What is Conversion Disorder
Conversion disorder, now termed functional neurological disorder (FND) in DSM-5, is a condition where patients experience genuine, involuntary neurological symptoms—such as weakness, tremor, seizures, speech difficulties, or sensory disturbances—that arise from a disorder of nervous system function rather than structural damage, and diagnosis is made based on positive clinical signs of internal inconsistency and suggestibility, not by exclusion. 1
Core Diagnostic Concept
The fundamental paradigm shift in understanding conversion disorder is that diagnosis should be made on positive clinical findings rather than by ruling out organic disease. 1 The condition represents a "psychodynamic lesion" where abnormal cerebral activation patterns affect motor, emotional, and limbic networks. 2
Defining Clinical Features
Symptoms are real and involuntary: Patients experience genuine neurological symptoms including motor dysfunction (weakness, abnormal movements, tremor), sensory disturbances (numbness, blindness), speech difficulties (mutism, dysphonia), seizure-like episodes, or autonomic dysfunction. 1, 3
Internal inconsistency: Symptoms lessen or resolve during spontaneous conversation, when attention is diverted, or during automatic functions like walking. 1
Suggestibility: Symptoms become more pronounced while the patient discusses them or is being examined for them. 1
Variability with attention: Symptoms typically worsen with focused attention and improve with distraction, often developing in the context of injury, illness, or psychological distress. 1, 4
Formal Diagnostic Criteria
The DSM-5 criteria require: 5
One or more somatic symptoms that are distressing or result in significant disruption of daily life. 5
Excessive thoughts, feelings, or behaviors related to the somatic symptoms, manifested by at least one of: disproportionate thoughts about symptom seriousness, persistently high anxiety about health or symptoms, or excessive time and energy devoted to symptoms. 5
Symptoms cause clinically significant distress or impairment in psychosocial functioning, including relationships, academic performance, or occupational difficulties. 1
Persistent symptomatic state typically lasting more than six months, though symptoms may not be continuously present. 5
Common Clinical Presentations
Conversion disorder presents with a wide range of manifestations: 1
Motor symptoms: Weakness, paralysis, dystonia, tremor, abnormal gait, difficulty walking. 3, 4
Sensory symptoms: Numbness, anesthesia, blindness, sensory disturbances. 3
Speech and communication: Mutism (inability to produce sound), dysphonia, foreign accent syndrome, speech difficulties. 6, 5
Seizure-like episodes: Psychogenic non-epileptic seizures (PNES). 3
Swallowing and respiratory: Functional dysphagia, globus, functional cough. 5
Critical Distinction from Other Conditions
Conversion disorder must be clearly differentiated from malingering and factitious disorder: 2
Conversion disorder: Unintentional production of neurological symptoms with no conscious motivation. 2
Malingering: Voluntary production of symptoms with external incentives (financial gain, avoiding work). 5, 2
Factitious disorder: Voluntary production of symptoms with internal psychological incentives, considered a mental illness requiring treatment. 2
Psychological Context (Not Required for Diagnosis)
While psychological factors may be present, symptoms do not always develop after major adverse life events or in the context of diagnosable psychological distress, and the absence of adversity should not be taken as evidence against the diagnosis. 5 Some patients may have a history of communication breakdown with significant others or conflict over expressing negative emotions, but this is not universal. 6
Prevalence in Clinical Practice
Medically unexplained symptoms represent approximately 30% of neurologist consultations, with functional disorders (excluding functional dysphonia) accounting for about 3% of patients with acquired communication disorders. 5, 2
Neurobiological Understanding
Functional neuroimaging has revealed abnormal cerebral activation patterns in conversion disorder affecting motor, emotional, and limbic networks, distinct from patterns seen in individuals who are feigning symptoms. 2 This supports the concept of a genuine disorder of nervous system function rather than deliberate symptom production. 7