Conversation: The conversation between human and AI assistant.
[|Human|] I have been told that I have mild cerebellar tonsillar ectopia, but the MRI showed my cerebellar tonsils only descend 3mm below my foramen magnum. All my head aches started when I was weight lifting. What is the possibility that what I am experiencing is just exertional headaches?
[|AI|]  Hi, Thanks for writing in. The cerebellar tonsils are the most inferior portion of the cerebellum, a part of the hind brain which is important for motor coordination. Normally, these tonsils are wholly inside the skull. A 3 mm low-lying tonsil does not clinical fit into the abnormal category. In the case of Arnold-Chiari, the tonsils are low-lying often more than 4 mm, below their normal level. It can cause severe headaches. The presence of a spring in the cervical cord needs to be ruled out and that will be mentioned on MRI should it be there. Cervical nerve root compression can also cause headache on lifting weights. Please discuss with your doctor.