CK blood test
A Creatinine Kinase test is a blood test that measures the levels of Creatinine phosphokinase (CPK). It is an enzyme found predominantly in the heart tissue, brain and skeletal muscle. The CK blood test is commonly used to diagnose the existence of heart muscle damage. The CK blood test result shows an increase above normal in a person's blood test about six hours after the start of a heart attack.
It reaches its peak in about 18 hours and returns to normal in 24 to 36 hours. When the total CPK level is substantially elevated, then it is indicative of injury or stress to heart, brain or skeletal areas. The small amount of CPK that is normally in the blood comes from the muscles. The CPK blood test also helps in cost-effective management of people with suspected coronary atherosclerosis. It also evaluates the extent of muscle damage caused by drugs, trauma or immobility.
Abnormal CK-MB (one of three CK isoenzymes) or troponin levels are associated with Myocyte Necrosis and the diagnosis of Myocardial infarction. The Cardiac Markers of Cardiac Myocyte Necrosis (damage to the Cardiac muscle cells), myoglobin, CK, CK-MB and troponin I and T are primarily used to identify acute Myocardial Infarction.
It is used in early detection of dermatomyositis and polymyositis. It is also used to distinguish malignant hyperthermia from a post operative infection. It helps to discover carriers of muscular dystrophy.
The normal range for Creatinine Kinase (CK or CPK) blood test:
Male: 38 - 174 units/L
Female: 96 - 140 units/L
Increased levels of CK also can be found in viral myositis and hypothyroidism. Higher than normal CPK levels is indicative of the following conditions:
Serum CKMB levels are tested to check for myocardial injury. It is another important cardiac marker. The primary source of CKMB is myocardium although it is also found in skeletal muscle. Typically CKMB tests have now been replaced by Troponin test. But in cases of abnormal Troponin assay results or suspected re-infarction in the hospital, the CKMB serum test is still used.
High levels of CK MB are noticed in cases of polymyositis and rhabdomyolysis. Patients suffering pulmonary embolism, hypothyroidism, and muscular dystrophy or carbon monoxide poisoning can also show higher levels of serum CKMB. The reference range is about 56.2 pg/mL.
Myotonia Congenita is a neuromuscular genetic disease that involves progressive muscle stiffness and enlargement. This rare disorder is characterized by bouts of sustained muscle stiffness or Myotonia. The resultant muscle tensing can range from mild to severe. Myotonia Congenita occurs due to mutation of the CLCNI gene. This gene is critical in the functioning of the skeletal muscles. Therefore the mutation leads to bouts of muscle weakness. Abnormal muscle enlargement or hypertrophy is noticed in persons suffering Myotonia, even in children.
Myotonia can affect muscles in any part of the body. In some it can affect the limbs. Some persons experience difficulty in swallowing or inability to relax their muscles quickly after contraction. Other symptoms include shortness of breath at the beginning of exercise.
Thomsen disease: In this form of the disorder, the symptoms manifest early in infancy. The main characteristic symptom of Thomsen disease is muscle stiffness or even muscle weakness after a bout of strenuous exercise. Even stress, fatigue or cold can act as triggers. The symptoms become noticeable in 2-3 years. Limbs and eyelid muscles are often affected. Thomsen disease is transmitted as an autosomal dominant trait.
Becker disease: This form of the disorder typically occurs later in life. The symptoms of Becker disease are noticed between 4-12 years. In Becker Myotonia, there is severe muscle stiffness which can often lead to mild muscle atrophy. Some medications such as beta blockers, diuretics and muscle relaxants can trigger Becker disease symptoms. Becker disease is inherited as an autosomal recessive trait.
An Electromyography is done to test the electrical activity within the muscles. Muscle biopsy is performed to check for absence of 2B fibers. CK blood test is done to check for elevated creatine kinase levels.
Myotonia Congenita Treatment
In the absence of a cure for Myotonia Congenita, a holistic approach encompassing lifestyle changes, physical therapy, and avoiding triggers is effective. Termed as the warm-up phenomenon, for most people regular exercise has been effective to relax the stiff muscles. Healthcare providers suggest making lifestyle modifications such as avoiding certain situations and physical therapy even before prescribing medications. Rehabilitative therapy to improve muscle function and relaxation techniques to reduce stress and mental discomfort which may worsen the disorder is also recommended.
Only when all these are insufficient, medications such as quinine and anticonvulsant drug such as phenytoin are prescribed. Children diagnosed with the disorder should have regular consultation with pediatric neurologist to understand and manage the disorder with the least disturbance during the growing years. Custom designed exercises, selecting suitable games and sports, avoiding foods that trigger lets children work around the symptoms and have a quality life.
Bibliography / Reference
Collection of Pages - Last revised Date: January 16, 2019