Mild motor impairment as prodromal state in amyotrophic lateral sclerosis: a new diagnostic entity.

Amyotrophic lateral sclerosis, when viewed as a biological entity rather than a clinical syndrome, probably evolves along a continuum, with the initial clinically silent phase eventually evolving into clinically manifest amyotrophic lateral sclerosis. Since motor neuron degeneration is incremental and cumulative over time, it stands to reason that the clinical syndrome of amyotrophic lateral sclerosis is probably preceded by a prodromal state characterized by minor motor abnormalities that are initially insufficient to permit a diagnosis of amyotrophic lateral sclerosis. This prodromal period, however, is usually missed, given the invariably long delays between symptom onset and diagnostic evaluation. The Pre-Symptomatic Familial ALS Study, a cohort study of pre-symptomatic gene mutation carriers, offers a unique opportunity to observe what is typically unseen. Here we describe the clinical characterization of 20 pre-symptomatic mutation carriers (in SOD1, FUS and C9orf72) whose phenoconversion to clinically manifest disease has been prospectively studied. In so doing, we observed a prodromal phase of mild motor impairment in 11 of 20 phenoconverters. Among the n = 12 SOD1 A4V mutation carriers, phenoconversion was characterized by abrupt onset of weakness, with a short (1-3.5 months) prodromal period observable in a small minority (n = 3); the observable prodrome invariably involved the lower motor neuron axis. By contrast, in all n = 3 SOD1 I113T mutation carriers, diffuse lower motor neuron and upper motor neuron signs evolved insidiously during a prodromal period that extended over a period of many years; prodromal manifestations eventually coalesced into a clinical syndrome that is recognizable as amyotrophic lateral sclerosis. Similarly, in all n = 3 C9orf72 hexanucleotide repeat expansion mutation carriers, focal or multifocal manifestations of disease evolved gradually over a prodromal period of 1-2 years. Clinically manifest ALS also emerged following a prodromal period of mild motor impairment, lasting >4 years and ∼9 months, respectively, in n = 2 with other gene mutations (SOD1 L106V and FUS c.521del6). On the basis of this empirical evidence, we conclude that mild motor impairment is an observable state that precedes clinically manifest disease in three of the most common genetic forms of amyotrophic lateral sclerosis (SOD1, FUS, C9orf72), and perhaps in all genetic amyotrophic lateral sclerosis; we also propose that this might be true of non-genetic amyotrophic lateral sclerosis. As a diagnostic label, mild motor impairment provides the language to describe the indeterminate (and sometimes intermediate) transition between the unaffected state and clinically manifest amyotrophic lateral sclerosis. Recognizing mild motor impairment as a distinct clinical entity should generate fresh urgency for developing biomarkers reflecting the earliest events in the degenerative cascade, with potential to reduce the diagnostic delay and to permit earlier therapeutic intervention.

Preventing amyotrophic lateral sclerosis: insights from pre-symptomatic neurodegenerative diseases.

Significant progress has been made in understanding the pre-symptomatic phase of amyotrophic lateral sclerosis. While much is still unknown, advances in other neurodegenerative diseases offer valuable insights. Indeed, it is increasingly clear that the well-recognized clinical syndromes of Alzheimer's disease, Parkinson's disease, Huntington's disease, spinal muscular atrophy and frontotemporal dementia are also each preceded by a pre-symptomatic or prodromal period of varying duration, during which the underlying disease process unfolds, with associated compensatory changes and loss of inherent system redundancy. Key insights from these diseases highlight opportunities for discovery in amyotrophic lateral sclerosis. The development of biomarkers reflecting amyloid and tau has led to a shift in defining Alzheimer's disease based on inferred underlying histopathology. Parkinson's disease is unique among neurodegenerative diseases in the number and diversity of non-genetic biomarkers of pre-symptomatic disease, most notably REM sleep behaviour disorder. Huntington's disease benefits from an ability to predict the likely timing of clinically manifest disease based on age and CAG-repeat length alongside reliable neuroimaging markers of atrophy. Spinal muscular atrophy clinical trials have highlighted the transformational value of early therapeutic intervention, and studies in frontotemporal dementia illustrate the differential role of biomarkers based on genotype. Similar advances in amyotrophic lateral sclerosis would transform our understanding of key events in pathogenesis, thereby dramatically accelerating progress towards disease prevention. Deciphering the biology of pre-symptomatic amyotrophic lateral sclerosis relies on a clear conceptual framework for defining the earliest stages of disease. Clinically manifest amyotrophic lateral sclerosis may emerge abruptly, especially among those who harbour genetic mutations associated with rapidly progressive amyotrophic lateral sclerosis. However, the disease may also evolve more gradually, revealing a prodromal period of mild motor impairment preceding phenoconversion to clinically manifest disease. Similarly, cognitive and behavioural impairment, when present, may emerge gradually, evolving through a prodromal period of mild cognitive impairment or mild behavioural impairment before progression to amyotrophic lateral sclerosis. Biomarkers are critically important to studying pre-symptomatic amyotrophic lateral sclerosis and essential to efforts to intervene therapeutically before clinically manifest disease emerges. The use of non-genetic biomarkers, however, presents challenges related to counselling, informed consent, communication of results and limited protections afforded by existing legislation. Experiences from pre-symptomatic genetic testing and counselling, and the legal protections against discrimination based on genetic data, may serve as a guide. Building on what we have learned-more broadly from other pre-symptomatic neurodegenerative diseases and specifically from amyotrophic lateral sclerosis gene mutation carriers-we present a road map to early intervention, and perhaps even disease prevention, for all forms of amyotrophic lateral sclerosis.

