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Editorial note: Meningomyelocele and other defects
Sharma et ah Hydatid Cysts of Spinal Cord
foreign-body-type giant cells were seen in the first specimen.
Discussion Primary intradural hydatid cysts are uncommon. AranaIniguez [1] commented that in virtually all cases of hydatid disease in the spine, compression of the spinal cord and intraspinal nerve roots is caused by hydatid material from an affected vertebra. D6v6 [4] claimed that in the literature there were no well-documented cases without bony involvement. Dew [5] pointed out the theoretical possibility of primary epidural or intradural lesions. In the first case, reported by Carrea and Murphy [3], the authors themselves noted that it was debatable whether the cyst originated in the arachnoid membrane or in white matter near the surface of the spinal cord. The case of Ley and Marti [6] was an example of a true intramedullary hydatid cyst. D6v~'s [4] theoretical suggestions that when a cyst developed in such a small organ as the spinal cord, it would be single and small, occurring in young adults and producing its symptoms over a short period (a few months), were supported by the features shown in these 2 cases [3, 6] and partly by features in our patient, except that the cysts were multiple. This may be explained by the hypothesis of possible rupture of a cyst because of pressure changes during a previous lumbar puncture. In our patient the discovery of cysts during
237
laminectomy was the only evidence of hydatid disease in the patient. There was no evidence of any pathology of the spine, and there was no clinical evidence of other visceral hydatid disease. Ley and Marti [6], to explain the intradural location of the cyst secondary to a pulmonary location, as seen in their patient, postulated that the parasite embryo circulating in the bloodstream enters through an intercostal artery. It is difficult to explain an isolated intradural location of multiple hydatid cysts, as seen in our patient. Up to the present time there has been no clinical evidence of hydatid disease in our patient, either in the vertebral column or in a visceral location, prompting us to report this case as a primary intradural hydatid cyst.
References 1. Arana-lniguez R: Echinococcus, in Vinken PJ, Bruyn GW (eds): Handbook of Clinical Neurology. Amsterdam, Oxford: North Holland, 1978, Vol 35, p 193 2. Arana-lniguez R: Hydatid echinococcosis of the nervous system, in Spillane JD (ed): Tropical Neurology. London: Oxford University, 1973, pp 413-414 3. Carrea R, Murphy G: Primaryhydatid cyst of the spinal cord. Acta Neurol Lat Am 10:308-312, 1964 4. l~v~ F: L'6chinococcoseosseuse. Montevideo:A. Monteverde& Cia, 1948 5. Dew HR: Hydatid disease. Sydney: Australia Medical Publication, 1928 6. Ley A Jr, Marti A: Intramedullaryhydatid cyst. J Neurosurg 33:45"t459, 1970
Editorial Note: Meningomyelocele and Other Defects One of the areas where improvement is badly needed is in the prevention of cerebral and spinal congenital defects, such as meningomyelocele. Although as yet there is no definite evidence as to the etiology of these malformations in humans, it has now become possible to detect such defects in the developing fetus of pregnant women who suffer a high risk of having a child with such a malformation. These defective fetuses can then be aborted to the advantage of all concerned, including the child. A recent letter in the Lancet (1:391, 1981) presents the results of a study regarding the tests on maternal serum and amniotic fluid. With the permission of the authors and of Lancet, the letter is reproduced here for the information of those readers of Surgical Neurology who may not have seen the original.
