This book provides a state-of-the-art overview of the pathogenesis, diagnosis, and treatment of a range of inflammatory, autoimmune, and idiopathic disorders. The opening section covers clinical tools with a particular focus on the role of electromyography and MRI imaging. The second section then presents the differential diagnosis of acquired myopathies based on clinical, electrophysiological, muscle biopsy, and serological criteria, discussing in detail relevant clinical conditions such as including myasthenia gravis, polymyositis, and statin myopathies. The third section examines acute and chronic immune-mediated neuropathies, multifocal motor neuropathies, amyotrophic lateral sclerosis, paraneoplastic diseases, and diabetic polyneuropathy, offering clear guidance on available treatments and descriptions of the latest advances in immunotheraphy, drug therapy, and physiotherapy.