Unraveling functional neurological disorder in pediatric populations: A systematic review of diagnosis, treatment, and outcomes

Table 1 Differences between pediatric and adult functional neurological disorder pathophysiology and clinical differences

Aspect	Pediatric FND	Adult FND
Developmental factors	Symptoms reflect ongoing brain development and plasticity. Symptoms may fluctuate with developmental stages. Greater sensitivity to immediate stressors and emotional disturbances	Symptoms arise from more established neural circuits. Often involves chronic, stable symptom patterns. Symptoms may be more entrenched due to long-standing psychological factors
Brain network dysregulation	Dysregulation affects developing neural networks (e.g., motor control, sensory processing). Connectivity between brain regions may be less stable, leading to variable symptoms	Involves established, but maladaptive, brain network patterns. Persistent alterations in connectivity, especially in areas like the prefrontal cortex and limbic system. Results in more consistent symptomatology
Psychological and environmental triggers	Often linked to acute stressors, family dynamics, and school issues. Immediate life events, such as bullying or trauma, trigger symptoms. Impacted by developmental stage and coping abilities	Influenced by long-term stress, complex trauma histories, and chronic life stressors. Accumulation of stress leads to persistent symptoms. Higher likelihood of pre-existing psychiatric conditions complicating symptoms
Clinical presentation and symptom profile	Symptoms include functional movement disorders, non-epileptic seizures, and gait abnormalities. Symptoms are often variable and change with developmental progress. Presentation may fluctuate with emotional state and developmental milestones	Symptoms include persistent functional motor impairments, chronic pain, and complex dissociative symptoms. Symptoms are more chronic and stable. Higher prevalence of comorbid psychiatric conditions such as anxiety or depression
Onset of symptoms	Sudden, often linked to a stressful event or minor illness	It can be sudden or gradual, often with a clear link to psychological stressors
Symptom variability	High variability, with symptoms fluctuating throughout the day	Symptoms can vary but may be more consistent compared to pediatric cases
Common symptoms	Motor symptoms (e.g., weakness, tremors), non-epileptic seizures, sensory loss, and speech disturbances (e.g., mutism)	Motor symptoms, sensory disturbances, non-epileptic seizures, gait abnormalities, chronic pain
Triggers	Often associated with acute stressors like school pressures, family issues, or peer conflicts	Commonly linked to chronic stress, psychological trauma, or significant life changes
Psychosocial context	Frequently involves school-related stress, family dynamics, or bullying	Often involves work-related stress, relationship issues, or past trauma
Cognitive Factors	Children may exhibit magical thinking or have difficulty articulating psychological stress	Adults may have a more complex understanding of their symptoms but may also exhibit denial or minimization
Comorbidities	Higher prevalence of anxiety, depression, and other mental health issues, as well as somatic symptom disorders	Often associated with chronic pain syndromes, anxiety, depression, and PTSD
Prognosis	Generally better with early intervention, especially with multidisciplinary approaches	Prognosis can be variable; some patients improve significantly, while others may have persistent symptoms
Treatment Approach	Focuses on education, cognitive-behavioral therapy, family involvement, and physical therapy	Cognitive-behavioral therapy physical therapy, psychotherapy, and sometimes pharmacological treatment are commonly used
Response to treatment	Generally good, particularly with early and supportive intervention	Response can be slower and more variable; some patients may require long-term therapy
Social support and education	Involves significant education and support for family members and teachers	Social support is important but may focus more on workplace accommodations and relationship counseling
Legal and disability issues	Less commonly involves legal or disability claims	More likely to involve disability claims, legal issues, or workers' compensation cases

FND: Functional neurological disorder; PTSD: Post-traumatic stress disorder.

Table 2 Comparison between the different patterns of symptom onset and progression in pediatric functional neurological disorder

Pattern	Onset characteristics	Progression	Common triggers	Prognosis
Sudden onset	Abrupt appearance of symptoms. Often after a significant stressor	Symptoms can be severe from the outset. May resolve quickly or persist	Acute psychological stress. Traumatic events	May resolve rapidly with early intervention. Can persist if underlying issues are not addressed
Gradual onset	Symptoms develop slowly over time. Initially mild and subtle	Symptoms progressively worsen. May become more disabling over time	Accumulation of stressors. Unresolved psychological issues	Delayed diagnosis is common. Symptoms may become chronic without treatment
Relapsing-remitting	Fluctuating symptoms. Periods of remission interspersed with exacerbations	Symptoms wax and wane. Exacerbations linked to stress	Fluctuating stress levels. Environmental changes	Requires ongoing management. Stress management can reduce relapses
Persistent chronic	Stable but persistent symptoms. Long-lasting with little fluctuation	Symptoms remain consistent over time. Can lead to significant disability	Long-standing psychological or emotional issues	Challenging to treat. Multidisciplinary approach needed for improvement

Table 3 The triggers and exacerbating factors in pediatric functional neurological disorder

Category	Trigger/exacerbating factor	Examples
Psychological stress	Acute stress	School-related stress (e.g., exams, academic pressure). Social stress (e.g., bullying, peer conflicts)
	Chronic stress	Family dynamics (e.g., conflict, divorce). Pressure to conform (e.g., social or familial expectations)
Psychological trauma	Acute trauma	Single traumatic events (e.g., car accident, sudden loss)
	Chronic trauma	Ongoing abuse or neglect (e.g., physical, emotional, sexual)
Environmental and social	Changes in environment	Relocation or change of school. Family financial stress
	Social influences	Peer pressure. Social media and cyberbullying
Physical health	Illness or injury	Previous medical conditions. Injury or pain
Cognitive and ermotional	Anxiety and Depression	Coexisting mental health conditions (e.g., anxiety, depression)
	Negative cognitive patterns	Catastrophizing. Negative beliefs about health

