Assessing bradykinesia in Parkinson's disease using gyroscope signals.

Parkinson's disease (PD) is a neurodegenerative brain disorder that slowly brings on the dopaminergic neurons death. The depletion of the dopaminergic signal causes the onset of motor symptoms such as tremor, bradykinesia and rigidity. Usually, neurologists regularly monitor motor symptoms and motor fluctuations using the MDS-UPDRS part III clinical scale. Nevertheless, to have a more objective and quantitative evaluation, it is possible to assess the cardinal motor symptoms of PD using wearable sensors and portable robotic devices. Unfortunately while there are several research papers on the use of these devices on PD patients, their use is not so common in clinical practice. In this work we recorded specific MDS-UPDRS motor tasks using magneto-inertial devices, worn by seven PD subjects and seven age-matched controls, in order to deeply analyze the kinematic and dynamic characteristics of goal-directed movements of upper limb, in addition to extract quantitative indices (peak velocity, smoothness, etc) useful for the assessment of motor symptoms. Using only gyroscope signals we looked at those parameters useful to assess bradykinesia. We observed parameters changes from OFF to ON phase congruent with the MDS-UPDRS changes, especially in the frequency domain. Our results suggest the prono-supination task is the more consistent to describe the bradykinesia symptom with the gyroscopes. Probably because of the amplitude of the movement performed. Moreover the peak power looks appropriate for bradykinesia symptom evaluation. We can conclude that, similar to the studies in which tremor symptom is evaluated, it is possible to monitor the bradykinesia using few wearable sensors and few simple parameters.

Echogenicity of basal ganglia structures in different Huntington's disease phenotypes.

In Huntington's disease (HD), a neurodegenerative-inherited disease, chorea as the typical kind of movement disorder is described. Beside chorea, however, all other kinds of movement disturbances, such as bradykinesia, dystonia, tremor or myoclonus can occur. Aim of the current study was to investigate alterations in the echogenicity of basal ganglia structures in different Huntington's disease phenotypes. 47 patients with manifest and genetically confirmed HD were recruited. All participants underwent a thorough neurological examination. According to a previously described method, classification into predominantly choreatic, mixed or bradykinetic-rigid motor phenotypes was performed depending on subscores of the Unified Huntington's Disease Rating Scale. In addition, findings in juvenile HD were compared to adult HD. Transcranial sonography was performed by investigators blinded to clinical classification. There were no significant differences in basal ganglia echogenicities between the three phenotypes. Size of echogenic area of substantia nigra (SN) correlated positively with CAG repeat and bradykinesia subscore, and negatively with age of onset and chorea subscore. Comparing juvenile and adult HD subtypes, SN hyperechogenicity was significantly more often detectable in the juvenile form (100 vs. 29.3 %, p = 0.002). Regarding echogenicity of caudate or lentiform nuclei, no significant differences were detected. HD patients with the juvenile variant exhibit marked hyperechogenicity of substantia nigra. No significant differences in basal ganglia echogenicities between predominantly choreatic, mixed or bradykinetic-rigid motor phenotypes were detected.

Do symptoms of sluggish cognitive tempo in children with ADHD symptoms represent comorbid internalizing difficulties?

OBJECTIVE: Symptoms of sluggish cognitive tempo (SCT) are correlated with inattention and internalizing difficulties. The purpose of the present study was to determine whether symptoms of SCT reflect comorbid internalizing disorder with ADHD or a separate syndrome. METHOD: Using a clinical sample of youth evaluated for behavioral and learning difficulties (N = 73), this study examined whether SCT remains associated with symptoms of ADHD after accounting for comorbid symptoms of anxiety and depression reported by children and parents. RESULTS: SCT symptoms were correlated with inattention and parent reports of child depression, but not with parent-reported anxiety or child reports of internalizing problems. Inattention (in the absence of hyperactivity/impulsivity) remained uniquely associated with SCT even after accounting for internalizing problems. CONCLUSION: The findings confirm SCT as a correlate of inattention and support its construct validity as separate from comorbid internalizing problems. Further research on the clinical utility of SCT is needed.

A classification system for delirium subtyping with the use of a commercial mobility monitor.

The usefulness of motor subtypes of delirium is unclear due to inconsistency in subtyping methods and a lack of validation with objective measures of activity. The activity of 40 patients was measured over 24h with a commercial accelerometer-based activity monitor. Accelerometry data from patients with DSM-IV delirium that were readily divided into hyperactive, hypoactive and mixed motor subtypes, were used to create classification trees that were subsequently applied to the remaining cohort to define motoric subtypes. The classification trees used the periods of sitting/lying, standing, stepping and number of postural transitions as measured by the activity monitor as determining factors from which to classify the delirious cohort. The use of a classification system shows how delirium subtypes can be categorised in relation to overall activity and postural changes, which was one of the most discriminating measures examined. The classification system was also implemented to successfully define other patient motoric subtypes. Motor subtypes of delirium defined by observed ward behaviour differ in electronically measured activity levels.

