"Loss" implies negative deficit like paralysis/blindness, but it commonly can be a "positive" deficit such as seizing. Change matches verbage in Criterion A for Conversion Disorder in the DSM 5 ("One or more symptoms of altered voluntary motor or sensory function"). Included qualifier that it is not explained by neurological condition as that is an important distinction/better describes psychiatric origin.
AMBOSS overview: "Patients present with neurological symptoms that cannot be fully explained by a neurological condition."
Clinical Features chart includes seizures and tremor as possible motor deficits
Source: AMBOSS - https://next.amboss.com/us/article/MP0M2T?q=conversion+disorder#Zfa03318ad9aeaedaac4cc232b95dca7c