Neurol India Home 
 

LETTER TO EDITOR
Year : 2014  |  Volume : 62  |  Issue : 6  |  Page : 708--709

The triad of holocord syringomyelia, Chiari malformation and tethered cord: Amelioration with simple detethering - A case for revisiting traction hypothesis?

Ankur Kapoor1, Sivashanmugam Dhandapani1, Paramjeet Singh2,  
1 Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India
2 Department of Radiology, Post Graduate Institute of Medical Education and Research, Chandigarh, India

Correspondence Address:
Sivashanmugam Dhandapani
Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh
India




How to cite this article:
Kapoor A, Dhandapani S, Singh P. The triad of holocord syringomyelia, Chiari malformation and tethered cord: Amelioration with simple detethering - A case for revisiting traction hypothesis?.Neurol India 2014;62:708-709


How to cite this URL:
Kapoor A, Dhandapani S, Singh P. The triad of holocord syringomyelia, Chiari malformation and tethered cord: Amelioration with simple detethering - A case for revisiting traction hypothesis?. Neurol India [serial online] 2014 [cited 2022 May 25 ];62:708-709
Available from: https://www.neurologyindia.com/text.asp?2014/62/6/708/149450


Full Text

Sir,

Chiari malformation is a common cause of cervical syringomyelia, extending caudally holocord occasionally, warranting foramen magnum decompression. The triad of Chiari malformation, holocord syringomyelia, and tethered cord is rare and poses therapeutic dilemma in choosing between foramen magnum decompression and filum detethering as the initial surgical strategy. We present a similar rare case.

A 12-year-old boy presented with progressive weakness and decreased sensation over both lower limbs of 2 years and hesitancy and slow stream of urine of 6-months duration. Examination revealed swelling low back, weakness of both lower limbs (right 4/5, left 4+/5), high stepping gait, and suspended/dissociated sensory impairment in upper limbs. Magnetic resonance imaging (MRI) demonstrated syrinx extending from C2 to L3 with cord tethered at L4-5 level, cerebellar tonsillar descent of 4 mm, occipitalization of atlas, and no hydrocephalus [Figure 1]. Uroflowmetry revealed poor flow rate. Patient underwent L4-5 laminotomy, had tethering of cord with thick filum attached to the dorsal dura. Detethering was carried out. Intra-operatively, there was upward recoil of cord. Post-operatively, patient had subjective improvement in weakness and numbness beginning immediately, with power of 5/5 both lower limbs at 6 weeks. MRI done 6 weeks later showed significant resolution of syrinx and tonsillar descent as compared to pre-operative MRI [Figure 2].

Syringomyelia associated with tethered cord and spinal dysraphism is usually seen below vertebral level T6. [1] Holocord syrinx associated with tethered cord is unusual and creates dilemma of initial surgical strategy between foramen magnum decompression and detethering. The congenital effect of tethering as early as the phase of gastrulation might influence neurulation or post-neurulation caudo-cranial vertebral growth collision causing altered cerebrospinal fluid (CSF) dynamics, as indicated by occipitalization of atlas. [2],[3]{Figure 1}{Figure 2}

However, immediate improvement in syringomyelia and relatively short history indicate congenital predisposition aggravated by growth spurt. Tension related to tethering of the bottom or middle of the spinal cord probably leads to stretch injury that can obstruct the flow of fluid within the central canal or produce fluid cavitation per se. This type of syrinx is unlikely to benefit from foramen magnum decompression, and best treated with surgery to untether the spinal cord. The remarkable improvement in clinical symptoms and radiology indicates the magnitude of tension within the whole of cord, with re-establishment of CSF dynamics. Though there have been isolated reports of sectioning of filum terminale benefitting Chiari or syringomyelia, [4] holocord syringomyelia improving after detethering of cord has not been reported previously. Holocord syringomyelia with tethered cord indicates caudal traction as the primary etiology, and so requires mere detethering of cord. Foramen magnum decompression is not needed even in presence of tonsillar descent. However, individual cases need to be evaluated carefully before deciding treatment.

References

1Erkan K, Unal F, Kiris T. Terminal syringomyelia in association with the tethered cord syndrome. Neurosurgery 1999;45:1351-9.
2Dhandapani S, Mehta VS, Sharma BS. "Horseshoe cord terminus" sans filum around a bone spur: A rare composite of faulty gastrulation with agenesis of secondary neurulation: Case report. J Neurosurg Pediatr 2013;12:411-3.
3Roth M. Cranio-cervical growth collision: Another explanation of the Arnold-Chiari malformation and of basilar impression. Neuroradiology 1986;28:187-94.
4Royo-Salvador MB, Solé-Llenas J, Doménech JM, González-Adrtio R. Results of the section of the filum terminale in 20 patients with syringomyelia, scoliosis and Chiari malformation. Acta Neurochir (Wien) 2005;147:515-23.