The association between vertebrobasilar dolichoectasia and hemifacial spasm

Role of a Tortuous Vertebrobasilar Artery and Anchoring Perforators in the Etiology of Hemifacial Spasm

BACKGROUND

In >70% of patients with hemifacial spasm (HFS), the offending artery is either the anterior inferior cerebellar artery (AICA) or posterior inferior cerebellar artery (PICA), without a tortuous vertebrobasilar artery (VBA). We hypothesized that anchoring perforators around the root exit zone (REZ) of the AICA or PICA might induce vascular deviation and compression. We investigated the occurrence of these perforators from the AICA or PICA and the extent of VBA tortuosity to reveal the pathology of vascular compression.

METHODS

This retrospective review included 110 patients after excluding those with vertebral artery (VA) compression alone. The occurrence of perforators was determined according to operative findings within 5 mm of the REZ, and VBA tortuosity was evaluated using MATLAB. We analyzed the association between perforators, VBA tortuosity, and the surgical implications.

RESULTS

The occurrence of perforators from the offending AICA or PICA around the REZ was significantly higher in the group without VA compression (Group A) than in the group with VA compression (Group B). VBA tortuosity was significantly lower in Group A. VBA tortuosity was inversely correlated with the presence of AICA or PICA perforators in all 110 patients. Operative results were similar between the groups, although patients with low VBA tortuosity tended to require interposition in decompression procedures.

CONCLUSIONS

Anchoring perforators around the REZ play a crucial role in vascular compression for patients with less tortuous VBAs. Moreover, surgeons should be prepared to deal with multiple perforators in a more complicated surgery in cases of less tortuous VBA.

Predictors of Multi-Vessel Identification, Outcome, and Optimal Surgical Timing for Microvascular Decompression in Hemifacial Spasm

OBJECTIVES AND BACKGROUND

Hemifacial spasm (HFS) is a disabling condition that imposes significant burden upon patients. Microvascular decompression (MVD) surgery is the most effective and long-lasting treatment for HFS, but outcomes following this surgery may vary based on a variety of clinical and operative factors. A more thorough understanding of the variables that impact patient outcome after MVD surgery is needed.

METHODS

A systematic review and meta-analysis of Medline, Embase, and Central was conducted (n = 2108 screened; n = 86 included) with the goal of determining the impact of the following variables on outcome: duration of disease, geographic location, intraoperative use of an endoscope, and intraoperative finding of single versus multi-vessel neurovascular compression.

RESULTS

Most cases of hemifacial spasm occur on the left side (53.9%, p < 0.001) and are more common in women than men (66.5% versus 33.5%, p < 0.0001). The offending vessel frequencies were: 40.8% anterior inferior cerebellar artery [AICA], 24.9% posterior inferior cerebellar artery [PICA], 17.2% multiple vessels, and 4.7% vertebral artery [VA]. Multiple vessel combinations involved: 26.5% PICA + AICA, 24.6% PICA + VA, 23.1% AICA + VA, and 4.7% AICA + PICA + VA. Relative to the Americas, AICA was less frequent in Europe (p = 0.005), while PICA more frequent in Europe (p = 0.009) and Asia (p < 0.0001). With endoscope assistance, frequency of multiple vessels identified was 31.7% (versus 14.7% with non-endoscopic, p = 0.005), and 27.4% for AICA (43.5% with non-endoscopic, p = 0.003). Spasm improvement was 94.1% near discharge and 96.0% at maximum follow-up. Complications occurred in 16.5% of cases, with spasm recurrence in 2.4%. Greatest frequency of spasm improvement (p < 0.0001) and lowest spasm recurrence rates (p = 0.0005) were reported in series from Asia. For every additional month of pre-operative spasm, the effect size of post-operative improvement decreased (p = 0.04). With every subsequent postoperative month, the effect size of spasm improvement increased (p = 0.0497). The frequency of spasm improvement was significantly higher in series published after 2005 (94.4% versus 97.4%, p = 0.005).

CONCLUSION

Clinical outcomes following MVD for HFS have improved since 2005. Consideration should be given to earlier operation (shorter disease duration) and use of an endoscope may increase detection of multiple offending vessels. Further studies are needed to understand regional differences in culprit vessel incidence and surgical outcomes in the Americas, Europe, and Asia.

The value of intraoperative indocyanine green angiography in microvascular decompression for hemifacial spasm to avoid brainstem ischemia

PURPOSE

Despite being rarely reported, ischemic insults resulting from compromising small brainstem perforators following microvascular decompression (MVD) remain a potential devastating complication. To avoid this complication, we have been using indocyanine green (ICG) angiography intraoperatively to check the flow within the small brainstem perforators. We aim to evaluate the safety and usefulness of ICG videoangiography in MVD.

