Genetic Hearing Loss: This is often the most common cause of bilateral sensorineural hearing loss in young adults, especially if there's a family history. Many forms of genetic hearing loss are not associated with other systemic findings or abnormalities on imaging, including MRI.

Ototoxicity: Exposure to certain medications (like aminoglycosides, cisplatin) or chemicals can cause bilateral sensorineural hearing loss. A detailed history of medication and chemical exposure is crucial.
Infectious Causes: Conditions such as congenital infections (e.g., rubella, CMV) can lead to sensorineural hearing loss, though these are more commonly identified in infancy or early childhood.
Autoimmune Inner Ear Disease: An autoimmune condition where the body's immune system attacks the inner ear, leading to hearing loss. This can be a consideration in young adults without a clear family history of hearing loss.

Neurosyphilis: Although less common, syphilis can cause sensorineural hearing loss among other neurological symptoms. Given the potential for serious complications if left untreated, it's crucial to consider and rule out syphilis with appropriate testing.
Sarcoidosis: This systemic disease can affect the inner ear and cause hearing loss. It's essential to consider sarcoidosis due to its potential for multi-organ involvement and the need for specific treatment.

Usher Syndrome: A genetic disorder characterized by sensorineural hearing loss and retinitis pigmentosa, leading to progressive vision loss. It's rare but important to consider due to its significant impact on quality of life.
Pendred Syndrome: Another genetic condition associated with sensorineural hearing loss and thyroid abnormalities. It's less common but should be considered, especially if there are thyroid function abnormalities.
Mitochondrial Disorders: Certain mitochondrial disorders can cause sensorineural hearing loss, among other systemic symptoms. These are rare but can have significant implications for family planning and management.