Clinical effects of transcranial magnetic stimulation in comorbid conversion disorder and major depressive disorder: a case report

Introduction

Conversion disorder, formally known as Functional Neurological Symptom Disorder (FNSD), is a complex neuropsychiatric condition involving motor, sensory, or consciousness alterations unexplained by recognized neurological diseases. These symptoms, often physical manifestations of psychological distress, are frequently accompanied by significant comorbidities like Major Depressive Disorder (MDD). Conventional management is challenging as many patients resist standard psychotherapy and pharmacotherapy. Recently, Transcranial Magnetic Stimulation (TMS) has emerged as a promising non-invasive neuromodulation technique. While its efficacy in targeting the left Dorsolateral Prefrontal Cortex (DLPFC) for treatment-resistant depression is well-established, its therapeutic potential for conversion symptoms is a burgeoning area of interest. It is hypothesized that modulating the prefrontal cortex may restore disrupted top-down regulation of motor and sensory circuits. This case report discusses the clinical efficacy of left DLPFC-targeted TMS in a patient with comorbid conversion disorder and MDD.

Case Presentation

A 49-year-old female presented with recurrent fainting episodes, tremors, dyspnea, depressive mood, and anhedonia. Her 10-year clinical history included chronic insomnia, progressive depressive symptoms, and long-term benzodiazepine use. Antiepileptic treatment for suspected epilepsy was discontinued after a neurological evaluation identified the episodes as indicative of Conversion Disorder. Following psychiatric assessment, a diagnosis of comorbid MDD and Conversion Disorder was established. Notably, medically unexplained physical symptoms (MUPS) emerged following behavioral activation interventions during follow-up. Clinical progress was monitored using a rigorous battery: Hamilton Depression Rating Scale (HAM-D), Clinical Global Impression Scale (CGI), Global Assessment of Functioning Scale (GAF), Maudsley Staging Method (MSM), Kocaeli Cognitive Assessment Scale, Depression, Anxiety and Stress Scale-21 (DASS-21), Pittsburgh Sleep Quality Index (PSQI), and Adult ADHD Self-Report Scale (ASRS). Due to symptom persistence despite multiple pharmacological trials, high-frequency TMS targeting the left DLPFC was initiated. A significant clinical response was observed starting from the fourth session. By the conclusion of twenty-one sessions, substantial improvement in both mood and functional symptoms was documented and supported by final assessments.

Discussion

This case suggests that high-frequency TMS targeting the left DLPFC provides both an early clinical response and significant scale-supported improvement in comorbid conversion disorder and depression. The rapid symptom reduction, starting as early as the fourth session, indicates that neuromodulation may accelerate recovery in treatment-resistant cases. Neurobiologically, this improvement may stem from the restoration of prefrontal control over the limbic system and motor planning areas, which are often dysregulated in FNSD. Utilizing a multi-dimensional battery, including the MSM and Kocaeli Cognitive Assessment Scale, was crucial in documenting the transition to clinical remission and ensuring cognitive safety. These findings emphasize the therapeutic importance of addressing conversive symptoms through advanced mood regulation techniques. Further controlled studies are warranted to establish standardized TMS protocols as a viable intervention for this specific patient group where conventional methods often fail.

Keywords: Conversion disorder, TMS, DLPFC, Neuromodulation, Major Depressive Disorder.

References

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