Reduction quality and nail fixation ratio as bone-implant stability factors associated with reoperation for trochanteric fractures

INTRODUCTION

Geriatric trochanteric fractures are a major global issue, and their incidence is steadily rising. Bone quality, fracture type, fracture reduction quality, implant selection, and implant placement affect bone-implant stability in osteoporotic fractures. Our aim in this study was to evaluate the association between bone-implant stability factors, including nail construct, and the rate of reoperation in a more extensive case series with comprehensive variables.

METHODS

This was a retrospective cohort study of 390 patients with trochanteric fractures aged ≥60 years and treated with intramedullary nailing. The primary outcome was the rate of reoperation due to any cause. Univariate and multivariable logistic regression analyses were used to identify factors associated with reoperation.

RESULTS

In this study, 15 patients (3.8%) required reoperation. Univariate analysis showed that the following variables were significantly different between patients who required reoperation and those who did not: T-score at the total hip and lumbar spine, cortical thickness index, fracture type, and reduction quality. Multivariable logistic regression analysis showed that the odds ratio (OR) for A3 fracture type was 2.76 (95% confidence interval [CI], 0.77-9.76; p=0.116) and that for inadequate reduction, assessed by computed tomography, was 2.94 (95% CI, 0.89-9.69; p=0.076). These were independent predictors of reoperation. There was only one case (6.7%) of reoperation among patients with a distal femoral fragment fixation ratio (FR) >0.8. Considering the intraoperative decision-making process, the combination of inadequate reduction and an FR ≤0.8 were associated with the highest reoperation at a rate of 9.3% (OR, 3.327; 95% CI, 1.091-10.142; p=0.043).

CONCLUSIONS

Risk factors on bone-implant stability for reoperation were the reduction quality and fracture type. Regarding the intraoperative decision-making process, the selection of a nail length with an FR >0.8 is a better option when the intramedullary reduction has been maintained intraoperatively.

Clinical prediction model for postoperative ambulatory ability outcomes in patients with trochanteric fractures

INTRODUCTION

Regaining independent ambulatory ability is one of the primary goals of treatment in patients with trochanteric fractures. This study aimed to develop and evaluate the discriminative accuracy of a clinical prediction model for ambulatory ability outcomes 3 months after surgery for trochanteric fractures.

METHODS

This retrospective cohort study included 346 patients treated with intramedullary nailing for trochanteric fractures who had independent ambulatory ability before their injury. Multiple regression models with preoperative and postoperative factors were used to predict ambulatory ability outcomes at 3 months. A clinical prediction model (CPM) was created based on a decision tree developed using a chi-square automatic interaction detector technique.

RESULTS

Three months after surgery, 263 (76.0%) and 83 (24.0%) patients regained and lost independent ambulatory ability, respectively. Univariate analysis showed that the Barthel index (BI) total score at 2 weeks predicted the ambulatory ability outcome at 3 months with good discriminative accuracy (area under the receiver operating characteristic curve [AUROC]: 0.819; 95% confidence interval [CI]: [0.769, 0.868], cut-off value: 22.5; sensitivity: 69.5%; specificity: 82.3%). Multiple logistic regression analysis showed that preoperative factors (residence before injury, diagnosis of dementia, and serum albumin at admission) and postoperative factors (BI total score at 2 weeks) predicted ambulatory ability outcomes at 3 months (AUROC: 0.710; 95%CI: [0.636, 0.783]; sensitivity: 91.3%; specificity: 41.8%). The CPM with the BI total score at 2 weeks (≤10; 10<, ≤50; >50 points) and dementia status (present; absent) had a moderate discriminative accuracy (AUROC: 0.676; 95%CI: [0.600, 0.752]; sensitivity: 94.7%; specificity: 40.5%).

CONCLUSIONS

We developed a CPM with moderate accuracy to predict ambulatory ability outcomes in patients 3 months after surgery for trochanteric fractures. Our results demonstrate the importance of the BI score measured soon after surgery and dementia status for the prediction of postoperative ambulation.

Postoperative computed tomography assessment of anteromedial cortex reduction is a predictor for reoperation after intramedullary nail fixation for pertrochanteric fractures

PURPOSE

Postoperative radiographs are routinely used to assess fracture reduction following intramedullary nail fixation for pertrochanteric fractures, even though computed tomography (CT) is a superior modality. We aimed to determine the association between reduction quality assessed by CT and rates of reoperation and to evaluate the association of reoperation and reduction quality according to the assessment modality (plain radiographs vs. CT).