METHODS

We extracted retrospective data of patients who received ICG videoangiography from our prospectively maintained database for microvascular decompression. We noted relevant data including demographics, offending vessels, operative technique, outcome, and complications.

RESULTS

Out of the 438 patients, 15 patients with a mean age (SD) of 53 ± 10.5 years underwent intraoperative ICG angiography. Male:female was 1:1.14. The mean disease duration prior to surgery was 7.7 ± 5.3 years. The mean follow-up (SD) was 50.7 ± 42.0 months. In 14 patients, the offending vessel was an artery, and in one patient, a vein. Intraoperative readjustment of the Teflon pledget or sling was required in 20% (3/15) of the cases. No patient had any sort of brainstem ischemia. Eighty percent of the patients (12/15) experienced complete resolution of the spasms. 86.7% (13/15) of the patients reported a satisfactory outcome with marked improvement of the spasms. Three patients experienced slight hearing affection after surgery, which improved in two patients later. There was no facial or lower cranial nerve affection.

CONCLUSION

Intraoperative ICG is a safe tool for evaluating the flow within the brain stem perforators and avoiding brainstem ischemia in MVD for hemifacial spasm.

The novel prognostic value of postoperative follow-up lateral spread response after microvascular decompression for hemifacial spasm

OBJECTIVE

The lateral spread response (LSR) is an aberrant electrophysiological response in which a stimulus on one branch of the facial nerve spills over to other branches of the nerve, which can be captured by electrodes near each branch. The authors performed this study to evaluate the prognostic value of the follow-up LSR with a sufficient time interval from intraoperative LSR (IO-LSR) after microvascular decompression (MVD) for hemifacial spasm (HFS), excluding the interference of various intraoperative situations.

METHODS

A total of 247 patients treated with MVD for HFS between June 2011 and March 2019 were enrolled in this study. The IO-LSR was routinely evaluated in all patients. The LSR was checked again on postoperative day (POD) 2 after surgery (POD2-LSR). A total of 228 patients (92.3%) were considered cured at the last clinical follow-up.

RESULTS

The IO-LSR disappeared in 189 patients (76.5%), and among them, 181 patients (95.8%) were cured 1 year after surgery. The POD2-LSR disappeared in 193 patients (78.1%), and 185 patients (95.9%) among them were cured. Among the 189 patients in which the IO-LSR disappeared, the POD2-LSR reappeared in 26 patients (13.8%). In contrast, the POD2-LSR disappeared in 30 (51.7%) of 58 patients for whom the IO-LSR continued at the end of surgery. When classified into groups according to the status of the IO-LSR and POD2-LSR, in the group of patients in whom both LSRs disappeared, the cure rate was 98.2%, which was significantly higher than that of the other 3 groups (p < 0.05, Cochran-Armitage trend test). The use of both LSRs was found to be significantly associated with better predictability (p < 0.05, McNemar's test).

CONCLUSIONS

Postoperative follow-up LSR examination may be beneficial in predicting clinical outcomes after MVD for HFS, especially when considered together with IO-LSR.

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.

Imaging the Substantia Nigra in Parkinson Disease and Other Parkinsonian Syndromes

Parkinson disease is characterized by dopaminergic cell loss in the substantia nigra of the midbrain. There are various imaging markers for Parkinson disease. Recent advances in MRI have enabled elucidation of the underlying pathophysiologic changes in the nigral structure. This has contributed to accurate and early diagnosis and has improved disease progression monitoring. This article aims to review recent developments in nigral imaging for Parkinson disease and other parkinsonian syndromes, including nigrosome imaging, neuromelanin imaging, quantitative iron mapping, and diffusion-tensor imaging. In particular, this article examines nigrosome imaging using 7-T MRI and 3-T susceptibility-weighted imaging. Finally, this article discusses volumetry and its clinical importance related to symptom manifestation. This review will improve understanding of recent advancements in nigral imaging of Parkinson disease. Published under a CC BY 4.0 license.

Is MVD the effective treatment for poorly controlled hypertension?

BACKGROUND

Studies have shown that microvascular decompression (MVD) surgery could improve the clinical symptoms of hemifacial spasm (HFS) and decrease the blood pressure (BP) in patients with refractory hypertension. More positive long-term results are required to establish MVD as a treatment option for high blood pressure (HBP) and to refine the patient selection criteria.

