Rachischisis

Rachischisis (Greek: 'rhachis - ῥάχις' - spine, and 'schisis - σχίσις' - split) is a developmental birth defect involving the neural tube. This anomaly occurs in utero, when the posterior neuropore of the neural tube fails to close by the 27th intrauterine day. As a consequence the vertebrae overlying the open portion of the spinal cord do not fully form and remain unfused and open, leaving the spinal cord exposed. Patients with rachischisis have motor and sensory deficits, chronic infections, and disturbances in bladder function. This defect often occurs with anencephaly. Rachischisis (Greek: 'rhachis - ῥάχις' - spine, and 'schisis - σχίσις' - split) is a developmental birth defect involving the neural tube. This anomaly occurs in utero, when the posterior neuropore of the neural tube fails to close by the 27th intrauterine day. As a consequence the vertebrae overlying the open portion of the spinal cord do not fully form and remain unfused and open, leaving the spinal cord exposed. Patients with rachischisis have motor and sensory deficits, chronic infections, and disturbances in bladder function. This defect often occurs with anencephaly. Craniorachischisis is a variant of rachischisis that occurs when the entire spinal cord and brain are exposed - simultaneous complete rachischisis and anencephaly. It is incompatible with life; affected pregnancies often end in miscarriage or stillbirth. Infants born alive with craniorachischisis die soon after birth. Rachischisis occurs most commonly in utero during the development of the child. Rachischisis is a neural tube defect characterised by a complete or severe defect in the spine. The defect can be located anywhere from the cervical region to the sacrum, or through the entire length of the spine. Typical defects are clefts or splits that open the spine to the exterior environment. Rachischisis occurs around 3–4 weeks after conception when the posterior neuropore of the neural tube does not close completely. It is a multifactorial aetiology and is most typically accompanied by other defects. Rachischisis is often described as a severe form of spina bifida, with the spine not only being exposed to the exterior environment, but with the opening being large enough to allow the neural plate to spread out of the opening and to the surface. Initial diagnosis is typically by ultrasonography to reveal any congenital abnormalities. Fetuses affected typically show cranial abnormalities and deformities in brain tissue as well as spinal abnormalities. Following ultrasonography, magnetic resonance imaging (MRI) is commonly used to confirm the diagnosis. The presence of rachischisis is indicated in imaging by the absence of an arch-cranial line. Other neural tube defect diagnostic tools such as assays of α-fetoprotein or acetylcholinesterase may also be helpful in determining any other conditions that can lead to development of rachischisis. If a sibling of the fetus has been affected by rachischisis, there is increased risk that another child will develop the condition. There is also a slightly higher chance that females will develop the condition over males.