METHODS

A retrospective analysis of 299 consecutive patients treated with intramedullary nail fixation for pertrochanteric fractures was conducted. Fracture reduction measured by postoperative radiographs and CT was categorized as anatomical type, extramedullary type, or intramedullary type. Postoperative data for analysis included reduction status, tip-apex distance (TAD), screw position in the femoral head, sliding distance, and conditions associated with reoperation.

RESULTS

Of the 299 patients included with a mean age of 83.1 ± 8.2 years, there were six patients who required reoperation (2.0%). According to the CT assessments, there were 42 intramedullary reductions (14.0%). Patients with a non-intramedullary reduction based on postoperative CT images were significantly more likely to have proper placement of the screw, a reduced TAD, a reduced sliding distance, and a lower reoperation rate than those with an intramedullary reduction (P < 0.05). The reduction quality assessed by postoperative CT was significantly associated with reoperation (95% CI, 1.45-29.31).

CONCLUSIONS

Intramedullary reduction assessed by CT was associated with reoperation. The reduction quality based on CT findings was more predictive for reoperation than that from plain radiographs.

Heat-killed Lactobacillus brevis KB290 attenuates visceral fat accumulation induced by high-fat diet in mice

AIMS

This study aimed to evaluate the anti-adiposity effect of heat-killed Lactobacillus brevis KB290 originating from traditional Japanese fermented pickles in mice fed a high-fat diet (HFD).

METHODS AND RESULTS

C57BL/6J mice were fed a normal-fat diet, HFD or HFD supplemented with heat-killed KB290 for 8 weeks. Epididymal and renal adipose tissue weights, as well as areas of epididymal adipocytes, were significantly lower in the mice fed a HFD supplemented with KB290 than in those fed an unsupplemented HFD. Mice whose diets were supplemented with KB290 had elevated adiponectin and β3-adrenergic receptor expression in epididymal adipose tissue and an accompanying higher serum free fatty acid level. Furthermore, the HFD-induced elevations in serum glucose, insulin and HOMA-IR were significantly suppressed by dietary supplementation with KB290. Amplicon sequencing of 16S rRNA genes revealed that KB290 ingestion altered the composition of the intestinal microbiota.

CONCLUSIONS

Heat-killed L. brevis KB290 suppressed diet-induced visceral fat accumulation and ameliorated diet-induced metabolic symptoms and intestinal gut microbiota modifications, suggesting possibility of novel paraprobiotic.

SIGNIFICANCE AND IMPACT OF THE STUDY

Heat-killed L. brevis KB290 is useable as a material to develop functional foods that attenuate visceral fat accumulation.

Radiological findings and outcomes of anterior wall fractures in pertrochanteric fractures

BACKGROUND

Anterior wall fractures with comminution at the anterior cortex in pertrochanteric fractures are relatively rare. We aimed to investigate the prevalence and clinical findings of anterior wall fractures in this comparative cohort study.

METHODS

We reviewed 516 consecutive patients who underwent internal fixation. Anterior wall fractures were classified into three types: proximal, distal, and proximal/distal. Outcome measures included demographic data, residual anterior cortex length, fracture reduction, tip-apex distance (TAD), sliding distance, bone union, and revision surgery. We compared radiological outcomes between patients with anterior wall fractures and posterior comminuted fractures without an anterior wall fracture. The groups were matched for age and sex.

RESULTS

Anterior wall fractures were noted in 44 patients (8.5%). Residual anterior cortex length was shorter for the proximal/distal type. The distal type was the most common, was the most difficult to achieve an acceptable reduction status for, and was associated with the longest sliding distance. The proportion of unacceptable reduction status was higher for anterior wall fractures. However, there were no statistically significant differences between anterior wall fractures and posterior comminuted fractures without an anterior wall fracture in terms of TAD, sliding distance, bone union, and revision rate.

CONCLUSIONS

This study suggests that anterior wall fracture is not a significant predictor of over-sliding distance.

Association of intravenous administration of human Muse cells with deficit amelioration in a rat model of spinal cord injury

OBJECTIVE

Multilineage-differentiating stress-enduring (Muse) cells are pluripotent stem cells, which can be harvested from the bone marrow. After transplantation, Muse cells can migrate to an injured site of the body and exert repair effects. However, it remains unknown whether Muse cell transplantation can be an effective treatment in spinal cord injury (SCI).

