Clonus Definition: A rare condition characterized by involuntary rhythmic contractions of the diaphragm, heart and lungs (also referred to as “breathing without breathing”). The rhythm may be irregular or continuous. These contractions are not caused by any external stimulus but rather result from internal mechanisms which control respiration.
Causes: There are no known causes of clonus. However, it has been suggested that clonus might have a genetic basis.
Symptoms: Clonus symptoms include:
Shortness of breath (may be noticeable even when exercising)
Difficulty in breathing (difficult to breathe normally)
Chest pain (may cause shortness of breath) and/or shortness of breath during exercise.
The most common symptom is difficulty in breathing while exercising. Other symptoms include chest pain, shortness of breath and fatigue.
Diagnosis: Diagnosing clonus is difficult because there are no physical tests available to diagnose this disorder. If a patient complains of these symptoms then they must undergo a medical examination.
Treatment: Treatment depends on the severity of the symptoms and whether they are due to other conditions such as asthma or lung disease. In some severe cases a heart-lung machine may be required to increase blood flow to the lungs.
Myotonia is a condition in which your muscles become rigid or stiff for an extended period of time following voluntary muscle contraction. This condition can affect any skeletal muscles in the body but is most commonly found in the pelvic region and the muscles attached to the elbows and knees. In addition, myotonia in the pelvic region (a condition known as ‘jelly’ legs) can result in temporary paralysis after a forced muscular contraction. Thus, an individual with this condition will have a delayed recovery from forced muscle contractions that are performed against resistance.
Myotonia congenita is an inherited condition that is passed from parents to children through genes. It is an autosomal dominant disorder, which means that if one parent has the condition, there is a 50 percent chance their child will inherit the myotonia gene. If both parents have the condition, the child has a 75 percent chance of inheriting the myotonia gene.
The gene for myotonia causes the skeletal muscles to not relax immediately after a voluntary contraction. This can be best explained by considering the example of your arm moving when you wave to someone. When you voluntarily contract your bicep (the muscle in the front of your arm) to wave, that muscle will more slowly relax, or return to its natural state, than it would for most people. This relaxation problem was first scientifically recognized in horses, which is where the term ‘myotonia’ comes from; it comes from the Greek words mys meaning “muscle” and tonos meaning “tension”.
This condition is sometimes called “frozen shoulder” because many individuals with this condition report locked-up sensation in their shoulder or other joints.
Myotonia congenita can be further broken down into two types:
The generalized type affects the whole body, including the muscles of the eye and the smooth muscle (the muscles that control involuntary actions of the internal organs). An example of a smooth muscle that is affected is the rings of muscle in the iris of your eye.
The segmental type is less severe and only involves the muscles attached to the elbows and/or knees. This form of myotonia is inherited from one of your parents who likely has the generalized type of myotonia.
This condition can also be classified by whether or not it affects other metabolic functions of the body, including controlling body temperature.
Generalized Myotonia Congenita:
In addition to the muscle problems described above, people with the generalized type of myotonia congenita have a problem with controlling their body temperature. When experiencing a fever, they are less able to cool their bodies by sweating and thereby maintaining an appropriate internal body temperature. These individuals also seem to be more susceptible to hypothermia (chills, cold extremities).
Segmental Myotonia Congenita:
In addition to the muscle problems described above, people with the segmental type of myotonia congenita may have some developmental issues. Specifically, they may have mild learning disabilities and speech delays.
While there is no known cure for myotonia congenita, there are treatment options available. A physical therapist can help to reduce discomfort and pain caused by this condition. Your physician may prescribe medication to help control the myotonia, as well as any other medical conditions you may have.
The best approach is to maintain a healthy lifestyle, including a balanced diet and exercise.
There are three types of sensory stimuli that can trigger involuntary muscle contractions: sound, light, and touch.
Some people with myotonia congenita experience more sensitivity to these stimuli than others do. Still, everyone experiences some level of sensory sensitivity. The most common misophonia is related to sounds, particularly those made by other people such as coughing, mouth noises (eating, lisping), and breathing. While it may be tempting to cover your ears or leave the room, these types of sensory triggers are unavoidable at times.
If you remain aware of your surroundings and your own reactions, adjustments can be made in order to minimize misophonia and promote comfort.
Affected individuals should remain mindful of their environment. For example, someone who works in an office should sit away from a noisy printer, cubicle mates who eat crunchy snacks should be aware of the noise they are making, and those who must speak should try to do so in as quiet a voice as possible. In this way, small changes in behavior can make a big difference in overall comfort.
