The excellent review article by Costa and Duyckaerts on oligodendroglial and neuronal inclusions in multiple system atrophy (MSA) which appears in this section prompted this commentator to discuss the current controversy that exists over these rather overlapping and ill-defined groups of neurodegenerative diseases . When Graham and Oppenheimer  coined the rubric of MSA in 1969 for a case of idiopathic orthostatic hypotension, they perhaps did not expect the term to be so popularized as to encompass many other complex neurodegenerative diseases such as pontocerebellar atrophy, olivopontocerebellar atrophy, Shy-Drager syndrome, Parkinsonism-amyotrophy syndrome, striatonigral degeneration, and more recently pure autonomic failure. Notable is a distinctive tendency for all of them to involve lower motor neurons. If the oligodendroglial inclusions, as purported in this review, are diagnostic hallmarks for MSA then elucidation of this inclusion may lead us to understand the common pathologic ground involved in this constellation of diseases. The controversy over whether Werdnig-Hoffmann disease (WHD) should belong to MSA rather than lower motor neuron disease has long existed, because pathologically WHD involves heterogeneous neuronal groups other than the motor neuron system [3–5]. A recent prospective clinical study claimed that all three types of spinal muscular atrophy (SMA) have variable onset, life span, and may be without loss of muscle function, casting doubt on the time-honored classification scheme currently used for SMA .