A case of Mills' syndrome: initially characterized by one cerebral hemisphere atrophy and decreased brain metabolism then evolving into amyotrophic lateral sclerosis.

This article reports a case of Mills' syndrome that initially manifested as atrophy of one cerebral hemisphere and decreased brain metabolism, which developed into amyotrophic lateral sclerosis in the fourth year of the disease. Mills' syndrome is a rare type of motor neuron disease, with only over 20 cases reported since 1990, but most lack imaging such as PET and DTI. This article provides a complete report of the 18F-FDG-PET and DTI images consistent with the characteristics of Mills' syndrome. In addition, we have discovered some new phenomena, which have certain clinical and teaching values. Firstly, the frontal, parietal and temporal lobes on the side of the lesion in the pyramidal tract of this patient were significantly atrophic, indicating that unilateral brain lobe atrophy may be a new feature of Mills' syndrome. Secondly, although there were no abnormalities in three EMG tests taken during the 4 years prior to the onset of the disease, amyotrophy and ALS-like EMG features appeared in the fourth year, suggesting that some Mills' syndrome may progress more rapidly to ALS. This highlights the importance of regular follow-up electromyography in Mills' syndrome patients.