the ALJ did not have the discretion to forgo consultation with a medical advisor. The requirement that, in all but the most plain cases, a medical advisor be consulted pri- or to inferring an onset date is merely a variation on the most pervasive theme in administrative law — that substantial evidence support an agency’s decision.” Id. at 79-80. As the Seventh Circuit explained in Eichstadt v. Astrue, 534 F.3d 663, 666 (7th Cir.2008), “SSR 83-20 addresses situations in which an ALJ finds that a person is disabled as of the date she applied for disability insurance benefits, but it is still necessary to ascertain whether the disability arose prior to an even earlier date— normally, when the claimant was last insured.” See also Key v. Callahan, 109 F.3d 270, 273-74 (6th Cir.1997) (<HOLDING>). Further, the Tenth Circuit, in Blea v.
holding that the alj erred in determining that the claimant was disabled when a retrospective diagnosis along with all other medical evidence supported a finding of disability holding that the testimony of a nonexamining medical advisor does not constitute evidence sufficient to override the treating physicians diagnosis holding that retroactive award of benefits proper remedy where district court made finding that claimant was disabled holding that no medical advisor was necessary when the evidence did not indicate that the claimant was disabled before his dli holding that opting for conservative treatment instead of surgery is not substantial evidence that the claimant was not disabled