What are causes behind Achalasia of oesophagus?

What are the causes behind Achalasia of oesophagus?

Achalasia of oesophagus or achalasia cardia is a neurodegenerative disorder involving the lower part of oesophagus. There is failure of the lower oesophageal sphincter(LES) to  relax.A a result, there is accumulation of undigested food particles mixed with salivary secretions above the part of construction. That causes dilation of the part of oesophagus above constriction. Also it is important to keep in mind that it is due to neuromuscular dysfunction, not due to fibrosis or cancer!!!!

Achalasia cardia

This condition manifest as:

1) Dysphagia: Progressive difficulty in swallowing.

2) Regurgitation of undigested foods.

3) Chest pain behind sternum.

4) Weight loss due to inadequacy of nutrient absorption from foods.

5) Sometimes there is cough in lying down position.

6) The undigested foods may cause aspiration pneumonia in some cases.

Now let's see what happens in case of achalasia.

It is primarily due to improper dilation of the LES. The tone of the LES is balenced by excitatory (acetylcholine,substance P) and inhibitory (nitric oxide,vasoactive intestinal peptide) neurotransmitters.There is disbalence between excitatory and inhibitory neurotransmitters in case of achalasia leading to failure of complete relaxation of LES. Also there is complete absence of peristalsis and elevation of intraoesophageal pressure.

It can be diagnosed be oesophageal manometry measuring increased intraoesophageal pressure and barium follow through X-ray showing "rat tail" or "birds beak" appearance.

Rat tail/birds beak appearence

Now coming to the aetiology of achalasia:

1) Primary achalasa: Aetiology is unknown.There is decreased number of ganglion cells in the Auerbach's plexus.

2) Secondary achalasia: It can occur secondary to-

- Chaga's disease(T cruzi infection)

- Diabetic autonomic neuropathy

- Amyloidosis

- Immune mediated destruction of neurones in Sjogrensyndrome or thyroiditis.