Harnessing the power of the electronic health record for ALS research and quality improvement: CReATe CAPTURE-ALS and the ALS Toolkit.

The electronic health record (EHR) is designed principally to support the provision and documentation of clinical care, as well as billing and insurance claims. Broad implementation of the EHR, however, also yields an opportunity to use EHR data for other purposes, including research and quality improvement. Indeed, effective use of clinical data for research purposes has been a long-standing goal of physicians who provide care for patients with ALS, but the quality and completeness of clinical data, as well as the burden of double data entry into the EHR and into a research database, have been persistent barriers. These factors provided motivation for the development of the ALS Toolkit, a set of interactive digital forms within the EHR that enable easy, consistent, and structured capture of information relevant to ALS patient care (as well as research and quality improvement) during clinical encounters. Routine use of the ALS Toolkit within the context of the CReATe Consortium's institutional review board-approved Clinical Procedures to Support Research in ALS (CAPTURE-ALS) study protocol, permits aggregation of structured ALS patient data, with the goals of empowering research and driving quality improvement. Widespread use of the ALS Toolkit through the CAPTURE-ALS protocol will help to ensure that ALS clinics become a driving force for collecting and aggregating clinical data in a way that reflects the true diversity of the populations affected by this disease, rather than the restricted subset of patients that currently participate in dedicated research studies.

Disrupted lymphocyte homeostasis in hepatitis-associated acquired aplastic anemia is associated with short telomeres.

Hepatitis-associated aplastic anemia (HAA) is a variant of acquired aplastic anemia (AA) in which immune-mediated bone marrow failure (BMF) develops following an acute episode of seronegative hepatitis. Dyskeratosis congenita (DC) is an inherited BMF syndrome characterized by the presence of short telomeres, mucocutaneous abnormalities, and cancer predisposition. While both conditions may cause BMF and hepatic impairment, therapeutic approaches are distinct, making it imperative to establish the correct diagnosis. In clinical practice, lymphocyte telomere lengths (TL) are used as a first-line screen to rule out inherited telomeropathies before initiating treatment for AA. To evaluate the reliability of TL in the HAA population, we performed a retrospective analysis of TL in 10 consecutively enrolled HAA patients compared to 19 patients with idiopathic AA (IAA). HAA patients had significantly shorter telomeres than IAA patients (P = 0.009), including four patients with TL at or below the 1st percentile for age-matched controls. HAA patients had no clinical features of DC and did not carry disease-causing mutations in known genes associated with inherited telomere disorders. Instead, short TLs were significantly correlated with severe lymphopenia and skewed lymphocyte subsets, features characteristic of HAA. Our results indicate the importance of caution in the interpretation of TL measurements in HAA, because, in this patient population, short telomeres have limited specificity.

High prevalence of HPV in non-cervical sites of women with abnormal cervical cytology.

BACKGROUND: Human papillomaviruses (HPV) are causally associated with ano-genital and a subset of head and neck cancers. Rising incidence of HPV+ anal cancers and head and neck cancers have now been demonstrated in the developed world over the last decade. The majority of published data on HPV prevalence at the anal and oro-pharyngeal sites are from studies of higher-risk populations. There is a paucity of data on the prevalence of HPV at non-cervical sites in lower risk, non-HIV+ women and this study was designed to provide initial pilot data on a population of women recalled for colposcopy as part of the UK cervical screening programme. METHODS: 100 non-HIV+ women with abnormal cervical cytology, attending clinic for colposcopic examination were recruited. Swabs from the oro-pharyngeal, anal and cervical sites were taken and DNA extracted. HPV detection and genotyping were performed using a standardised, commercially available PCR-line blot assay, which is used to genotype 37 HPV subtypes known to infect the ano-genital and oro-pharyngeal areas. Strict sampling and laboratory precautions were taken to prevent cross-contamination. RESULTS: There was a very high prevalence of HPV infection at all three sites: 96.0%, 91.4% and 92.4% at the cervix, anus and oro-pharynx, respectively. Multiple HPV subtype infections were dominant at all 3 mucosal sites. At least one or more HR genotype was present at both the cervix/anus in 39/52 (75.0%) patients; both the cervix/oro-pharynx in 48/56 (85.7%) patients; and both the anus/oro-pharynx in 39/52 (75.0%) patients. HPV 16 infection was highly dominant across all mucosal sites, with over a 2-fold increase over the next most prevalent subtype (HPV 31). CONCLUSIONS: Women with abnormal smears have widespread infection with high-risk HPV at the cervical, anal and oro-pharyngeal mucosal sites and may represent a higher risk population for HPV disease in the future.