MRI scanning of the inner ear usually shows widened or large vestibular aqueducts with enlarged endolymphatic sacs and may show abnormalities of the cochleae that are known as Mondini dysplasia. Genetic testing to identify the pendrin gene usually establishes the diagnosis. If the condition is suspected, a "perchlorate discharge test" is sometimes performed. This test is highly sensitive, but may also be abnormal in other thyroid conditions. If a goitre is present, thyroid function tests are performed to identify mild cases of thyroid dysfunction even if they are not yet causing symptoms. Treatment
No specific treatment exists for Pendred syndrome. If thyroid hormone levels are decreased, thyroid hormone supplements may be required. Patients are advised to take precautions against head injury. References
External links
GeneReviews/NCBI/NIH/UW entry on Pendred Syndrome/DFNB4
NCBI Genes and Diseases
Irregular menstruation is a menstrual disorder whose manifestations include irregular cycle lengths as well as metrorrhagia (vaginal bleeding between expected periods). The possible causes of irregular menstruation may vary. The common factors of it are related to lifestyle, such as stress, body weight, and smoking status. Several studies indicate that COVID-19 vaccine of any type may disrupt the menstrual cycle, although only momentarily. This side effect should resolve on its own in the following month. Irregular cycles or periods
Irregular cycles or irregular periods is an abnormal variation in length of menstrual cycles. An individual usually experiences cycle length variations of up to eight days between the shortest and longest cycle lengths. Lengths ranging between eight and 20 days are considered moderately irregular. Variation of 21 days or more is considered very irregular.Alternatively, a single menstruation cycle may be defined as irregular if it is less than 24 days or more than 38 days. If they are regularly shorter than 21 days or longer than 36 (or 35) days, the condition is termed polymenorrhea or oligomenorrhea, respectively.Additionally, irregular menstruation is common in adolescence. A regular menstrual cycle can be set within a year of menarche. However, other studies suggest that it can take anywhere between 2 and 7 years to establish regularity after an individuals first menses. Other types
Other types of conditions that can be referred to by "irregular menstruation" include:

Metrorrhagia, which generally refers to vaginal bleeding that occurs between the expected menstrual periods. The distinction between irregular cycle lengths and metrorrhagia is not always clear.