METHODS

The authors used a rat model of thoracic spinal cord contusion injury. For Muse cell transplantation, the clinical product CL2020 containing 300,000 Muse cells was administered intravenously 1 day after midthoracic SCI. Animals were divided into CL2020 (n = 11) and vehicle-treated (n = 15) groups. Behavioral and histological evaluations were conducted over a period of 8 weeks to see whether intravenous CL2020 administration provided therapeutic effects for SCI. The effects of human-selective diphtheria toxin on reversion of the therapeutic effects of CL2020 were also investigated.

RESULTS

Hindlimb motor function significantly improved after CL2020 transplantations. Importantly, the effects were reverted by the human-selective diphtheria toxin. In immunohistochemical analyses, the cystic cavity formed after the injury was smaller in the CL2020 group. Furthermore, higher numbers of descending 5-hydroxytryptamine (5-HT) fibers were preserved distal to the injury site after CL2020 administration. Eight weeks after the injury, Muse cells in CL2020 were confirmed to differentiate most predominantly into neuronal cells in the injured spinal cord.

CONCLUSIONS

Following SCI, Muse cells in CL2020 can reach the injured spinal cord after intravenous administration and differentiate into neuronal cells. Muse cells in CL2020 facilitated nerve fiber preservation and exerted therapeutic potential for severe SCI.

SARC-F Predicts Mortality Risk of Older Adults during Hospitalization

OBJECTIVES

To determine the association between SARC-F scores and the in-hospital mortality risk among older patients admitted to acute care hospitals.

DESIGN

Single-center retrospective study.

SETTING

A university hospital.

PARTICIPANTS

All consecutive patients aged older than 65 were admitted and discharged from the study hospital between July 2019 and September 2019.

MEASUREMENTS

Relevant patient data included age, sex, body mass index, nutritional status, fat-free mass, disease, activities of daily living (ADL), duration of hospital stay, SARC-F, and occurrence of death within 30 days of hospitalization. The diseases that caused hospitalization and comorbidities (Charlson Comorbidity Index; CCI) were obtained from medical records. The Eastern Cooperative Oncology Group-performance status (PS) was used to determine ADL, and the in-hospital mortality rate within 30 days of hospitalization as the outcome.

RESULTS

We analyzed 2,424 patients. The mean age was 75.9±6.9 and 55.5% were male. Fifty-three in-hospital mortalities occurred among the participants within the first 30 days of hospitalization. Patients who died in-hospital were older, had poorer nutritional status and severer PS scores, and more comorbidities than those who did not. A SARC-F score of ≥4 predicted a higher mortality risk within those 30 days with the following precision: sensitivity 0.792 and specificity 0.805. There were significantly more deaths in Kaplan-Meier curves regarding a score of SARC-F≥4 than a score of SARC-F<4 (p<0.001). Cox proportional hazard analysis was used to identify the clinical indicators most associated with in-hospital mortality. SARC-F≥4 (Hazard Ratio: HR 5.65, p<0.001), CCI scores (HR1.11, p=0.004), and infectious and parasitic diseases (HR3.13, p=0.031) were associated with in-hospital mortality. The SARC-F items with significant in-hospital mortality effects were assistance with walking (HR 2.55, p<0.001) and climbing stairs (HR 2.46, p=0.002).

CONCLUSION

The SARC-F questionnaire is a useful prognostic indicator for older adults because a SARC-F ≥4 score during admission to an acute care hospital predicts in-hospital mortality within 30 days of hospitalization.

Validation of the Japanese version of the Dementia Screening Questionnaire for Individuals with Intellectual Disabilities

BACKGROUND

Dementia in people with intellectual disabilities (IDs) is difficult to detect because of preexisting cognitive deficits. An effective screening method is required. The Dementia Screening Questionnaire for Individuals with Intellectual Disabilities (DSQIID) was developed as an observer rating tool to screen dementia in people with ID. The aim of this study was to verify the screening accuracy of the DSQIID for Japanese people with ID.

