What is the most severe form of spinal closure defect that results in loss of motor function and sensation in the lower body?

Meningomyelocele is indeed the most severe form of spinal closure defect among the options listed. This condition occurs when the spinal cord and surrounding nerve roots protrude through an opening in the vertebrae, leading to significant impairment. As a result, individuals with meningomyelocele often experience profound loss of motor function and sensation in the lower body, as the affected nerves are compromised.

The severity is due to the involvement of both the meninges (the protective coverings of the spinal cord) and the spinal cord itself, which can result in serious neurological deficits. Associated complications can include paralysis, developmental delays, and issues with bowel and bladder control.

Other conditions, such as meningocele, which involves only the covering of the spinal cord without nerve involvement, demonstrate fewer neurological impairments. Spina bifida occulta involves a small defect in the bony encasement of the spinal cord but typically does not impact the neural structures in the same way, thus leading to milder symptoms. Herniation generally refers to the displacement of tissue, such as a herniated disk, which affects nerve function but is not classified as a spinal closure defect. This distinction clarifies why meningomyelocele represents the most severe impact on motor function and sensation