Generally, no space is needed between a parenthesis and a word:
* (Example) This is an example of a sentence with a parenthesis.
However, a space is sometimes used for clarity:
* ( Example ) This might be used if the parenthesis is meant to highlight the word, especially in a list or table.
In some cases, a space is required by specific style guides:
* For example, the APA style guide recommends a space before and after parentheses.
Ultimately, the best approach is to follow the style guide relevant to your writing. If you're unsure, it's always best to err on the side of caution and add a space.