Kinematic analysis of motor dysfunction in Niemann-Pick type C

Clinical correlates of movement disorders in adult Niemann-Pick type C patients measured via a Personal KinetiGraph

Background

Niemann-Pick type C (NPC) is an autosomal recessive progressive neurodegenerative disorder caused by mutations in the NPC1 or NPC2 genes. Patients with this disorder have variable phenotypic presentations that often include neuropsychiatric manifestations, cognitive decline, and movement disorders. There is considerable interpatient variation in movement disorders, with limited quantitative measurements describing the movements observed. Objective measurements using wearable sensors provide clinically applicable monitoring of patients with Parkinson’s disease, and hence may be utilized in patients with NPC.

Objective

To explore the relationship between objective measurements of movement obtained via the use of the Personal KinetiGraph (PKG) with the clinical information obtained via questionnaires and clinical rating tools of patients with Niemann-Pick type C.

Methods

Twelve patients with Niemann-Pick type C were recruited who wore the PKG for 6 days during regular activities. A 6-day output was provided by the manufacturer, which provided bradykinesia (BK) and dyskinesia (DK) scores. BK and DK scores were further divided into their interquartile ranges. A fluctuation score (FDS), percentage time immobile (PTI), and percent time with tremors (PTT) were also provided. Clinical assessments included Abnormal Involuntary Movement Scale (AIMS), Epworth Sleepiness Score (ESS), Falls, Neuropsychiatric Unit Assessment Tool (NUCOG), Parkinson’s disease questionnaire (PDQ), and modified Unified Parkinson’s Disease Rating Scale (UPDRS) which were performed over telehealth within 2 weeks of PKG use. Pearson’s correlation analyses were utilized to explore the relationship between DK and BK quartiles and clinical measures.

Results

We found bradykinesia to be a feature among this cohort of patients, with a median BKS of 22.0 (7.4). Additionally, PTI scores were elevated at 4.9 (8.2) indicating elevated daytime sleepiness. Significant correlations were demonstrated between BK25 and Falls (r =  − 0.74, 95% CI = [− 0.95, − 0.08]), BK50 and Falls (r =  − 0.79, 95% CI = [− 0.96, − 0.19]), and BK75 and Falls (r =  − 0.76, 95% CI = [− 0.95, − 0.11]). FDS correlated with PDQ (r =  − 0.7, 95% CI = [− 0.92, − 0.18]), UPDRS IV (r =  − 0.65, 95% CI = [− 0.90, − 0.09]), UPDRS (r =  − 0.64, 95% CI = [− 0.9, − 0.06]), and AIMS (r =  − 0.96, 95% CI = [− 0.99, − 0.49]). DK25 in comparison with NUCOG-A (r = 0.72, 95% CI = [0.17, 0.93]) and DK75 in comparison with NUCOG (r = 0.64, 95% CI = [0.02, 0.91]) and NUCOG-A (r = 0.63, 95% CI = [0.01, 0.90]) demonstrated significant correlations. Additionally, duration of illness in comparison with PTI (r = 0.72, 95% CI = [0.22, 0.92]) demonstrated significance.

Conclusions

Utilization of PKG measures demonstrated that bradykinesia is under recognized among NPC patients, and the bradykinetic patients were less likely to report concerns regarding falls. Additionally, the FDS rather than the DKS is sensitive to the abnormal involuntary movements of NPC—reflecting a differing neurobiology of this chorea compared to levodopa-induced dyskinesias. Furthermore, dyskinetic individuals performed better in cognitive assessments of attention which may indicate an earlier timepoint within disease progression.

