Diffuse idiopathic skeletal hyperostosis

Diffuse idiopathic skeletal hyperostosis (DISH) is a disease of the ligamentous apparatus of the spine. The cause of DISH is unknown. The sign of the disease is continuous ossification of the ligamentous structures of the spine, which extends to at least three vertebral spaces. Most often, diffuse idiopathic skeletal hyperostosis develops in the thoracolumbar region, but can also affect the cervical spine, ribs and pelvic bones.

Diffuse idiopathic skeletal hyperostosis causes stiffness and pain in the cervical and thoracolumbar spine. Symptoms are worse on awakening and at night. When the disease affects the cervical spine, cervical myelopathy may develop. Dysphagia may occur when the anterior structures of the cervical spine are involved. Diffuse idiopathic skeletal hyperostosis occurs in people in their 50s and 60s. It can also cause spinal stenosis with inhermitting claudication. Men are affected twice as often. The disease affects Caucasians more often. Patients with DISH are more likely to have diabetes, hypertension, and obesity than the general population. Diffuse idiopathic skeletal hyperostosis is usually diagnosed by spinal radiography.

[ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ], [ 6 ]

Symptoms of diffuse idiopathic skeletal hyperostosis

Patients with DISH complain of stiffness and pain in the area of the affected spinal segment or bone. Patients may also notice numbness, weakness, and loss of coordination in the limbs innervated by the affected segment. Muscle spasms and back pain radiating to the affected area are common. Sometimes, patients with DISH experience compression of the spinal cord, nerve roots, and cauda equina, leading to myelopathy or cauda equina syndrome. Diffuse idiopathic skeletal hyperostosis is the second most common cause of cervical myelopathy after cervical spondylosis. Patients suffering from lumbar myelopathy or cauda equina syndrome experience varying degrees of weakness in the lower limbs and symptoms of bladder and bowel dysfunction, which is a neurosurgical emergency requiring appropriate treatment.

Survey

Diffuse idiopathic skeletal hyperostosis is diagnosed by radiography. The pathognomonic symptom is continuous ossification of the ligamentous structures of the spine, spreading to at least 3 segments. The height of the intervertebral disc is preserved. If myelopathy is suspected, MRI provides the clinician with the most complete information about the condition of the spinal cord and spinal roots. MRI is highly reliable and helps to identify other pathologies that can expose the patient to the risk of developing irreversible spinal cord damage. For patients who are contraindicated for MRI (the presence of pacemakers), CT or myelography is indicated as a second choice. Radionuclide bone examination or radiography is indicated if fractures or bone pathology are suspected.

These tests provide the clinician with useful information about neuroanatomy, and electromyography and nerve conduction velocity studies provide neurophysiological data that can establish the current status of each nerve root and lumbar plexus. Laboratory tests, including a complete blood count, ESR, and blood chemistry, should be performed if the diagnosis of diffuse idiopathic skeletal hyperostosis is in doubt.

Complications and diagnostic errors

Failure to accurately diagnose diffuse idiopathic skeletal hyperostosis may expose the patient to the risk of developing myelopathy, which, if untreated, may progress to paraparesis or paraplegia. Electromyography helps differentiate plexopathy from radiculopathy and diagnose coexisting entrapment neuropathy, which may confound the diagnosis.

Given the association of diffuse idiopathic skeletal hyperostosis with multiple myeloma and Paget's disease, these potentially life-threatening conditions must be included in the differential diagnosis. Diffuse idiopathic skeletal hyperostosis may coexist with degenerative arthritis and discogenic disease. Each disease requires its own specific treatment.

[ 7 ]

Differential diagnosis of diffuse idiopathic skeletal hyperostosis

Diffuse idiopathic skeletal hyperostosis is a radiographic diagnosis that is confirmed by a combination of history, physical examination, and MRI. Pain syndromes that may mimic diffuse idiopathic skeletal hyperostosis include neck and low back strains, inflammatory arthritis, ankylosing spondylitis, and diseases of the spinal cord, roots, plexuses, and nerves. 30% of patients with multiple myeloma or Paget's disease have DISH. Laboratory testing that includes a complete blood count, erythrocyte sedimentation rate, antinuclear antibodies, HLA B-27 antigen, and serum chemistry panel should be performed to exclude other causes of pain if the diagnosis of diffuse idiopathic skeletal hyperostosis is in doubt.

[ 8 ], [ 9 ], [ 10 ], [ 11 ]

Treatment of diffuse idiopathic skeletal hyperostosis

In the treatment of diffuse idiopathic skeletal hyperostosis, a multi-component approach is most effective. Physical therapy, including heat treatments, moderate exercise and deep relaxing massage in combination with NSAIDs and muscle relaxants (eg, tizanidine) are the most preferred initial treatment. In case of persistent pain, epidural blocks are indicated. In the treatment of underlying sleep disorders and depression, tricyclic antidepressants such as amitriptyline are most effective, treatment with which can be started with 25 mg at night.