Referred Trigeminal Facial Pain from Occipital Neuralgia Occurring Much Earlier than Occipital Neuralgia

We report a very rare case in which a patient believed to have auriculotemporal neuralgia due to the repeated recurrence of paroxysmal stabbing pain in the preauricular temporal region for four years developed occipital neuralgia, which finally improved with decompression of the greater occipital nerve (GON). The pain of occipital neuralgia has been suggested to be referred to the frontoorbital (V1) region through trigeminocervical interneuronal connections in the trigeminal spinal nucleus. However, the reports of such cases are very rare. In occipital neuralgia, the pain referred to the ipsilateral facial trigeminal region reportedly also occurs in the V2 and V3 distributions in addition to that in the V1 region. In the existing cases of referred trigeminal pain from occipital neuralgia, continuous aching pain is usually induced, but in the present case, typical neuralgic pain was induced and diagnosed as idiopathic auriculotemporal neuralgia. In addition, recurrent trigeminal pain occurred for four years before the onset of occipital neuralgia. If the typical occipital neuralgia did not develop in four years, it would be impossible to infer an association with the GON. This case shows that the clinical manifestations of referred trigeminal pain caused by the sensitization of the trigeminocervical complex by chronic entrapment of the GON can be very diverse.

Reevaluation of reflex responses of the human masseter muscle to electrical lip stimulation

We examined the human masseter reflex response to electrical stimulation of lower lip to uncover realistic postsynaptic potentials in the trigeminal motor nucleus. We found that the stimulation generates a long-lasting single or compound inhibitory response that is followed by a late, long-lasting excitation. These findings have important implications on the redrawing of the neuronal pathways of the trigeminal nerve that are frequently used to judge neuromuscular disorders of the trigeminal region.

Dopamine D2/D3 imbalance during migraine attack and allodynia in vivo

Objective:To evaluate in vivo the dynamics of endogenous dopamine (DA) neurotransmission during migraine ictus with allodynia.Methods:We examined 8 episodic migraineurs and 8 healthy controls (HC) using PET with [11C]raclopride. The uptake measure of [11C]raclopride, nondisplaceable binding potential (BPND), would increase when there was a reduction in endogenous DA release. The opposite is true for a decrease in [11C]raclopride BPND. Patients were scanned twice: one PET session was during a spontaneous migraine ictus at rest, followed by a sustained thermal pain threshold (STPT) challenge on the trigeminal region, eliciting an allodynia experience; another was during interictal phase.Results:Striatal BPND of [11C]raclopride in migraineurs did not differ from HC. We found a significant increase in [11C]raclopride BPND in the striatum region of migraineurs during both headache attack and allodynia relative to interictal phase. However, when compared to the migraine attack at rest, migraineurs during the STPT challenge had a significant sudden reduction in [11C]raclopride BPND in the insula. Such directional change was also observed in the caudate of HC relative to the interictal phase during challenge. Furthermore, ictal changes in [11C]raclopride BPND in migraineurs at rest were positively correlated with the chronicity of migraine attacks, and negatively correlated with the frequency during challenge.Conclusions:Our findings demonstrate that there is an imbalanced uptake of [11C]raclopride during the headache attack and ictal allodynia, which indicates reduction and fluctuation in ictal endogenous DA release in migraineurs. Moreover, the longer the history and recurrence of migraine attacks, the lower the ictal endogenous DA release.

Some experience of trigeminal neuralgia treatment by glycerol rhizolysis

<p><strong>Aim.</strong> The study was to evaluate the advantages and disadvantages of trigeminal neuralgia treatment by Hakanson S. glycerol rhizolysis method. <br /><strong>Methods.</strong> The results of glycerol rhizolysis treatment were retrospectively evaluated in 96 patients with trigeminal neuralgia, who had been operated at Neurosurgical Department of Irkutsk City Hospital over a period from 2009 to 2016. To study the prospective follow-up, 53 patients operated during 2009 – 2014 were surveyed over the phone. The comparison of our long-term results and the results of other authors from literature sources was then performed.<br /><strong>Results.</strong> The median of follow-up period was 43 months. The pain recurrence (III-V rate of Barrow Neurological Institute score for trigeminal neuralgia) was observed in 30.2 % of patients, with the mean rate of the visual analogue scale amounting to 1.96. Complications included aseptic meningitis in 3.1 % cases, intracerebral hematoma – 1.04 %, hyperesthesia in appropriate trigeminal region – 3.8%, labial herpes – 40.7 %, temporary anesthesia in appropriate trigeminal region – 30.2%, temporary decrease of corneal reflex sensitivity – 41.5 %. There was no postoperative mortality.<br /><strong>Conclusion.</strong> Glycerol rhizolysis is an effective method of trigeminal neuralgia treatment and its results are comparable with those of other surgical methods. Strict adherence to all surgical steps and contrast cistenography is the key to success of intervention. The method is minimally invasive, applicable for anesthesia and particularly promising for patients over 70 years old.</p><p>Received 25 May 2016. Accepted 14 September 2016.</p><p><strong>Funding:</strong> The study had no sponsorship. <br /><strong>Conflict of interest:</strong> The authors declare no conflict of interest.</p>