Likely Diagnosis: Restless Legs Syndrome (RLS)
This 72-year-old patient most likely has Restless Legs Syndrome (RLS), possibly with an atypical variant affecting the eyes, and should be started on a dopamine agonist after checking serum ferritin levels.
Clinical Reasoning
The constellation of new-onset insomnia, electric-like sensations in the thighs, and twitchy eyes in an elderly patient strongly suggests RLS. The "electric current" sensation is a classic description of RLS dysesthesias, and while eye involvement is rare, recent case reports document "restless eyes" as a novel RLS variant 1.
Diagnostic Workup
Essential diagnostic criteria for RLS 2:
- Urge to move the legs accompanied by uncomfortable sensations (your patient's "electric current" in thighs)
- Symptoms begin or worsen during rest (sitting or lying down)
- Relief with movement (walking, stretching)
- Worse in evening/night (causing the insomnia)
Required laboratory testing:
- Serum ferritin level - Values <50 ng/mL are consistent with RLS and indicate need for iron supplementation 2
- Thorough neurologic examination to exclude peripheral neuropathy or radiculopathy as secondary causes 2
Regarding the eye twitching: While traditionally not part of RLS, a 2025 case report documented nocturnal ocular symptoms relieved by eye movements as an RLS variant 1. This expands the diagnostic concept to "restless X syndrome" affecting non-traditional body regions.
Management Algorithm
First-Line Treatment: Dopamine Agonists
For patients requiring pharmacologic therapy, start with FDA-approved dopamine receptor agonists 2:
Option 1: Ropinirole
- Start 0.25 mg orally 1-3 hours before bedtime
- Increase to 0.5 mg after 2-3 days
- Increase to 1 mg after 7 days
- Titrate weekly by 0.5 mg increments up to maximum 4 mg at week 7 if needed
Option 2: Pramipexole
- Start 0.125 mg orally 2-3 hours before bedtime
- Double dose every 4-7 days if needed
- Maximum 0.5 mg
Critical caveat for elderly patients: Monitor closely for orthostatic hypotension, drug interactions, nausea, sleepiness, and compulsive behaviors 2. These side effects are particularly problematic in 72-year-olds.
Alternative if Dopamine Agonists Fail
If the patient doesn't respond to dopamine agonists (as occurred in the eye-variant case), switch to gabapentin enacarbil 1, 3. This is especially appropriate for patients with:
- Augmentation (worsening symptoms on dopamine agonists)
- Impulse control disorders
- Hypersomnia from dopamine agonists
Non-Pharmacologic Interventions (Concurrent)
Implement immediately 2:
- Moderate exercise (avoid within 2 hours of bedtime)
- Smoking cessation
- Alcohol avoidance
- Caffeine elimination
- Review and discontinue offending medications if possible
Important Pitfalls to Avoid
Augmentation syndrome: Watch for earlier symptom onset, increased intensity, or spread to other body parts (calves to thighs) after initial medication control 2. More common with levodopa-carbidopa than newer dopamine agonists, but frequency with ropinirole/pramipexole is unknown 2.
Management of augmentation:
- Take dose earlier in the day
- Split doses (early evening + bedtime)
- Switch to anticonvulsant class (gabapentin) 2
Differential diagnosis to exclude:
- Peripheral neuropathy
- Radiculopathy
- Vascular disease/intermittent claudication
- Neuroleptic-induced akathisia
- Arthritis
- Venous varicosities 2
Do not treat the insomnia as primary insomnia - treating the underlying RLS will resolve the sleep disturbance. Cognitive behavioral therapy for insomnia (CBT-I) is first-line for primary chronic insomnia 4, but this patient's insomnia is secondary to RLS.
Regarding Periodic Limb Movement Disorder (PLMD)
While 90% of RLS patients have periodic limb movements during sleep (PLMS), no FDA-approved treatment exists specifically for PLMS/PLMD, and there is insufficient evidence to support pharmacologic treatment 2. The limb movements support the RLS diagnosis but are neither necessary nor sufficient for diagnosis 2.