Nervous system problems may occur in Pagets disease, resulting from increased pressure on the brain, spinal cord, or nerves, and reduced blood flow to the brain and spinal cord. When Pagets disease affects the facial bones, the teeth may become loose. Disturbance in chewing may occur. Chronic dental problems may lead to infection of the jaw bone. Angioid streaks may develop, possibly as a result of calcification of collagen or other pathological deposition.Pagets disease is not associated with osteoporosis. Although Pagets disease and osteoporosis can occur in the same patient, they are different disorders. Despite their marked differences, several treatments for Pagets disease are also used to treat osteoporosis. Causes
Viral
Pagets disease may be caused by a slow virus infection (i.e., paramyxoviridae) present for many years before symptoms appear. Associated viral infections include respiratory syncytial virus, canine distemper virus, and the measles virus. However, recent evidence has cast some doubt upon the measles association. Laboratory contamination may have played a role in past studies linking paramyxovirus (e.g. measles) to Pagets disease. Genetic
There is a hereditary factor in the development of Pagets disease of bone. Two genes, SQSTM1 and RANK, and specific regions of chromosome 5 and 6 are associated with Pagets disease of bone. Genetic causes may or may not involve a family history of Pagets disease.About 40–50% of people with the inherited version of Pagets disease have a mutation in the gene SQSTM1, which encodes a protein, called p62, that is involved in regulating the function of osteoclasts (bone cells).
Differential diagnosis
Treatment
Although initially diagnosed by a primary care physician, endocrinologists (internal medicine physicians who specialize in hormonal and metabolic disorders), rheumatologists (internal medicine physicians who specialize in joint and muscle disorders), orthopedic surgeons, neurosurgeons, neurologists, oral and maxillofacial surgeons, and otolaryngologists are generally knowledgeable about treating Pagets disease and may be called upon to evaluate specialized symptoms. It can sometimes be difficult to predict whether a person with Pagets disease, who otherwise has no signs or symptoms of the disorder, will develop symptoms or complications (such as a bone fracture) in the future. Medication
The goal of treatment is to relieve bone pain and prevent the progression of the disease. These medications are usually recommended for people with Pagets disease who:
have bone pain, headache, back pain, or a nerve-related symptom (such as "shooting" pains in the leg) that is directly associated with the disease;
have elevated levels of serum alkaline phosphatase (ALP) in their blood;
display evidence that a bone fracture will occur;
require pretreatment therapy for affected bones that require surgery;
have active symptoms in the skull, long bones, or vertebrae (spine);
have the disease in bones located next to major joints, placing them at risk of developing osteoarthritis;
develop hypercalcemia that occurs when a person, with several bones affected by Pagets disease and a high serum alkaline phosphatase level, is immobilized. Bisphosphonates
Five bisphosphonates are currently available. In general, the most commonly prescribed are risedronic acid, alendronic acid, and pamidronic acid. Etidronic acid and other bisphosphonates may be appropriate therapies for selected patients but are less commonly used.