METHODS

Four-hundred ninety-three subjects with ID participated in this study. Caregivers who had observed the participants for more than 2 years scored the Japanese version of the DSQIID (DSQIID-J) of the participants. Three doctors examined participants directly and diagnosed dementia using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria. To identify the key screening items that predict dementia, the specificities of a single and pairs of items with 100% sensitivity were evaluated relative to the dementia diagnosis.

RESULTS

Of 493 participants, 34 were people with Down syndrome (DS), and 459 were people without DS. Seventeen participants were diagnosed with dementia. The suitable cut-off score of the DSQIID-J was 10/11 (sensitivity 100% and specificity 96.8%) for screening dementia. The inter-rater reliability, test-retest reliability and internal consistency of the DSQIID-J were excellent. Regarding key items, there was no single item with 100% sensitivity, and the best two-item combination was the pair of 'Cannot dress without help' and 'Walks slower' (sensitivity 100% and specificity 93.5%).

CONCLUSIONS

We identified several important question items of the DSQIID-J related to the diagnosis of dementia in people with ID. The DSQIID-J is a useful screening tool for dementia in adults with ID.

Risk Factor Analysis of Facet Fusion Following Cervical Lateral Mass Screw Fixation with a Minimum 1-Year Follow-up: Assessment of Maximal Insertional Screw Torque and Incidence of Loosening

Posterior stabilization is a common surgical procedure, which aims for rigid stabilization by facet fusion. Facet non-union has a potential risk of the screw loosening and malalignment. Although some authors have reported the influencing factors about screw loosening in the lumbar spine, there are few reports about the risk factor contributing to the facet non-union in the cervical spine. In all, 22 patients (78 facets and 122 screws) with degenerative cervical kyphosis or spondylolisthesis who underwent decompression and lateral mass screw (LMS) fixation were analyzed. Age, gender, smoking, bone mineral density (BMD), the degree of facet decortication with bone packing, and screw loosening were investigated as risk factors contributing to the facet non-union at each segmental fused level. Facet fusion rate was 85.9% (67/78 facets) and the incidence of loosening was 4.9% (6/122 screws, 4 patients). Insufficient facet decortication with bone packing is a significant risk factor of facet non-union (p <0.05, odds ratio: 26.5). All six loosened screws were associated with bony non-union of the facet and were located in the uppermost or lowermost vertebrae. Comparing loosened screws and stable screws, the average maximal insertional screw torque (MIT) was 9.8 cNm and 39.5 cNm, respectively (p <0.05). Additionally, the length of the stable screws was significantly longer versus the loosened screws (p <0.05). Lower MIT and shorter screw length located near the ends of the lateral mass may predict loosening, which can lead to facet non-union. Sufficient facet decortication with bone packing is one of the important factors contributing to the facet fusion.

Prediction of Functional Outcome in Patients with Acute Stroke by Measuring tRNA Derivatives

BACKGROUND AND PURPOSE

Transfer RNA (tRNA) is a noncoding RNA that delivers amino acids to ribosomes for protein synthesis. tRNA is also involved in cell stress response programs. Oxidative stress induces direct conformational change in tRNA structure that promotes subsequent tRNA fragmentation. Using an antibody against tRNA-specific modified nucleoside 1-methyladenosine (m1A), we can detect tRNA derivatives such as conformationally changed tRNA, tRNA-derived fragments, and mononucleotide-free m1A. Based on these findings, tRNA derivatives may have potential as an early tissue damage marker. The purpose of this study was to investigate the plasma tRNA derivatives in stroke patients to clarify whether tRNA derivatives in the acute phase can detect early brain damage and then predict the functional outcome.

METHODS

Patients (75 patients with ischemic and 66 with hemorrhagic stroke) and 22 healthy volunteers were prospectively enrolled for this study between November 2016 and February 2019. Plasma samples were collected within 24 h and at 1 day, 7 days, and 30 days from the onset. Plasma tRNA derivative concentrations were measured by ELISA kit using the anti-m1A antibody.

RESULTS

The plasma tRNA derivative level on admission was significantly increased in both ischemic (mean ± standard error, 232.2 ± 33.1 ng/mL) and hemorrhagic stroke patients (212 ± 23.4 ng/mL) compared to the healthy volunteers (86.0 ± 7.9 ng/mL) (p = 0.00042 and p = 0.00018, respectively). The infarction size (r = 0.445, p = 0.00018) and hematoma volumes (r = 0.33, p = 0.0072) were also significantly correlated with tRNA derivatives. The concentrations of tRNA derivatives were associated with poor functional outcome (Modified Rankin Scale score 3-6 at 30 days from the onset) in patients with ischemic stroke at 7 days after onset (p = 0.020).

