Considering Spastic Paraplegia Type 7 and Adult-Onset Alexander Disease

To the Editor We read with interest the recently published clinicopathological case by Dubey et al¹ describing a patient with slowly progressive cerebellar ataxia and myelopathy. Recognizing the concomitant occurrence of cerebellar ataxia and spasticity provides an important diagnostic clue for a relatively small group of rare disorders, provided that brainstem vascular malformations, infections, metabolic changes, neoplastic causes, or demyelinating disorders have been excluded. The authors critically examined the differential diagnosis and provided a complete and useful description of several relevant conditions that may also present with spastic-ataxia. However, 2 additional disorders were not discussed and should be included in the differential.