Patients have exercise-induced or permanent extraocular pareses with with progressive external ophthalmoplegia. This is also known as opthalmoplegia plus.
On imaging patients have similar features to Kearns-Sayre with calcification of the deep cerebral and cerebellar nuclei. Patients have increased T2 signal in the dorsal midbrain, medial and posterior thalami, and the globi pallidi. Patients have increased T2 signal in the subcortical U fibres with preservation of the periventricular white matter signal. Affected white matter shows restricted diffusion. MRS shows increased lactate and reduced NAA.