When to refer patients with sacral Tarlov cysts: a practical framework for identifying likely symptomatic cysts

Tarlov cysts are frequently identified during magnetic resonance imaging of the lumbosacral spine, although the majority carry no clinical relevance. A smaller but important subgroup causes symptoms through deformation or irritation of the sacral nerve roots. These patients often experience prolonged diagnostic pathways, and many are assessed by several specialities (often appropriately) before neurosurgical review is considered. Referral patterns remain inconsistent, in part because many specialists are uncertain which symptom profiles reliably indicate sacral nerve dysfunction. In this connection, the aim of this review is to provide a structured and clinically grounded framework for identifying symptomatic Tarlov cysts, emphasising the importance of symptom pattern recognition, correlation with anatomical level, exclusion of differential diagnosis and careful interpretation of radiological findings. Sitting intolerance and sacral or perineal sensory change, represent particularly discriminating features of sacral root involvement. Radiological markers such as dorsal root ganglion displacement and sacral foraminal remodelling strengthen the case for clinical relevance, although cyst size alone is not predictive. This framework also outlines differential diagnoses that merit consideration, including gynaecological, urological and colorectal causes of pelvic or perineal symptoms. The role of pelvic neurophysiology in selected cases is discussed, as well as the occasional use of single photon emission computed tomography (SPECT-CT) when pain localisation is uncertain. The proposed structure is intended to assist multi-disciplinary clinicians and neurosurgeons, in determining when specialist referral is appropriate. This review draws on the authors' experience within a tertiary neurosurgical referral practice as well as select evidence from the published literature.