Death from bulbar involvement in Friedreich's ataxia.

Cheyne-Stokes breathing occurs in patients with Friedreich's ataxia. In some cases, this form of periodic breathing may be caused by degenerative changes at the bulbar level. In view of decreased levels of glycine in the spinal cord in patients with Friedreich's ataxia, though medullary levels have not been measured, it is hypothesized that glycine (and perhaps other inhibitory amino acids) reverses Cheyne-Stokes breathing and could perhaps prolong life expectancy in patients with Friedreich's ataxia.