What is the best course of treatment for a patient experiencing persistent full-body tremors, anxiety, insomnia, and fatigue, with a history of neck injury, whiplash, and plasma donation, despite normal cardio workup, brain MRI, EEG, and EMG results, and partial relief from gabapentin (Neurontin)?

Management of Persistent Full-Body Tremors with Whiplash History and Normal Workup

This presentation is most consistent with functional neurological disorder (FND) with tremor, likely precipitated by cervical trauma, and requires a structured rehabilitation approach focused on retraining normal movement patterns rather than escalating pharmacotherapy.

Clinical Reasoning and Diagnosis

The constellation of sudden-onset full-body tremors (hands, head, torso, tongue, eyelids) that persist despite normal EEG, EMG, brain MRI, and cardiac workup, combined with anxiety, insomnia, and progressive symptoms following whiplash injury, strongly suggests functional tremor rather than organic neurological disease 1. The key diagnostic features include:

• Entrainability and distractibility: Functional tremors typically vary with attention and can be modified by voluntary movements 1
• Sudden onset following trauma: The temporal relationship to whiplash injury is characteristic of post-traumatic functional symptoms 2
• Multi-system involvement without objective findings: The combination of tremor, anxiety, insomnia, and subjective sensory symptoms with normal investigations points away from structural pathology 1

The history of frequent plasma donation may have contributed to electrolyte disturbances or volume depletion, but this would not explain persistent tremor months later with normal cardiac workup.

Treatment Approach

Primary Intervention: Occupational/Physical Therapy for Functional Tremor

The cornerstone of treatment should be specialized rehabilitation targeting functional movement retraining, not medication escalation 1. Specific strategies include:

• Tremor entrainment techniques: Superimpose alternative voluntary rhythms on the existing tremor, gradually slowing all movement to complete rest 1
• For full-body tremor: Use gross rather than fine movements initially, as these require less concentration and are easier to control 1
• Muscle relaxation: Actively assist the patient to relax muscles and prevent co-contraction, which can perpetuate tremor 1
• Discourage compensatory strategies: Tensing muscles to suppress tremor is counterproductive and should be avoided 1

Addressing Anxiety and Functional Jerks

The anxiety and nighttime muscle jerks require integrated management 1:

• Pre-jerk cognition modification: Address unhelpful thoughts, anxiety, frustration, or breath-holding that precede jerking movements 1
• Relaxation techniques: Implement diaphragmatic breathing and progressive muscular relaxation 1
• Sensory grounding: Use strategies to bring awareness to the present moment (noticing environmental details, textured items, cognitive distractors) 1
• Slow movement activities: Encourage yoga or tai chi to regain movement control and redirect attention away from symptoms 1

Cervical Spine Management

Given the C5-C6 bulging discs and persistent neck tightness 1:

• Manual therapy: Consider manual treatment of the neck, which has weak evidence support for post-concussive symptoms that may overlap with whiplash sequelae 1
• Postural optimization: Encourage optimal alignment and even weight distribution to normalize movement patterns 1
• Avoid prolonged end-range positioning: Prevent postures that maintain joints at extreme ranges 1

Role of Gabapentin: Limited and Potentially Problematic

Gabapentin should be continued at the current dose only if it provides meaningful benefit for the nighttime jerks, but should not be escalated 3, 4. Critical considerations:

• Paradoxical effects: Gabapentin can actually cause tremor, myokymia, and dystonia, particularly at higher doses 5, 4
• Case report evidence: A patient taking 9600 mg daily developed myokymia, tremors, and muscle spasms that resolved with dose reduction 4
• Mechanism: Gabapentin-induced movement disorders are dose-related and reversible 5, 4
• Current indication: Gabapentin has weak evidence for central post-stroke pain but is not first-line for functional tremor 1

If gabapentin is providing partial relief of nighttime symptoms, maintain the current dose but monitor for toxicity (therapeutic range 2.0-20.0 μg/mL) 4. If symptoms worsen or tremor intensifies, consider a brief medication holiday 4.

Psychological Treatment

Psychological intervention is essential and should be initiated concurrently with physical rehabilitation 1, 2:

• Psychoeducation: Stress the generally good long-term outcome and explain the mechanism of functional symptoms 2
• Brief psychological treatment: This has proven efficacy in reducing severity and duration of post-whiplash symptoms 2
• Address comorbidities: Treat depression, anxiety, and fatigue as distinct targets 2
• Post-traumatic stress: Screen for and treat PTSD symptoms, which are common after whiplash 2

Interdisciplinary Coordination

An interdisciplinary team approach is recommended 1:

• Coordinate care between neurology, physical/occupational therapy, psychology, and pain management 1
• Avoid aids and adaptive equipment in the acute phase, as these can interrupt normal automatic movement patterns 1
• If equipment is necessary for safety, use minimally and with a clear plan to progress toward independence 1

What NOT to Do: Common Pitfalls

• Do not escalate gabapentin dosing: Higher doses increase risk of paradoxical movement disorders 5, 4
• Avoid multiple medication trials: Polypharmacy is unlikely to help functional tremor and increases adverse effects 1
• Do not pursue additional imaging: Repeated negative investigations can reinforce illness beliefs 1
• Avoid prolonged rest or disability: This promotes deconditioning and symptom chronification 1

Monitoring and Follow-up

• Short-term (2-4 weeks): Assess response to rehabilitation techniques and psychological intervention 1
• Medium-term (3 months): Evaluate for reduction in tremor severity, improved function, and decreased anxiety 1
• Consider gabapentin level: If symptoms worsen or new movement disorders emerge, check serum gabapentin concentration 4

Alternative Pharmacotherapy (If Needed)

If anxiety and insomnia remain refractory despite psychological treatment:

• For anxiety: Consider SSRI/SNRI rather than benzodiazepines for long-term management 1
• For insomnia: Address sleep hygiene and consider cognitive behavioral therapy for insomnia (CBT-I) before medications 2
• Not recommended: Propranolol or primidone, which are for essential tremor, not functional tremor 6, 7