A 45y male with limb weakness progressed from 3 days from power 4\5 to 0\5 all 4 limbs, known diabetic 2y, no h\o trauma fever loose stools loc ENMG s\o mortar axonal neuropathy CSF s\o no cells with protein of 54, diagnosed as GB syndrome on IgG immunoglobulin but no improvement. Other blood tests normal.

MRI brain s\o lacunar infarcts. What best can be made to improve his power?