Cervical myelopathy (CM) is primarily characterized by motor and sensory deficits, but it can indirectly cause dizziness. CM results from spinal cord compression in the neck, which disrupts the neural pathways connecting the neck to the body’s balance system. This unsteadiness occurs because the neck plays a significant role in the body’s overall balance system. The resulting symptoms of imbalance and lightheadedness are often termed cervicogenic dizziness.
Understanding Cervical Myelopathy
Cervical myelopathy arises when the spinal canal in the neck narrows, placing pressure on the spinal cord. This narrowing, known as spinal stenosis, is typically caused by age-related degeneration, such as discs losing height and the formation of bone spurs (osteophytes). This chronic compression disrupts the normal flow of nerve signals traveling up and down the spinal cord, leading to neurological dysfunction.
The classic symptoms of CM result from pressure on the long nerve tracts. Patients often experience a loss of fine motor skills, which manifests as difficulty performing tasks like buttoning a shirt or handling small objects. Gait instability, characterized by clumsiness or unsteadiness in walking, is also common, sometimes requiring a wider stance to compensate for poor balance.
Sensory changes are typical, often presenting as numbness, tingling, or paresthesia in the extremities. Patients may also exhibit hyperreflexia (exaggerated reflex response) or spasticity (abnormal muscle contractions). These symptoms tend to develop slowly and worsen over time.
Mechanism Linking Myelopathy and Dizziness
The link between CM and dizziness is attributed to the disruption of the body’s proprioceptive system. Proprioception is the sense of the body’s position in space, with sensory receptors in the neck joints and muscles constantly sending signals to the brain about the head’s orientation relative to the body.
Spinal cord compression interferes with the transmission of these signals, sending inaccurate information to the brain’s vestibular nuclei, the central hub for balance. This mismatch between visual, vestibular (inner ear), and cervical signals confuses the brain about the body’s true position. The resulting sensation is typically unsteadiness, disequilibrium, or lightheadedness, rather than true spinning vertigo.
Degenerative changes causing CM, such as severe bone spur formation, can also affect the vertebral arteries traveling through the cervical spine. These arteries supply blood to the brainstem and cerebellum, which are necessary for coordination and balance. Compromised blood flow, known as vertebrobasilar insufficiency, is less common but can cause true vertigo or other neurological symptoms.
Diagnosis and Confirmation
Diagnosing CM as the source of dizziness requires confirmation and exclusion. The initial step involves a thorough physical and neurological examination, where a physician looks for classic signs of myelopathy, including changes in reflexes, muscle weakness, and impaired coordination. A gait assessment, such as asking the patient to walk heel-to-toe (tandem walking), is performed to evaluate balance.
Imaging studies confirm structural compression of the spinal cord. Magnetic Resonance Imaging (MRI) is the preferred method, providing detailed visualization of soft tissues and the degree of spinal cord compression and any associated damage. X-rays and CT scans are also used to assess bone structure and spinal alignment.
A crucial part of diagnosis is ruling out other common causes of dizziness, particularly those originating in the vestibular system. Specialists like an otolaryngologist (ENT) may be consulted to exclude conditions such as benign paroxysmal positional vertigo (BPPV) or vestibular neuritis. Confirming cervicogenic dizziness due to CM is often a diagnosis of exclusion, reached after other causes have been investigated.
Treatment Approaches
Management of CM and associated dizziness focuses on relieving pressure on the spinal cord. For mild cases, non-surgical management aims to manage symptoms and slow progression. This typically includes physical therapy focused on improving posture, strengthening neck muscles, and using vestibular rehabilitation techniques for balance and gait training.
Anti-inflammatory medications may address neck pain and inflammation but do not resolve the underlying compression. For moderate to severe CM, or when neurological symptoms continue to decline despite conservative measures, surgical decompression is recommended. The goal is to mechanically remove the source of pressure on the spinal cord.
Surgical procedures may involve laminectomy, laminoplasty, or discectomy with fusion. Successful decompression halts the progression of neurological deficits and often improves symptoms, including dizziness and gait unsteadiness. Restoring space allows for better nerve signal transmission, which helps normalize proprioceptive information. Post-surgery rehabilitation, including dedicated balance training, is important for adjustment.