Blink Reflex: Difference between revisions

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== Introduction ==
== Introduction ==
It is an electrodiagnostic test that is analogous to the clinically ubiquitous corneal reflex.<ref>Hartmann J.E. (2013) Blink Reflex. In: Kountakis S.E. (eds) Encyclopedia of Otolaryngology, Head and Neck Surgery. Springer, Berlin, Heidelberg. <nowiki>https://doi.org/10.1007/978-3-642-23499-6_904</nowiki></ref>
It is an electrodiagnostic test that evokes the corneal reflex.<ref name=":0">Hartmann J.E. (2013) Blink Reflex. In: Kountakis S.E. (eds) Encyclopedia of Otolaryngology, Head and Neck Surgery. Springer, Berlin, Heidelberg. <nowiki>https://doi.org/10.1007/978-3-642-23499-6_904</nowiki></ref> It evaluates the integrity of the trigeminal and facial nerve.
 
== Neuroanatomy ==
The supraorbital branch of the ophthalmic division of the trigeminal nerve constitutes the afferent arm, while the motor fibers of the facial nerve form the efferent arm of this reflex.<ref name=":1">Kimura J (2001) The blink reflex. In: Electrodiagnosis in diseases of nerve and muscle: principles and practice. Oxford University Press, New York</ref>
 
== Technique ==
The subject is supine with their eyes closed. The active electrode is placed over the orbicularis oculus while the reference electrode is placed over the chin or nose. The ground electrode can be placed over the forehead or at the nape of the neck.<ref name=":1" />
 
== Interpretation ==
Normally, as with the corneal reflex, the ipsilateral electrical stimulation of the trigeminal nerve will produce an eye blink bilaterally.<ref name=":1" />
 
== Indications ==
It is indicated in facial palsies (especially Bell's palsy), acoustic neuromas, brain stem lesions such as stroke or tumors, multiple sclerosis, and polyneuropathies like Guillain-Barre syndrome.<ref name=":0" />
 
== Contraindications ==
There are no absolute contraindications, but an uncooperative patient or post-operative wounds or dressings can hamper the test procedure.<ref name=":0" />
 
== Advantages ==
No effort is needed on the patient's end. Unlike traditional tests like the nerve conduction study, this test evaluates both the intracranial and extracranial sections of the trigeminal and facial nerve.<ref name=":0" />
 
== Disadvantages ==
For better accuracy, the patient must be completely relaxed and extend full co-operation. The stimulation of the supraorbital nerve can be quite painful for some.<ref name=":0" />


== References ==
== References ==
<references />
<references />

Revision as of 06:29, 29 August 2020

Original Editor - Arnold Fredrick D'Souza

Top Contributors - Arnold Fredrick D'Souza

Introduction[edit | edit source]

It is an electrodiagnostic test that evokes the corneal reflex.[1] It evaluates the integrity of the trigeminal and facial nerve.

Neuroanatomy[edit | edit source]

The supraorbital branch of the ophthalmic division of the trigeminal nerve constitutes the afferent arm, while the motor fibers of the facial nerve form the efferent arm of this reflex.[2]

Technique[edit | edit source]

The subject is supine with their eyes closed. The active electrode is placed over the orbicularis oculus while the reference electrode is placed over the chin or nose. The ground electrode can be placed over the forehead or at the nape of the neck.[2]

Interpretation[edit | edit source]

Normally, as with the corneal reflex, the ipsilateral electrical stimulation of the trigeminal nerve will produce an eye blink bilaterally.[2]

Indications[edit | edit source]

It is indicated in facial palsies (especially Bell's palsy), acoustic neuromas, brain stem lesions such as stroke or tumors, multiple sclerosis, and polyneuropathies like Guillain-Barre syndrome.[1]

Contraindications[edit | edit source]

There are no absolute contraindications, but an uncooperative patient or post-operative wounds or dressings can hamper the test procedure.[1]

Advantages[edit | edit source]

No effort is needed on the patient's end. Unlike traditional tests like the nerve conduction study, this test evaluates both the intracranial and extracranial sections of the trigeminal and facial nerve.[1]

Disadvantages[edit | edit source]

For better accuracy, the patient must be completely relaxed and extend full co-operation. The stimulation of the supraorbital nerve can be quite painful for some.[1]

References[edit | edit source]

  1. 1.0 1.1 1.2 1.3 1.4 Hartmann J.E. (2013) Blink Reflex. In: Kountakis S.E. (eds) Encyclopedia of Otolaryngology, Head and Neck Surgery. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-23499-6_904
  2. 2.0 2.1 2.2 Kimura J (2001) The blink reflex. In: Electrodiagnosis in diseases of nerve and muscle: principles and practice. Oxford University Press, New York