Surgical treatment of cranial neuralgias

Nerve Compression Syndromes in the Posterior Cranial Fossa

BACKGROUND

Nerve compression syndromes in the posterior cranial fossa can severely impair patients' quality of life. There is often uncertainty about the best treatment. In this article, we provide an overview of these conditions and the corresponding treatment strategies.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed and on a scientific analysis of the authors' patient collective.

RESULTS

These syndromes are caused by compression of a cranial nerve by an artery or vein at the zone of the nerve's entry to or exit from the brainstem. The best-known neurovascular compression syndrome is trigeminal neuralgia, followed by hemifacial spasm. Less well known are glossopharyngeal neuralgia, nervus intermedius neuralgia, and vestibular paroxysmia. The initial treatment of trigeminal neuralgia is medical: the first line of treatment is with sodium-blocking anticon- vulsants, such as carbamazepine. For patients with hemifacial spasm, botulinum toxin injection is the recommended initial treatment and often leads to a satisfactory regression of the spasms. If these treatments fail, a microvascular decompression operation is indicated. The aim of the procedure is to separate the irritating vessel from the nerve and to keep these structures apart permanently. There is hardly any available evidence on these treatment strategies from randomized controlled trials.

CONCLUSION

Nerve compression syndromes in the posterior cranial fossa can generally be treated nonsurgically at first. Over the course of the condition, however, treatment failure or intolerable side effects may arise. In such cases, a microvascu- lar decompression operation is indicated. This is a causally directed form of treat- ment that generally yields very good results.

Glossopharyngeal Neuralgia Treatment Outcomes After Nerve Section, Microvascular Decompression, or Stereotactic Radiosurgery: A Systematic Review and Meta-Analysis

BACKGROUND

Glossopharyngeal neuralgia (GPN) is a rare neuralgic pain syndrome amenable to neurosurgical treatments, including nerve section (NS), microvascular decompression (MVD), and stereotactic radiosurgery (SRS). However, thorough comparisons of the modalities have not been performed to date. The objective of the present study was to compare the pain and complication outcomes after these approaches to GPN.

METHODS

Searches of 7 electronic databases from inception to June 2018 were conducted following the appropriate guidelines. The incidence rates (IRs) of short-term (≤3 months) and long-term (≥12 months) pain relief and complications were extracted and analyzed using a meta-analysis. Meta-regression was used to assess for heterogeneity.

RESULTS

A total of 792 GPN cases managed by NS, MVD, or SRS were described by 6, 11, and 6 studies, reporting outcomes for 282 (36%), 446 (56%), and 67 (8%) cases. The short-term pain relief rate was highest after NS postoperatively (IR, 94%; 95% confidence interval [CI], 88%-98%) and lowest after SRS at 3 months postoperatively (IR, 80%; 95% CI, 68%-96%). The postoperative complication rate was greatest after MVD (IR, 26%; 95% CI, 16%-38%) and lowest after SRS (IR, 0%; 95% CI, 0%-4%). The long-term pain relief rate was greatest after NS (IR, 96%; 95% CI, 91%-99%) and lowest after SRS (IR, 82%; 95% CI, 67%-94%). Statistically significant differences between the approaches were found for each outcome.

CONCLUSION

Neurosurgical treatment of GPN is frequently performed by 1 of 3 modalities with unique outcomes profiles. NS might provide the most favorable treatment response, with respect to short- and long-term pain relief and postoperative outcomes.

Neuropathic Orofacial Pain

Neuropathic pain of the orofacial region can cause much distress in individuals presenting with this condition. It may be easily mistaken for dental pain, and hence many individuals may undergo unnecessary dental work. Knowledge of the types of neuropathic orofacial pain may assist in timely diagnosis and improvement of a patient's quality of life.

Treatments of glossopharyngeal neuralgia: towards standard procedures

The degree of disability due to glossopharyngeal neuralgia (GN) refractory to conservative treatments justifies surgical procedures as second-line treatments. Since the first description of this facial pain disorders, many surgical options have been described either via a percutaneous or an open surgical way. Actually, when a neurovascular conflict on root entry zone (REZ) or cisternal portion of the ninth and tenth cranial nerves is identified, microvascular decompression (MVD) is the first surgical option to consider. Many studies have demonstrated its efficacy and safety for the treatment of GN. Recently, stereotactic radiosurgery has gained space in the treatment of selected cases of GN. We provide an overview of the surgical procedures for the treatment of GN and of our own experience.

Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients

Approximately 30% of epilepsy patients are refractory to antiepileptic drugs. In these cases, surgery is the only alternative to eliminate/control seizures. However, a significant minority of patients continues to exhibit post-operative seizures, even in those cases in which the suspected source of seizures has been correctly localized and resected. The protocol presented here combines a clinical procedure routinely employed during the pre-operative evaluation of temporal lobe epilepsy (TLE) patients with a novel technique for network analysis. The method allows for the evaluation of the temporal evolution of mesial network parameters. The bilateral insertion of foramen ovale electrodes (FOE) into the ambient cistern simultaneously records electrocortical activity at several mesial areas in the temporal lobe. Furthermore, network methodology applied to the recorded time series tracks the temporal evolution of the mesial networks both interictally and during the seizures. In this way, the presented protocol offers a unique way to visualize and quantify measures that considers the relationships between several mesial areas instead of a single area.