Optional medical device diagnostics – depending on the results of the history, physical examination, laboratory diagnostics, and obligatory medical device diagnostics – for differential diagnostic clarification.
- Polysomnography (sleep laboratory; measurement of various body functions during sleep that provide information about sleep quality) – indicates sleep quality via measurement of various body functions [RLS: usually periodic limb movements in sleep (PLMS, “periodic limb movements in sleep”) and in wakefulness (PLMW, “periodic limb movements of wakefulness”); duration is 0.5-1.0 seconds, intervals are 5-90 seconds]
- Electromyography (EMG; measurement of electrical muscle activity) – measurement of muscle activity.
- Measurement of nerve conduction velocity (NLG).
- Renal sonography (ultrasound examination of the kidneys).
- Thyroid sonography (ultrasound examination of the thyroid gland).
- Magnetic resonance imaging (MRI; computer-assisted cross-sectional imaging method (using magnetic fields, that is, without X-rays)).
- Spinal MRI – in cases of clinical suspicion of myelopathy or radiculopathy.
