[Dysphagia] Trigeminal

[eripley at yahoo.com (Irene Campbell-Taylor)]

I believe there was a question recently about the influence of damage to the trigeminal ans swallowing. Since one branch innervates the mylohyoid, then the swallow, at least unilaterally may be impaired:
   
            mylohyoid
    mylohyoid line of mandible
    midline raphe and body of the hyoid bone
    elevates the hyoid bone and the tongue; depresses the mandible
    mylohyoid nerve from the inferior alveolar nerve, a branch of the mandibular division of the trigeminal nerve (V)
    the nerve to mylohyoid also innervates the anterior belly of digastric m.; both muscles are derivatives of the second pharyngeal arch

   
  Trigeminal motor nerve conduction: deep temporal and mylohyoid nerves. 
  Muscle Nerve. 1996 Mar;19(3):277-84.
  Dillingham TR, Spellman NT, Chang AS.
  Walter Reed Army Medical Center, Washington, DC, USA.
  This article describes nerve conduction studies of the deep temporal nerve (DTN) and the mylohyoid nerve (MHN) motor branches of the trigeminal nerve. These nerves were stimulated intraorally with a pediatric surface stimulator. Compound muscle action potentials were recorded over the temporalis and mylohyoid muscles with surface electrodes. Forty-two subjects were studied. In all subjects the MHN response was elicited bilaterally, giving an upper latency limit of 2.3 ms. The mean MHN amplitude was 4.9 mV (SD = 1.8 mV, minimum = 1.3 mV). The maximal side-to-side amplitude difference was 0.4 ms. and the maximal side-to-side amplitude difference was 2.2 mV. The DTN response was only elicited bilaterally in 25 (60%) subjects. The average DTN latency was 2.1 ms (SD = 0.3, maximum = 2.7 ms). The average DTN amplitude was 4.3 mV (SD = 2.0, minimum = 0.3 mV). The MHN responses were the least technically demanding, and were more consistently elicited than the DTN responses. These
 nerve conduction techniques should prove useful in patients with trigeminal nerve disorders.
   
  
   


Dr I Campbell-Taylor
Clinical Neuroscientist
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