Centronuclear myopathy
Centronuclear myopathy Definition
Centronuclear myopathy belongs to a group of rare diseases called congenital myopathies. Congenital myopathies are conditions wherein the cell's nuclei is located within the skeletal muscle cells, an abnormal condition. Normally, the nuclei would be positioned in the periphery of the cell, but with centronuclear myopathy the nuclei is in the center, hence the name.
Centronuclear myopathy Diagnosis
Because muscle weakness can be caused by other medical conditions, such as neurological conditions and brain problems, proper diagnosis of the condition is necessary in ruling out other factors. The first step in diagnosis is undergoing an electrodiagnostic testing, sometimes known as electrophysiologic testing. The importance of this type of diagnostic procedure is that it rules out neuropathies from myopathies, because many of the symptoms are present in both conditions. This diagnostic process involves nerve conduction studies. These stimulate the peripheral motor and sensory nerves in order to study its response. A needle electromyography is also done, wherein thin electrodes are placed in muscle tissue, looking out for any anomalous activity. An analysis of the motor unit action potential shown in the electromyography is significant in determining the difference between a myography and a neuropathy. Once it is determined that the condition is a myopathy, muscle biopsy and genetics can help determine exactly what kind of myopathy is present.
Centronuclear myopathy Historical Background
The first recorded incidence of centronuclear myopathy was in 1966, when a doctor named Dr. Spiro came out with a report about a boy who had myopathy. The boy?s muscle biopsy revealed that the cell nuclei were in the center, instead of being in the periphery. He came up with the term myotubular myopathy because the image reminded him of myotubular stage during embryonic development, wherein the nucleus appears in the center. Dr. Spiro also theorized that the boy?s embryonic muscle development is a result of the halt in growth during his myotubular phase. Today, however, it still remains unknown if his theory is correct or not, but researchers state that this may be applicable to some cases of infant centronuclear myopathy.
Centronuclear myopathy Types
The most common type of centronuclear myopathies is Myotubular Myopathy. Symptoms include hypotonia, wherein a patient has extremely low muscle tone, resulting in decreased muscle strength. Oxygen deficiencies, also known as hypoxia, are also a common symptom, resulting in the need for breathing devices. Scaphocephaly is also another typical symptom. Centronuclear myopathies are congenital but some symptoms are more evident during later stages in life.