Surprisingly, there is little to no legal authority for the proposition that dizziness and vertigo type symptoms affect the tests for PIP and ESA.
For example, the (physical) mobility test for ESA and PIP are somewhat the same in that they ask – How far can the Claimant mobilise without the aid of another person, but with any other aids the Claimant might reasonably be expected to use.
A Claimant suffering from severe vertigo may say they cannot mobilise due to the spinning sensation they suffer; but Tribunals are reluctant to accept this falls into the legal test and prefer, though it is against the true reading of the test, to say that the test focuses on the Claimant’s lower half and perhaps the back or neck.
There are a number of Upper Tribunal cases attempting to determine the ESA test of ‘loss of consciousness’ which discuss the dizziness sensation but only in relation to that test. see for example: BB v SSWP(ESA)  UKUT AACR 2 and CB v SSWP(ESA)  UKUT 0287(AAC)
Should dizziness (which is difficult to test / prove medically) of such a level that prevents the Claimant from mobilising to a reasonable standard be considered in the tests?