Paul C. Bucy, M.D., Editor
Role of Amniotic Fluid, Acetylcholinesterase in Screening for Neural Tube Defects SIR,--The measurement of maternal serum alpha-fetoprotein
(AFP) followed by ultrasonography and estimation of amniotic fluid AFP has proved a useful way of diagnosing fetuses affected by neural tube defects (NTD) and of providing indications for termination [6]. Occasionally, however, these tests give conflicting or equivocal data and this poses problems for the clinician. Acetylcholinesterase (ACHE) of fetal origin is not detected in the liquor amnii of normal pregnancies by gel electrophoresis [7] but it is detected in pregnancies affected by open NTDs [8] and in some cases of fetal exomphalos [9]. Retrospective studies [7, 9] have suggested that this estimation may be a useful adjunct to the AFP level in diagnosing NTDs. We describe two cases in which the AChE test gave information to complement that obtained from AFP estimations and ultrasonography and substantially influenced the management of the case. Case I . - - A 25-year-old patient had a serum AFP at 16 weeks' gestation of 170 U/ml (5.3 x the median for that gestation). A repeat specimen 1 week later gave a value of 160 U/ml (4.4 × median). Concentrations above 2.5 x the median are indications
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Surgical Neurology Vol 16 No 3 September 1981
for further investigation. Uhrasonography indicated a possible open NTD and the biparietal diameter was 5.4 cm (equivalent to a gestation of 21 weeks as against a clinical dating of 18 weeks) and the cerebral ventricles were dilated. The amniotic fluid AFP was 7,000 U/ml × (normal up to 20,000 U/ml). A repeat ultrasonogram 2 weeks later showed abnormally rapid growth of the biparietal diameter with a proportionately greater growth in the size of the ventricles and confirmed the NTD. AChE was found in the liquor. These findings were taken to indicate a pregnancy which, despite a normal amniotic fluid AFP, was affected by both hydrocephalus and spina bifida. The pregnancy was terminated and this diagnosis was confirmed. Case 2. --This 25-year-old woman had semm-AFP values of 90 U/ml (2.5 × median) at 16 weeks and 150 U/ml (3.6 × median) at 18 weeks. An uhrasonogram confirmed the gestation and excluded obvious skeletal abnormality. The amniotic fluid AFP at 18 weeks was 37,000 U/ml (levels over 20,000 requiring further investigation). A third semm-AFP was 250 U/ml (6.0 × median). AChE was not detected in the liquor. Despite the abnormal and increasing semm-AFP and the raised liquor AFP this pregnancy was not terminated. The negative AChE test and normal scan raised doubts about the presence of a lesion. 21 weeks later a normal male baby weighing 4.2 kg was delivered. The raised AFP levels remain unexplained. In another case, a 21-year-old patient had a first serum AFP of 130 U/ml (2.9 x median) and the result of a second test was 180 U/ml (3.6 x median). Serial ultrasonograms suggested hydrocephalus and the possibility of a lumbar spina bifida. The amniotic fluid AFP value was marginal (24,000 U/ml). The pregnancy was terminated. The hydrocephalus was confirmed but there was no spina bifida. The fetus did have an extensive cleft lip and palate, and this lesion probably accounted for the AFP. Retrospectively AChE was not detected in the liquor. The AChE test has been positive in five other cases where other clinical data had suggested open NTDs and where the diagnosis was confirmed after termination. In one pregnancy, terminated with raised AFP and AChE in the liquor, the fetus had a massive exomphalos. In Middlesbrough we have recently introduced testing of liquor
amnii for AChE as well as AFP as part of our routine screening programme for the prenatal diagnosis of NTDs. Our early experience with this test when used prospectively is most favourable. We feel that it is a useful additional test which has increased our diagnostic accuracy. Ray Garry John Atkins S. J. Richardson Brian Webb Departments of Obstetrics and Gynaecology and of Chemical Pathology Middlesbrough General Hospital Middlesbrough, Cleveland TS5 5AZ
References 1. BarnesPJ, KarlinerJS, Hamilton CA, DolleryCT. Demonstrationof cq-adrenoceptors in guinea pig lung using aH-prazosin. Life Sci 1979; 25:1207-14. 2. BarnesPJ, KarlinerJS, DolleryCT. Human lung adrenoceptorsstudied by radioligandbinding. Clin Sci 1980; 58:457-61. 3. Bames PJ, Dollery Cq', MacDermot J. Increased pulmonary c~adrenergic and reduced~-adrenergicreceptors in experimentalasthma. Nature 1980; 285:569-71. 4. Graham RM, Pettinger WA. Prazosin. N. Engl J Med 1979; 300:232-36. 5. Barnes PJ, Ind P, Dollery CT. Inhaled prazosin in asthma, Thorax 1980, 35:239. 6. Jordan JA, SymmondsEM, eds. The diagnosis and management of neural tube defects. London: Royal College of Obstetricians and Gynaecologists, 1978. 7. Buamah PK, Evans L, Milford-Ward A. Amniotic fluid acetylcholinesterase isoenzymepatterns in the diagnosisof neural tube defects. Clin Chim Acta 1980; 103:147-51. 8. Wald NJ, Cuckel HS, Barlow RD, Smith AD, Stirrat GM, Tumbull AC, BorrowM, Brock DJH. Early antenatal diagnosisof exomphalos. Lancet 1980; i:1368-69. 9. Smith AD, Wald NJ, Cuckel HS, Stirrat GM, Borrow M, Lagercrantz H. Amniotic-fluidacetylcholinesteraseas a possiblediagnostictest for neural tube defects in early pregnancy. Lancet 1979; ii:685-88.
foreign-body-type giant cells were seen in the first specimen.
