reliability, responsiveness, and validity of the Scale for the Assessment and Rating of Ataxia (SARA) in patients with lysosomal storage disorders (LSDs) who present with neurological symptoms, and quantify the threshold for a clinically meaningful change. METHODS: We analyzed data from three clinical trial cohorts (IB1001-201, IB1001-202, and IB1001-301) of patients with Niemann-Pick disease type C (NPC) and GM2 Gangliosidoses (Tay-Sachs and Sandhoff disease) comprising 122 patients and 703 visits. Reproducibility was described as re-test reliability between repeat baseline visits or baseline and post-treatment washout visits. Responsiveness was determined in relation to the Investigator's, Caregiver's, and Patient's Clinical Global Impression of Improvement (CGI-I). The CGI-I data was also used to quantify a threshold for a clinically meaningful improvement on the SARA scale. Using a qualitative methods approach, patient/caregiver interviews from the IB1001-301 trial were further used to assess a threshold of meaningful change as well as the breadth of neurological signs and symptoms captured and evaluated by the SARA scale. RESULTS: The Inter-Class Correlation (ICC) was 0.95 or greater for all three trials, indicating a high internal consistency/reliability. The mean change in SARA between repeat baseline and post-treatment washout visit assessments in all trials was -0.05, SD 1.98, i.e., minimal, indicating no significant differences, learning effects or other systematic biases. For the CGI-I responses and change in SARA scores, Area Under the Curve (AUC) values were 0.82, 0.71, and 0.77 for the Investigator's, Caregiver's, and Patient's CGI-I respectively, indicating strong agreement. Further qualitative analyses of the patient/caregiver interviews demonstrated a 1-point or greater change on SARA to be a clinically meaningful improvement which is directly relevant to the patient's everyday functioning and quality of life. Changes captured by the SARA were also paralleled by improvement in a broad range of neurological signs and symptoms and beyond cerebellar ataxia. CONCLUSION: Qualitative and quantitative data demonstrate the reliability and responsiveness of the SARA score as a valid measure of neurological signs and symptoms in LSDs with CNS involvement, such as NPC and GM2 Gangliosidoses. A 1-point change represents a clinically meaningful transition reflecting the gain or loss of complex function.

Huntington's disease: Mortality and risk factors in an Australian cohort.

INTRODUCTION: There has not been any examination of the risk factors associated with mortality in Huntington's Disease (HD) in an Australian cohort. METHOD: This retrospective study included inpatients admitted to a specialist neuropsychiatry service in Melbourne, Australia. HD status was based on genetic testing. Risk factors included age of onset, CAG repeat length and neuroimaging. Mortality data was acquired through the Australian Institute of Health and Welfare National Death Index. RESULTS: The cohort included 83 participants, with 44 (53%) deceased. The median age of death was 59 years and median survival was 18.8 years from onset age (median 41.0 years). CAG repeat length (median 44.0, IQR 42.5, 47.0) was inversely correlated with age of onset (r = -0.73) and age at death (r = -0.80) but was not correlated with mortality status. There was no difference in functional and cognitive assessments, nor brain volumes, in the alive group compared to the deceased group. There were more people who were alive who had a positive family history of a psychiatric condition (p = 0.006) or dementia (p = 0.009). Standardised mortality ratios demonstrated a 5.9× increased risk of death for those with HD compared to the general population. CONCLUSIONS: This is the first study to examine risk factors of mortality in HD in an Australian cohort. Median survival in our cohort is consistent with previous studies in HD, and markedly reduced compared to the general Australian population. CAG repeat length was not associated with mortality suggesting that non-genetic factors contribute to mortality status and warrant further investigation.