Table 4 The differential diagnosis of functional neurological disorder in pediatric patients

Condition	Condition overlaps with FND	Key differentiating features
Epilepsy	NES resemble epileptic seizures (convulsions, altered consciousness)	NES lacks characteristic EEG findings of epilepsy. NES may be triggered by psychological stressors and can often be interrupted by distraction
MS	Symptoms like weakness, sensory disturbances, and visual changes can mimic MS	MS is typically associated with characteristic MRI lesions. Presence of oligoclonal bands in CSF. FND usually has normal imaging and lab results
Migraine with Aura	Visual disturbances, sensory changes, and motor symptoms (e.g., hemiplegia) may be confused with FND	Migraines are episodic with clear triggers and resolution. Accompanied by headache and often a family history of migraines
GBS	Sudden-onset weakness and sensory changes might be mistaken for FND	GBS typically involves ascending weakness and areflexia. Abnormal nerve conduction studies and elevated CSF protein in GBS, absent in FND
Anxiety disorders	Physical symptoms like tremors, dizziness, and palpitations may resemble neurological symptoms of FND	Anxiety symptoms typically correlate with excessive worry or panic and may improve with anxiolytic treatment, unlike the more persistent symptoms of FND
Depression	Presents with psychomotor retardation, fatigue, or somatic symptoms similar to FND	Depression is accompanied by pervasive low mood, anhedonia, and cognitive symptoms, whereas FND's neurological symptoms are more prominent and less tied to mood
Conversion Disorder	Historically considered synonymous with FND, involves neurological symptoms with no organic cause	Conversion disorder often follows psychological conflict. FND now understood as a broader category with various psychological and biological underpinnings
Somatic symptom disorder	Involves excessive preoccupation with physical symptoms, overlapping with FND presentation	Somatic Symptom Disorder focuses on distress or anxiety caused by symptoms, while FND symptoms are the primary focus, often less connected to emotional distress
ADHD	Tics or motor disturbances in ADHD may be confused with FND	ADHD is characterized by inattention, hyperactivity, and impulsivity across settings. FND symptoms are more variable and not typically linked to behaviour patterns

NES: Non-epileptic seizures; GBS: Guillain-Barré Syndrome; MS: Multiple Sclerosis; FND: Functional neurological disorder; ADHD: Attention-deficit/hyperactivity disorder.

Table 5 The pharmacotherapy options for pediatric functional neurological disorder

Medication class	Common medications	Indications
Selective serotonin reuptake inhibitors	Fluoxetine, Sertraline, Citalopram	Anxiety, depression, obsessive-compulsive disorder
Serotonin-norepinephrine reuptake inhibitors	Venlafaxine, duloxetine	Anxiety, depression, chronic pain
Antiepileptic drugs	Gabapentin, pregabalin	Neuropathic pain, severe somatic symptoms
Benzodiazepines	Lorazepam, clonazepam	Acute anxiety, severe stress, non-epileptic seizures (short-term use)
Melatonin and sedative-hypnotics	Melatonin, zolpidem	Sleep disturbances, insomnia

Table 6 Factors affecting prognosis of pediatric functional neurological disorder

Predictors	Favourable outcomes	Unfavourable outcomes
Time of diagnosis and treatment	Timeliness of intervention: Early diagnosis and prompt treatment are crucial for favorable outcomes. Early intervention leads to better symptom resolution and improvement. Access to specialized care: Multidisciplinary care from pediatric neurologists, psychologists, and physical therapists enhances prognosis	Late diagnosis: Delayed diagnosis, especially with extended symptom duration, is linked to poorer outcomes. Chronic symptoms are harder to treat and may become resistant
Severity of symptomatology	Less severe initial symptoms: Mild symptoms at onset are often more responsive to treatment and less likely to become chronic. Limited symptom duration: Shorter symptom duration before treatment correlates with better outcomes, reducing risk of entrenched dysfunction	High symptom severity: Severe symptoms like persistent motor dysfunction or significant sensory loss are more challenging to manage and require intensive treatment. Widespread symptomatology: Multiple, widespread symptoms affecting various aspects of functioning complicate treatment and impact prognosis negatively
Levels of family and social support	Family involvement: Active family engagement, emotional support, and a positive environment contribute to better outcomes. Supportive social environment: Understanding peers and teachers, and a supportive social environment facilitate better outcomes by reducing stress and encouraging normal activities	Inadequate family support: Lack of family involvement or a stressful home environment can worsen symptoms and hinder recovery. Negative social environment: Social isolation, bullying, or lack of peer and teacher support increase stress and decrease motivation, leading to poorer outcomes
Presence/absence of comorbid psychiatric conditions	Lack of mental health disorders: The absence of comorbid psychiatric conditions like anxiety or depression reduces complexity and allows for focused FND treatment	Co-occurring mental health disorders: The presence of psychiatric conditions such as anxiety, depression, or PTSD complicates treatment and is associated with less favorable outcomes. Psychological resistance: Difficulty accepting the diagnosis or resisting psychological interventions may lead to slower progress and persistent symptoms
Level of adherence to treatment	Consistency in following treatment plans: High adherence to therapies and medications is a strong predictor of favorable outcomes, leading to symptom improvement and long-term stability	Poor compliance: Non-adherence to treatment plans due to resistance, family challenges, or other factors results in chronic symptoms and reduced quality of life

PTSD: Post-traumatic stress disorder; FND: Functional neurological disorder.