Factors Related to the Delayed Cure of Hemifacial Spasm after Microvascular Decompression: An Analysis of 175 Consecutive Patients

Detailed studies assessing the factors related to delayed cure of hemifacial spasm (HFS) after microvascular decompression (MVD) are sparse. We aimed to evaluate the effect of 11 clinical factors on the time until the patient became spasm free after MVD. We enrolled 175 consecutive patients with HFS who underwent MVD between 2012 and 2018. The end point was defined as the time point at which the patient became spasm free based on the outpatient interview. Patients were divided into six groups depending on when they became spasm free after the operation, as follows: <7 days (n = 62), 7 days to 1 month (n = 28), 1 to 3 months (n = 38), 3 to 6 months (n = 25), 6 to 12 months (n = 17), and >12 months (n = 5). The median time to become spasm free after MVD was 30.0 days. Association of 11 factors (age, sex, laterality, number of offending arteries, vertebral artery compression, number of compression sites, compression at root detachment zone, preoperative Botox treatment, indentation of the brain stem on preoperative magnetic resonance image, transposition, and interposition) with spasm-free rate was assessed using the Cox's proportional hazards model. Spasm-free rate curve after MVD for the significant factor was obtained using the Kaplan–Meier method. In univariate and multivariate analyses, nontransposition was significantly related to delayed HFS cure after MVD (hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.42, 0.87; p = 0.0068 and HR, 0.60; CI, 0.43, 0.85; p = 0.042, respectively). The spasm-free rate was higher in the transposition than in the nontransposition group (p = 0.0013). As shortening the time until spasm free after MVD improves patients' quality of life, transposition should be recommended. Prediction of spasm-free time could relieve the anxiety of postoperative patients.

Pain in Patients with Post Paralytic Hemifacial Spasm: Before, during and after Botulinum Toxin Injections

It is well-established that botulinum toxin (BT) injections improve quality of life in patients with postparalytic hemifacial spasm. Nevertheless, injection-related pain and contracture-related pain have not yet been studied. The primary objective of our study was to evaluate injection-related pain in patients with facial palsy sequelae, and to compare the standard technique (syringe) with the Juvapen device. The secondary objective was to evaluate the improvement of contracture-related pain one month after BT injection. Methods: We conducted an observational, prospective, monocentric study based on 60 patients with facial palsy sequelae who received BT injections in our university ENT (ear, nose throat) department. There were 30 patients in the Juvapen group (J) and 30 in the standard technique group (ST). All patients completed Numerical Rating Scale (NRS) questionnaires immediately after the injections and one month later. Results: The average NRS score was 1.33/10 with Juvapen and 2.24/10 with the standard technique (p = 0.0058; Z = 2.75). In patients with contracture-related pain, the average NRS score was 3.53 before BT injection, and 0.41 one month after BT injection (p = 0.0001). Conclusions: Juvapen is a less-painful injection technique than the standard one. BT reduces contracture-related pain one month after injection.

Predicting Early Loss of Lateral Spread Response before Decompression in Hemifacial Spasm Surgery

Recent studies have shown the evocation of lateral spread response (LSR) due to the compression of the facial nerve in hemifacial spasm (HFS). Intraoperative monitoring (IOM) of LSR could help locate neurovascular conflicts and confirm adequate micro-vascular decompression (MVD) while treatment of hemifacial spasm (HFS). However, studies on early LSR loss before decompression in HFS surgery are sparse, indicating the need to understand various perceptions on it. Therefore, we retrospectively analyzed 50 adult HFS patients who underwent MVD during the period of September 2018–June 2021. We employed IOM combining traditional LSR (tLSR) and dual LSR (dLSR). One patient was excluded owing to the lack of LSR induction throughout the surgery, while 49 were divided into groups A (n = 14) and B (n = 35), designated as with or without early LSR loss groups, respectively, and offending vessels were analyzed. The mean age of group A patients was significantly younger (47.8 ± 8.6) than that of group B (53.9 ± 10.6) (p = 0.0393). The significant predominating offending vessel in group A was the anterior inferior cerebellar artery (AICA, 78.57%). However, group B included those with AICA (28.57%), posterior inferior cerebellar artery (PICA, 22.86%), vertebral artery (VA) involved (25.71%), and combined AICA and PICA (22.86%). Group B exhibited poorer clinical outcomes with more complications. Conclusively, early LSR loss might occur in the younger population, possibly due to the AICA offending vessel. The compression severity of offending vessels may determine the occurrence of early LSR loss.

Altered Functional Connectivity and Sensory Processing in Blepharospasm and Hemifacial Spasm: Coexistence and Difference

Background: Blepharospasm (BSP) and hemifacial spasm (HFS) are both facial hyperkinesia however BSP is thought to be caused by maladaptation in multiple brain regions in contrast to the peripherally induced cause in HFS. Plausible coexisting pathophysiologies between these two distinct diseases have been proposed.Objectives: In this study, we compared brain resting state functional connectivity (rsFC) and quantitative thermal test (QTT) results between patients with BSP, HFS and heathy controls (HCs).Methods: This study enrolled 12 patients with BSP, 11 patients with HFS, and 15 HCs. All subjects received serial neuropsychiatric evaluations, questionnaires determining disease severity and functional impairment, QTT, and resting state functional MRI. Image data were acquired using seed-based analyses using the CONN toolbox.Results: A higher cold detection threshold was found in the BSP and HFS patients compared to the HCs. The BSP and HFS patients had higher rsFC between the anterior cerebellum network and left occipital regions compared to the HCs. In all subjects, impaired cold detection threshold in the QTT of lower extremities had a correlation with higher rsFC between the anterior cerebellar network and left lingual gyrus. Compared to the HCs, increased rsFC in right postcentral gyrus in the BSP patients and decreased rsFC in the right amygdala and frontal orbital cortex in the HFS subjects were revealed when the anterior cerebellar network was used as seed.Conclusions: Dysfunction of sensory processing detected by the QTT is found in the BSP and HSP patients. Altered functional connectivity between the anterior cerebellar network and left occipital region, especially the Brodmann area 19, may indicate the possibility of shared pathophysiology among BSP, HFS, and impaired cold detection threshold. Further large-scale longitudinal study is needed for testing this theory in the future.

