Frontal Lobe Dysfunction and Impulse Control Problems as a Neuropsychiatric Manifestation of Progressive Multiple Sclerosis: A Case Report
T. Üğüden, Y. Çiçek, N. G. Usta Sağlam, F. S. Bayır, M. Tütüncü, S. TuranIntroduction
Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system characterized by sensory and motor deficits and a wide spectrum of neuropsychiatric manifestations, including mood disorders, cognitive decline and behavioral disinhibition.Impulse control problems are rare but clinically relevant, as they may mimic primary neurodegenerative syndromes and complicate management.
Objectives
We present a patient with MS with a progressive course and bilateral frontal lobe involvement manifesting impulsive and disinhibited behaviors. This case highlights the importance of recognizing MS-related neurodegeneration as a potential cause of dysexecutive syndromes and distinguishing it from frontotemporal dementia (FTD).
Methods
Psychiatric assessment included a mental status examination, neuropsychological testing and the Barratt Impulsiveness Scale–Short Form (BIS-11-SF). Neurological evaluation comprised lumbar puncture and cranial MRI.
Results
A 57-year-old man presented with three years of progressively worsening inappropriate spending, perseverative gambling, and compulsive hoarding. His psychiatric history included irritability and aggression treated in 2016, and he was most recently on escitalopram 20 mg/day and mirtazapine 30 mg/day.On examination, he displayed indifference, delayed responses due to word-finding difficulty, impaired attention, apathetic mood, restricted affect, and poor abstraction, while other cognitive functions were relatively preserved and no psychotic features were observed. Neuropsychological testing demonstrated slowed mental control, impaired attention and markedly reduced verbal fluency, consistent with frontal dysfunction. On the BIS-11-SF, he scored 36 out of 60. MS had been diagnosed in 2011 after persistent left leg weakness, confirmed by CSF analysis and MRI. Initial therapy with glatiramer acetate was switched to rituximab in 2016 due to radiological and clinical progression, achieving clinical stability.However, cranial MRI in 2022 revealed global cortical atrophy disproportionate to age, most prominent in the bilateral frontal lobes, with confluent subcortical, juxtacortical and periventricular demyelinating lesions (Image 1–3).These findings, attributed to the progressive course of MS, could explain his cognitive, emotional and behavioral symptoms associated with a dysexecutive syndrome.
Image 1: Long description.