Syringomyelia is a disease characterized by progressive cavitation of the central canal, usually in the cervical spinal cord but may involve other cord regions. In the early stage of the disease, there is a bilateral loss of pain and temperature sensation in the hands and forearms as a result of the destruction of spinothalamic fibers crossing in the anterior white commissure. When the cavitation expands, lower motoneurons in the ventral horns are compressed, resulting in bilateral flaccid paralysis of upper limb muscles.
A late manifestation of syringomyelia is Horner syndrome, which occurs as a result of the involvement of descending hypothalamic fibers innervating preganglionic sympathetic neurons in the T1 through T4 cord segments. Many cases are associated with Chiari malformations (usually type I in which there is caudal herniation of the cerebellar tonsils exceeding 5 mm below the foramen magnum).
What are the Causes of Syringomyelia
- Congenital development (or idiopathic)
- Arnold-Chiari malformation
- Associated with tumors (intramedullary)
Clinical Features of Syringomyelia
- It is a chronic disorder that is very common in females.
- The age of onset is 3rd to 4th decade of life.
- Numbness in upper limbs with frequent burns and injuries that are painless.
- Later, spastic weakness in lower limbs with urinary bladder involvement occurs
- Physical findings that suggest central cord syndrome or syringomyelic syndrome are
- Bilateral loss of pain and temperature at the level of the lesion
- As the disease progresses, there is muscle weakness; eventually flaccid paralysis and atrophy of the upper limb muscles due to destruction of ventral horn cells
- Thoracic kyphoscoliosis
How is Syringomyelia diagnosed?
- Plain radiograph of the cervical spine may show widened cervical spinal canal and associated bony craniovertebral anomalies
- Myelograrn may show the widening of the spinal cord (rarely done).
- CT scan shows the widened cord.
- MRI is the most sensitive method. It shows fluid-filled cavitation and dilated central canal. MRI of the brain and entire spinal cord should be done.
- Surgical removal of obstruction of CSF flow, if any, along with syringo-subarachnoid shunt
- Decompression if indicated
Read more about Neuromuscular junction disorder.
- Medicine: Prep Manual for Undergraduates, 3/e