Discussion Primary intradural hydatid cysts are uncommon. AranaIniguez [1] commented that in virtually all cases of hydatid disease in the spine, compression of the spinal cord and intraspinal nerve roots is caused by hydatid material from an affected vertebra. D6v6 [4] claimed that in the literature there were no well-documented cases without bony involvement. Dew [5] pointed out the theoretical possibility of primary epidural or intradural lesions. In the first case, reported by Carrea and Murphy [3], the authors themselves noted that it was debatable whether the cyst originated in the arachnoid membrane or in white matter near the surface of the spinal cord. The case of Ley and Marti [6] was an example of a true intramedullary hydatid cyst. D6v~'s [4] theoretical suggestions that when a cyst developed in such a small organ as the spinal cord, it would be single and small, occurring in young adults and producing its symptoms over a short period (a few months), were supported by the features shown in these 2 cases [3, 6] and partly by features in our patient, except that the cysts were multiple. This may be explained by the hypothesis of possible rupture of a cyst because of pressure changes during a previous lumbar puncture. In our patient the discovery of cysts during
237
laminectomy was the only evidence of hydatid disease in the patient. There was no evidence of any pathology of the spine, and there was no clinical evidence of other visceral hydatid disease. Ley and Marti [6], to explain the intradural location of the cyst secondary to a pulmonary location, as seen in their patient, postulated that the parasite embryo circulating in the bloodstream enters through an intercostal artery. It is difficult to explain an isolated intradural location of multiple hydatid cysts, as seen in our patient. Up to the present time there has been no clinical evidence of hydatid disease in our patient, either in the vertebral column or in a visceral location, prompting us to report this case as a primary intradural hydatid cyst.
References 1. Arana-lniguez R: Echinococcus, in Vinken PJ, Bruyn GW (eds): Handbook of Clinical Neurology. Amsterdam, Oxford: North Holland, 1978, Vol 35, p 193 2. Arana-lniguez R: Hydatid echinococcosis of the nervous system, in Spillane JD (ed): Tropical Neurology. London: Oxford University, 1973, pp 413-414 3. Carrea R, Murphy G: Primaryhydatid cyst of the spinal cord. Acta Neurol Lat Am 10:308-312, 1964 4. l~v~ F: L'6chinococcoseosseuse. Montevideo:A. Monteverde& Cia, 1948 5. Dew HR: Hydatid disease. Sydney: Australia Medical Publication, 1928 6. Ley A Jr, Marti A: Intramedullaryhydatid cyst. J Neurosurg 33:45"t459, 1970
Editorial Note: Meningomyelocele and Other Defects One of the areas where improvement is badly needed is in the prevention of cerebral and spinal congenital defects, such as meningomyelocele. Although as yet there is no definite evidence as to the etiology of these malformations in humans, it has now become possible to detect such defects in the developing fetus of pregnant women who suffer a high risk of having a child with such a malformation. These defective fetuses can then be aborted to the advantage of all concerned, including the child. A recent letter in the Lancet (1:391, 1981) presents the results of a study regarding the tests on maternal serum and amniotic fluid. With the permission of the authors and of Lancet, the letter is reproduced here for the information of those readers of Surgical Neurology who may not have seen the original.