People with myotonia congenita can pursue enjoyable and fulfilling lives. Below are some additional recommendations for day-to-day living:
Children who experience learning disabilities can benefit from smaller classroom sizes and individual tutoring. In addition, they need breaks during the day to exercise. While physical activity helps everyone stay focused, it is especially beneficial to those with Myotonia Congenita. Those with less severe cases of myotonia congenita may not experience any benefit from increased activity, but those with more serious cases will be able to regain their strength.
It is best for people with myotonia congenita to focus on shorter careers and have a backup plan to fall back on. Those in physically demanding careers should be aware of the physical toll that career choice may take on their bodies. They should consider a less strenuous line of work, perhaps changing later in life when they have built up strength and stamina to handle the new career.
Because people with myotonia congenita experience muscle pain, extreme temperature changes should be avoided when possible. This means they should stay away from extremely hot and cold climates.
People with this condition should remain in cool rooms and wear thin clothing.
When someone with myotonia congenita becomes angry, startled, or frightened, their muscle stiffness is intensified. They may feel sharp, shooting pains throughout their body. By remaining calm in stressful situations, they can avoid the painful effects of myotonia. This is easier said than done, but there are ways of managing one’s temper and stress level.
Making time for fun and socializing can improve emotional well-being. This can be as simple as playing a board game with friends or going out for ice cream after work. By engaging in enjoyable activities, individuals may be less likely to experience anxiety and depression.
Stretching, yoga, and other forms of exercise can help improve muscle tone. Gentle stretching should be done on a regular basis in order to maintain flexibility and range of motion.
Heat is known to exacerbate the symptoms of myotonia congenita. People with this condition should avoid becoming overheated or dehydrated, as this may lead to heat stroke. The elderly in particular should take care when going outside on hot days, and should drink plenty of water during these times.
People with myotonia congenita can have a normal life expectancy. As people age, they experience wear and tear on their bodies, but those with myotonia may experience this to a lesser degree. In order to combat age-related muscle weakness, it is recommended that adults engage in regular exercise regimes and maintain a healthy diet.
While there is currently no cure for myotonia congenita, those with the condition should not lose hope. There are a number of ways to manage the condition, and as technology advances there is always the possibility of future treatment options.
For Further Reading
Blow, Michael. “The Muscle Disease Myotonia Congenita: An Overview.” Advances in Neurology 32 (1982):591-601.
Glenn, Kathryn E. “Surface ElectroMyography in Patients With Congenital Myotonic Muscle Spasms.” Muscle & Nerve 41.10 (2010): 1597-1602.
Morton, Patricia K. “Myotonia Congenita.” Emedicine. Web.
28 July 2014.
Reyes, Isidro J., and John P. Garner. “Acquired Myotonia Due to Cocaine Poisoning.” Muscle & Nerve 31.4 (2009): 469-472.
Saunders, Kate E.
Sources & references used in this article:
Prognosis after a first untreated tonic-clonic seizure by RDC Elwes, P Chesterman, EH Reynolds – The Lancet, 1985 – Elsevier
Phenytoin versus valproate monotherapy for partial onset seizures and generalized onset tonic‐clonic seizures by CT Smith, AG Marson… – Cochrane Database of …, 2001 – cochranelibrary.com
Generalized tonic-clonic activity after remifentanil administration by GW Haber, RS Litman – Anesthesia & Analgesia, 2001 – cdn.journals.lww.com
Tonic-clonic seizures in a patient with primary hypoparathyroidism: a case report by C Armelisasso, ML Vaccario… – Clinical EEG and …, 2004 – journals.sagepub.com
Critical evaluation of four different seizure detection systems tested on one patient with focal and generalized tonic and clonic seizures by A Van de Vel, K Verhaert, B Ceulemans – Epilepsy & Behavior, 2014 – Elsevier
Phenytoin versus valproate monotherapy for partial onset seizures and generalised onset tonic‐clonic seizures by SJ Nolan, AG Marson, J Pulman… – Cochrane Database of …, 2013 – cochranelibrary.com
Dynamical changes in neurons during seizures determine tonic to clonic shift by B Beverlin, J Kakalios, D Nykamp, TI Netoff – Journal of computational …, 2012 – Springer
Development of a Validated Clinical Case Definition of Generalized Tonic–Clonic Seizures for Use by Community‐based Health Care Providers by K Anand, S Jain, E Paul, A Srivastava, SA Sahariah… – …, 2005 – Wiley Online Library
Phenytoin versus valproate monotherapy for partial onset seizures and generalised onset tonic‐clonic seizures: an individual participant data review by SJ Nevitt, AG Marson, J Weston… – Cochrane Database of …, 2016 – cochranelibrary.com