Absence of Meckel Cave: A Rare Cause of Trigeminal Neuralgia

Abstract

Trigeminal neuralgia is a debilitating condition with numerous etiologies. In this retrospective case series, we report a cohort of patients with a rarely described entity, absence of Meckel cave, and propose this as a rare cause of trigeminal neuralgia. A search of the electronic medical record was performed between 2000 and 2020 to identify MR imaging reports with terms including "Meckel's cave" and "hypoplasia," "atresia," "collapse," or "asymmetry." Images were reviewed by 2 blinded, board-certified neuroradiologists. Seven cases of the absence of Meckel cave were identified. Seven patients (100%) had ipsilateral trigeminal neuralgia and ipsilateral trigeminal nerve atrophy, suggesting an association between absence of Meckel cave and trigeminal neuralgia. Absence of Meckel cave is a rare entity of unknown etiology, with few existing reports that suggest the possibility of an association with trigeminal neuralgia. Its recognition may have important implications in patient management. Future studies and longitudinal data are needed to assess treatment outcomes and added risks from surgical intervention in these patients.ABBREVIATION: TN ¼ trigeminal neuralgia T rigeminal neuralgia (TN) is a debilitating condition resulting in a severely compromised quality of life in affected people. 1 It more commonly affects women and has an overall prevalence of 0.07% of the population. 2 Treatment of TN revolves around accurate identification of the potential etiology. Advances in neuroimaging, particularly MR imaging, have played a crucial role in assessing various structural causes of TN, such as neurovascular compression, compressive mass, or multiple sclerosis. 3 Depending on the suspected etiology, various treatment options may be used, including medication, neurovascular decompression, stereotactic radiosurgery, or percutaneous balloon compression.A rarely reported entity, absence of Meckel cave, has been described in a few patients with TN, including 2 case reports and 3 patient case series. [4][5][6] Most important, there are only a few reports, to our knowledge, on the absence of Meckel cave in patients other than those with TN. This retrospective study aimed to demonstrate the potential relationship of an absent Meckel cave with TN versus without TN, which may have important diagnostic and treatment implications.

Absent Meckel's cave as a possible cause of trigeminal neuralgia: A case report

“…An absent Meckel's cave as a possible cause of TN is a rarely described and poorly understood entity. Such a phenomenon has been described in only 2 case series, 7 patients and 3 patients, respectively, and 2 case reports, adding up to a total of 12 cases [10] , [11] , [12] , [13] . Interestingly, all cases reported in the literature, including ours, were female.…”

Absence of Meckel's Cave with Trigeminal Neuralgia: A Case Report

“…The association between TN and the absence of Meckel's cave was described and suggested in the literature. 1 Meckel's cave is a potential space filled with cerebrospinal fluid (CSF) in the middle cranial fossa and acts as a channel for the trigeminal nerve and Gasserian ganglion. 2,10 It measures 15 mm in length and 9 mm in width.…”

“…2,10 Flattening of Meckel's cave can be seen in spontaneous intracranial hypotension secondary to CSF volume loss. 1 Many patients with spontaneous intracranial hypotension may suffer from facial pain and headache. 2 There are only a handful of reported cases in the literature of patients with absent Meckel's cave presenting with TN.…”

“…2 There are only a handful of reported cases in the literature of patients with absent Meckel's cave presenting with TN. 1,2,7,8 . All reported patients were females with an age range from 35 to 80 years, with a mean of 44.6 years and a median of 41.5 years.…”

The Focus and New Progress of Percutaneous Balloon Compression for the Treatment of Trigeminal Neuralgia

“…Few trigeminal neuralgia patients do not have Meckel’s cave. 11 , 12 Meckel’s cave is divided into upper, lower, anterior, posterior walls, inner and lateral walls. The anterior and upper walls are adjacent to the posterior venous space of the posterior cavernous sinus; the lateral wall is adjacent to the dura of the medial fossa, and the front of the inner wall is adjacent to the posterior cavernous sinus segment of the internal carotid artery.…”