Some unions have negotiated special 'disability leave' for employees. The aim of disability leave is to give time and job security to newly disabled employees. The leave allows you to assess whether you would be able to resume work following adaptations to the premises or to your workstation, by learning new skills or by doing your job in different ways.
Even if there is no negotiated agreement in place, it is possible that this might be a reasonable adjustment in some situations. It all depends on your individual circumstances, including factors such as the size and resources of your employer, the length of the leave you need, the kind of job you do, the nature of your disability and so on. Bear in mind that crucially, an adjustment will only ever be reasonable if you can show that there is a good chance that making it will help you return to or stay in your job, so this should be a key focus of your request.
It is a good idea to make sure you have the support of your GP or another medical specialist who can explain in writing why this adjustment would help you carry on with your job.