Infantile spinal muscular atrophy
Infantile spinal muscular atrophy Causes
Many hypotheses had been suggested to explain the motor neuron degeneration observed in SMAs. The hypotheses include (1) arrested development of spinal cord during fetal life with degeneration of surviving motor neurons, (2) abnormal neuronal RNA and oxidative enzyme metabolism, (3) prominent glial proliferation in the proximal portion of the anterior spinal roots with secondary neuronal degeneration, (4) lack or inhibition of muscle-derived neuronal growth factors, (5) impaired muscle maturation, (6) abnormal apoptosis (programmed cell death), and (7) various adverse environmental influences.
Infantile spinal muscular atrophy Definition
Spinal Muscular Atrophy (SMA) is a term used to describe a number of different disorders, all having in common a genetic cause and the manifestation of weakness due to loss of the motor neurons of the spinal cord and brainstem.
Infantile spinal muscular atrophy Diagnosis
The diagnosis of SMAs includes a detailed clinical history. Obtaining a complete family history aids in genetic counseling. Inidividuals with SMA present with weakness and muscle wasting in the limbs, respiratory, and bulbar or brainstem muscles. They have no signs of cerebral or other CNS dysfunction. Patients with SMA often have above-average IQs and demonstrate high degrees of intelligence.
Infantile spinal muscular atrophy Symptoms and Signs
Infantile SMA is the most severe form of SMA. The symptoms include: muscle weakness; poor muscle tone; weak cry; limpness or a tendency to flop; the legs tend to be weaker than the arms; feeding difficulties; increased susceptibility to respiratory tract infections; and developmental milestones, such as lifting the head or sitting up, can't be reached.
Infantile spinal muscular atrophy Treatment
Infantile SMA is a fatal disorder and there is no known cure. Treatment can only alleviate any associated complications. For instance, since a child with infantile SMA is susceptible to respiratory infections and pneumonia, treatment focuses on trying to maintain the child's lung function and health.