International Cooperative Ataxia Rating Scale Subscores Research Articles

OP9 – 2583: Phosphomanomutase deficiency (PMM2-CDG): Assessment of cerebellar dysfunction through ICARS

Objective To assess the validity of the International Cooperative Ataxia Rating Scale (ICARS) in children and adolescents with genetically confirmed PMM2-CDG deficiency. Secondary objectives: To compare ICARS results with Nijmegen paediatric CDG rating scale (NPCRS), neuroimaging findings, intelligence quotient (IQ) and molecular data. Methods Observational study including 13 PMM2-CDG patients and 21 control subjects. Ethical permission and informed consents were obtained. Three independent child neurologists rated PMM2-CDG patients with the ICARS, whereas the NPCRS was administered by a single observer. All patients underwent brain MRI and midsaggital vermis relative diameter was obtained. Psychometric evaluations were available in 6 patients. Mann-Whitney U test was used to compare ICARS between patients and controls. To evaluate inter-observer agreement in patients' ICARS, intraclass correlation coefficients (ICC) were calculated. ICARS Internal consistency was evaluated using Cronbach's alpha. Spearman's rank correlation coefficient test was used to correlate ICARS with NPCRS, midsaggital vermis relative diameter, and intelligence quotients (IQ). Results ICARS and ICARS subscores differed between patients and controls (p Conclusion ICARS is a reliable instrument for assessment of PMM2-CDG patients, without significant inter-rater variability. Despite limited sample size, results hint a good correlation between functional cerebellar assessment, IQ and neuroimaging data. ICARS may represent a valuable tool to evaluate therapeutic interventions on cerebellum dysfunction in PMM2-CDG patients.

The correlation between magnetic resonance imaging features of the brainstem and cerebellum and clinical features of spinocerebellar ataxia 3/Machado-Joseph disease

Brainstem and cerebellar atrophy are the most important features in magnetic resonance imaging (MRI) in spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD). However, the correlation between brainstem and cerebellar atrophy and the clinical features has not been well studied. To study the correlation between MRI features of the brainstem and cerebellum and predominant clinical features in SCA3/MJD. University teaching hospital. By using the linear measurement method, we assessed 32 patients with SCA3/MJD to study the correlations between the morphometric data of the brainstem and cerebellum and clinical features: Duration of the disease, age of onset, total international cooperative ataxia rating scale (ICARS) score; total scale for the assessment and rating of ataxia (SARA) score; ICARS subscores, and SARA subscores. Pearson correlation test. There was a significant inverse correlation between anteroposterior diameter of the midbrain and pons and total ICARS scores, total SARA scores, ICARS and SARA subscores (r = -0.381 approximately -0.57, P < 0.05 or 0.01) and disease duration (r = -0.42 approximately -0.51, P < 0.05 or 0.01). Additionally, superoinferior diameter of the cerebellum was inversely correlated with total SARA scores and ICARS and SARA subscores except for ataxia of posture and gait in both scales (r = - 0.37 approximately -0.44, P < 0.05). The superoinferior diameter of the fourth ventricle was inversely correlated with age of onset (r = -0.45, P < 0.05). The effect on the cerebellum and brainstem is related to predominant clinical features in SCA3/MJD patients.

Reliability and validity of ICARS in focal cerebellar lesions

To evaluate the therapies for cerebellar diseases appropriate neurological assessment methods to measure severity of ataxia are required. Reliability and validity of the semiquantitative International Cooperative Ataxia Rating Scale (ICARS) has recently been examined in patients with degenerative ataxias. We evaluated reliability (internal consistency), criterion-related validity and internal construct validity of ICARS for the first time in patients with focal cerebellar lesions (68 patients with surgical lesions and 68 patients with ischemic lesions). For comparison 45 patients with degenerative cerebellar ataxia were included. We found an excellent Cronbach's alpha as a measurement for internal consistency which was independent from underlying disease. Criterion-related validity was high. Total ICARS score mirrored clearly the immediate postsurgical worsening and the improvement during the first 3 months after focal surgical and ischemic lesions, whereas in chronic state of focal and degenerative cerebellar disorders ICARS score remained nearly unchanged. Principal component analysis in patients with focal lesions revealed five distinct and clinically meaningful factors which corresponded to the four ICARS subscores and reflected the laterality of kinetic functions. In degenerative disorders, however, the items for the subscore "kinetic function" loaded to more than one factor. Total ICARS score seems to be a useful and valid measurement to describe the time course of ataxia in patients with focal and degenerative disorders affecting primarily the cerebellum. Validity of subscores however is good in focal, but not in degenerative disorders.

Degree of Cerebellar Ataxia Correlates with Three-Dimensional MRI-Based Cerebellar Volume in Pure Cerebellar Degeneration

The aim of the present study was to compare the severity of cerebellar ataxia as measured by the International Cooperative Ataxia Rating Scale (ICARS) by Trouillas et al. [ J Neurol Sci 1997;145:205–211] with the cerebellar volume in chronic cerebellar disease. Fifteen patients with pure cerebellar degeneration were investigated. Seven patients suffered from spinocerebellar ataxia type 6, 5 from idiopathic late-onset cerebellar ataxia, 2 from autosomal dominant cerebellar ataxia type III and 1 from episodic ataxia type 2. Volumetric analysis was based on individual three-dimensional MR images. Total ICARS score significantly inversely correlated with the cerebellar volume (r = –0.805, p < 0.0001), correlations between ICARS subscores and cerebellar volume were significant for upper and lower limb ataxia, ataxia of posture and gait, and dysarthria, but not for the oculomotor subscore. The results suggest that the degree of cerebellar atrophy in pure cerebellar degenerative disorders is accompanied by comparable functional impairment (i.e. degree of cerebellar ataxia).