All About Amitabh Bachan’s Incurable Illness - Myasthenia Gravis

Myasthenia Gravis

The famous Bollywood actor, Amitabh Bachan, has been struggling with a rare autoimmune condition that affects the neuromuscular system. He was diagnosed with Myasthenia Gravis in 1984 and has been battling the condition ever since. 

The rare condition is characterized by extreme weakness and fatigue of the muscles that are under your voluntary control. It occurs when the communication between the nerves and body muscles breaks down.

There is no cure for the illness but proper treatment and care helps recoup from the symptoms.

Let’s learn more about Myasthenia Gravis in the article below. 

Also read: Justin Beiber’s Rare Condition: Ramsay Hunt Syndrome Explained 

Myasthenia Gravis 

Myasthenia Gravis is a disorder that affects the neuromuscular junction (NMJ) of the skeletal muscles. It manifests as a generalized muscle weakness which is caused due to reduced transmission of electrical impulses across the neuromuscular junction.

Formation of autoantibodies against specific postsynaptic membrane proteins is what causes the muscle weakness. 

  • It is a Type II Hypersensitivity Reaction > Type V Hypersensitivity Reaction.
  • The receptors of Acetylcholine are affected. 
  • It is a post-junctional defect.
  • Acetylcholine has 5 subunits- alpha subunit activation will lead to sodium influx, subsequently leading to depolarization, thus muscles contract. 

Causes of Myasthenia Gravis

The exact cause of the Myasthenia Gravis is unknown. However, some of the factors that play a role are as follows –

Thymus Gland

Thymus abnormality, thymic hyperplasia and thymoma can cause MG. 

Antibodies

In MG the immune system produces antibodies that tend to block or destroy several muscles’ receptor sites for acetylcholine – a neurotransmitter. With fewer receptor sites available, the nerve signals received by the muscles are also reduced, which causes weakness. These anti-acetylcholine receptor antibodies are as follows-

  • Anti-Acetylcholine Receptor Antibody (85%)
  • Anti-MUSK Antibody (Muscle Specific Kinase Antibody) (10%)
  • Anti-LRP-4 (Low-density lipoprotein-related protein 4)
  • Anti-Netrin – 1 receptor
  • Anti CASPR – 2
  • Anti-striated Muscle Antibody against TITIN

Other Causes

Some children are born with neonatal myasthenia gravis because their mothers had the condition. In such cases if the treatment is imparted promptly then the children recover within two months after birth.

In the rare case, children are born with a hereditary form of myasthenia gravis called congenital myasthenic syndrome.

Symptoms

  • Ptosis (Asymmetrical ptosis weakness)
  • Diplopia
  • Snarling facies – when asked to smile
  • Chewing muscle weakness
  • Nasal Twang to voice – weakness of soft palate
  • Nasal Regurgitation of food
  • Aspiration risk is high
  • Dysphagia – Oropharyngeal Dysphagia
  • Dysarthria – muscles of vocal cords are affected
  • Deep tendon reflexes are preserved
  • Sensory function normal
  • Proximal Muscle weakness

Treatment/ Management

Pyridostigmine is the drug Of choice to manage MG. If Anti-Musk Antibody is present, then they have a poor response. This may lead to worsening of symptoms. So, treatment of choice is Thymectomy

In case of Ocular Myasthenia gravis, Thymectomy is not recommended. Pyridostigmine is generally the first-line drug. Steroids +++ /Azathioprine are started if the response is poor. 

For generalized myasthenia gravis, Pyridostigmine is recommended. It has a substantially good response if the forced vital capacity is good. 

Intravenous immunoglobulins (IVIG) / Plasmapheresis is the recommended treatment of choice for the myasthenic crisis and also in cases that are resistant to immunosuppressive drugs.

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Kashika Walia

Kashika Walia is a Senior Content Writer at PrepLadder. She is devoted to give her readers easily digestible and high-value content that makes their journey towards their dream career incredibly easy.