The Underlying Pathogenesis of Neurovascular Compression Syndromes: A Systematic Review

Abstract

Neurovascular compression syndromes (NVC) are challenging disorders resulting from the compression of cranial nerves at the root entry/exit zone. Clinically, we can distinguish the following NVC conditions: trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia. Also, rare cases of geniculate neuralgia and superior laryngeal neuralgia are reported. Other syndromes, e.g., disabling positional vertigo, arterial hypertension in the course of NVC at the CN IX-X REZ and torticollis, have insufficient clinical evidence for microvascular decompression. The exact pathomechanism leading to characteristic NVC-related symptoms remains unclear. Proposed etiologies have limited explanatory scope. Therefore, we have examined the underlying pathomechanisms stated in the medical literature. To achieve our goal, we systematically reviewed original English language papers available in Pubmed and Web of Science databases before 2 October 2021. We obtained 1694 papers after eliminating duplicates. Only 357 original papers potentially pertaining to the pathogenesis of NVC were enrolled in full-text assessment for eligibility. Of these, 63 were included in the final analysis. The systematic review suggests that the anatomical and/or hemodynamical changes described are insufficient to account for NVC-related symptoms by themselves. They must coexist with additional changes such as factors associated with the affected nerve (e.g., demyelination, REZ modeling, vasculature pathology), nucleus hyperexcitability, white and/or gray matter changes in the brain, or disturbances in ion channels. Moreover, the effects of inflammatory background, altered proteome, and biochemical parameters on symptomatic NVC cannot be ignored. Further studies are needed to gain better insight into NVC pathophysiology.

Fully endoscopic microvascular decompression for the treatment of hemifacial spasm, trigeminal neuralgia, and glossopharyngeal neuralgia: a retrospective study

“…Hemifacial spasm (HFS), trigeminal neuralgia (TN), and glossopharyngeal neuralgia (GPN) are the most common neurovascular compression syndromes (NVC) in clinical practice. The symptoms are closely related to patients’ quality of life and often cause pain and discomfort [ 1 – 3 ].…”

“…The pathogenesis of the above diseases is still unclear, but it is generally believed that the FN, TGN and glossopharyngeal nerves are compressed by peripheral blood vessels (neurovascular compression), leading to nerve demyelination. At present, microvascular decompression (MVD) is already the preferred surgical treatment for NVC such as HFS, TN, and GPN [ 8 ]. In recent years, with the increasingly mature application of neuroendoscopic surgical techniques in neurosurgery, more and more studies have been reported on the treatment of HFS, TN, and GPN by endoscopy-assisted MVD, but there are few reports on MVD with the full endoscope [ 9 ].…”

Management of patients with a neurovascular conflict involving the optic nerve and a non-diseased intracranial artery: Three cases

“…However, as opposed to the optic nerve, symptomatic compression of the trigeminal nerve or the facial nerve usually occurs at the root entry/exit zone. This so-called Redlich-Obersteiner's zone is a transition zone between the central and peripheral nervous system, and histologically characterized by the fact that myelin covering the neurons is produced by Schwann cells (peripheral nervous system) while this is produced by oligodendrocytes within the central nervous system ( Szmyd et al, 2022 ). This transition zone is suspected to be a susceptible zone for demyelination caused by compression.…”

The Anterior Inferior Cerebral Artery Variability in the Context of Neurovascular Compression Syndromes: A Narrative Review

“…Therefore, it is presumably more vulnerable to mechanical factors, especially pulse waves [3]. The compression is speculated to be the cause of the onset of clinical symptoms; however, the exact pathological path remains unclear [4]. The proposed chain of pathogenetic events is vascular compression in the REZ/transition zone leading to demyelination; this causes nucleus hyperexcitability, which causes symptoms [4].…”