Isaac’s Syndrome

Isaac’s syndrome, or also known as neuromyotonia and Isaac-Mertin syndrome is an incurable type of disorder that affects muscular actions resulting to abnormal, spontaneous and repetitive muscular activity. It is characterized by a rare neuromuscular disorder that continuously sends signals to the peripheral nerve endings which activates muscle fibers.

Forms of Isaac’s Syndrome

Both men and women from ages 15 to 60 years old can develop this rare disease. This disorder consists of three different forms.

• Acquired (focal or generalized sporadic) is the most common form. It is suspected to be caused by an autoimmune deficiency. Autoimmune condition is a result of the body’s reaction to the immune system’s abnormal production of anti bodies caused by damage in the cells or nerves resulting to hyper excitability. Acquired forms of Isaac syndrome are classified into two, they are:

1. Focal neuromyotonia – only a certain part of the body is affected.

2. Generalized sporadic neuromyotonia – the disorder affects the entire body.

• Hereditary (generalized familial) is when a parent is diagnosed with this type of syndrome and the possibility of passing the disorder to the offspring is likely.

• Paraneoplastic syndrome is a disease which is caused by underlying neoplasm. This disorder is triggered by the immune system’s response to neoplasm which directly affects the nervous system causing problems in the muscular movement. This type of disease is usually associated with Isaac’s syndrome.

Symptoms of Issac’s Syndrome

The symptoms of Isaac’s syndrome are diverse. Its symptoms range from mild inconvenience to debilitating, which rarely happens. Most people diagnosed with Isaac’s syndrome often feel tired and weak, and they usually don’t engage in physical activities that exert muscular strength. Here are some symptoms associated with Isaac’s syndrome:

• Persistent myokymia. Myokymia is a form of involuntary movement of muscles, which are usually visible on the skin.

• Lower limb contractures. Contractures are muscles that are permanently tighten, thus becoming shorter and only released through orthopedic surgery.

• Increased muscle tone (muscle stiffness).

• Cyanotic episodes. Cyanosis is a severe condition resulting from lack of oxygen supply in the blood stream.

• Transient stiffness

• Muscle cramps

• Muscle pain

• Weakened reflexes

• Increase in sweating

• Slurred speech

• Difficulty in swallowing and chewing

• Difficulty in walking

Causes

The main cause of Isaac’s syndrome has not yet been figured out. But aside from being hereditary, there are several conditions that can affect or trigger its development, such as:

1. Chronic lung disease

2. Diabetes mellitus

3. Iron deficiency

4. Peripheral neuropathies

5. Huntington’s chorea

6. Anemia and other related Hemoglobin deficiencies

Diagnosis

Isaac’s syndrome can be diagnosed through the following;

• Based on the patients’ medical history, doctors can determine if the patients may have developed this syndrome through genes or may have resulted from the development of other neurological disorder.

• Physical examination

• Electromyography (EMG) is a standard examination for a suspected Isaac’s syndrome patient. It is used to record electrical activities in the muscle areas by inserting a needle into the muscles and record the activity. An abnormal activity indicates Isaac’s syndrome disorder.

• Cerebrospinal fluid analysis is obtained through a lumbar puncture. It helps confirm the diagnosis of this syndrome.

• Computer tomography (CAT scan) and Magnetic resonance imaging (MRI) are used to diagnose the syndrome excluding the presence of thymoma which is 20% more likely to appear in most cases.

When Isaac’s syndrome is confirmed, examination in the blood salt concentration is measured to confirm the presence of VGKC antibodies.

Treatment

Specific cure for Isaac’s syndrome has not yet been discovered and treatments available are for the relief of certain symptoms. There are three types of drugs used in treatment, they are; benzodiazepines, Parkinson drugs and narcotics. Benzodiazepine is a chemical compound used as muscle relaxants, anti anxiety agents, hypnotics, sedatives or sometimes as anticonvulsants. Parkinson drug are drugs used to treat Parkinson’s disease. Narcotics are drugs used to relieve pain, suppress cough, control diarrhea, relieve anxiety, and to induce anesthesia.

Other medical treatments:

• Anticonvulsant medicines are given to an Isaac syndrome patient to provide relief from pains like stiffness and muscle spasm. Such medicines slow down activities in the nervous system, allowing muscles to relax.

• Baclophen is a drug used as treatment for spasticity. Spasticity is an increased uncontrollable muscle tone movement.

• Botox injections can also give temporary relief.

• Plasmapheresis is a short term treatment given to severe cases of acquired Isaac’s syndrome. It aims to filter out VGKC antibodies in the blood stream to keep patients’ symptom-free for about 1 to 2 years.

• Immunosuppressants, like prednisone, are drugs that provide long term relief for patients with acquired Isaac’s syndrome.

• It’s important to seek the help of a physiotherapist and together design a daily exercise program depending on the degree of disability.

There has been no immediate cure for Isaac’s syndrome but management of the symptoms is possible. The symptoms do not deteriorate into something serious but when treated right away, symptoms can be controlled and patients can live normal lives.