Have nerves of steel for GBS

GBS is a rare disabling, potentially life-threatening neurological disorder wherein our immune system starts attacking nerves of the extremities, warns Dr Mohan P C

Guillain Barre Syndrome (GBS) is a rare and serious neurological disorder. It is an autoimmune disease that mistakenly attacks parts of the peripheral nervous system — the network of nerves located outside of the brain and spinal cord — which transmits signals from the brain to various parts of the body for voluntary movement of muscles. Rarely, it can affect parts of the brain too. It affects anyone at any age but is common in adults and older people. Men are slightly more affected than women. GBS affects approximately 1-2 persons per lakh population each year. It is not contagious or inherited. The exact cause is unknown. Most cases occur 1-2 weeks after respiratory or gastrointestinal, viral or bacterial infections like influenza virus, Epstein Barr virus, Cytomegalovirus, Zika virus, mycoplasma pneumonia and Campylobacter Jejuni bacteria. Recently, the Covid-19 virus is known to cause GBS. Very rarely it occurs after surgery, vaccination for influenza or Covid-19. The chance of getting GBS is much more with infections than vaccination.

When any organism infects the body, the immune system produces an antibody which attacks organisms accordingly. Sometimes molecules on nerves and organisms may be similar and these antibodies mistakenly damage the person’s own myelin and axons.

Types of GBS

There are different types of GBS. Commonest being acute inflammatory demyelinating polyradiculoneuropathy (AIDP) wherein myelin, the coating of nerves is predominantly affected. In acute motor axonal neuropathy (AMAN) and acute motor sensory neuropathies (AMSAN), axons are damaged. In a rare variant of Miller-Fischer syndrome, the disease is characterised by acute onset of ophthalmoplegia, areflexia and ataxia.

Symptoms: The symptoms of GBS begin with tingling, numbness, pain in the legs and progressive weakness of lower limbs more than upper limbs. As the disease progresses, muscles of the face, eyes, respiration and swallowing may involve leading to complete paralysis over few days to four weeks. By four weeks, the disease may peak and stabilise. When the autonomic nervous system is involved, rapid and irregular heart rate, fluctuations in blood pressure, problems in digestion and bladder control may occur. GBS can be life-threatening when severe muscle weakness occurs leading to respiratory failure and cardiac problems. At this stage, the patient may require ventilator support and ICU care.

Diagnostic methods: Diagnosis of GBS can be made clinically depending on characteristic symptoms and signs of monophasic, bilateral, symmetrical, progressive paralysis of muscles with reduced tendon reflexes. Nerve conduction studies show slow conduction of signals indicating myelin damage and reduced amplitude suggesting axonal damage. Cerebrospinal analysis shows reduced cells and an increase in protein.

Treatment: Treatment consists of observation for progression of disease in mild cases. In moderate to severe cases, it is necessary to arrest the disease and improve muscle power. Intravenous immunoglobulin (IVIG) 2g/ kg over 5 days will help in reducing autoimmune response. Another approach is giving plasmapheresis over 5 days which involves removing the patient’s blood and separating blood cells and plasma. Blood cells are reinfused. Plasma is discarded as it contains autoantibodies that are attacking healthy nerves. These two therapies are more effective if started early after the onset of illness. IVIG therapy is preferred because of its ready availability, ease of administration and minimal side effects but is comparatively expensive. 75% improve completely by these two methods.

Early physiotherapy and respiratory therapy greatly help in improvement. Due to immobility, the patient can have clotting disorders and subsequent pulmonary embolism. Recovery starts after 1-2 weeks of therapy and continues up to 2 years. GBS is fatal in about 5% of patients. In 3% of people, the disease can relapse at any time and can be treated in a similar way. There is no definite therapy available for the prevention of GBS except avoidance of infections.

(The author is a consultant neurologist.)