Geniculate neuralgia treatment
The treatment for geniculate neuralgia has not been established, although it seems reasonable that the therapeutic approaches used in other more common craniofacial neuralgias, such as trigeminal neuralgia, should be effective.
Conservative medical treatment is always the first-line therapy.
May responde to valproic acid.
Topical antibiotics for secondary infections of herpetic lesions.
Local anesthetic to external auditory canal.
Surgical treatment should be offered if medical treatment fails. The two commonest surgical options are transection of the nervus intermedius, and microvascular decompression of the nerve at the nerve root entry zone of the brainstem. However, extracranial intratemporal division of the cutaneous branches of the facial nerve may offer a safer and similarly effective treatment.
The response to medical treatment for this condition varies between individuals. The long-term outcomes of surgery remain unknown because of limited data 1).
Rupa et al., postulate that geniculate ganglionectomy may be ineffective as the sole treatment for certain cases of geniculate neuralgia, and that nervus intermedius section may also be required to achieve a more complete deafferentation 2).
Excision of the nervus intermedius and/or of the geniculate ganglion by the middle cranial fossa approach without the production of facial paralysis, sometimes in combination with selective section of the Vth cranial nerve, has been successful in relieving the pain of geniculate neuralgia.
Microvascular decompression may be effective as a treatment. Along its cisternal course, the nerve may be difficult to distinguish from the facial nerve. Based on case reports and small series, long-term pain control can be seen after nerve sectioning or microvascular decompression, but no prospective studies exist. Such studies are now necessary to shed light on the efficacy of surgical treatment of nervus intermedius neuralgia 3).
High-frequency hearing loss occurred after MVD for TGN, GPN, or GN, and the greatest incidence occurred on the ipsilateral side. This hearing loss may be a result of drill-induced noise and/or transient loss of cerebrospinal fluid during the course of the procedure. Changes in intraoperative BAEP waveforms were not useful in predicting HFHL after MVD. Repeated postoperative audiological examinations may be useful in assessing the prognosis of HFHL 4).
Surgically excision of the nervus intermedius and geniculate ganglion via the middle cranial fossa approach, Review the long-term outcomes in 64 patients who were treated in this manner. Findings indicate that excision of the nervus intermedius and geniculate ganglion can be routinely performed without causing facial paralysis and that it is an effective definitive treatment for intractable geniculate neuralgia 5).
A total of 31 surgical procedures were performed. Seventeen patients had sequential rhizotomies and one patient had microvascular decompression alone. Based on the clinical diagnosis, the nerves sectioned were singly or in combination: the nervus intermedius (14 patients), geniculate ganglion (10 patients), ninth nerve (14 patients), 10th nerve (11 patients), tympanic nerve (four patients), and chorda tympani nerve (one patient). Microvascular decompression of the involved nerves was undertaken in nine patients, in whom vascular loops were discovered. Adhesions (six patients), thickened arachnoid (three patients), and benign osteoma (one patient) were other intraoperative abnormalities noted. The overall success of these procedures in providing pain relief was 72.2%, and the mean follow-up period was 3.3 years (range 1 month to 14.5 years). There was no surgical mortality. Expected side effects were: decreased lacrimation, salivation, and taste related to nervus intermedius nerve section, and transient hoarseness and diminished gag related to ninth and 10th nerve section. Four patients developed sequelae consisting of sensorineural hearing loss, vertigo, and transient facial nerve paresis. One patient had a cerebrospinal fluid leak and another developed aseptic meningitis as postoperative complications. Except when primary glossopharyngeal neuralgia is the working diagnosis, a combined posterior cranial fossa-middle cranial fossa approach is recommended for adequate exploration and/or section of the fifth, ninth, and 10th cranial nerves as well as the geniculate ganglion and nervus intermedius 6).
Excision of the nervus intermedius and/or of the geniculate ganglion by the middle cranial fossa approach without the production of facial paralysis, in any of 15 cases with geniculate neuralgia is reported. Use of these new techniques, sometimes in combination with selective section of the Vth cranial nerve, has been successful in relieving the pain of geniculate neuralgia 7).
A 39-year-old man presented with a history of left “deep” ear pain within his ear canal. He noted occasional pain on the left side of his face around the ear. He had been treated with neuropathic pain medications without relief. His wife described suicidal ideations discussed by her husband because of the intense pain.
The patient’s neurologic examination was normal, and otolaryngologic consultation revealed no underlying structural disorder. Anatomic imaging revealed a tortuous vertebral artery-posterior inferior cerebellar artery complex with the posterior inferior cerebellar artery loop impinging on the root entry zone of the nervus intermedius-vestibulocochlear nerve complex and just inferior to the root entry zone of the facial nerve and a small anterior inferior cerebellar artery loop interposed between the cranial nerve VII-VIII complex and the hypoglossal and glossopharyngeal nerves. A left-sided retromastoid craniotomy was performed, and the nervus intermedius was transected. An arterial loop in contact with the lower cranial nerves at the level of the brainstem was mobilized with a polytetrafluoroethylene implant.
The patient indicated complete relief of his preoperative pain after surgery. He has remained pain-free with intact hearing and balance 8).