Review Question - QID 217747

This patient who presents with bilateral impaired pain and temperature sensation and decreased grip strength most likely has syringomyelia. Syringomyelia is associated with Arnold Chiari malformation I.

Syringomyelia refers to the presence of a cystic cavity within the spinal cord that disrupts the surrounding spinal cord tracts. The lesion typically is located in the central spinal cord, but may expand outwards. Therefore, the lateral spinothalamic tract is the first to be affected; however, in advanced disease, motor fibers can be affected. The lesion is most commonly located in the cervical spinal levels, though the thoracic and lumbar spinal cord can also be affected. Typical symptoms of cervical spinal cord syringomyelia include bilateral loss of pain and temperature sensation in a "cape-like" distribution (located over the bilateral upper extremities). In expanding lesions, bilateral areflexic paralysis can occur. The condition is associated with malignancy, trauma, scoliosis, Arnold Chiari malformation I (herniation of the cerebellar tonsils into the foramen magnum), and other disorders which disrupt the flow of cerebrospinal fluid (CSF). Treatment of syringomyelia typically involves surgery.

Holly and Batzdorf discuss the association between Arnold Chiari malformation I and syringomyelia and note that the prevalence of syringomyelia in patients with Chiari abnormalities is 69% in adults and 40% in children.

Incorrect Answers:
Answer 2: Herniation of the nucleus pulposus describes the pathophysiology of a herniated disc. Herniated discs lead to impingement of nerve roots and can present with radicular pain, most often affecting levels C6-7 and L5-S1. A herniated disc would be unlikely to cause bilateral symptoms affecting the spinothalamic tract (pain and temperature sensation).

Answer 3: Macrocytic anemia may occur in vitamin B12 deficiency, which can present with subacute combined degeneration. This syndrome can affect the spinocerebellar tracts, lateral corticospinal tract, and dorsal columns. Demyelination of these areas would present with deficits in vibration/proprioception sense and ataxia.

Answer 4: Superoxide dismutase mutations are seen in amyotrophic lateral sclerosis (ALS). ALS is a progressive neurodegenerative disease that leads to combined upper motor neuron (UMN) and lower motor neuron (LMN) deficits. ALS affects the dorsal horns and corticospinal tracts and leads to motor deficits, most commonly first noticed in the upper extremities.

Answer 5: Vitamin D deficiency is associated with multiple sclerosis (MS). MS presents with multiple neurologic deficits spread across space and time. Findings may include diplopia, urinary incontinence, optic neuritis, or sudden weakness.

Bullet Summary:
Syringomyelia is associated with Arnold Chiari malformation I, in which the cerebellar tonsils have herniated through the foramen magnum.