Abstract
Background Trigeminal neuralgia is a pain disorder classically linked to vascular compression of the trigeminal nerve, although a number of other pathological sources of compression may cause the same clinical picture. Understanding the aetiology is an important part of the work-up and guides treatment. Meckel's cave is a cerebrospinal fluid-filled space that contains the trigeminal ganglion and through which the trigeminal nerve runs. Its absence is uncommon, and the aetiology of this is unknown. In recent years two small case series and a few case reports have suggested an association with intractable trigeminal neuralgia. Optimal management, inclusive of neurosurgical options, and prognosis, remains unknown.
Case Presentation A 32 year old female was referred to Neurology clinic with symptoms of right-sided trigeminal neuralgia in the V2, V3 branches and on occasion also V1 branch of the trigeminal nerve. There was no absence of sensation on examination. An MRI brain showed an ipsilateral hypoplastic or absent right-sided Meckel's cave. She had been given amitriptyline in the community, followed by low dose carbamazepine which was up-titrated after clinic review. Subsequently she was admitted to hospital with a pain crisis. Despite maximal up-titration of carbamazepine and addition of pregabalin her symptoms were unable to be controlled, so a Neurosurgical opinion was sought.
Conclusion Ipsilateral absence of Meckel's cave appears to be an emerging cause of trigeminal neuralgia that is often challenging to manage with medication. We present a literature review of this rare entity, alongside the clinical developments in this case.