Mokken scale analysis of the UPDRS: dimensionality of the Motor Section revisited.

The dimensionality and reliability of the Motor Section of the Unified Parkinson Disease Rating Scale (UPDRS III) was studied with non-parametric Mokken scale analysis. UPDRS measures were obtained on 147 patients with PD (96 men, 51 women, mean age 61, range 35-80 yrs). Mokken scale analysis revealed a four-dimensional structure of the UPDRS III. Left-sided bradykinesia and rigidity appeared to co-occur with axial signs, gait disturbance, and speech/hypomimia, whereas right-sided bradykinesia and rigidity formed a second scale. Two further small scales were found consisting of right- and left-sided tremor. Results from the scale analysis reveal that all four subscales are strong. The reliability of the two tremor scales is low because they only contain three and four items, respectively.

Broadening a classic clinical triad: The hypokinetic motor disorder of normal pressure hydrocephalus also affects the hand.

The clinical spectrum of normal pressure hydrocephalus is thought to comprise the triad of hypokinetic gait disorder, dementia and urinary incontinence. In contrast, motor abnormalities involving the upper limbs in normal pressure hydrocephalus have not yet received a great deal of attention. The present study was designed to quantitatively assess grasping movements in normal pressure hydrocephalus and to compare the performance with that in Parkinson's disease. Eight subjects with normal pressure hydrocephalus, eight subjects with Parkinson's disease and eight healthy control subjects grasped to lift an instrumented object. The built-up of fingertip forces during the early phase and the kinematics of the lifting movement during the late phase of the grip-lift synergy were slower for patients compared to healthy controls. Patients generated abnormally high fingertip forces when lifting and holding the object stationary. The slowness of the grip-lift synergy and the force overshoot was similar for both patient groups. Our data demonstrate that the hypokinetic motor deficit in normal pressure hydrocephalus also involves the hand, and that the pattern of deficits shares several features of those found in Parkinson's disease.

Perceptual and premotor neglect: is there an ideal task to categorise patients?

This review focuses on Edoardo Bisiach's particular input into the perceptual/premotor taxonomy within the neglect syndrome and assesses arguments and experimental designs that have been presented both for and against the dichotomy. Bisiach made most crucial contributions to this topic as well as increasing insights into the syndrome of hemispatial neglect more generally. Most importantly, he elucidated its relevance to visual neuropsychological and neuroscientific research.

The Bradykinesia Akinesia Incoordination Test (BRAIN TEST), an objective and user-friendly means to evaluate patients with parkinsonism.

The BRAIN TEST, a computerized alternating finger tapping test, was performed on 154 patients with parkinsonism to assess whether the test could be used as an objective tool to evaluate reliably the severity of Parkinson's disease (PD). Patients were instructed to tap two marked computer keyboard keys as fast and as accurately as possible for 60 seconds. The test generates the following variables: (1) kinesia score (KS)--number of keystrokes/min, (2) akinesia time (AT)--cumulative time that keys are depressed, (3) dysmetria score (DS)--a weighted score generated from incorrectly hit keys and corrected for speed, and (4) arrhythmia score (AS)--variance of the time interval between individual keystrokes. Among parkinsonian patients, we found a significant correlation between the four test parameters and PD rating scores of the Hoehn & Yahr, Schwab & England, and Unified PD Rating Scales (KS, AS, and AT p <0.001 and DS p <0.05). When compared with 73 parkinsonian patients 73 age- and sex-matched control subjects showed significantly higher KS and lower AT (p <0.001) as well as lower DS and AS (p = 0.05). The BRAIN TEST is a reliable and practical tool for evaluating the severity of parkinsonism and for distinguishing subjects with parkinsonism from normal control subjects. A version of the BRAIN TEST is available by FTP on the worldwide web (http://www.anaesthetist.com/software/brain.htm).

Bradykinesia akinesia inco-ordination test (BRAIN TEST): an objective computerised assessment of upper limb motor function.