METHODS

From October 2015 to September 2018, based on patient selection for cases with both HFS and poorly controlled HBP of nervous origin, MVD surgeries were performed on 12 patients aiming for better BP control. The patients were followed-up for at least 2 years. The surgical outcomes and associated factors were analyzed.

RESULTS

With respect to neurovascular compression (NVC) of facial nerve, the intra-operative findings concurred with pre-operative radiological findings except that in one case. Intra-operatively ipsilateral cranial nerve (CN) IX-X root exit zone (REZ) and rostral ventrolateral medulla (RVLM) NVCs were confirmed and concordant with pre-operative radiological findings in all 12 cases. 9 Of the 12 cases were completely free of facial spasm after surgery. 2 patients achieved partial relief. 1 patient still suffered from frequent facial spasm. 10 out of 12 patients achieved BP lowering after surgery. The BP of those 10 patients stayed at a relatively stable scale over the follow-up period. Although statistical significance was not obtained, for patients who are operated on the left side and those who have only 1 offensive artery, the surgery might lead to better BP control.

CONCLUSIONS

MVD is a safe and effective treatment for hypertension due to central nervous system (CNS) NVC in patients with both HBP and HFS. Further studies are required to examine long-term outcomes and establish criteria for patient selection.

Serum level of lipoprotein-associated phospholipase A2 is a potential biomarker of vertebrobasilar dolichoectasia and its progression to cerebral infarction

BACKGROUND

There are no effective therapies to prevent the occurrence and progression of vertebrobasilar dolichoectasia (VBD). In this study, we investigated the relationship between serum levels of lipoprotein-associated phospholipase A2 (Lp-PLA2) and the occurrence and progression of VBD.

METHODS

Sixty (60) cases without VBD and ischemia stroke were considered as Group A, 100 cases with VBD were further divided into Group B (VBD without ischemic stroke, n = 54) and Group C (VBD with first ever acute posterior circulation ischemic stroke, n = 46). Demographic data (such as gender and age) and past medical history (such as hypertension, diabetes, and smoking history) were collected. The levels of serum low-density lipoprotein cholesterol (LDL-C), hypersensitivity C reactive protein (hs-CRP), glycosylated hemoglobin (HbAlc), homocysteine (HCY), uric acid (UA), fibrinogen (Fib), and Lp-PLA2, etc. were measured. Logistic regression analysis was used to assess the related factors of VBD and ischemic stroke secondary to VBD.

RESULTS

Logistic multivariate regression analysis showed that only age and the level of serum Lp-PLA2 were significantly higher in group B than those in group A (P < 0.012, P < 0.001, respectively), however, only the level of serum Lp-PLA2 was significantly higher in group C than those in group B (P < 0.001).

CONCLUSIONS

The serum marker Lp-PLA2 is an independent risk factor for the occurrence of VBD and the progression of VBD to posterior circulation ischemic stroke. Whether intervening on atherosclerosis could prevent the occurrence and development of VBD needs to be further studied.

Severe Hemifacial Spasm is a Predictor of Severe Indentation and Facial Palsy after Microdecompression Surgery

Background and Purpose

Hemifacial spasm (HFS) is mostly caused by the compression of the facial nerve by cerebral vessels, but the significance of spasm severity remains unclear. We investigated the clinical significance of spasm severity in patients with HFS who underwent microvascular decompression (MVD).

Methods

We enrolled 636 patients with HFS who underwent MVD between May 2010 and December 2013 at Samsung Medical Center (SMC), Seoul, Korea. Subjects were divided into two groups based on spasm severity: severe (SMC grade 3 or 4) and mild (SMC grade 1 or 2). We compared demographic, clinical, and surgical data between these two groups.

Results

The severe-spasm group was older and had a longer disease duration at the time of MVD compared to the mild-spasm group. Additionally, hypertension and diabetes mellitus were more common in the severe-spasm group than in the mild-spasm group. Regarding surgical findings, there were more patients with multiple offending vessels and more-severe indentations in the severe-spasm group than in the mild-spasm group. Even though the surgical outcomes did not differ, the incidence of delayed facial palsy after MVD was higher in the severe-spasm group than in the mild-spasm group. Logistic regression analysis showed that severe-spasm was correlated with longer disease duration, hypertension, severe indentation, multiple offending vessels, and delayed facial palsy after MVD.

Conclusions

Spasm severity does not predict surgical outcomes, but it can be used as a marker of pathologic compression in MVD for HFS, and be considered as a predictor of delayed facial palsy after MVD.