Review Question - QID 214535

This patient likely has post-traumatic syringomyelia as demonstrated by the characteristic bilateral pain and loss of sensation at the C8-T1 distribution. This is due to damage of the anterior white commissure of the spinothalamic tract.

Syringomyelia describes a fluid-filled cavity within the spinal cord that often occurs between C2-T9. It is most commonly associated with Chiari malformation type I; however, other conditions including infections, inflammation (e.g., transverse myelitis), neoplasms, and trauma can also cause syringomyelia. Due to its location at the intramedullary cavity, syringomyelia leads to damage of the anterior white commissure of the spinothalamic tract. Patients may present asymptomatically with incidental findings on imaging studies. Others may present with loss of pain and temperature and sometimes bowel and bladder deficits depending on its location. It is worth noting that some patients may experience progressive pain and weakness later in the disease course due to neuropathic pain. Post-traumatic syringomyelia can develop within months to years following the initial trauma. Diagnosis is usually via magnetic resonance imaging (MRI), which typically shows the intramedullary cavity. Treatment is often supportive. Surgical options including cyst fenestration or shunt placement are indicated in patients with neurologic deterioration or intractable pain.

Incorrect Answers:
Answer 1: Collection of infectious material at the epidural space describes a spinal epidural abscess. Risk factors include epidural catheters, diabetes, alcoholism, HIV infection, bacteremia, and intravenous drug use. Bacteria can gain access to the site hematogenously or via direct inoculation. Patients commonly present with fever, general malaise, spinal pain, and neurologic deficits. This patient does not have a fever and only endorses pain at his upper extremities.

Answer 3: Demyelinating lesions at the central nervous system that are separated by space and time describes multiple sclerosis (MS). The disease is characterized by its relapsing and progressive nature and presents initially with clinically distinct episodes of central nervous system (CNS) dysfunction (e.g., optic neuritis or partial transverse myelitis). Although this patient’s pain and sensory deficit of the upper extremities may suggest transverse myelitis, he lacks previous episodes of CNS dysfunction to satisfy diagnostic criteria. In addition, this patient does not fit the demographic of MS, which often presents in patients in their late twenties or early thirties.

Answer 4: Entrapment of the median nerve at the carpal tunnel describes carpal tunnel syndrome. Patients often complain of pain, numbness, and tingling sensation at the thumb, index finger, and middle finger. Risk factors include obesity, repetitive wrist work, pregnancy, and rheumatoid arthritis. This patient’s symptoms (e.g., pain and decreased sensation at bilateral upper extremities) do not align with that of carpal tunnel syndrome.

Answer 5: Neuronal ischemia secondary to chronic hyperglycemia describes diabetic neuropathy. In a patient with poorly controlled diabetes, it is important to consider diabetic neuropathy as a differential diagnosis. Long nerve fibers are affected to a greater degree than shorter ones and therefore sensation and loss of reflexes first occur at the feet and extend upward in a glove-stocking distribution. It is therefore uncommon to see isolated sensory deficits in the bilateral upper extremities, as seen in this patient. In addition, the condition often occurs in conjunction with autonomic neuropathy, which can present with orthostatic hypotension or gastroparesis.

Bullet Summary:
Syringomyelia presents with pain and decreased sensation secondary to damage to the anterior white commissure at the spinothalamic tract.