Depending on the organization of your medical clinic, you could ask your neurologist for a referral. They also make referrals to rheumatology. This approach is more likely to work if your neurologist and primary care doctor are not in the same clinic system. Some medical clinics only allow the primary care doctor to make referrals. In that case, you could ask your neurologist to recommend to your primary care doctor that she provide a referral to rheumatology.