In this case report, a physical therapist recognized the need for emergency care for a patient with low back pain. The patient was a 38-year-old woman who was five and a half months pregnant. She was initially seen by her physician with a complaint of low back pain. The pain had come on without any known cause.
The medical exam was reportedly unremarkable. At the time of the physician’s exam, her symptoms were mild and common for a normal second trimester pregnancy. But when she arrived at the physical therapist’s clinic, she was unable to walk and was using a wheelchair to get around. This was a major downturn in her condition since the appointment with her physician.
The therapist recognized four red flags indicating a need for medical attention: 1) insidious onset (no known cause), 2) no diagnostic imaging was done, 3) symptoms had progressed (gotten worse) since she was last seen by her physician, and 4) symptoms of were present bilaterally (on both sides).
She had weakness, numbness, and tingling in both legs. She could not feel herself urinating, which is a sign of a cauda equina lesion. Deep tendon reflexes (test of neurologic function) were normal at the knee but absent at the feet.
Cauda equina syndrome is a serious neurologic condition. There is a sudden loss of function of the nerve roots of the spinal canal below the conus (end of the spinal cord). The spinal cord travels down the spine inside the spinal canal. The canal is a circular opening formed by the vertebral bodies.
The spinal cord ends around the first or second lumbar vertebra in most people. After that, there is a mass of nerves called the cauda equina. Translated literally, this means horse tail. As part of the cauda equina, nerve roots branch off from the spinal cord from L1-5 and S1-5.
Anything that compresses the function of the cauda equina can disturb the nerves. The most common problem leading to a cauda equina lesion is a central disc prolapse. This means the disc located between two vertebrae (in this case between L4 and L5) pushes straight back and presses on the spinal cord.
The therapist escorted this patient to the emergency department and requested a medical examination and lumbar magnetic resonance imaging (MRI) study. The results showed a disc protruding at the L4-L5 level. The disc was pressing on the cauda equina. All of her symptoms were from a cauda equina syndrome.
Immediate surgery was performed despite the pregnancy. The risk of permanent paralysis with this kind of problem is too great to treat progressive cauda equina in any other way. Surgery to remove the bulging disc (discectomy was done. No harm was done to the baby with the MRI or the surgery. The child was born six weeks after the discectomy without complications.