Recess stenosis is a condition where a passage within the spinal canal narrows, compressing nerves. This narrowing often occurs in the lower back or neck. When these spaces constrict, nerves experience pressure, leading to various physical sensations. This condition can impact comfort and mobility, with symptoms often worsening if left unaddressed.
Anatomical Basis of Recess Stenosis
The spine provides a protective bony channel for the spinal cord and branching nerves. Within this channel, lateral recesses act as passageways for nerve roots exiting the spinal column. These recesses are located towards the sides, just before the neural foramina, the openings through which spinal nerve roots exit. This region is bordered by the pedicle laterally, the superior articular facet and ligamentum flavum posteriorly, and the vertebral body, endplate margin, and disc margin anteriorly.
The lateral recess is a funnel-shaped area, with its narrowest point typically at its cranial part, near the superior border of the pedicle. When this space constricts, it can directly impinge upon the nerve roots. Any reduction in space can compress the nerve, leading to discomfort and symptoms. This compression is often exacerbated by certain spinal movements, as the lateral recess volume can change with spinal position.
Common Causes and Risk Factors
Recess stenosis typically develops from degenerative spinal changes, often part of the natural aging process. As individuals age, intervertebral discs, facet joints, and other spinal structures undergo wear and tear.
Common causes include bone spurs (osteophytes), abnormal bone growths that can protrude into the lateral recess and compress nerves. These spurs often develop due to injury or degenerative conditions like osteoarthritis.
Another factor is the thickening of spinal ligaments, particularly the ligamentum flavum. This ligament can thicken and buckle inwards, encroaching on nerve root space. Bulging or herniated discs can also push into the lateral recess, directly compressing nerves. Facet joint arthritis further contributes to narrowing by causing inflammation and bone overgrowth. While age-related changes are the most frequent cause, genetic predispositions or previous spinal injuries can also increase susceptibility.
Identifying the Symptoms
Symptoms of recess stenosis arise from nerve root compression and vary based on severity and location. Pain is common, manifesting as a dull ache in the lower back or sharp, radiating pain down one or both legs, often called sciatica. Leg pain may be accompanied by cramping.
Neurological symptoms in affected limbs include numbness, tingling, or a “pins-and-needles” feeling in the legs or feet. Muscle weakness, particularly in the legs, can also occur as nerve compression progresses, affecting mobility and balance. Neurogenic claudication is frequently observed, characterized by leg pain, numbness, or weakness that worsens with walking or standing and improves with rest or leaning forward. Symptoms often intensify with activities that place further pressure on nerves, such as bending backward.
Diagnosis and Management Options
Diagnosis typically involves a review of medical history and a physical examination. During this examination, healthcare providers assess reflexes, muscle strength, and sensation to identify nerve compression. Imaging techniques confirm the narrowing’s presence and extent. Magnetic Resonance Imaging (MRI) visualizes the spine and nerve compression, while Computed Tomography (CT) scans and X-rays provide detailed images of bony structures and help rule out other conditions. Nerve tests, such as electromyography (EMG) or nerve conduction studies, may evaluate nerve function.
Management generally begins with conservative approaches to alleviate symptoms and improve function. Physical therapy is a common treatment, involving exercises to strengthen spinal muscles, improve flexibility, and reduce nerve impingement. Medications, including anti-inflammatory drugs and pain relievers, are often prescribed to manage discomfort. Epidural injections deliver anti-inflammatory medication directly to the affected area, providing temporary relief by reducing inflammation around compressed nerves.
If conservative treatments do not adequately relieve symptoms, surgical interventions may be considered. Procedures like laminectomy involve removing part of the vertebra to create more space for nerves. A foraminotomy may also enlarge nerve root exit openings. In some cases, microdiscectomy (removing a portion of a herniated disc) or spinal fusion (to stabilize vertebrae) might be necessary.