MR Signal Changes of Trigeminal Nuclei in a Case of Suspected Idiopathic Trigeminal Neuropathy in a Staffordshire Bull Terrier.
An 8-year 9-month old male Staffordshire bull terrier presented to the neurology department
of Dick White Referrals (Newmarket, UK) with a 4-day history of an inability to close the jaw,
excessive salivation and difficulty eating and drinking. On neurological examination, there was
a complete absence of jaw tone with normal visual and palpable temporal muscle mass.
On the T2 weighted images symmetrical, ill-defined hyperintensities within the pons at the level of the trigeminal nuclei were seen (Figure 1). These areas appeared isointense on T1W images. There was mild heterogeneous contrast enhancement of the trigeminal nerve and ganglion bilaterally (Figure 2), with no enhancement seen within the pons itself. No mass lesion or mass effect was seen with the remainder of the brain parenchyma unremarkable on all sequences. There was no evidence
of muscle atrophy or signal changes within the masticatory muscles. Regional lymph nodes appeared normal.
At follow-up with the owner 2 weeks later by phone call he was continuing to do well, with gradually returning function and strength of the jaw. The owners reported he still required assistance to eat and drink but was improving with significantly reduced hypersalivation. The owners had noticed significant atrophy of the masseter muscles bilaterally, however, he had only recently returned to chewing food. At this point, the dexamethasone was reduced to 0.04 mg/kg every 24 hours and all other medications stopped. At a further phone call 2 months after discharge, the owners reported that gradual improvement had continued and he had recently become clinically normal in their opinion.
Vet Med Open J. 2017; 2(1): 19-21. doi: 10.17140/VMOJ-2-112