Development of ophthalmoplegia in amyotrophic lateral sclerosis during long-term use of respirators

Patients with amyotrophic lateral sclerosis (ALS), who survive longer on a life-support system, exceeding the natural course of this disease, show new features of ALS. We report here a clinico-pathologic study of a 51-year-old patient with sporadic ALS who developed progressive external ophthalmoplegia 3 years after he remained on a respirator and died 5 years later, 13 years after the onset of his illness. The external ophthalmoplegia was initially accompanied by preserved doll's eye phenomenon, which later became absent. Autopsy revealed not only degeneration of the upper and lower motor neuron systems typical of ALS, but also degeneration of the Clarke's dorsal nuclei, spinocerebellar tracts, substantia nigra and inferior olives in addition to intracytoplasmic neuronal inclusion bodies in various areas. The oculomotor and abducens nuclei were variably involved, accompanied by neurogenic atrophy of the extraocular muscles. Our case report is consistent with the idea that ALS comprises a heterogeneous group of disorders, and also indicates that long-term use of respirators may make some patients with this illness prone to developing atypical clinical and neuropathologic features which are not observed during the natural course of ALS.