"The term "tight filum terminale syndrome" is synonymous with "tethered cord syndrome" secondary to a "tight filum terminale." The emphasis on "syndrome" highlights a clinical diagnosis made by the synthesis of symptoms, neurologic exam signs, and laboratory tests such as urodynamics. In contrast, "tight filum terminale" is a pathoanatomic finding, which may or may not be visible radiologically or associated with the clinical syndrome."
"Confusingly, "tethered cord syndrome" is sometimes used synonymously, as if to imply that a tight filum terminale is the main aetiology of the tethered cord syndrome, even though in actuality there are many other aetiologies. This ambiguity dates back to the first introduction of the term "tethered cord syndrome" by Hoffman and colleagues in 1976, who described a series of patients with spina bifida occulta and neurologic symptoms as well as a low conus and/or thick filum identified on iophenyldate myelography, i.e. the entity previously termed filum terminale syndrome 11. These authors claimed that this aetiology "far outnumbers the more obvious forms of spinal dysraphism," even though patients with those disorders were excluded from the study 11. Since that time, the concept of tethered cord syndrome has been expanded to include that associated with the other spinal dysraphisms and other causes such as acquired adhesions."
"American orthopaedic surgeon George J Garceau (1896–1977) first described "the filum terminale syndrome" in 1953, hypothesising that "a tight filum terminale may cause the cord-traction symptoms known as the Arnold-Chiari syndrome" 10."
"When the clinical syndrome is present but imaging is normal (conus medullaris is normally positioned, filum terminale appears normal in size and signal, and other tethering agents are absent), the term occult filum terminale syndrome is used to imply that an inelastic but grossly normal-appearing filum terminale may be the culprit 2,4. This diagnosis remains controversial 7. The term occult tethered cord syndrome is synonymous because a histologic abnormality in the filum terminale is the implied diagnosis by exclusion 8."
"When the clinical syndrome is present but imaging is normal (conus medullaris is normally positioned, filum terminale appears normal in size and signal, and other tethering agents are absent), the term occult filum terminale syndrome is used to imply that an inelastic but grossly normal-appearing filum terminale may be the culprit 2,4. This diagnosis remains controversial 7. The term occult tethered cord syndrome is synonymous because a histologic abnormality in the filum terminale is the implied diagnosis by exclusion 8."
"Confusingly, "tethered cord syndrome" is sometimes used synonymously, as if to imply that a tight filum terminale is the main aetiology of the tethered cord syndrome, even though in actuality there are many other aetiologies. This ambiguity dates back to the first introduction of the term "tethered cord syndrome" by Hoffman and colleagues in 1976, who described a series of patients with spina bifida occulta and neurologic symptoms as well as a low conus and/or thick filum identified on iophenyldate myelography, i.e. the entity previously termed filum terminale syndrome 11. These authors claimed that this aetiology "far outnumbers the more obvious forms of spinal dysraphism," even though patients with those disorders were excluded from the study 11. Since that time, the concept of tethered cord syndrome has been expanded to include that associated with the other spinal dysraphisms and other causes such as acquired adhesions."