Arachnoiditis is a rare and serious condition characterized by inflammation of the arachnoid, which is the middle layer of the meninges (the membranes that surround and protect the brain and spinal cord). Here’s a detailed description: ### **Symptoms:** – **Chronic Pain**: Often described as burning or stinging, this pain can be severe and is typically located in the lower back, legs, or feet. – **Nerve Issues**: Patients might experience numbness, tingling, or weakness in the lower limbs due to nerve root compression or irritation. – **Loss of Function**: Muscle spasms, loss of bladder or bowel control, and sexual dysfunction can occur due to nerve damage. – **Sensory Changes**: There might be an altered sensation or hypersensitivity to touch in the affected areas. ### **Causes:** – **Medical Procedures**: The most common cause is complications from spinal surgery, particularly if there’s exposure to contrast dyes used in myelograms, which can be toxic to the arachnoid membrane. – **I