Damage to the conus medullaris following spinal anaesthesia

Seven cases are described in which neurological damage followed spinal or combined spinal‐epidural anaesthesia using an atraumatic spinal needle. All patients were women, six obstetric and one surgical. All experienced pain during insertion of the needle, which was usually believed to be introduced at the L2−3 interspace. In all cases, there was free flow of cerebrospinal fluid before spinal injection. There was one patchy block but, in the rest, anaesthesia was successful. Unilateral sensory loss at the levels of L4–S1 (and sometimes pain) persisted in all patients; there was foot drop in six and urinary symptoms in three. Magnetic resonance imaging showed a spinal cord of normal length with a syrinx in the conus (n = 6) on the same side as both the persisting clinical deficit and the symptoms that had occurred at insertion of the needle. The tip of the conus usually lies at L1−2, although it may extend further. Tuffier's line is an unreliable method of identifying the lumbar interspaces, and anaesthetists commonly select a space that is one or more segments higher than they assume. Because of these sources of error, anaesthetists need to relearn the rule that a spinal needle should not be inserted above L3.

[1]  J. Kendell,et al.  Costing anaesthetic practice , 2000, Anaesthesia.

[2]  Nathaniel Katz,et al.  Epidural anesthesia complicated by fluid collection within the spinal cord. , 1993, Anesthesia and analgesia.

[3]  L. Irestedt,et al.  Neurological complications in obstetric regional anaesthesia. , 2000, International journal of obstetric anesthesia.

[4]  H. Abe,et al.  Gliomas of the conus medullaris , 1994, Paraplegia.

[5]  I. Russell,et al.  A survey of anaesthetic techniques used for caesarean section in the UK in 1997. , 2000, International journal of obstetric anesthesia.

[6]  N. Todd,et al.  Intradural conus and cauda equina tumours: a retrospective review of presentation, diagnosis and early outcome. , 1993, Journal of neurology, neurosurgery, and psychiatry.

[7]  K. Drasner,et al.  Cauda Equina Syndrome After Continuous Spinal Anesthesia , 1991, Anesthesia and analgesia.

[8]  Q. Hogan.  Tuffier's line: the normal distribution of anatomic parameters. , 1994, Anesthesia and analgesia.

[9]  J. Balblanc,et al.  Vascular complication involving the conus medullaris or cauda equina after vertebral manipulation for an L4-L5 disk herniation. , 1998, Revue du rhumatisme.

[10]  W. J. Oakes,et al.  Tethered Cord Syndrome: The Low-lying and Normally Positioned Conus , 1994 .

[11]  A. Friedman,et al.  Conus medullaris nerve root avulsions. , 1987, Journal of neurosurgery.

[12]  A. Sodano,et al.  Neurological deficit following spinal anaesthesia: MRI and CT evidence of spinal cord gas embolism , 1999, Neuroradiology.

[13]  F Reynolds,et al.  Logic in the safe practice of spinal anaesthesia , 2000, Anaesthesia.

[14]  B. Andrews,et al.  Infarct of the conus medullaris simulating a spinal cord tumor: case report. , 1991, Surgical neurology.

[15]  A. Friedman,et al.  Dorsal root entry zone lesions for intractable pain after trauma to the conus medullaris and cauda equina. , 1995, Journal of neurosurgery.

[16]  F. Reynolds.  Maternal sequelae of childbirth. , 1995, British journal of anaesthesia.

[17]  S. Rahman,et al.  Long-term neurological complication following traumatic damage to the spinal cord with a 25 gauge whitacre spinal needle. , 1999, International journal of obstetric anesthesia.

[18]  M. Coolican,et al.  Injuries of the conus medullaris , 1988, Paraplegia.

[19]  E. Willoughby,et al.  Infarction of the conus medullaris , 1987, Annals of neurology.

[20]  A. Forster,et al.  Continuous spinal anesthesia: where do spinal catheters go? , 1993, Anesthesia and analgesia.

[21]  R. Matsubayashi,et al.  Cystic dilatation of ventriculus terminalis in adults: MRI , 1998, Neuroradiology.

[22]  M. Selçuki,et al.  Management of tight filum terminale syndrome , 1998 .

[23]  B. Anson,et al.  Vertebral level of termination of the spinal cord with report of a case of sacral cord , 1944 .

[24]  P. Seed,et al.  Paraesthesiae and nerve damage following combined spinal epidural and spinal anaesthesia: a pilot survey. , 2000, International journal of obstetric anesthesia.

[25]  T. B. Watson,et al.  Conus medullaris injury following both tetracaine and lidocaine spinal anesthesia. , 1996, Journal of clinical anesthesia.

[26]  A. Thomson.  Fourth Annual Report of Committee of Collective Investigation of the Anatomical Society of Great Britain and Ireland for the Year 1892-93. , 1893, Journal of anatomy and physiology.

[27]  C. Render.  The reproducibility of the iliac crest as a marker of lumbar spine level , 1996, Anaesthesia.

[28]  G. Strichartz,et al.  Irreversible Conduction Block in Isolated Nerve by High Concentrations of Local Anesthetics , 1994, Anesthesiology.

[29]  A. Denys,et al.  Ventriculus terminalis of the conus medullaris: MR imaging in four patients with congenital dilatation. , 1991, AJNR. American journal of neuroradiology.

[30]  K. Sridhar,et al.  Isolated eccentric syrinx of the conus medullaris simulating a tumour. , 1999, British journal of neurosurgery.

[31]  S. Garfin,et al.  Organization of intrathecal nerve roots at the level of the conus medullaris. , 1990, The Journal of bone and joint surgery. American volume.

[32]  Oakes Wj,et al.  Tethered Cord Syndrome: The Low-lying and Normally Positioned Conus , 1994 .

[33]  J. D. Greaves,et al.  Serious spinal cord injury due to haematomyelia caused by spinal anaesthesia in a patient treated with low‐dose heparin , 1997, Anaesthesia.

[34]  D. Wilson,et al.  Ability of anaesthetists to identify a marked lumbar interspace , 2000 .

[35]  A. Saifuddin,et al.  The Variation of Position of the Conus Medullaris in an Adult Population: A Magnetic Resonance Imaging Study , 1998, Spine.

[36]  T. Cadoux-Hudson,et al.  Delayed paraplegia following spinal anaesthesia , 1996, Anaesthesia.