Overview
Definition:
Conversion disorder, now often referred to as Functional Neurological Disorder (FND) with conversion symptoms, is a neurological condition characterized by symptoms that affect voluntary motor or sensory function, but are incompatible with recognized neurological pathways or diseases
These symptoms are not intentionally feigned and are thought to be triggered by psychological stress or trauma, manifesting as neurological deficits.
Epidemiology:
Prevalence varies, but estimates suggest it affects 1-3% of patients presenting to neurology clinics
in adolescents, it can be a significant cause of unexplained neurological symptoms
It is more common in females than males, with a ratio of approximately 2:1 to 5:1
Onset is typically in adolescence or early adulthood.
Clinical Significance:
Conversion disorder poses a diagnostic challenge due to the variety and potential severity of symptoms, which can mimic serious neurological conditions
Misdiagnosis can lead to unnecessary investigations, delayed appropriate treatment, and significant patient distress
Understanding its presentation and management is crucial for pediatricians and neurologists managing adolescents with unexplained symptoms, impacting their quality of life and academic performance.
Clinical Presentation
Symptoms:
Motor symptoms: Weakness or paralysis of limbs
Tremors or shaking
Gait abnormalities, such as unsteadiness or inability to walk
Speech difficulties (dysarthria) or voice changes (aphonia)
Swallowing difficulties (dysphagia)
Sensory symptoms: Numbness or tingling sensations
Loss of sensation (e.g., touch, pain)
Vision changes (e.g., blurred vision, tunnel vision)
Hearing loss
Other symptoms: Seizure-like episodes (pseudoseizures or psychogenic non-epileptic seizures - PNES)
Balance problems
Dizziness.
Signs:
Motor examination may reveal incongruent findings, such as preserved strength when tested for proximal versus distal muscles, or Hoover's sign (weakness in hip abduction that disappears when the patient attempts to adduct the other hip)
Sensory deficits may have sharp demarcation lines inconsistent with dermatomes or nerve distributions
Tremors may be suppressed by distraction or when the patient is observed
Pseudoseizures often have preserved consciousness and coordinated movements, contrasting with epileptic seizures.
Diagnostic Criteria:
According to DSM-5, the criteria for FND (conversion disorder) include: 1
A symptom or deficit that is incompatible with recognized neurological or medical conditions
2
The symptom or deficit is not better explained by another neurological or mental disorder
3
The symptom or deficit causes clinically significant distress or impairment in social, occupational, or other important areas of functioning, or warrants medical evaluation
4
The symptom or deficit is not intentionally produced or feigned (this distinguishes it from factitious disorder or malingering).
Diagnostic Approach
History Taking:
A detailed history is paramount
Elicit the onset, duration, and nature of symptoms
Inquire about stressors, recent life events (e.g., school issues, family conflict, abuse, trauma), and prior episodes of similar symptoms
Explore the patient's and family's understanding and beliefs about the symptoms
Red flags include incongruent findings on examination, lack of distress, or a clear external benefit from the symptoms (suggesting malingering or factitious disorder).
Physical Examination:
A thorough neurological examination is essential to rule out organic causes
Pay close attention to motor strength, sensation (including precise testing of distribution and boundaries), reflexes, coordination, gait, and cranial nerves
Perform specific maneuvers to elicit incongruent findings, such as Hoover's sign or distraction techniques for tremors
Assess for pseudoseizures by observing their characteristics.
Investigations:
Investigations are primarily to exclude organic causes
For motor or sensory deficits, consider MRI brain and spine to rule out structural lesions
EEG is indicated for suspected seizures, especially to differentiate epileptic from non-epileptic seizures
Nerve conduction studies (NCS) and electromyography (EMG) may be used to assess peripheral nerve or muscle function but can also reveal functional deficits
Neuropsychological testing may be helpful in some cases
Blood tests (e.g., CBC, electrolytes, thyroid function) are typically normal but may be done to rule out metabolic causes of neurological symptoms.
Differential Diagnosis:
Key differentials include: Multiple Sclerosis (MS), Guillain-Barré syndrome, myasthenia gravis, epilepsy, stroke, brain tumors, peripheral neuropathies, functional neurological disorder subtypes (e.g., pain disorder, fatigue disorder), malingering, and factitious disorder
Careful clinical assessment and targeted investigations are crucial for accurate differentiation.
