“Convergence” Esotropia – as A Rare presentation of Hypothalamic hamartoma with Supra-sellar and Pre pontine Arachnoid cyst
Venkata Sriram Chintha1, Bhaswar Bhattacharya1, Debarup Das1, Kuntal Biswas1, Adreesh Mukherjee1, Goutam Gangopadhyay1
1Neurology, Bangur Institute of Neurosciences, IPGMER & SSKM
Background:
A young male in his twenties presented with complaints of double vision which he noticed 1½ months back, gradually progressive and on distant vision. No h/o headache/Painful eye movements/Drooping of eye lids/trauma to the eyes. On examination right eye Esotropia was noted. There was no apparent restriction of any extra ocular muscles. Diplopia was noted on distant vision, with horizontal separation of the image, without crossing of images, in all directions. No other neurological abnormality was detected on clinical examination. We provisionally diagnosed it as a case of Acute Esotropia and were evaluating for the cause. MRI Brain revealed a Suprasellar and Pre pontine Arachnoid cyst, Hypothalamic hamartoma. No endocrine abnormalities were found after examination and investigations. He was treated surgically later by cyst fenestration. There was no improvement of Diplopia or Esotropia post surgery. Patient didn’t want any further surgical intervention and was discharged.
Results:
There have been multiple case reports where strabismus has been mentioned in patients of Hypothalamic hamartoma but there was no explanation or search for the cause was done as the emphasis was laid on Gelastic seizures and other endocrine abnormalities. After an extensive literature search we suspect the involvement of Convergence pathway in this case. We suspect the disruption of the contralateral prefrontal cortico-oculomotor bundle which are probably located near the Thalamus and posterior surface of third ventricle. These are part of the convergence pathway exerting an inhibitory influence upon the neurons of the Oculomotor nucleus, thus their disruption causes an excessive action of the medial rectus resulting in a Esotropia simulating a lateral rectus palsy.
Conclusions:
Furthermore research is required in this regard for a detailed understanding of the Convergence pathway.