CONCLUSIONS

Stress-induced tRNA derivatives can detect brain tissue damage, predicting functional outcome in patients with ischemic stroke.

Effects of cyclic stretching exercise on long-lasting hyperalgesia, joint contracture, and muscle injury following cast immobilization in rats

The effects of exercise on mechanical hyperalgesia, joint contracture, and muscle injury resulting from immobilization are not completely understood. This study aimed to investigate the effects of cyclic stretching on these parameters in a rat model of chronic post-cast pain (CPCP). Seventeen 8-week-old Wistar rats were randomly assigned to (1) control group, (2) immobilization (CPCP) group, or (3) immobilization and stretching exercise (CPCP+STR) group. In the CPCP and CPCP+STR groups, both hindlimbs of each rat were immobilized in full plantar flexion with a plaster cast for a 4-week period. In the CPCP+STR group, cyclic stretching exercise was performed 6 days/week for 2 weeks, beginning immediately after cast removal prior to reloading. Although mechanical hyperalgesia in the plantar skin and calf muscle, ankle joint contracture, and gastrocnemius muscle injury were observed in both immobilized groups, these changes were significantly less severe in the CPCP+STR group than in the CPCP group. These results clearly demonstrate the beneficial effect of cyclic stretching exercises on widespread mechanical hyperalgesia, joint contracture, and muscle injury in a rat model of CPCP.

Clinical determinants and prognostic impact of osteoporosis in patients with chronic heart failure

Background

Despite accumulating evidence of a close association between orthopedic fractures and chronic heart failure (CHF), the clinical risk factors of osteoporosis, defined as reduction in bone mineral densities (BMDs), in CHF patients have not been systematically analyzed. In addition, the impact of osteoporosis on prognosis of CHF remains unclear.

Aims

We aimed to clarify the prevalence, clinical risk factors, and prognostic impact of osteoporosis in CHF patients.

Methods

We retrospectively examined 303 CHF patients (75 years, [interquartile range (IQR), 66–82 years]; 41% female). BMDs at the lumber spine, femoral neck, and total femur were measured by dual-energy X-ray absorptiometry (DEXA), and osteoporosis was diagnosed when BMD at any of the three sites was less than 70% of Young Adult Mean.

Results

The prevalence of osteoporosis in the CHF patients was 40%. Patients with osteoporosis were older (79 [IQR, 74–86] vs. 72 [IQR, 62–80] years), included a large percentage of females, had slower gait speed and had lower body mass index (BMI). Loop diuretics and warfarin were used more frequently and direct oral anticoagulants (DOACs) were used less frequently in patients with osteoporosis than in patients without osteoporosis. Multivariate logistic regression analysis indicated that sex (odds ratio [OR] 5.07, 95% Confidence Interval [CI] 2.68–9.61, p&lt;0.01), BMI (OR, 0.83; 95% CI, 0.75–0.91; p&lt;0.01), gait speed (OR, 0.80; 95% CI, 0.70–0.92; p&lt;0.01), loop diuretics use (OR, 2.52; 95% CI, 1.20–5.27; p=0.01) and no DOACs use (OR, 0.43; 95% CI, 0.19–0.96; p=0.04) were independently associated with osteoporosis. During the mean follow-up period of 290±254 days, 92 patients (30.4%) had adverse events. When patients with osteoporosis were divided into subgroups according to the number of sites with BMD of an osteoporosis level, Kaplan-Meier survival curves showed that the rate of adverse events (death and cardiovascular events) was higher in patients with osteoporotic BMD at two or more sites than in patients without osteoporosis (51% vs. 23%, p=0.03) (Figure). In multivariate Cox regression analyses, osteoporotic BMD at two or more sites was an independent predictor of adverse events after adjustment for age, sex, and NT-proBNP level (Hazard ratio, 1.74; 95% CI, 1.01–2.99; p=0.04).