OBJECTIVES: A simple and rapid computerised keyboard test, based on the alternating finger tapping test, has been developed to quantify upper limb motor function. The test generates several variables: (1) kinesia score: the number of keystrokes in 60 seconds; (2) akinesia time: cumulative time that keys are depressed; (3) dysmetria score: a weighted index calculated using the number of incorrectly hit keys corrected for speed; (4) incoordination score: a measure of rhythmicity which corresponds to the variance of the time interval between keystrokes. METHODS: The BRAIN TEST(Copyright ) was assessed on 35 patients with idiopathic Parkinson's disease, 12 patients with cerebellar dysfunction, and 27 normal control subjects. RESULTS: The mean kinesia scores of patients with Parkinson's disease or cerebellar dysfunction were significantly slower than normal controls (Parkinson's disease=107 (SD 28) keys/min v cerebellar dysfunction=86+/- (SD 28) v normal controls=182 (SD 26), p<0.001) and correlated with the UPDRS (r =-0.69, p<0.001). The akinesia time is very insensitive and was only abnormal in patients with severe parkinsonism. The median dysmetria (cerebellar dysfunction=13.8 v Parkinson's disease=6.1 v normal controls=4.2, p=0.002) and inco-ordination scores (cerebellar dysfunction=5.12 v Parkinson's disease=0.84 v normal controls=0.15, p=0.002) were significantly higher in patients with cerebellar dysfunction, in whom the dysmetria score correlated with a cerebellar disease rating scale (r=0.64, p=0.02). CONCLUSION: The BRAIN TEST(Copyright ) provides a simple, rapid, and objective assessment of upper limb motor function. It assesses speed, accuracy, and rhythmicity of upper limb movements regardless of their physiological basis. The results of the test correlate well with clinical rating scales in Parkinson's disease and cerebellar dysfunction. The BRAIN test will be useful in clinical studies. It can be downloaded from the Internet ().

Nosology of fetal hypokinesia sequence based on CNS abnormalities: is there an Aase-Smith syndrome?

Aase-Smith syndrome (ASS) is usually defined as a dominantly inherited combination of arthrogryposis, Dandy-Walker malformation and cleft palate. We describe a sporadic case of foetal akinesia with abnormal fossa posterior, fitting the diagnosis of ASS, and discuss the nosology of this entity among syndromes with distal arthrogryposis. ASS shows a "hybrid" phenotype: adults with mild ASS could be classified as distal arthrogryposis, whereas severely affected newborns overlap with the Marden-Walker phenotype, which is recessively inherited. The specificity of the disorder comes from the coexistence of both forms in the same pedigree, so that ASS appears impossible to diagnose with certitude in sporadic cases. We suggest that the severe expression of ASS is only the extreme but aspecific expression of a dominantly inherited form of distal arthrogryposis. Implications for genetic counselling in distal arthrogryposis are outlined.

Hypokinesia in Parkinson's disease: influence of age, disease severity, and disease duration.

The aim of this cross-sectional study was to compare the role of aging in measures reflecting diurnal activity and immobility in 60 parkinsonian patients with predominant features of hypokinesia and rigidity and 100 healthy subjects aged 50 to 98 years. In the patients, we also studied the relation between disease duration and subjective and objective measures of disease severity. Motor activity was recorded during 5 successive days at home with a wrist-worn activity monitor. For each subject, two mean measures reflecting the diurnal activity level and the relative proportion of activity and immobility were calculated. Diurnal measures of activity revealed in both groups a prominent absolute reduction of activity and an increase of the time spent without movement ("immobility") with advancing age. Parkinsonian patients showed significantly lower values for both motor-activity measures than did the healthy subjects. The rate of the age-related decline of both diurnal activity measures in both groups, however, is comparable. Disease duration showed no relation with subjective and objective measures reflecting disease severity. This study shows that if care is taken to control for disease severity, the rate of the age-related decline of measures reflecting diurnal activity and immobility is similar in both groups. The lack of relation between disease duration and subjective and objective measures of disease severity suggests that the rate of progression of Parkinson's disease can be reliably studied only by means of longitudinal studies.

The clinimetrics of hypokinesia in Parkinson's disease: subjective versus objective assessment.

In this study we evaluate the feasibility of measures that reflect different characteristics of motor activity and immobility in the objective quantification of hypokinesia. Because by definition hypokinesia can only be assessed over a period of time, continuous activity monitoring was used during 5 successive days in the home setting in 64 patients with Parkinson's disease (PD) and 104 healthy elderly subjects. In the patients we also evaluated the relation between the monitor measures and subjective measures of hypokinesia and age. Compared to the healthy elderly subjects, PD patients have a decreased activity level, increased proportion of time without movement, elevated mean duration of immobility, and decreased percentage of short-lasting immobility periods. Differences between both groups were most prominent for those measures that incorporate or reflect immobility. Moreover, in the PD patients the mean duration of immobility and percentage of short-lasting immobility periods show an apparent lack of relation with age and clinical ratings obtained from the UPDRS. In conclusion, our findings underscore the poor representation of hypokinesia in the UPDRS and value of objective quantification of this fundamental impairment of PD.