Hi.
It is not a rule that if the 8th nerve (vestibulocochlear nerve) is weak, the 7th nerve (facial nerve) should be weak. This happens in a condition where either there is an infection or tumor in the area which is common to both nerves (Internal Auditory Canal). If someone does have a weakness of both the nerves, it must be evaluated in detail at the earliest.
Regards, Dr Aanchal A Mittal, Therapeia centre, Bangalore
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