Management
Initial Management:
The initial management focuses on establishing trust and rapport, validating the patient's experience without confirming an organic disease, and facilitating a positive therapeutic alliance
Avoid premature labeling as "psychological." A multidisciplinary approach involving neurology, psychiatry, psychology, and physiotherapy is often necessary.
Medical Management:
There are no specific medications for conversion disorder itself
However, pharmacotherapy may be used to treat comorbid psychiatric conditions like anxiety or depression, which are common
Selective serotonin reuptake inhibitors (SSRIs) or other antidepressants may be considered if significant mood or anxiety symptoms are present
Anticonvulsants are used for PNES, though often cautiously as they are not effective for non-epileptic events.
Psychological Therapy:
Psychotherapy is the cornerstone of treatment
Cognitive Behavioral Therapy (CBT) helps patients understand the link between thoughts, emotions, and physical symptoms, and teaches coping mechanisms
Psychodynamic psychotherapy can explore underlying conflicts and trauma
Hypnotherapy may be beneficial for certain symptoms like pain or paralysis
Physiotherapy is crucial for motor symptoms, focusing on regaining function and confidence.
Supportive Care:
Supportive care involves educating the patient and family about FND, emphasizing the reality of their symptoms despite the lack of organic cause, and encouraging gradual reintegration into daily activities, school, and social life
Reassurance and a positive prognosis are important
Regular follow-up is essential to monitor progress and address any emerging issues.
Complications
Early Complications:
Social isolation due to physical limitations
School absenteeism leading to academic decline
Increased anxiety and depression
Functional decline in mobility and self-care abilities
Relapse of symptoms if stressors are not adequately addressed.
Late Complications:
Chronic disability and long-term dependence
Development of somatic symptom disorder
Persistent psychological distress
Stigma associated with misdiagnosis or perceived malingering
Social and occupational dysfunction.
Prevention Strategies:
Early and accurate diagnosis
Prompt initiation of evidence-based psychotherapy and physiotherapy
Addressing psychosocial stressors
Educating patients and families about FND to reduce fear and stigma
Promoting resilience and coping skills in adolescents.
Prognosis
Factors Affecting Prognosis:
Good prognosis is associated with: earlier diagnosis and treatment, fewer and less severe symptoms, absence of comorbid psychiatric disorders, presence of social support, and a good patient-physician relationship
Factors associated with a poorer prognosis include: chronicity of symptoms, severe underlying trauma or stressors, significant comorbid psychiatric illness (especially personality disorders), and lack of engagement in therapy.
Outcomes:
With appropriate treatment, many adolescents can achieve significant improvement or complete remission of symptoms, leading to a return to normal functioning
However, some may experience persistent symptoms or recurrent episodes
The goal is to improve functional capacity and quality of life, rather than solely eliminating all physical sensations.
Follow Up:
Regular follow-up appointments with a multidisciplinary team (neurologist, psychiatrist, psychologist, physiotherapist) are recommended
The frequency depends on the patient's progress and needs
Long-term monitoring may be required to manage relapses, address ongoing stressors, and reinforce coping strategies
Emphasis should be placed on functional recovery and reintegration.
Key Points
Exam Focus:
Understand the DSM-5 criteria for FND
Differentiate conversion symptoms from true neurological deficits
Recognize Hoover's sign as a key indicator
Know that psychotherapy (CBT, psychodynamic) is the primary treatment
Be aware of high comorbidity with anxiety and depression.
Clinical Pearls:
Validate the patient's experience of their symptoms, even if the cause is functional
Avoid confrontational approaches
focus on collaboration
Encourage graded exposure to feared activities and a return to normal routines
The absence of neurological findings does not mean the symptoms are not real to the patient.
Common Mistakes:
Over-investigating to "prove" an organic cause when functional symptoms are evident
Dismissing the patient's symptoms as "all in their head." Delaying psychiatric or psychological referral
Failing to involve physiotherapy early
Not adequately addressing underlying psychosocial stressors or trauma.