DEFINITIONS

Arachnoid: The cover or lining of the spinal cord is scientifically called the thecal sac or meninges. The inner layer is called the “Pia Mater”. It is extremely thin and fragile. The outer layer is the dura which is thick and firm. The arachnoid is the middle layer. It contains blood vessels and inflammatory cells and can become inflamed if irritated or damaged.

Arachnoiditis (ARC): ARC means inflammation of the arachnoid layer of the spinal canal covering or lining which can be caused by trauma, infection, toxins, or friction between the covering and spinal cord or nerve roots. ARC most commonly develops in the lumbar spine area, but it can also occur in the brain, cervical (neck), and thoracic spine.

Adhesive Arachnoiditis (AA): This condition is present when there are adhesions between the arachnoid-dural covering and nerve roots in the cauda equina.

Central Nervous System (CNS): CNS is the brain, spinal cord, and cauda equina nerve roots.

Cerebral Spinal Fluid (CSF): Fluid made in the brain that bathes, protects, and nourishes the spinal cord and brain.

Medication Dosage: Milligram is mg. Milliliter is ml.

Nerve Roots: The actual spinal cord runs from the brain down to the top of the lumbar area. Below the spinal cord hangs about 2 dozen string-like structures called nerve roots. Collectively they are called the cauda equina. The nerve roots can become damaged, inflamed, clump together, and stick or adhere by adhesions to the arachnoid layer of the spinal canal cover. When sticking and adhesions occur, the term AA is applied. If only enlargement, displacement, and clumping of nerve roots is seen on MRI, the term “cauda equina syndrome” is sometimes applied. Symptoms can be like AA.

Neuroinflammation (NI): NI is inflammation that occurs inside the CNS. It is the basic cause of AA that must be suppressed if an AA patient is to improve.

Neuroregeneration or Neurogenesis (NR): NR is regrowth of damaged nerve tissue, including nerve roots and supporting cells called glia.

Spinal Canal: The spinal canal is fundamentally a pipe that contains 4 components: (1) spinal cord; (2) nerve roots; (3) covering or lining called the meninges; and (4) cerebral spinal fluid. Think of the spinal canal as a closed pipe filled with structures bathed in fluid.

Tarlov Cysts: A cyst or outpouching of a spinal nerve root. They are often called “perineural” cysts. Tarlov cysts are frequently associated with ARC/AA.

Two Strategies for Treatment of AA: (1) medication and (2) physiologic measures.

Three Component Medical Treatment of AA: (1) suppression of neuroinflammation, (2) promotion of neuroregeneration, and (3) pain control.