A new T2 lesion in a patient with the clinically isolated syndrome does not necessarily imply a conversion to multiple sclerosis

In the follow-up of patients with the clinically isolated syndrome, both clinical and MRI findings should be carefully evaluated by clinicians to avoid misinterpretation and inappropriate diagnosis of multiple sclerosis. We describe a case of a patient with a previous diagnosis of clinically isolated syndrome who developed a new asymptomatic brain lesion at the MRI follow-up. The careful evaluation of clinical history and radiological findings allowed the correct diagnosis of cocaine-associated ischemic stroke. Our case highlights that, in patients with the clinically isolated syndrome, the appearance of a new lesion on MRI does not necessarily imply a conversion to multiple sclerosis. Among "better explanations", ischemic lesions are of relevance and, in patients without typical risk factors for stroke, rarer causes such as cocaine assumption should be considered.