Hand Dexterity and Pyramidal Dysfunction in Friedreich Ataxia, A Finger Tapping Study

Effectiveness of functional trunk training on trunk control and upper limb functions in patients with autosomal recessive hereditary ataxia

BACKGROUND: Ataxia is a clinical syndrome characterized by coordination problems and postural disorders. OBJECTIVE: This study aimed to examine the effects of functional trunk training on trunk control and upper limb functions in autosomal recessive hereditary ataxia. METHODS: Twenty patients were randomly divided into treatment and control groups. Both groups received trunk stabilization and balance exercises, and the treatment group received additional functional trunk training sessions (3 days/week for 8 weeks). The International Cooperative Ataxia Rating Scale, Trunk Impairment Scale, Modified Functional Reach Test, Nine-Hole Peg Test and Quick-Disabilities of the Arm Shoulder and Hand questionnaire were used for assessments. RESULTS: The treatment group showed an increase in the upper limb performance bilaterally, whereas increased performance was seen only in the dominant upper limb in the control group. While the functional reach improved in the anterior-posterior (AP) and medial-lateral (ML) directions in the treatment group, it was improved only in the AP direction in the control group. Also, the mean changes in outcomes were not significantly different between the groups except for modified functional reach test. CONCLUSIONS: Functional trunk training may be a more effective method to improve upper limb performance and dynamic trunk balance in autosomal recessive hereditary ataxia.

The cognitive profile of Friedreich ataxia: a systematic review and meta-analysis

BACKGROUND

Study the cognitive profile of individuals with Friedreich ataxia (FRDA) and seek evidence for correlations between clinical, genetic and imaging characteristics and neuropsychological impairments.

METHODS

Based on PRISMA guidelines, a meta-analysis was realized using the Pubmed and Scopus databases to identify studies (1950-2021) reporting neuropsychological test results in genetically confirmed FRDA and control participants in at least one of the following cognitive domains: attention/executive, language, memory and visuo-spatial functions as well as emotion. Studies using identical outcomes in a minimum of two studies were pooled. Pooled effect sizes were calculated with Cohen's d.

RESULTS

Eighteen studies were included. Individuals with FRDA displayed significantly lower performance than individuals without FRDA in most language, attention, executive function, memory visuospatial function, emotion regulation and social cognitive tasks. Among the included studies, thirteen studies examined the relationship between neuropsychological test results and clinical parameters and reported significant association with disease severity and six studies reviewed the relationship between neuroimaging measures and cognitive performance and mainly reported links between reduced cognitive performance and changes in cerebellar structure.

CONCLUSIONS

Individuals with FRDA display significantly lower performances in many cognitive domains compared to control participants. The spectrum of the cognitive profile alterations in FRDA and its correlation with disease severity and cerebellar structural parameters suggest a cerebellar role in the pathophysiology of FRDA cognitive impairments.

Automatic Classification and Severity Estimation of Ataxia From Finger Tapping Videos

Digital assessments enable objective measurements of ataxia severity and provide informative features that expand upon the information obtained during a clinical examination. In this study, we demonstrate the feasibility of using finger tapping videos to distinguish participants with Ataxia (N = 169) from participants with parkinsonism (N = 78) and from controls (N = 58), and predict their upper extremity and overall disease severity. Features were extracted from the time series representing the distance between the index and thumb and its derivatives. Classification models in ataxia archived areas under the receiver-operating curve of around 0.91, and regression models estimating disease severity obtained correlation coefficients around r = 0.64. Classification and prediction model coefficients were examined and they not only were in accordance, but were in line with clinical observations of ataxia phenotypes where rate and rhythm are altered during upper extremity motor movement.

Age of onset modulates resting-state brain network dynamics in Friedreich Ataxia

This magnetoencephalography (MEG) study addresses (i) how Friedreich ataxia (FRDA) affects the sub‐second dynamics of resting‐state brain networks, (ii) the main determinants of their dynamic alterations, and (iii) how these alterations are linked with FRDA‐related changes in resting‐state functional brain connectivity (rsFC) over long timescales. For that purpose, 5 min of resting‐state MEG activity were recorded in 16 FRDA patients (mean age: 27 years, range: 12–51 years; 10 females) and matched healthy subjects. Transient brain network dynamics was assessed using hidden Markov modeling (HMM). Post hoc median‐split, nonparametric permutations and Spearman rank correlations were used for statistics. In FRDA patients, a positive correlation was found between the age of symptoms onset (ASO) and the temporal dynamics of two HMM states involving the posterior default mode network (DMN) and the temporo‐parietal junctions (TPJ). FRDA patients with an ASO <11 years presented altered temporal dynamics of those two HMM states compared with FRDA patients with an ASO > 11 years or healthy subjects. The temporal dynamics of the DMN state also correlated with minute‐long DMN rsFC. This study demonstrates that ASO is the main determinant of alterations in the sub‐second dynamics of posterior associative neocortices in FRDA patients and substantiates a direct link between sub‐second network activity and functional brain integration over long timescales.