Prenatal Diagnosis of Diastematomyelia in a 15-Week-Old Fetus

MRI Characteristics of Split Cord Malformation

Split cord malformation (SCM), a subtype of spinal dysraphism, represents a rare entity of congenital malformation in the spine that occurs rarely in adults. SCM commonly presents with back pain. MRI is the gold standard for diagnosis. We report a case of a previously healthy 25-year-old woman who presented with lower back pain for a duration of 6 months. MRI confirmed a diagnosis of type I SCM. This case highlights the neuroimaging characteristics of SCM, although it might remain asymptomatic for many years. Surgical intervention might not be indicated in case of absent clinical complications.

The Value of Prenatal Ultrasonographic Diagnosis of Diastematomyelia

OBJECTIVES

To evaluate the value of prenatal ultrasonographic diagnosis of diastematomyelia, and to provide a basis for the diagnosis and differential diagnosis of fetal diastematomyelia.

METHODS

Four fetuses with suspected diastematomyelia based on prenatal ultrasonography are presented. Detailed prenatal ultrasonography was performed to examine spinal cord abnormalities. The region of interest-based spine sagittal plane was defined and 3D volumetric scans were performed, as needed. Images were stored and compared with MRI or ultrasonographic images after abortion.

RESULTS

In the four cases of diastematomyelia diagnosed by prenatal ultrasonography, two were confirmed by MRI after birth, and the other two were confirmed by autopsy and pathologic examination after abortion. Varying degrees of spine or spinal cord deformities were noted. Two pregnancies were terminated, and two newborns underwent surgery.

CONCLUSIONS

Prenatal ultrasonography contributes to the diagnosis of diastematomyelia and provides a basis for prenatal counseling and prognosis.

Prenatal Evaluation of the Fetal Conus Medullaris on a Routine Scan

Objective: To assess the ability to identify the conus medullaris (CM) and measure the conus-sacrum distance (CS distance) on a routine scan and the relationship with maternal and fetal factors. Methods: This was a prospective study. The assessment of the CM and the CS distance and the influence of the body mass index (BMI), gestational age (GA) and fetal position were analyzed. The correlation between the femur length (FL) and the GA with the CS distance was evaluated. Results: A total of 696 fetuses were analyzed. The CM could be visualized in 82.3% of the cases, and the CS distance could be analyzed in 81.2% of the cases. The CM assessment was statistically associated with BMI and fetal position but not with GA. The CS distance assessment was statistically associated with BMI and GA but not with fetal position. We determined a significant association between the FL/CS distance and between the GA/CS distance. Conclusions: Assessment of the CM is possible on most routine scans. The CS distance could be introduced to routine scans for the assessment of prenatal skin-covered spinal dysraphism. High BMI, advanced GA and breech presentation could be potential factors limiting the feasibility of evaluating the CM.

Prenatal diagnosis of diastematomyelia: a case report and review of the literature

Diastematomyelia is a rare congenital disorder in which the spinal cord is divided longitudinally for part of its length. It can be accurately identified in the prenatal period by detailed sonographic examination of the spine. We report a case of diastematomyelia localized to spinal levels T6-T9 diagnosed prenatally at 31 weeks' gestation and review the existing literature on the diagnosis and management of this condition during pregnancy.

Prenatal diagnosis of diastematomyelia: presentation of eight cases and review of the literature

OBJECTIVES

Diastematomyelia is a rare form of spinal dysraphism. We present eight cases of diastematomyelia diagnosed prenatally in our institution as well as a review of the literature in order to determine the prognosis of isolated cases of this very unusual condition.

METHODS

Records of fetuses with diastematomyelia diagnosed in our institution between January 2000 and June 2005 were collected. All liveborn fetuses were examined by a pediatric neurologist. Pre- and postnatal data were analyzed. A search was then conducted using PubMed to review previously reported cases in the literature.

RESULTS

Eight cases of diastematomyelia were diagnosed during the study interval. The mean (range) gestational age at diagnosis was 21 (13-25) weeks. The main sonographic findings were widening of the spinal canal in the coronal view and an additional echogenic focus in the posterior part of the spinal column in the axial view. The diagnosis of associated open spina bifida was made in one fetus with elevated levels of amniotic fluid alpha-fetoprotein (AF-AFP) and acetylcholinesterase (AF-AChE) and the pregnancy was terminated. The other seven cases of diastematomyelia had normal levels of AF-AFP and AF-AChE and were considered isolated. One pregnancy miscarried spontaneously 1 week following amniocentesis and the remaining six were delivered at term. Review of the literature revealed 14 reports involving 26 cases of prenatally diagnosed diastematomyelia. Twelve cases had normal biochemistry and/or no additional abnormalities and all had a favorable outcome.

CONCLUSIONS

When diastematomyelia is not associated with other spinal anomalies, the prognosis is favorable. Prenatal diagnosis is generally made in the second trimester but sonographic signs may be recognized as early as the first trimester. Intrauterine diagnosis of diastematomyelia should facilitate appropriate management of affected cases.