Which of the following conditions is characterized by the destruction of facial nerve function in patients?

Malignant otitis externa is characterized by the destruction of facial nerve function due to the inflammation and infection associated with this condition. It is a severe infection of the external ear canal, commonly seen in immunocompromised individuals, such as those with diabetes.

The infection can extend into surrounding structures, particularly if it begins to affect cranial nerves, which may include the facial nerve, resulting in dysfunction. This can manifest as weakness or paralysis of the facial muscles on the affected side, a hallmark of facial nerve involvement.

In contrast, Huntington's disease is a genetic neurodegenerative disorder that primarily affects motor control and cognitive function but does not selectively destroy facial nerve function. Toxoplasmosis can affect the brain, particularly in immunocompromised patients, leading to neurological deficits, but it does not typically cause isolated facial nerve destruction. Amyotrophic lateral sclerosis is a progressive neurodegenerative disease that affects motor neurons generally, leading to muscle weakness and atrophy but is not associated with the specific destruction of the facial nerve function in the context of ear infections.

Thus, malignant otitis externa stands out as the condition most directly associated with the destruction of facial nerve function.