Familial cerebellar ataxia with muscle coenzyme Q10 deficiency

Neurology. 2001 Apr 10;56(7):849-55. doi: 10.1212/wnl.56.7.849.


Objective: To describe a clinical syndrome of cerebellar ataxia associated with muscle coenzyme Q10 (CoQ10) deficiency.

Background: Muscle CoQ10 deficiency has been reported only in a few patients with a mitochondrial encephalomyopathy characterized by 1) recurrent myoglobinuria; 2) brain involvement (seizures, ataxia, mental retardation), and 3) ragged-red fibers and lipid storage in the muscle biopsy.

Methods: Having found decreased CoQ10 levels in muscle from a patient with unclassified familial cerebellar ataxia, the authors measured CoQ10 in muscle biopsies from other patients in whom cerebellar ataxia could not be attributed to known genetic causes.

Results: The authors found muscle CoQ10 deficiency (26 to 35% of normal) in six patients with cerebellar ataxia, pyramidal signs, and seizures. All six patients responded to CoQ10 supplementation; strength increased, ataxia improved, and seizures became less frequent.

Conclusions: Primary CoQ10 deficiency is a potentially important cause of familial ataxia and should be considered in the differential diagnosis of this condition because CoQ10 administration seems to improve the clinical picture.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Brain / pathology
  • Cerebellar Ataxia / genetics
  • Cerebellar Ataxia / metabolism*
  • Cerebellar Ataxia / pathology
  • Cerebellar Ataxia / physiopathology
  • Child
  • Electron Transport Complex III / deficiency
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Muscles / metabolism*
  • Muscles / pathology
  • Seizures / physiopathology
  • Ubiquinone / deficiency*


  • Ubiquinone
  • Electron Transport Complex III