Lipomyelomeningocele

Lipomyelomeningocele is a condition in which an abnormal growth of fat attaches to the spinal cord and its membranes.

Lipomyelomeningocele arises from an event very early in an embryo’s development. About the third week after conception, a sheet of cells called the neural plate folds to form a tube called the neural tube. The top of the neural tube becomes the brain, and the rest of the tube becomes the spinal cord. Lipomyelomeningocele occurs when an error in the closure of the neural tube allows a type of cell called mesenchyme to contact the inside of the neural tube. These cells prevent the tube from closing properly, disrupting the formation of meninges (membranes, or coverings) and bones around the spinal cord.

Wherever the mesenchymal cells touch the outside of the neural tube, they develop into spinal meninges as usual. Everywhere else, they develop into fat cells. The end result is a fatty growth called a lipoma that begins in or near the spinal cord, connects with the meninges, and extends past the bones of the spinal canal to form a pad of fat beneath the skin.

Symptoms

• When lipomyelomeningocele causes symptoms, they are usually due to pressure or pulling on the tethered spinal cord. Symptoms can include problems with bowel and bladder function, frequent urinary tract infections, spasticity, back and leg pain, muscle weakness or sensory loss in the legs, neuromuscular scoliosis, foot and leg orthopedic abnormalities, and difficulty walking.
• As many as half of the infants and children diagnosed with lipomyelomeningocele have no neurological symptoms at the time of diagnosis.