Techniques of Surgical Modalities and Their Comparative Analysis in The Treatment of Pharmaceutically Refractory Classical Trigeminal Neuralgia: A Comprehensive Review

Abstract

Trigeminal neuralgia (TN) is the most common neurovascular conflict syndrome characterized by unilateral, lancinating, electric shock like paroxysms and recurrent pain attacks restricted to innervation of one or multiple branches of the 5th cranial nerve. The prevailing type of TN is the classical trigeminal neuralgia (cTN), associated by an underlying neurovascular conflict (NVC) within the cerebellopontine angle (CPA) impacting trigeminal nerve´s morphological integrity. With the probable etiopathogenesis of an underlying neurovascular compression causing subsequent ephaptic transmission of impulses in cTN, first line treatment is the pharmacotherapeutic approach with voltage-gated sodium channel blocking anticonvulsants. Nevertheless, 75% of all individuals diagnosed with trigeminal neuralgia (TN) are predisposed to develop pharamacotherapheutically refractory TN, necessitating eventual surgical intervention. Since the first surgical intervention for TN in 1856, the medical research community and neurosurgical pioneers proposed a range of various surgical modalities that have been clinically implemented to alleviate the symptoms of TN. This literature review aims to undertake a comprehensive comparative analysis of various surgical procedures in the treatment of pharamacotherapheutically refractory cTN by assessing certain indicators and parameters to evaluate the appropriate surgical choice of pharmaceutically refractory cTN. By critically reviewing the existing literature, this thesis seeks to guide clinical decision-making for the most appropriate surgical procedure in pharamacotherapheutically refractory cTN based on patients’ characteristics/profile, risk-benefit assessment, pain relief, recurrence rate and post-interventional complications and their incidences. The collected data advocates that microvascular decompression (MVD) has the best outcomes among all surgical modalities. Despite the risks associated with a posterior fossa craniotomy, including those related to major surgery and general anesthesia, the available data indicates that MVD provides the most advantageous balance between benefit and risk, demonstrates high success rates and its ability to provide long-term pain relief while minimizing postoperative facial sensory disturbances, making it an effective and first line treatment for patients with pharamacotherapheutically refractory cTN.However, the decision making and judgment for the adequate surgical modality should be made on an individual basis and driven by a thorough comprehension of success and recurrence rates, the unique patient characteristics and careful risk-benefit assessment. The review critically discusses the findings in literature, highlighting shortcomings, risks, advantages and disadvantages of certain interventions and sheds light on the current state of knowledge, identifies crucial parameters for preferential treatment and guides evidence-based decision-making to optimize individualized treatment.