Review Question - QID 102582

Sensorineural hearing loss is expected. The patient's symptoms and laboratory findings are indicative of Paget's disease of bone, which is associated with sensorineural hearing loss.

The patient's symptoms such as right hip pain, elevated alkaline phosphatase with high bone fraction, and urinary markers indicate Paget's disease of bone. This is a localized disorder of bone remodeling that leads to enlarged and disorganized bone architecture. Paget's disease can lead to complications such as fractures, arthritis, and sensorineural hearing loss due to involvement of the temporal bone. Narrowing of the internal auditory meatus leads to compression of the vestibulocochlear nerve and subsequently to sensorineural hearing loss.

Schneider et al. report that while the most common symptom is pain in the affected bone, other common manifestations include neurologic, hearing, vision, cardiac, and oncologic complications. They report that the diagnosis is primarily made by radiographs and bisphosphonates are the most common treatment.

Dimitriadis et al. looked at the pathophysiology of hearing loss in patients with Paget's disease. They hypothesize that sensorineural hearing loss in patients with Paget's disease of the temporal bone may, in some cases, be attributed to obliteration of Cotugno's canal by remodeling pagetoid bone through obstruction of the venous drainage of the cochlea, with a subsequent effect on the function of stria vascularis and spiral ligament.

Illustration A displays a head CT in Paget's disease. Note the thickening of the skull.

Incorrect Answers:
Answer 1: Conductive hearing loss is less likely expected. Paget's disease of bone is more commonly associated with sensorineural hearing loss rather than conductive hearing loss.

Answer 2: He does not have familial hypophosphatemia. The patient's calcium and PTH levels are normal, ruling out a phosphate-related disorder.

Answer 3: His condition is not primarily caused by vitamin D deficiency. Vitamin D levels are normal, and Paget's disease is not primarily caused by vitamin D deficiency.

Answer 5: The disease is not reversible with treatment. Paget's disease is generally not reversible. Treatment aims to manage symptoms and prevent complications but does not cure the disease.

Bullet Summary:
Paget's disease of bone is associated with elevated alkaline phosphatase and can lead to complications such as sensorineural hearing loss due to narrowing of the internal auditory meatus leads to compression of the vestibulocochlear nerve.