FND is either Focal Neurological Deficit or Functional Neurological Disorder.
In spine exams and emergency evaluations, FND usually stands for Focal Neurological Deficit (frequently noted as “no FND” or “+FND”). This refers to localized loss of nerve function corresponding to a specific spinal nerve root in the lower back (lumbar radiculopathy or cauda equina syndrome).
Key signs evaluated during a lumbar exam include:
Motor weakness: Difficulty lifting the foot/toes (foot drop, L4/L5) or pushing down through the toes (S1).
Sensory loss: Numbness, tingling, or diminished sensation mapped to a specific dermatome along the thigh, leg, or foot.
Reflex changes: Diminished or absent patellar (knee jerk, L4) or Achilles (ankle jerk, S1) deep tendon reflexes.
Cauda equina signs: Perianal numbness (“saddle anesthesia”) or acute loss of bowel/bladder control, representing a surgical emergency.
Functional Neurological Disorder
FND can also stand for Functional Neurological Disorder. In relation to the spine:
It describes neurological symptoms (such as leg weakness, altered gait, or numbness) that stem from a problem with how the nervous system sends and receives signals, rather than structural compression or irreversible physical nerve damage.
It can be triggered by acute lumbar spine injuries, severe back pain, or the stress of spinal surgery.
Symptoms typically do not follow standard anatomical nerve pathways (non-dermatomal) and are diagnosed via positive clinical signs (such as Hoover’s sign for functional leg weakness).
Whether FND requires surgery depends entirely on which medical definition applies to your situation.
How do I avoid lumbar spinal fusion surgery?
The L5-S1 spinal motion segment, also called the lumbosacral joint, is the transition region between the lumbar spine and sacral spine in the lower back. In this region, the curvature of the spine changes from lumbar lordosis (forward curve) to sacral kyphosis (backward curve). L5-S1 helps transfer loads from the spine into the pelvis and legs.
The L5-S1 motion segment has distinctive anatomy and receives a higher degree of mechanical stress and loads compared to the segments above.
These characteristics may make L5-S1 susceptible to traumatic injuries, degeneration, disc herniation, and/or nerve pain.
Several structures in the lumbar spine can cause lower back pain, including the nerve roots that exit the spine, facet joints, intervertebral discs, vertebral bones, and the spinal muscles.
Facet joint instability can lead to disc degeneration, which in turn can compress or irritate the nerve roots.
Over 23 years ago, I was told I was too young for spinal fusion surgery, frustrated and in pain I discovered that they were doing disc replacement surgery in Germany and had been doing it for years.
My journey to eliminate my pain took me to Stenum hospital in Germany, where I received an artificial disc replacement at L4-5.
Are you eligible for disc replacement or do you need fusion?
Determining whether you are eligible for artificial disc replacement or require a fusion depends on a formal evaluation of your imaging and spine stability.
Where can I get more information about disc replacement surgery?
For Dedicated Patient Portals & Remote MRI Reviews go to betterdiscreplacement.com
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