Paul C. Bucy, M.D., Editor
Role of Amniotic Fluid, Acetylcholinesterase in Screening for Neural Tube Defects SIR,--The measurement of maternal serum alpha-fetoprotein
(AFP) followed by ultrasonography and estimation of amniotic fluid AFP has proved a useful way of diagnosing fetuses affected by neural tube defects (NTD) and of providing indications for termination [6]. Occasionally, however, these tests give conflicting or equivocal data and this poses problems for the clinician. Acetylcholinesterase (ACHE) of fetal origin is not detected in the liquor amnii of normal pregnancies by gel electrophoresis [7] but it is detected in pregnancies affected by open NTDs [8] and in some cases of fetal exomphalos [9]. Retrospective studies [7, 9] have suggested that this estimation may be a useful adjunct to the AFP level in diagnosing NTDs. We describe two cases in which the AChE test gave information to complement that obtained from AFP estimations and ultrasonography and substantially influenced the management of the case. Case I . - - A 25-year-old patient had a serum AFP at 16 weeks' gestation of 170 U/ml (5.3 x the median for that gestation). A repeat specimen 1 week later gave a value of 160 U/ml (4.4 × median). Concentrations above 2.5 x the median are indications
238
Surgical Neurology Vol 16 No 3 September 1981
for further investigation. Uhrasonography indicated a possible open NTD and the biparietal diameter was 5.4 cm (equivalent to a gestation of 21 weeks as against a clinical dating of 18 weeks) and the cerebral ventricles were dilated. The amniotic fluid AFP was 7,000 U/ml × (normal up to 20,000 U/ml). A repeat ultrasonogram 2 weeks later showed abnormally rapid growth of the biparietal diameter with a proportionately greater growth in the size of the ventricles and confirmed the NTD. AChE was found in the liquor. These findings were taken to indicate a pregnancy which, despite a normal amniotic fluid AFP, was affected by both hydrocephalus and spina bifida. The pregnancy was terminated and this diagnosis was confirmed. Case 2. --This 25-year-old woman had semm-AFP values of 90 U/ml (2.5 × median) at 16 weeks and 150 U/ml (3.6 × median) at 18 weeks. An uhrasonogram confirmed the gestation and excluded obvious skeletal abnormality. The amniotic fluid AFP at 18 weeks was 37,000 U/ml (levels over 20,000 requiring further investigation). A third semm-AFP was 250 U/ml (6.0 × median). AChE was not detected in the liquor. Despite the abnormal and increasing semm-AFP and the raised liquor AFP this pregnancy was not terminated. The negative AChE test and normal scan raised doubts about the presence of a lesion. 21 weeks later a normal male baby weighing 4.2 kg was delivered. The raised AFP levels remain unexplained. In another case, a 21-year-old patient had a first serum AFP of 130 U/ml (2.9 x median) and the result of a second test was 180 U/ml (3.6 x median). Serial ultrasonograms suggested hydrocephalus and the possibility of a lumbar spina bifida. The amniotic fluid AFP value was marginal (24,000 U/ml). The pregnancy was terminated. The hydrocephalus was confirmed but there was no spina bifida. The fetus did have an extensive cleft lip and palate, and this lesion probably accounted for the AFP. Retrospectively AChE was not detected in the liquor. The AChE test has been positive in five other cases where other clinical data had suggested open NTDs and where the diagnosis was confirmed after termination. In one pregnancy, terminated with raised AFP and AChE in the liquor, the fetus had a massive exomphalos. In Middlesbrough we have recently introduced testing of liquor
amnii for AChE as well as AFP as part of our routine screening programme for the prenatal diagnosis of NTDs. Our early experience with this test when used prospectively is most favourable. We feel that it is a useful additional test which has increased our diagnostic accuracy. Ray Garry John Atkins S. J. Richardson Brian Webb Departments of Obstetrics and Gynaecology and of Chemical Pathology Middlesbrough General Hospital Middlesbrough, Cleveland TS5 5AZ
References 1. BarnesPJ, KarlinerJS, Hamilton CA, DolleryCT. Demonstrationof cq-adrenoceptors in guinea pig lung using aH-prazosin. Life Sci 1979; 25:1207-14. 2. BarnesPJ, KarlinerJS, DolleryCT. Human lung adrenoceptorsstudied by radioligandbinding. Clin Sci 1980; 58:457-61. 3. Bames PJ, Dollery Cq', MacDermot J. Increased pulmonary c~adrenergic and reduced~-adrenergicreceptors in experimentalasthma. Nature 1980; 285:569-71. 4. Graham RM, Pettinger WA. Prazosin. N. Engl J Med 1979; 300:232-36. 5. Barnes PJ, Ind P, Dollery CT. Inhaled prazosin in asthma, Thorax 1980, 35:239. 6. Jordan JA, SymmondsEM, eds. The diagnosis and management of neural tube defects. London: Royal College of Obstetricians and Gynaecologists, 1978. 7. Buamah PK, Evans L, Milford-Ward A. Amniotic fluid acetylcholinesterase isoenzymepatterns in the diagnosisof neural tube defects. Clin Chim Acta 1980; 103:147-51. 8. Wald NJ, Cuckel HS, Barlow RD, Smith AD, Stirrat GM, Tumbull AC, BorrowM, Brock DJH. Early antenatal diagnosisof exomphalos. Lancet 1980; i:1368-69. 9. Smith AD, Wald NJ, Cuckel HS, Stirrat GM, Borrow M, Lagercrantz H. Amniotic-fluidacetylcholinesteraseas a possiblediagnostictest for neural tube defects in early pregnancy. Lancet 1979; ii:685-88.