Assessment of upper limb use in children with typical development and neurodevelopmental disorders by inertial sensors: a systematic review

Understanding development of bimanual upper limb (UL) activities in both typical and atypical conditions in children is important for: i) tailoring rehabilitation programs, ii) monitoring progress, iii) determining outcomes and iv) evaluating effectiveness of treatment/rehabilitation. Recent technological advances, such as wearable sensors, offer possibilities to perform standard medical monitoring. Body-worn motion sensors, mainly accelerometers, have shown very promising results but, so far, these studies have mainly focused on adults. The main aim of this review was to report the evidence of UL activity of both typically developing (TD) children and children with neurodevelopmental disorders (NDDs) that are reliably reported and comparable, using a combination of multiple wearable inertial sensors, both in laboratory and natural settings. Articles were selected from three research databases (PubMed, Web of Science and EBSCO). Included studies reported data on children aged 0-20 years old simultaneously wearing at least two inertial sensors on upper extremities. The collected and reported data were relevant in order to describe the amount of physical activity performed by the two ULs separately. A total of 21 articles were selected: 11 including TD, and 10 regarding NDDs. For each article, a review of both clinical and technical data was performed. We considered inertial sensors used for following aims: (i) to establish activity intensity cut-points; (ii) to investigate validity and reliability of specified markers, placement and/or number of inertial sensors; (iii) to evaluate duration and intensity of natural UL movements, defined motor tasks and tremor; and (iv) to assess efficacy of certain rehabilitation protocols. Our conclusions were that inertial sensors are able to detect differences in use between both hands and that all reviewed studies support use of accelerometers as an objective outcome measure, appropriate in assessing UL activity in young children with NDDs and determining intervention effectiveness. Further research on responsiveness to interventions and consistency with use in real-world settings is needed. This information could be useful in planning UL rehabilitation strategies.

Gait, Balance, and Coordination Impairments in Niemann Pick Disease, Type C1

This is the first study to objectively measure gait, balance, and upper limb coordination in a group of patients with NPC1 and compare the results to age and gender matched controls. This is also the first study to report effect sizes in these measures. Spatiotemporal gait analysis, static and dynamic posturography, and upper limb reaching motion analysis were performed. The findings showed that the NPC1 subjects had statistically significant deficits on 12 out of the 16 parameters investigated compared to controls, and large effect sizes for all but 1 parameter. When ranking the variables in terms of the effect sizes, the top 5 included at least 1 parameter from each of the 3 motor domains investigated. These results can provide insight to clinical researchers on the selection of outcome measures for longitudinal and interventional studies.

Results from a 9-year Intensive Safety Surveillance Scheme (IS(3) ) in miglustat (Zavesca(®) )-treated patients

BACKGROUND

Following approval in the EU in 2002 and the USA in 2003, an Intensive Safety Surveillance Scheme (IS(3) ) was initiated to educate prescribers on the appropriate use of miglustat for the treatment of type I Gaucher disease (GD1), and to actively solicit safety-relevant information. This report summarises data from all patients enrolled in IS(3) between its initiation in 2003 and its closure in October 2012.

METHODS

The IS(3) was a prospective observational drug registry with a secure internet-based data capture system. All patients receiving miglustat at participating sites received standard medical care according to routine medical practice. Data on patient and disease characteristics were collected at patient enrolment, subsequent follow-up visits and treatment discontinuation (if applicable). Data were summarised using descriptive statistics.

RESULTS

During the 9 years of IS(3) , 407 patients were enrolled at 111 sites across 15 European countries. Approximately half (n = 202) had GD1, and half had other diseases (mainly Niemann-Pick disease type C (NP-C), for which miglustat was approved in Europe in 2009). In total, 368 patients had data from at least one follow-up visit, 192 of whom had GD1. IS(3) provided data from 798 patient-years exposure to miglustat. Safety-relevant data were consistent with earlier published 5-year findings from IS(3) , the safety profile reported for miglustat in GD1 clinical trials and other published information on GD1 manifestations.

CONCLUSIONS

Overall, the results of this long-term safety surveillance programme were in line with the well-known, documented safety profile of miglustat.

Subcortical volumetric reductions in adult Niemann-Pick disease type C: a cross-sectional study

BACKGROUND AND PURPOSE

Voxel-based analysis has suggested that deep gray matter rather than cortical regions is initially affected in adult Niemann-Pick type C. We sought to examine a range of deep gray matter structures in adults with NPC and relate these to clinical variables.

MATERIALS AND METHODS

Ten adult patients with NPC (18-49 years of age) were compared with 27 age- and sex-matched controls, and subcortical structures were automatically segmented from normalized T1-weighted MR images. Absolute volumes (in cubic millimeters) were generated for a range of deep gray matter structures and were compared between groups and correlated with illness variables.

