Isolated pulmonary recovery in a veteran with late stage bulbar ALS following edaravone treatment and cessation.

Context: Amyotrophic lateral sclerosis (ALS) is a group of rare neurological diseases which cause progressive loss of upper and lower motor neurons at the spinal or bulbar level. ALS affects voluntary muscles of the body which control eating, talking, and moving. Individuals with ALS manifest difficulty breathing on their own due to weakness of the respiratory system. The average life expectancy of individuals with ALS is 2-5 years from the time of diagnosis, with death resulting from respiratory failure. There is no cure for ALS. At present, riluzole and edaravone are the only FDA-approved treatments that impact survival. Adverse reactions to edaravone include hypoxia and respiratory failure. To date, there are no published reports describing isolated dramatic respiratory improvement in ALS with continued global clinical worsening including limb and face function, particularly following edaravone use.

Findings: We present a case report of late stage bulbar ALS, in which a dramatic respiratory improvement is seen following edaravone use, and subsequent cessation.

Conclusion/clinical Relevance: Isolated pulmonary decline and subsequent recovery following cessation of edaravone in the setting of continued systemic neurologic decline has not yet been described and may suggest potential for reversibility of edaravone-related pulmonary decline. Research is needed to evaluate this possibility further, and this case report may lead to further investigation to evaluate this possibility. Alternatively, although less likely, it is possible the observed that pulmonary improvement may either be beneficially attributed to edaravone, or unrelated to edaravone entirely - representing an undescribed phenomenon of isolated pulmonary decline and improvement in the setting of systemic continued ALS progression, possibly related to the bulbar subtype. Further investigation is warranted to evaluate both the role of edaravone in causing in a potentially reversible pulmonary decline upon cessation of the medication, and the possibility of other undefined variables including various subtypes of ALS contributing to this phenomenon.