syringomyelia

Syringomyelia is a disorder in which a syrinx, a fluid-filled cavity, forms within the spinal cord. The syrinx can expand and damage neural tissue, causing a characteristic loss of pain and temperature sensation in a cape-like distribution over the shoulders and arms. As it enlarges, weakness and wasting of hand muscles may occur, and if the syrinx extends to the brainstem it is called syringobulbia.

The condition can be primary or secondary. Secondary syringomyelia is associated with events that alter CSF dynamics or scar the surrounding tissues, such as Chiari I malformation, spinal trauma, tumors, arachnoiditis, or inflammatory conditions. Idiopathic syringomyelia refers to cases without an identifiable cause.

Symptoms vary with size and location of the syrinx. Common findings include dissociated sensory loss, weakness and atrophy of intrinsic hand muscles, chronic back or neck pain, and scoliosis in younger patients. Autonomic changes may include impaired sweating or bladder function.

Diagnosis relies on magnetic resonance imaging (MRI), which shows the syrinx and its extent and can reveal associated conditions such as Chiari malformation. CT myelography or additional studies may be used in selected cases.

Treatment aims to halt progression and treat underlying causes. Some patients are watched if asymptomatic. When CSF flow is disrupted, surgical options include decompression for Chiari malformation, syringostomy, or syringo-subarachnoid or syringo-peritoneal shunting. Physical therapy and pain management are supportive.

Prognosis varies; some patients experience stabilization for years, while others progress. Outcomes improve with early identification of treatable causes.