Beware of Bells palsy in children as this may be the wrong diagnosis! It may actually be sclerosteosis (marble bone disease).
Bells palsy is a rare condition and is estimated to occur in 18- 20 per 100 000 children per year. It is characterized by the rapidly evolving initial facial paralysis, involving usually one side of the face. The face may still retain some function (paresis) which indicates a milder form of involvement of the facial nerve with a good outcome. Patients with a total loss of function (paralysis) are more likely to end up with a partial recovery.
Sclerosteosis (marble bone disease) can present in children with facial nerve palsy, mimicking Bells palsy. Facial nerve palsy is often the first presenting feature of sclerosteosis. It is common to recur and involve both sides of the face over time. Jerome Waterval, Dutch ENT, found that in 9 patients with sclerosteosis, facial nerve palsies occurred on 15 occasions.
Since sclerosteosis, also referred to as Hyperostosis cranialis interna, is a rare hereditary autosomal recessive genetic bone disorder it is often missed. It affects the skull base and causes narrowing of the bony canals which contains structures such as the hearing and facial nerves. Narrowing and pressure then causes facial nerve palsy, often misdiagnosed as Bells palsy.
Another common finding in patients with sclerosteosis is the presence of abnormal fingers and sometimes toes. Finger abnormalities include deviation, webbing, syndactyly and misformed nails.
The management of the acute facial paralysis in sclerosteosis is the same as Bells palsy. Later on surgical decompression of the facial nerve via the middle fossa may be indicated to prevent further attacks of facial nerve paralysis and avoid long term damage due to repeated attacks.
In the event that your child is diagnosed with Bells palsy make sure that the feet and hands are included in the examination and if uncertain ask to see an ENT specialist. A cone beam computed tomogram(CT) of the skull base will confirm the diagnosis and poses a very low risk for radiation, compared with conventional CT.
For further information regarding sclerosteosis follow the link to the Rare Bone Disease Foundation.
Rare Bone Disease Foundation
