Tag: Vagus nerve

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The tethered effect of the arachnoid in vago-glossopharyngeal neuralgia: a real associated alternative mechanism?

Acta Neurochir (2018) 160:151–155

Vago-glossopharyngeal neuralgia (VGPN) is a rarely seen disease when compared to trigeminal neuralgia. When the pain is resistant to medical therapy, microvascular decompression can be performed if a vascular conflict is suspected on magnetic resonance imaging (MRI). In addition, arachnoid pathology may play a role in VGPN. We report two cases of VGPN caused by tethered arachnoid, associated with a vascular contact in which pain was reduced by freeing rootlets from arachnoid compression.

We report two cases relating to 50-year-old and 30-year-old men with a history of electric shooting pain triggered by swallowing in the right pharyngeal and auricular regions. Preoperative MRI documented a neurovascular conflict in the first case and an arachnoid cyst in the second. Surgery was performed via a retrosigmoid craniotomy. In both cases, the intraoperative findings documented a tethered arachnoid membrane compressive to cranial nerves IX and X. Untethering was performed by liberation of the rootlets from the arachnoid with microvascular decompression. No additional rhizotomy was performed. The postoperative course was uneventful and pain was relieved in the first case and decreased in the second.

In VGPN, a tethered arachnoid may play a role in causing the neuralgia, either alone or associated with a neuro-vascular conflict.

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Intraoperative Mapping and Monitoring for Rootlets of the Lower Cranial Nerves Related to Vocal Cord Movement

Intraoperative Mapping and Monitoring for Rootlets of the Lower Cranial Nerves Related to Vocal Cord Movement

Neurosurgery 78:829–834, 2016

Damage to the motor division of the lower cranial nerves that run into the jugular foramen leads to hoarseness, dysphagia, and the risk of aspiration pneumonia; therefore, its functional preservation during surgical procedures is important. Intraoperative mapping and monitoring of the motor rootlets at the cerebellomedullary cistern using endotracheal tube electrodes is a safe and effective procedure to prevent its injury.

OBJECTIVE: To study the location of the somatic and autonomic motor fibers of the lower cranial nerves related to vocal cord movement.

METHODS: Twenty-four patients with pathologies at the cerebellopontine lesion were studied. General anesthesia was maintained with fentanyl and propofol. A monopolar stimulator was used at amplitudes of 0.05 to 0.1 mA. Both acoustic and visual signals were displayed as vocalis muscle electromyographic activity using endotracheal tube surface electrodes.

RESULTS: The average number of rootlets was 7.4 (range, 5-10); 75% of patients had 7 or 8 rootlets. As many as 6 rootlets (2-4 in most cases) were responsive in each patient. In 23 of the 24 patients, the responding rootlets congregated on the caudal side. The maximum electromyographic response was predominantly in the most caudal or second most caudal rootlet in 79%.

CONCLUSION: The majority of motor fibers of the lower cranial nerves run through the caudal part of the rootlets at the cerebellomedullary cistern, and the maximal electromyographic response was elicited at the most caudal or second most caudal rootlet.

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Vago-glossopharyngeal neuralgia

Vago-glossopharyngeal neuralgiaActa Neurochir (2015) 157:311–321

Glossopharyngeal neuralgia (GPN), or better named vago-glossopharyngeal neuralgia (VGPN), is a rare disorder amounting to 1 % of the incidence of trigeminal neuralgia (TN). Pain is paroxysmal, of the electrical shooting type, and mainly provoked by stimulation of the pharynx or deep throat, especially during swallowing. Due to its rarity, VGPN is often misdiagnosed. The front line of medical treatment is based on anticonvulsants. Surgery should be considered when the pain is refractory to medications. In most patients, the cause is neurovascular conflict on root entry zone (REZ) or midcistern portion, of the IXth and/or Xth cranial nerves. Compressive vessels can be evidenced by means of a high sensibility and a high specificity resolution MR imaging in most centers.

Present consensus is that the first option of neurosurgical treatment be microvascular decompression. In patients with precarious general conditions, stereotactic radiosurgery may be considered. Also, thermo-rhizotomy at the pars nervosa of foramen jugularis or tractotomy-nucleotomy at brainstem may be alternatives, but these methods entail a significant risk of deficits.

In this article, the authors reviewed the main literature series on neurosurgical treatments of this disease.

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