A. Hyperacusis – Explanation
Hyperacusis results from paralysis of the stapedius muscle. Overflow of tears may occur but
hyperlacrimation does not.
Facial nerve
Supply – ‘face, ear, taste, tear’
- face: muscles of facial expression
- ear: nerve to stapedius
- taste: supplies anterior two-thirds of tongue
- tear: parasympathetic fibres to lacrimal glands, also salivary glands
Causes of bilateral facial nerve palsy
- sarcoidosis
- Guillain-Barre syndrome
- polio, Lyme disease
Lower motor neuron
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Upper motor neuron
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