Three Cases of Trigeminal Neuralgia with Radiographic Absence of Meckel’s Cave

Abstract

Trigeminal neuralgia (TN) is a debilitating but treatable disease. Classic TN has referable vascular compression of the trigeminal nerve, but rarely secondary sources of anatomic compression will present, including vascular malformations, aneurysms, or tumors. Understanding the etiology of the patients’ symptoms leads to targeted treatment. Three patients presented with symptoms consistent with TN: shooting, paroxysmal pains in the distribution of the trigeminal nerve. However, imaging revealed no vascular conflict at the root entry zone of the trigeminal nerve. Instead, on the affected side Meckel’s cave was absent. No other compressive mass lesion was identified. In all three cases, patients were offered both Gamma Knife Radiosurgery and surgical decompression of Meckel’s cave. All 3 patients elected to proceed with stereotactic radiation and reported improvement in pain. Many cases of classic TN can be explained by neurovascular conflict at the trigeminal root entry zone, but secondary sources of compression or restriction along the nerve can result in similar symptomology. In this case series, an absent or hypoplastic ipsilateral Meckel’s cave may have produced symptoms consistent with TN. Imaging with fine cuts through Meckel’s cave is an important diagnostic tool.

Flatness of the Meckel cave may cause primary trigeminal neuralgia: a radiomics-based study

“…Morphological changes in the MC are very important in the diagnosis [ 17 – 22 ] and treatment [ 23 , 24 ] of intracranial diseases, such as radiofrequency thermocoagulation and PBC of PTN [ 25 – 29 ]. Ipsilateral hypoplastic MC and crowded MC have been suggested to produce symptoms consistent with TN [ 8 , 9 ] At present, there is little research on the morphology of MC in patients with PTN and healthy people, and therefore a lack of statistical data comparing the MC morphology between these two groups.…”

“…The MC is an important part of the trigeminal nerve, which is composed of numerous small fibers and the trigeminal ganglion consisting of a small amount of solid tissue [ 7 ]. Some cases studies [ 8 , 9 ] have reported that ipsilateral hypoplastic MC, which may lead to morphological atrophy, as well as crowded MC, may produce symptoms consistent with TN. Percutaneous balloon compression (PBC) can effectively relieve the pain symptoms of patients with PTN by changing the shape of the MC, which expands after balloon dilation; moreover, the balloon shape is a parameter that has a very strong impact on outcome [ 10 , 11 ].…”

Flatness of the Meckel Cave May Cause Primary Trigeminal Neuralgia: a Radiomics-based Study

“…Morphological changes in the MC are very important in the diagnosis [17][18][19][20][21][22] and treatment 23,24 of intracranial diseases, such as radiofrequency thermocoagulation and PBC of PTN [25][26][27][28][29] . Some cases 8,9 report that ipsilateral hypoplastic MC, which may lead to morphological atrophy, as well as crowded MC, may have produced symptoms consistent with TN. At present, there is little research on the morphology of MC in patients with PTN and in healthy people, and there is also a lack of statistical data comparing the MC morphology between these groups.…”

“…In this study, we introduced the method of the MC morphological features extraction based on radiomics. In the identification of MC anatomy by MRI, most studies 8,[17][18][19] only use one of the T1 or T2 sequences. T1 enhanced sequence is helpful to determine the wall of the MC 30 , but lacks sensitivity of cerebrospinal fluid and nerves in the MC.…”

“…The MC is an important part of the trigeminal nerve after the REZ, which is composed of numerous small fibers and the trigeminal ganglion consisting of a small amount of solid tissue 7 . Some cases 8,9 report that ipsilateral hypoplastic MC, which may lead to morphological atrophy, as well as crowded MC, may have produced symptoms consistent with TN. Percutaneous balloon compression (PBC) can effectively relieve the pain symptoms of patients with PTN by changing the shape of the MC, which expands after balloon dilation; moreover, the balloon shape is a parameter that has a very strong impact on outcome 10,11 .…”