Painless legs and moving toes syndrome associated with a sacral Tarlov cyst: a case report

BACKGROUND Painless legs and moving toes syndrome is a very rare syndrome characterized by continuous and involuntary movement of the toes. The etiology of the disease is not clear though it has been linked to a wide range of neuronal insults including proximal root compression and neuropathy. A previous study has reported bilateral painful legs and moving toes syndrome in a patient with a sacral Tarlov cyst. In this report we present a case of unilateral painless legs and moving toes syndrome in a woman with a sacral Tarlov cyst. CASE PRESENTATION A 50-year-old Mediterranean woman presented with a 1-year history of involuntary sustained movement of her right toes. Her physical examination and laboratory findings did not show any remarkable abnormality. Her lumbosacral magnetic resonance imaging scan showed a sacral Tarlov cyst. Our patient was given gabapentin, 100 mg per day as a starting dose, and showed modest improvement. Our patient preferred not to continue with the treatment as her symptoms were not disabling and she was only concerned about the cosmetic appearance. CONCLUSIONS This report presents a new case of a very rare syndrome called painless legs and moving toes syndrome, which is possibly a variant of painful legs and moving toes syndrome. This is considered to be the first case of unilateral painless legs and moving toes syndrome that is associated with a sacral Tarlov cyst. Although the disease etiology is still unknown and the presence of the cyst can be accidental, neurologists should be aware that Tarlov cyst is a possible cause. In addition, patients with the painless variant who are not disabled by movement of the toes may not require treatment.