Evidence for genetically determined degeneration of proprioceptive tracts in Friedreich ataxia

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Brice Marty
  • Naeije Gilles
  • Mathieu Bourguignon
  • Vincent Wens
  • Veikko Jousmäki

  • David R Lynch
  • William Gaetz
  • Serge Goldman
  • Riitta Hari

  • Massimo Pandolfo
  • Xavier De Tiège

Research units

  • Université Libre de Bruxelles
  • Children's Hospital of Philadelphia
  • ULB

Abstract

OBJECTIVE:
To assess with magnetoencephalography the developmental vs progressive character of the impairment of spinocortical proprioceptive pathways in Friedreich ataxia (FRDA).
METHODS:
Neuromagnetic signals were recorded from 16 right-handed patients with FRDA (9 female patients, mean age 27 years, mean Scale for the Assessment and Rating Of ataxia [SARA] score 22.25) and matched healthy controls while they performed right finger movements either actively or passively. The coupling between movement kinematics (i.e., acceleration) and neuromagnetic signals was assessed by the use of coherence at sensor and source levels. Such coupling, that is, the corticokinematic coherence (CKC), specifically indexes proprioceptive afferent inputs to the contralateral primary sensorimotor (cSM1) cortex. Nonparametric permutations and Spearman rank correlation test were used for statistics.
RESULTS:
In both groups of participants and movement conditions, significant coupling peaked at the cSM1 cortex. Coherence levels were 70% to 75% lower in patients with FRDA than in healthy controls in both movement conditions. In patients with FRDA, coherence levels correlated with genotype alteration (i.e., the size of GAA1 triplet expansion) and the age at symptom onset but not with disease duration or SARA score.
CONCLUSION:
This study provides electrophysiologic evidence demonstrating that proprioceptive impairment in FRDA is mostly genetically determined and scarcely progressive after symptom onset. It also positions CKC as a reliable, robust, specific marker of proprioceptive impairment in FRDA.

Details

Original languageEnglish
Pages (from-to)e116-e124
Number of pages9
JournalNeurology
Volume93
Issue number2
Early online date13 Jun 2019
Publication statusPublished - 9 Jul 2019
MoE publication typeA1 Journal article-refereed

    Research areas

  • Friedreich ataxia, human, MEG, Corticokinematic coherence

ID: 35077755