Enhanced auditory postauricular evoked responses after corticobulbar lesions

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Clinical Neurology

Background:

• The auditory postauricular response is a microreflex originating in the posterior auricular muscle.
• This response exhibits two main components at 12 and 16 msec latencies.
• Recording requires tension in neck extensor or facial muscles, and is absent with relaxed scalp muscles.

Purpose of the Study:

• To investigate alterations in the auditory postauricular response following upper motor neuron lesions.
• To characterize the changes in this specific neurophysiological marker in response to neurological damage.

Main Methods:

• Recording of auditory postauricular responses.
• Evaluation of response characteristics under varying muscle tension conditions.
• Correlation of response changes with the presence of upper motor neuron lesions above the foramen magnum.

Main Results:

• Significantly enlarged auditory postauricular responses were observed.
• These enlarged responses occurred specifically after upper motor neuron lesions located above the foramen magnum.

Conclusions:

• Upper motor neuron lesions above the foramen magnum markedly enhance the auditory postauricular response.
• This enhanced response serves as a potential indicator for specific types of neurological damage.