<s>[INST] This is for my son-in-law, he is seeing flashes of light describes as stars, having difficulty swallowing, like something is stuck in his throat, then when he swallows he has chest pain to the right of his chest. any ideas? The stars are in his left eye only and has been there a few days. This was his first symptom. He is concerned he has a neurological disorder like MS. [/INST] Hello!I read carefully your question and understand your concern.In my opinion the symptoms you describe may be related to anxiety. Multiple sclerosis can affect the visual function and the swallowing but not both in the first episode . The visual disorders in multiple sclerosis often occur as difficulty in seeing colors , pain behind the eyes with loss of vision , or double vision. Flashes and stars are visual hallucinations , which are not a common sign in MS. The pain in the chest after swallowing is not related to any neurological disorder. I would recommend to consult with a neurologist, have a good neurological examination. A chest xray and an abdominal ultrasound would be necessary to rule out any other cause of the pain. If the neurological examination is not normal a brain MRI would be helpful to rule out MS. Hope to have been of help!Greetings!Dr. Abaz Quka </s>