If 10% weight loss doesn't work for intracranial hypertension, is that a could indication that weight isn't the cause behind the raised pressures? 97kg to 78kg and no remission. continue to 70kg?

I agree that overweight is not considered a cause of idiopathic intracranial hypertension. As a matter of fact the cause is actually unknown. If one knows the cause then it wouldn't be the idiopathic type but a secondary type of intracranial hypertension. I don't even think weight reduction often improves IIH although it is often recommended.. Your neurosurgeon can advise you best however.