The Relationship Between Idiopathic Acute Peripheral Facial Paralysis and Homocysteine Level in Adult Patients

Bell's palsy, also known as "acute facial palsy of unknown cause", is a common cranial neuropathy that characteristically causes facial muscle paresis or complete paralysis on one side, occurs suddenly and may progress over 48 hours. It is accompanied by postauricular pain, dysgeusia, subjective alteration of facial sensation, and hyperacusis. Bell's palsy accounts for 60-75 percent of all cases of facial palsy. It occurs in 7-40 cases per 100,000 people each year, and the prevalence is similar in both sexes. Its cause remains idiopathic, but it is strongly associated with certain viral infections, which cause neuritis leading to focal edema, demyelination, and ischemia. Although the exact pathogenesis of Bell's palsy is unknown and is considered idiopathic, specific immune, ischemic, and hereditary factors are strongly associated with its etiology. Homocysteine is an amino acid that is not provided by the diet and can be converted to cysteine with the help of specific B vitamins or converted back to methionine, an essential amino acid. Homocysteine levels vary between men and women and are usually in the normal range of 5 to 15 micromoles/L. When homocysteine levels exceed 15 micromoles/L, it is called hyperhomocysteinemia.

The estimated prevalence of mild hyperhomocysteinemia in the general population is 5% to 7%. Several studies have shown that it is an independent risk factor for thrombotic disorders (i.e., deep vein thrombosis). It has even been reported that lowering a patient's homocysteine level by 25% reduces the risk of stroke by 19%.

A significant relationship was found in the meta-analysis conducted in the literature regarding sudden sensorineural hearing loss and high homocysteine levels. Due to the similar anatomical location of the facial nerve and N. vestibulocochlearis, it was planned to examine the relationship between acute idiopathic peripheral paralysis and homocysteine. There is no previous study in the literature. Therefore, this study will be the pioneering research in the literature regarding blood homocysteine levels in patients diagnosed with Idiopathic Acute Peripheral Facial Paralysis.