Ventureyra Enrique C G, Aziz Hani Abdel, Vassilyadi Michael
Division of Neurosurgery, Children's Hospital of Eastern Ontario, University of Ottawa, 401 Smyth Road, Ottawa, Ontario, KIH 8LI Canada.
Childs Nerv Syst. 2003 Feb;19(2):109-13. doi: 10.1007/s00381-002-0701-1. Epub 2003 Jan 30.
Since the introduction of MRI, the incidence of Chiari I malformations (cerebellar tonsils ectopia) has increased. The clinical significance of this finding remains questionable in some instances. Recently, cine flow MRI has added to the understanding of the dynamics of cerebrospinal fluid at the craniocervical junction and to the pathophysiology of the Chiari I malformation. The present study attempts to analyze the role of cine flow MRI in Chiari I malformations.
Between January 1990 and December 2000, 24 patients were identified who met the following inclusion criteria: patients diagnosed with Chiari I malformation who had had an MRI of the brain including the craniocervical junction, clinical follow-up for at least six months, and cine flow studies had to have been performed pre- and postoperatively. The cine flow studies were repeated during follow-up if the patients were not surgical candidates. Patients harboring intracranial space occupying lesions or lumboperitoneal shunts were excluded. Sixteen of the 24 selected patients underwent 18 operations and 8 were followed conservatively. There was a wide variation in clinical presentations. Twelve patients had cerebellar tonsils protruding more than 5 mm below the foramen magnum, and in 12 patients the descent of the cerebellar tonsils was less than 5 mm. Despite this difference in the degree of protrusion, there was no significant difference in clinical presentation. The cisterna magna was small or absent in 20 patients with sluggish cine flow posteriorly, 19 of whom were symptomatic, in contrast to 1 symptomatic patient who had satisfactory cine flow.
All patients with Chiari I malformation and an associated cervical syrinx had absent cine flow at the craniovertebral junction, and this finding was statistically significant. There was a good correlation between the clinical presentation and cine flow preoperatively, and between clinical improvement and cine flow postoperatively. Patients with Chiari I malformation, cervical syrinx, and absent cine flow preoperatively improved after suboccipital decompression and duroplasty. Patients with Chiari I malformations without syrinx and absent cine flow underwent suboccipital bony decompression alone and had satisfactory outcomes.
自从磁共振成像(MRI)问世以来,Chiari I型畸形(小脑扁桃体下疝)的发病率有所上升。在某些情况下,这一发现的临床意义仍存在疑问。最近,电影流动MRI增进了我们对颅颈交界处脑脊液动力学以及Chiari I型畸形病理生理学的理解。本研究旨在分析电影流动MRI在Chiari I型畸形中的作用。
在1990年1月至2000年12月期间,确定了24例符合以下纳入标准的患者:被诊断为Chiari I型畸形且已进行包括颅颈交界处的脑部MRI检查、临床随访至少6个月,并且必须在术前和术后进行电影流动研究。如果患者不是手术候选者,则在随访期间重复进行电影流动研究。排除患有颅内占位性病变或腰大池腹腔分流术的患者。24例入选患者中,16例接受了18次手术,8例接受保守治疗。临床表现差异很大。12例患者的小脑扁桃体突出超过枕骨大孔下方5毫米,12例患者的小脑扁桃体下降小于5毫米。尽管突出程度存在差异,但临床表现并无显著差异。20例患者的小脑延髓池小或不存在,其后方电影流动缓慢,其中19例有症状,相比之下,1例有症状患者的电影流动情况良好。
所有患有Chiari I型畸形并伴有颈髓空洞症的患者在颅颈交界处均无电影流动,这一发现具有统计学意义。术前临床表现与电影流动之间以及术后临床改善与电影流动之间存在良好的相关性。患有Chiari I型畸形、颈髓空洞症且术前无电影流动的患者在枕下减压和硬脑膜成形术后有所改善。患有Chiari I型畸形且无空洞症且无电影流动的患者仅接受枕下骨性减压,效果良好。