56 yrs old male C/O frequent fall down and clumsy gait, other | sᴘᴏᴛ ᴅɪᴀɢɴᴏsɪs

56 yrs old male C/O frequent fall down and clumsy gait, other symptoms patient report include :urine Dripping and severe occasional pain in the back on E/X decreased DTR bilaterally, impaired epicritic sensation and irregular pupil, best next step in Rx: