Chiari malformation and its influence on trigeminal neuralgia: a systematic review

Abstract

Objective: In order to properly understand the correlation between TN and Chiari malformation type I (CMI), it is imperative to delve into the underlying processes and develop efficacious treatment strategies.

Methods: A comprehensive search was performed regarding trigeminal neuralgia (TN) in individuals diagnosed with CMI. A total of 19 cases were identified in the existing literature.

Results: The review of 19 studies showed that the most commonly affected division was V2 (31.6%), followed by V3 (10.5%) and V1 (5.3%). Radiological findings were variable. The medulla oblongata was compressed in 6 patients (31.6%), the cervical spinal cord showed abnormalities in 3 patients (15.8%) abnormalities; one cervical myelocele (5.26%), two cervical syringomyelia (10.53%) while 5 patients (26.3%) showed normal findings. The skull bones in 4 patients (21,1%) showed deformity in the form of small posterior fossa or platybasia. The surgical treatment was conducted in 14 patients (73.7%). The study suggested that posterior fossa decompression (PFD) plus microvascular decompression (MVD) dual surgical modality yielded the best results for V2 distribution (P=0.017).

Conclusion: Chiari malformation type I can directly influence the occurrence and severity of trigeminal neuralgia. Therefore, an effective management of this malformation, like neurovascular decompression, PFD or ventriculoperitoneal shunt, can act as a potential treatment for trigeminal neuralgia. While the PFD alone was effective in the V3 and V1 distribution of trigeminal neuralgia, PFD plus microvascularplus plus microvascular decompression (MVD) as a dual surgical modality yielded the best results for V2 distribution.

Keywords: Chiari malformation; microvascular decompression; posterior fossa decompression; trigeminal neuralgia.

Figure 1

Prisma flowchart. Reason 1: Commentary. Reason 2: Erratum. Reason 3: Full-text not available.

Figure 2

Histogram showing the age distribution in patients with trigeminal neuralgia.

Figure 3

Showing the distribution of the affected divisions of the trigeminal nerve.

Figure 4

Showing the affected side of the TN. TN, trigeminal neuralgia.

Figure 5

Showing the prevalence of hydrocephalus in the documented radiological findings.

Figure 6

Showing the surgical modalities used among the patients. MVD, microvascular decompression; PFD, posterior fossa decompression; VPS, ventriculoperitoneal shunt.

Figure 7

An anatomical illustration showing the relation of CMI and the trigeminal nerve. C, cerebellum; CL, clivus; D, dens; OB, occipital bone; P, pons; SS, sphenoid sinus.

Figure 8

Showing the pathophysiology of the trigeminal neuralgia.