Conclusion

The risk of osteoporosis may be increased in users of loop diuretics and may be decreased in users of DOACs in CHF patients. Extent of osteoporosis is a novel predictor of adverse events in CHF patients.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): The Japan Society for the Promotion of Science KAKENHI

Practice patterns, feasibility and efficacy of coronary artery angiography using distal radial approach

Background

Most patients undergo coronary angiography by transradial approach. However, recently distal radial approach has been introduced as a novel approach for coronary angiography and intervention. There is uncertainty on the feasibility and safety of distal radial approach for coronary angiography.

Methods

All consecutive 1450 coronary angiography cases (distal radial approach 237 cases, conventional transradial approach 1213 cases) between October 2018 and December 2019 were included in this study. Emergency coronary angiography cases and ad hoc coronary intervention cases were excluded. Patients were stratified into distal radial approach and conventional radial approach subgroups. Baseline characteristics, contrast amount, procedure time, radiation amount, fluoroscopy time, and complications in catheterization laboratory were statistically analyzed.

Results

There were no significant differences in age and gender between distal radial vs transradial groups: mean age, 70.8±10.5 vs 70.8±11.0 years; % of males, 77.2% vs 66.9%. Procedure time was significantly shorter in distal radial approach group (28.7±13.3 min vs 32.3±14.2 min, p&lt;0.05) and total radiation amount during procedure was significantly less in distal radial approach group (366.4±189.5 ml vs 412.9±220.3 mGy, p&lt;0.05).

Conclusions

Coronary angiography with distal radial approach decreases the procedure time and total radiation amount. It is feasible and safe in most stable patients.

Funding Acknowledgement

Type of funding source: None

XGBoost, a Machine Learning Method, Predicts Neurological Recovery in Patients with Cervical Spinal Cord Injury

The accurate prediction of neurological outcomes in patients with cervical spinal cord injury (SCI) is difficult because of heterogeneity in patient characteristics, treatment strategies, and radiographic findings. Although machine learning algorithms may increase the accuracy of outcome predictions in various fields, limited information is available on their efficacy in the management of SCI. We analyzed data from 165 patients with cervical SCI, and extracted important factors for predicting prognoses. Extreme gradient boosting (XGBoost) as a machine learning model was applied to assess the reliability of a machine learning algorithm to predict neurological outcomes compared with that of conventional methodology, such as a logistic regression or decision tree. We used regularly obtainable data as predictors, such as demographics, magnetic resonance variables, and treatment strategies. Predictive tools, including XGBoost, a logistic regression, and a decision tree, were applied to predict neurological improvements in the functional motor status (ASIA [American Spinal Injury Association] Impairment Scale [AIS] D and E) 6 months after injury. We evaluated predictive performance, including accuracy and the area under the receiver operating characteristic curve (AUC). Regarding predictions of neurological improvements in patients with cervical SCI, XGBoost had the highest accuracy (81.1%), followed by the logistic regression (80.6%) and the decision tree (78.8%). Regarding AUC, the logistic regression showed 0.877, followed by XGBoost (0.867) and the decision tree (0.753). XGBoost reliably predicted neurological alterations in patients with cervical SCI. The utilization of predictive machine learning algorithms may enhance personalized management choices through pre-treatment categorization of patients.

Intractable Hiccups as the Primary Symptom of a Perimedullary Arteriovenous Fistula at the Craniocervical Junction

BACKGROUND

Hiccups are a well-known short-term phenomenon in daily life. If they persist or become intractable, they may be a primary symptom of a disease. Recent studies identified the medulla oblongata as the neuroanatomic center of the hiccup reflex arc. In previous cases, an isolated lesion at the dorsal side of the medulla oblongata induced intractable hiccups.

CASE DESCRIPTION

We herein describe a patient with a perimedullary arteriovenous fistula (PMAVF) at the craniocervical junction who had intractable hiccups. A 70-year-old male presented with a 3-year history of intractable hiccups that continued for a few days every week. An initial examination failed to identify the underlying cause, and neither medicine nor self-treatment attenuated his symptoms. Intracranial T2-weighted magnetic resonance imaging showed a hyperintensity area within the dorsolateral medulla and flow voids along the dorsal side of the cervical spine. Angiography revealed PMAVF fed by the left C1 radiculomedullary artery. Obliteration of the fistula was performed, after which intractable hiccups had completely disappeared within 1 week.

CONCLUSIONS

This is the first case report of PMAVF at the craniocervical junction presenting with intractable hiccups that suggested a lesion in the dorsal side of the medulla. The mechanisms underlying hiccups are also discussed.