RESULTS

Most structures were smaller in patients with NPC compared with controls. The thalamus, hippocampus, and striatum showed the greatest and most significant reductions, and left hippocampal volume correlated with symptom score and cognition. Vertex analysis of the thalamus, hippocampus, and caudate implicated regions involved in memory, executive function, and motor control.

CONCLUSIONS

Thalamic and hippocampal reductions may underpin the memory and executive deficits seen in adult NPC. Volume losses in other subcortical regions may also be involved in the characteristic range of motor, psychiatric, and cognitive deficits seen in the disease.

Niemann-Pick disease type C

Niemann-Pick C disease (NP-C) is a neurovisceral atypical lysosomal lipid storage disorder with an estimated minimal incidence of 1/120 000 live births. The broad clinical spectrum ranges from a neonatal rapidly fatal disorder to an adult-onset chronic neurodegenerative disease. The neurological involvement defines the disease severity in most patients but is typically preceded by systemic signs (cholestatic jaundice in the neonatal period or isolated spleno- or hepatosplenomegaly in infancy or childhood). The first neurological symptoms vary with age of onset: delay in developmental motor milestones (early infantile period), gait problems, falls, clumsiness, cataplexy, school problems (late infantile and juvenile period), and ataxia not unfrequently following initial psychiatric disturbances (adult form). The most characteristic sign is vertical supranuclear gaze palsy. The neurological disorder consists mainly of cerebellar ataxia, dysarthria, dysphagia, and progressive dementia. Cataplexy, seizures and dystonia are other common features. NP-C is transmitted in an autosomal recessive manner and is caused by mutations of either the NPC1 (95% of families) or the NPC2 genes. The exact functions of the NPC1 and NPC2 proteins are still unclear. NP-C is currently described as a cellular cholesterol trafficking defect but in the brain, the prominently stored lipids are gangliosides. Clinical examination should include comprehensive neurological and ophthalmological evaluations. The primary laboratory diagnosis requires living skin fibroblasts to demonstrate accumulation of unesterified cholesterol in perinuclear vesicles (lysosomes) after staining with filipin. Pronounced abnormalities are observed in about 80% of the cases, mild to moderate alterations in the remainder ("variant" biochemical phenotype). Genotyping of patients is useful to confirm the diagnosis in the latter patients and essential for future prenatal diagnosis. The differential diagnosis may include other lipidoses; idiopathic neonatal hepatitis and other causes of cholestatic icterus should be considered in neonates, and conditions with cerebellar ataxia, dystonia, cataplexy and supranuclear gaze palsy in older children and adults. Symptomatic management of patients is crucial. A first product, miglustat, has been granted marketing authorization in Europe and several other countries for specific treatment of the neurological manifestations. The prognosis largely correlates with the age at onset of the neurological manifestations.

Spiral analysis in Niemann-Pick disease type C

Spiral analysis is a computerized method of analyzing upper limb motor physiology through the quantification of spiral drawing. The objective of this study was to determine whether spirals drawn by patients with Niemann-Pick disease type C (NPC) could be distinguished from those of controls, and to physiologically characterize movement abnormalities in NPC. Spiral data consisting of position, pressure, and time were collected from 14 NPC patients and 14 age-matched controls, and were analyzed by the Mann-Whitney U test. NPC spirals were characterized by: lower speed (2.67 vs. 9.56 cm/s, P < 0.001) and acceleration (0.10 vs. 2.04 cm/s(2), P < 0.001), higher loop width variability (0.88 vs. 0.28, P < 0.001), tremor (5/10 vs. 0/10 trials in the dominant hand, P < 0.001), and poor overall spiral rating (2.53 vs. 0.70, P < 0.005). NPC spirals also exhibited sustained drawing pressure profiles that were abnormally invariant with time. Other features, such as the tightness of loop widths, were normal. Our findings reveal that differing aspects of tremor, Parkinsonism, ataxia, and dystonia are quantifiable in NPC patients.