What is the condition where neurological deficits occur after a stressful situation?

Conversion Disorder (Functional Neurological Symptom Disorder)

Conversion disorder, also known as functional neurological symptom disorder, is the condition where neurological deficits occur after a stressful situation without an underlying organic cause. This condition manifests as genuine neurological symptoms that cannot be explained by medical disease, but are instead associated with psychological factors such as stress, trauma, or emotional distress 1.

Clinical Presentation

Conversion disorder presents with a wide range of neurological symptoms that develop following psychological stressors:

• Motor symptoms: Weakness, paralysis, abnormal movements, tremors, difficulty walking
• Sensory symptoms: Numbness, tingling, blindness, deafness
• Seizure-like episodes: Non-epileptic seizures
• Cognitive symptoms: Memory problems, attention difficulties, executive function impairment 1

The key diagnostic feature is that these symptoms cannot be explained by neurological disease or other medical conditions despite thorough investigation.

Diagnostic Criteria

For diagnosis of conversion disorder, the following criteria must be present:

1. One or more symptoms of altered voluntary motor or sensory function
2. Clinical findings provide evidence of incompatibility between the symptoms and recognized neurological conditions
3. The symptom is not better explained by another medical or mental disorder
4. The symptom causes clinically significant distress or impairment 1

Pathophysiology

The pathophysiology involves complex interactions between:

• Stress response: Activation of the hypothalamic-pituitary-adrenal axis leading to elevated cortisol levels 2
• Neuroinflammation: Stress-induced inflammatory responses in the brain 3
• Brain structure alterations: Functional changes in the hippocampus, amygdala, and prefrontal cortex, areas involved in emotional processing and stress response 2
• Abnormal neural circuitry: Disruption in the normal communication between brain regions responsible for emotional processing and motor/sensory function

Differential Diagnosis

Important conditions to consider in the differential diagnosis include:

• Post-Intensive Care Syndrome (PICS): Neurological impairments following ICU stay 4
• Mild Traumatic Brain Injury: May present with similar symptoms but has evidence of brain injury 1
• Post-traumatic Stress Disorder: Often comorbid but focuses more on re-experiencing trauma 1
• Stroke or TIA: Acute onset with corresponding anatomical lesions 1
• Multiple Sclerosis: Demyelinating lesions visible on MRI
• Encephalitis: Associated with fever, altered mental status 1

Evaluation

Evaluation should include:

1. Detailed neurological examination: To identify inconsistencies typical of conversion disorder
2. Neuroimaging: MRI brain to rule out structural lesions
3. Laboratory testing: To exclude metabolic, infectious, or autoimmune causes
4. Psychological assessment: To identify stressors and comorbid psychiatric conditions

Management

Management should be multidisciplinary and include:

1. Psychoeducation: Explaining the diagnosis in a non-judgmental way, emphasizing that symptoms are real but not caused by structural damage

2. Cognitive Behavioral Therapy (CBT): First-line treatment to address underlying psychological factors and develop coping strategies

3. Physical therapy: Particularly for motor symptoms, focusing on normal movement patterns

4. Stress management techniques: Mindfulness, relaxation training, and biofeedback

5. Pharmacotherapy: For comorbid conditions like anxiety or depression

Prognosis

Prognosis varies based on:

• Duration of symptoms before diagnosis (shorter duration has better outcomes)
• Presence of comorbid psychiatric conditions
• Quality of therapeutic relationship
• Patient's acceptance of the diagnosis

Early intervention is associated with better outcomes, with approximately 60-80% of patients showing improvement with appropriate treatment 1.

Common Pitfalls

• Dismissing symptoms as "not real": Symptoms are genuinely experienced by patients despite lack of organic cause
• Excessive testing: Repeated negative tests can reinforce illness beliefs
• Failure to diagnose: Missing conversion disorder can lead to unnecessary treatments and procedures
• Neglecting psychological factors: Not addressing underlying stressors limits treatment effectiveness

Conversion disorder represents a complex interaction between psychological stressors and neurological manifestation. Early recognition and appropriate management can significantly improve outcomes and prevent chronicity of symptoms.