Von-Recklinghausen's disease and spine canal ectasis: An exceptional complication and a new therapeutic approach

ABSTRACT

Von-Recklinghausen's disease or neurofibromatosis type 1 [NF1] is a hereditary disorder in which the genetic transmission is autosomic dominant and supported by the chromosome 17. Scoliosis is a classical complication of this disease. Spinal canal ectasis, at the extremities of the arthrodesis, is a rare complication of scoliosis occurring in the context of NF1 and there is no clear treatment described in the literature. We report 3 observations of patients who were admitted for the complex association of NF1 and spinal canal ectasis occurring after the surgical treatment of scoliosis and discuss our concept of treating the spinal ectasis which weakened the fusion of arthrodesis. These 3 cases of NF1 in males whose mean age was 22-years-old [19, 23, 24 years-old] were operated at the age of 8, 9 and 14 years-old respectively for severe thoraco-lumbar scoliosis. At the initial surgical management, the spine canal diameter was within normal range. They underwent a two-stage surgery with anterior and posterior spinal arthrodesis. The abnormal spinal canal dilatation [spinal ectasis] appeared during the follow-up and was revealed by back pain of the lumbar and thoracic spine. Magnetic resonance imaging and computed tomography scan concluded a posterior body vertebral destruction with clear enlargement of the subdural space, mainly located at the extremity of the arthrodesis, which was directly at risk. It was hypothesized an abnormal hyperpression of the cerebrospinal fluid [CSF]. Magnetic resonance imaging of the whole spine and the brain did not show any spinal cord anomaly, Chiari's malformation or hydrocephalus. We decided to mearure the CSF pressure via lumbar puncture. It was abnormal in all 3 cases [18 - 21 mm Hg], as was the biochemical analysis of the CSF. All 3 patients underwent surgery with a lumbo-peritoneal programmeable shunt [Sophysa shunt]. The prostoperative follow-up [9months to 3 years] was good without recurrence of pain and no cerebral hypotension symptoms. Vertebral bone destruction was seen to be halted on control MRI or CT scan. The CFS hyperpression theory must be studied more carefully so as to understand the intrinsic mechanisms in this particular clinical context by a prospective larger series with monitoring of the CSF pressure before lumbo-periotoneal shunting and a longer postoperative course to confirm the validity of this therapeutic approach: