ALS Regional Variants (Brachial Amyotrophic Diplegia and Amyotrophic Leg Diplegia): Still A Diagnostic Challenge in Neurology

Purpose: We illustrate three patients with regional amyotrophic lateral sclerosis (ALS) variants and hope to improve accuracy in diagnosis for this scarce group of diseases.

Case report: Amyotrophic lateral sclerosis (ALS) represents a broad spectrum of acquired and inherited neurodegenerative conditions involving the upper and motor neurons. Typical ALS remains a clinical diagnosis that is not hard to diagnose. Still, when it comes to atypical forms of ALS, the physicians may face some difficulties differentiating between atypical forms of ALS and other neurological diseases, such as multifocal motor neuropathy, chronic inflammatory demyelinating polyneuropathy, and spinal muscular atrophy. Both brachial amyotrophic diplegia (BAD) and leg amyotrophic diplegia (LAD) are considered regional variants of ALS. We are here to report two cases of BAD and one case of LAD. All these 3 cases showed progression of the disease after longitudinal follow- up for approximately two years. However, after two years, their disease progressions were slow and confined to their 'regions' of upper or lower limbs.

Conclusion: BAD and LAD are unique regional variants of ALS with a significantly better prognosis than typical ALS. The phenotypic characteristics of regional ALS variants must be recognized when physicians are to tailor advice on disease progression, disease outcome, drug therapy, and end-of-life planning for patients with ALS or ALS variants.