Neurology and Neurorehabilitation

Progressive acquired or hereditary neuromuscular diseases (NMDs) are disorders caused by an abnormality of any component of the lower motor neuron - anterior horn cell, peripheral nerve, neuromuscular junction (pre-synaptic or post-synaptic region), or muscle. The notion that a pathologic abnormality in a neuromuscular disease may be purely isolated to one anatomic region of the lower motor neuron with primary or secondary changes isolated to muscle is only true for selected conditions. Many neuromuscular diseases are multi-system disorders affecting multiple organ systems. For example, RNA toxicity generated from expansion of trinucleotide repeat sequences in myotonic muscular dystrophy gives rise to skeletal muscle, smooth muscle, myocardial, endocrine, brain and ocular abnormalities; Duchenne muscular dystrophy gives rise to abnormalities of skeletal and cardiac muscle, the cardiac conduction system, smooth muscle and the brain; Fukuyama congenital muscular dystrophy affects skeletal muscle and brain; mitochondrial encephalomyelopathies may affect the mitochondria of multiple tissues. The most common NMDs are acquired peripheral neuropathies. Other acquired NMDS include amyotrophic lateral sclerosis (ALS), poliomyelitis, Guillain Barre syndrome, myasthenia gravis, and polymyositis. Hereditary NMDs are also quite common and include such disorders as spinal muscular atrophy (SMA), Charcot Marie Tooth disease, congenital myasthenia, and Duchenne muscular dystrophy. Clinical NMD syndromes described over the decades in the literature have recently been redefined based molecular genetic advances and documentation of genetic heterogeneity within specific syndromes. For example, at least 70 genetically distinct subtypes of Charcot Marie Tooth have been described, some with undetermined gene loci; over 14 genetically distinct subtypes of autosomal recessive limb girdle muscular dystrophy have been identified; and 3 genetically distinct subtypes of Emery Dreifuss exist.58 In fact, the gene loci for over 500 distinct neuromuscular and mitochondrial disorders have been identified at the time this manuscript went to press. This information can be published in our peer reviewed journal with impact factors and are calculated using citations not only from research articles but also review articles (which tend to receive more citations), editorials, letters, meeting abstracts, short communications, and case reports. The inclusion of these publications provides the opportunity for editors and publishers to manipulate the ratio used to calculate the impact factor and try to increase their number rapidly. Impact factor plays a major role for the particular journal. Journal with higher impact factor is considered to be more important than other ones.