Bilateral thinning of the parietal bones, also known as biparietal osteodystrophy, is an uncommon, slowly progressive acquired disease of middle-aged people with a slight female predilection. It is typically an incidental finding.
Pathology
The aetiology is unknown but is thought to be an age-related process due to osteoporosis.
Microscopic appearance
On histologic examination, there is a lack of osteoclasts.
Radiographic features
Nuclear medicine
The bone scan usually shows well-defined areas of photopenia, which further supports the osteoporotic aetiology of this process.
Treatment and prognosis
In severe cases where the brain is exposed to atmospheric pressure, cranioplasty may be indicated.