Temporal relationship between multiple sclerosis relapses and mood episodes in bipolar disorder: a case report

Introduction:Multiple sclerosis(MS) is a chronic inflammatory demyelinating disorder of the central nervous system and a leading cause of neurological disability in young adults[1].Psychiatric comorbidity is common in MS, with depression, anxiety, and bipolar disorder(BD).The lifetime prevalence of BD in MS is higher than in the general population(1–2%), estimated at 3.2% in a recent meta-analysis[2].Although the underlying mechanisms remain unclear, neuroinflammation and demyelination during MS relapses may influence fronto-limbic circuits, potentially triggering or exacerbating mood episodes[3].However, prospective data examining the temporal relationship between MS relapses and mood episodes are scarce.Here, we report a patient with BD demonstrating a clear temporal association between MS relapses and mood episodes.

Case:A 47-year-old woman diagnosed with MS in 2009 presents with MS relapses, gait instability, lower extremity pain and weakness, dysarthria, right eye pain accompanied by blurred vision, and urinary and fecal incontinence.Her first depressive episode in 2000(9 years prior to the MS diagnosis), with a diagnosis of recurrent depressive disorder until 2015.In 2015, she experienced her first manic episode, characterized by decreased need for sleep, grandiosity, increased energy, and increased amount of speech, leading to a revised diagnosis of BD-I.Collateral history indicated that psychiatric symptoms consistently exacerbated concurrently with neurological symptoms during each MS relapse, whereas residual depressive symptoms, including anhedonia and low mood, persisted during remission periods.Her most recent hospitalization occurred in December 2025, presenting with a mood episode marked by irritability, decreased need for sleep, increased speech, grandiosity, hypersexuality, and increased spending, alongside urinary and fecal incontinence and neuropathic pain.Brain MRI demonstrated demyelinating plaques in the supratentorial and periventricular regions.At admission, YMRS/HAM-D scores were 16/15, respectively.Treatment was initiated with lithium 900mg/day and aripiprazole-LAI 400mg/month, while MS therapy was switched from fingolimod to ocrelizumab.At discharge, complete remission was achieved in both psychiatric(YMRS:1;HAM-D:0) and neurological symptoms.

Discussion:In patients with MS, focal neuronal demyelination may disrupt communication between frontal brain regions involved in emotional regulation, manifesting as affective lability or elevated mood, which are common features of manic or depressive episodes.The clinical characteristics of mania associated with MS relapses are largely similar to those observed in BD[4].However, MS relapses may additionally present with focal neurological symptoms such as visual impairment, fatigue, urinary incontinence, and cognitive dysfunction.Radiologically, relapses may be accompanied by an increased demyelinating lesion burden on MRI compared to prior imaging.Notably, plaques in the bilateral temporal horn regions have been associated with manic and psychotic symptoms in MS patients[5].In our case, the presence of urinary and fecal incontinence, neuropathic pain, increased lesion burden on MRI, and the parallel remission of neurological and mood symptoms collectively suggested an MS-related mood episode.

Conclusion:The etiology of neuropsychiatric disorders in MS remains incompletely understood and likely involves a complex interplay of biological, disease-related, behavioral, and psychosocial factors.Neuropsychiatric symptoms may emerge concurrently with mood episodes.However, current evidence is largely limited to case reports and uncontrolled studies.Optimal management of MS requires a comprehensive biopsychosocial neuropsychiatric approach, as early recognition and treatment of comorbid psychiatric conditions may reduce morbidity and mortality and improve overall outcomes.

References

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