Association Study of Apolipoprotein E Gene Polymorphism With Incidence and Delayed Resolution of Hemifacial Spasm

Objective: This study investigates the correlation between Apolipoprotein E gene (APOE) polymorphism and the incidence and delayed resolution of hemifacial spasms.Methods: The APOE genotypes of 151 patients with hemifacial spasm and 73 control cases were determined by cleaved amplification polymorphism sequence-tagged sites. The distribution of three APOE alleles (ε2, ε3, and ε4) in two groups and the delayed resolution rate in 6 genotypes were calculated and statistically analyzed.Results: The proportion of patients with APOE ε3/ε4 genotype in the hemifacial spasm group (25.17%) was significantly higher than that in the control group (12.33%) (P = 0.027). In terms of allele frequency, the proportion of the APOE ε4 allele in the hemifacial spasm group (15.56%) was significantly higher than that in the control group (6.85%) (P = 0.009). Meanwhile, the proportion of APOE ε4 allele carriers in the hemifacial spasm group (29.80%) was significantly higher than that in the control group (13.7%) (P = 0.009). Logistic regression analysis showed that the ε4 allele significantly increased the incidence of hemifacial spasm (OR 2.675, 95%CI 1.260-5.678, P = 0.010). Among the 32 patients with a delayed resolution, the ε3/ε3 and ε3/ε4 had the highest proportion in 6 genotypes. The delayed resolution rate of APOE ε3/ε4 (34.21%) was significantly higher than APOE ε3/ε3 (17.78%) (P &lt; 0.05). The delayed resolution rate of APOE ε4 carriers was the highest (33.33%) in the 3 allele carriers, but there was no significant difference among the 3 allele carriers (P = 0.065).Conclusion: The polymorphism of APOE is relevant to the incidence rate of hemifacial spasms. APOE ε4 allele increases the incidence of hemifacial spasm. The APOE ε4 allele may promote the occurrence of delayed resolution.

Botulinum Toxin for the Treatment of Hemifacial Spasm: An Update on Clinical Studies

Hemifacial spasm (HFS) is a movement disorder characterized by involuntary contractions of the facial muscles innervated by the seventh cranial nerve. Generally, it is associated with a poor quality of life due to social embarrassment and can lead to functional blindness. Moreover, it is a chronic condition, and spontaneous recovery is rare. Intramuscular injections of Botulinum Toxin (BoNT) are routinely used as HFS treatment. Methods: We reviewed published articles between 1991 and 2021 regarding the effectiveness and safety of BoNT in HFS as well as any reported differences among BoNT formulations. Results: The efficacy of BoNT for HFS treatment ranged from 73% to 98.4%. The mean duration of the effect was around 12 weeks. Effectiveness did not decrease over time. Adverse effects were usually mild and transient. The efficacy and tolerability of the different preparations appeared to be similar. Among the studies, dosage, injected muscles, intervals of treatment, and rating scales were variable, thus leading to challenges in comparing the results. Conclusions: BoNT was the treatment of choice for HFS due to its efficacy and safety profile. Further studies are needed to investigate the factors that influence the outcome, including the optimal timing of treatment, injection techniques, dosage, and the best selection criteria for formulations.

Microvascular decompression for hemifacial spasm involving the vertebral artery

Objective Microvascular decompression (MVD) has become an accepted treatment modality for the vertebral artery (VA)–involved hemifacial spasm (HFS). The aim of this retrospective study was to evaluate clinical and surgical outcomes of HFS patients undergoing MVD and surgical and cranial nerve complications and investigate reasonable transposition procedures for two different anatomic variations of VA. Methods Between January and December 2018, 109 patients underwent first MVD for HFS involving VA at Nanjing Drum Tower Hospital. Based on whether the VA could be moved ventrally at the lower cranial nerves (LCNs) level, patients were assigned to Group A (movable VA, n = 72) or B (unmovable VA, n = 37), and clinical and surgical outcomes and complications on the day of post-surgery and during follow-up were assessed. All patients were followed up ranging from 17 to 24 months with a mean follow-up period of 21 months. Results After a mean follow-up of 21 months, the total cure rate significantly decreased in all patients compared to that achieved on the day of surgery, and Group A patients exhibited a higher cure rate versus Group B (93.1% vs. 75.7%, P = 0.015). Group B patients with unmovable VA revealed both higher incidence of surgical complications (45.9% vs. 15.3%, P = 0.001) and frequency of bilateral VA compression (27% vs. 8.3%, P = 0.009) versus Group A. No significant difference was observed in long-term cranial nerve complications. Conclusions VA-involved HFS can benefit from MVD strategies after preoperative assessment of VA compression. HFS patients with movable VA may receive better long-term efficacy and fewer complications. A Teflon bridge wedged between the distal VA and medulla gives rise to adequate space for decompression surgery.