Intramedullary cystic lesions of the conus medullaris.

Fifth ventricle: an unusual cystic lesion of the conus medullaris

“…[1][2][3][4][5][6][7] The process of neurulation, which begins at 3 weeks of embryonic age, leads to the formation of the neural tube by a progressive fusion of the lateral edges of the neural plate starting from the level, of the third and fourth somite. From this level, the fusion process progresses at the same time cephalad and caudad.…”

“…Currently, most of the authors [1][2][3][4][5][6][7] believe that isolated cystic dilatation of the fifth ventricle is due to the persistence of this lesion in adulthood and to the abnormal closure of the communication between the ventriculus terminalis and the central canal by ependyma (disembryogentic theory).…”

“…Of the 17 cases described in the literature, 13 presented ingravescent or, at least, invalidating symptoms, 1,[5][6][7][8][9][10][11][12] whereas in the other 4, clinical status remained stable at follow-up. 2,6,13 However, clinical symptoms were entirely nonspecific, even in the cases that evolved, ranging from just low back pain (as in our case) to deficits (lower limb paresis, sphincter dysfunction, etc.).…”

“…Of the 17 cases described, 14 underwent surgical treatment consisting of emptying of the cyst and marsupialization, [5][6][7][8][9][10][11][12] because they presented progressively worsening or, in any case, invalidating symptoms: regression of clinical symptoms was achieved in six of these cases 1,5,7,8,10,12 and marked clinical improvement in six. 7,11,12 Postoperative control MRI was performed in seven cases 1,6,[8][9][10] and documented complete obliteration of the cystic dilatation in one case, 8 partial obliteration in four 1,9,10 and no change in the last one. 6 In the other four cases, 2,6,13 a conservative policy was adopted, with clinical and radiological follow-up (lasting over 6 years in Celli et al's report) because both the clinical and neuroradiological situation remained more or less stable.…”

“…6 In the other four cases, 2,6,13 a conservative policy was adopted, with clinical and radiological follow-up (lasting over 6 years in Celli et al's report) because both the clinical and neuroradiological situation remained more or less stable. In six of the 14 cases surgically treated, the authors emphasized that the liquid that came out of the cystic lesion was clear and uncolored 6,7,11,12 as in normal CSF. This finding seems to support the hypothesis of a preserved turnover of the intracystic content with the CSF spaces, even though the mechanism by which this occurs remains unknown.…”