Mills' syndrome: a rare clinical entity

Introduction. Mills'syndrome is a rare motor neuron disease, initially described by Mills in 1900 as a progressive ascending or descending herniplegia without significant sensory involvement. This syndrome is of uncertain nosological status, and is supposedly due to unilateral primary degeneration of corticospinal pathway. Some authors have suggested that it could represent a variant of primary lateral sclerosis. Methods. We retrospectively studied the clinical and paractinical data from eight patients with suspected Mills' syndrome hospitalized for diagnosis. Results. For all patients, the clinical course was slowly progressive, with motor deficiency, unilateral pyramidal signs (or bilateral with asymmetry), without bulbar signs, fasciculations or sensory deficit. Final diagnosis was Mills'syndrome (n=3), primary lateral sclerosis (n=1), myelitis of unknown origin (n=2), progressive primary multiple sclerosis (n=1), and antiphospholipid syndrome (n=1). The main arguments for final diagnosis were brought by electrophysiology and brain and spinal MRI. Conclusion. Mills'syndrome is a rare clinical diagnosis, requiring exhaustive investigations.