Some favor therapy because of evidence that treated patients have improved neurobehavioral and muscle function, while others adopt a wait and see approach in the patient who has no obvious symptoms. If therapy is selected, a low dose of thyroxine should be prescribed, as these patients need only a partial supplement to restore TSH to normal. In most patients, the ultimate supplement dose will be 50 mcg or less. As the thyroid function continues to decrease, the replacement dose eventually increases. Therefore, an annual TSH test is advised.
Results are best when steroid and antiviral treatment is begun within three days of symptom onset.
For surgery, the window of opportunity is less than three weeks. There's convincing evidence that Bell's palsy, an acute peripheral facial weakness and paralysis, is related to a herpes simplex type I infection of the facial nerve. Current thinking is that fever blisters provide the initial route for the virus to gain access to the nerve and migrate to the ganglion, where it lies dormant until reactivated by unknown factors. The facial nerve runs through a bony canal in the skull between the brain and the face. In the meatal foramen, where the bony canal is the narrowest, the nerve takes up 99 percent of available space.