Epileptic Seizures As the Sole Presentation of a Radiologically Isolated Syndrome: A Case Report and Review of the Literature

Multiple sclerosis (MS) is the most prevalent long-term inflammatory condition affecting the central nervous system in adults. However, seizures are rarely described as the first presentation of MS or as a sole manifestation of radiologically isolated syndrome (RIS) or clinically isolated syndrome (CIS). The diagnosis of MS typically requires clinical evidence of neurological deficits and supportive radiological findings; however, RIS is characterized by incidental magnetic resonance imaging (MRI) findings suggestive of MS in the absence of clinical symptoms. The management of RIS remains a subject of ongoing debate. Although the majority of individuals with RIS remain clinically asymptomatic, the presence of radiological lesions suggests a potential risk for progression to clinically definite MS. The decision to initiate disease-modifying therapies (DMTs) in RIS is influenced by factors such as lesion burden, lesion characteristics, and patient risk factors for conversion to MS. The association between RIS and epilepsy is not well established, and the timing of initiating long-term treatment in such cases remains uncertain. In cases where seizures occur in the context of RIS or CIS, it is important to balance the treatment of epilepsy with the careful monitoring of disease progression. While antiepileptic drugs (AEDs) may be necessary to control seizures, early initiation of DMTs may be considered to prevent further neurological damage and clinical exacerbations, particularly in patients with high-risk features on MRI. We report the case of a 29-year-old woman with no previous medical history who presented with an inaugural generalized tonic-clonic seizure with numerous MS-like demyelinating lesions in the supratentorial, brainstem and medullary areas and the presence of cerebrospinal fluid-specific oligoclonal bands. The AEDs were started after the second occurrence of seizures, raising the question of the mean time to start long-term treatment in MS/RIS/CIS disease.