Neurological complications of ankylosing spondylitis: neurophysiological assessment

Association of nociplastic and neuropathic pain components with the presence of residual symptoms in patients with axial spondyloarthritis receiving biological disease-modifying antirheumatic drugs

OBJECTIVE

To evaluate the association of nociplastic (NoP) and neuropathic pain (NP) components with residual symptoms in patients with radiographic axial spondyloarthritis (r-axSpA) receiving biological disease-modifying antirheumatic drugs (bDMARDs).

METHODS

78 patients with r-axSpA from the GErman SPondyloarthritis Inception Cohort receiving a bDMARD for at least 3 months were included in this analysis. The Widespread Pain Index (WPI) and the PainDETECT (PD) questionnaire were used to quantify the NoP and the NP components, respectively. Axial Spondyloarthritis Disease Activity Score (ASDAS) and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) were used as measures of residual symptoms. C reactive protein (CRP) was used as a measure of systemic inflammatory activity. Univariable and multivariable regression analyses of disease activity were performed. The regions of the WPI score and items of the PD score were used for cluster analyses.

RESULTS

Linear multivariable regression analysis showed that WPI and PD were independently associated with ASDAS (b=0.1, 95% CI 0.04 to 0.17, and b=0.05, 95% CI 0.02 to 0.08, respectively) and BASDAI (b=0.24, 95% CI 0.08 to 0.39, and b=0.17, 95% CI 0.1 to 0.25, respectively) in r-axSpA patients receiving stable treatment with bDMARDs. Furthermore, WPI and PD were found to be significantly associated with the presence of relevant residual symptoms as defined by BASDAI ≥4 (OR 1.93, 95% CI 1.09 to 4.15, and OR 1.32, 95% CI 1.04 to 1.85, respectively). The effects were present also in patients with normal level of CRP. Cluster analysis revealed three distinct pain distribution profiles and four specific sensory symptom constellations allowing differentiation of different pain subtypes.

CONCLUSION

Both NoP and NP components seem to be associated with residual symptoms in patients with r-axSpA receiving treatment with bDMARDs.

Disrupted Neural Regeneration in Dry Eye Secondary to Ankylosing Spondylitis-With a Theoretical Link between Piezo2 Channelopathy and Gateway Reflex, WDR Neurons, and Flare-Ups

This study aimed at analyzing the corneal neural regeneration in ankylosing spondylitis patients using in vivo corneal confocal microscopy in correlation with Langerhans cell density, morphology, and dry eye parameters. Approximately 24 ankylosing spondylitis subjects and 35 age- and gender-matched control subjects were enrolled. Data analysis showed that all corneal nerve-fiber descriptives were lower in the ankylosing spondylitis group, implicating disrupted neural regeneration. Peripheral Langerhans cell density showed a negative correlation with nerve fiber descriptions. A negative correlation between tear film break-up time and corneal nerve fiber total branch density was detected. The potential role of somatosensory terminal Piezo2 channelopathy in the pathogenesis of dry eye disease and ankylosing spondylitis is highlighted in our study, exposing the neuroimmunological link between these diseases. We hypothesized earlier that spinal neuroimmune-induced sensitization due to this somatosensory terminal primary damage could lead to Langerhans cell activation in the cornea, in association with downregulated Piezo1 channels on these cells. This activation could lead to a Th17/Treg imbalance in dry eye secondary to ankylosing spondylitis. Hence, the corneal Piezo2 channelopathy-induced impaired Piezo2-Piezo1 crosstalk could explain the disrupted neural regeneration. Moreover, the translation of our findings highlights the link between Piezo2 channelopathy-induced gateway to pathophysiology and the gateway reflex, not to mention the potential role of spinal wide dynamic range neurons in the evolution of neuropathic pain and the flare-ups in ankylosing spondylitis and dry eye disease.

Neuromyelitis optica spectrum disorder in a patient with ankylosing spondylitis: A case report

Neuromyelitis optica spectrum disorder is an autoimmune disease which tends to have other coexisting autoimmune or connective tissue diseases. However, coexisting with ankylosing spondylitis is rare. Here, we report a 57-year-old man with concomitant autoantibodies against aquaporin 4-positive neuromyelitis optica spectrum disorder and HLA-B27-positive ankylosing spondylitis.

Comparison of shoulder muscle strength, shoulder range of motion and scapular motion in men with ankylosing spondylitis and healthy men: a case-controlled study

Background/Aims

Ankylosing spondylitis mainly affects the vertebral column, meaning that the assessment of the physical function of the upper extremity and scapulothoracic region in ankylosing spondylitis is often overlooked. Therefore, the aim of this study was to investigate shoulder muscle strength, shoulder active range of motion and three-dimensional scapular motion in patients with ankylosing spondylitis.

Methods

The study included 18 men with ankylosing spondylitis, and 16 age-matched typically healthy men as the control group. Muscle strength, active range of motion, and three-dimensional scapular motion were assessed with a digital hand-held dynamometer, an inclinometer, and an electromagnetic tracking device respectively.

Results

A decrease in shoulder flexion and abduction muscle strength on both the dominant side (P<0.001, P=0.001) and non-dominant side (P<0.001, P<0.001) was found in the ankylosing spondylitis group compared to the control group. A decrease in shoulder flexion, abduction, and external and internal rotation active range of motion on both the dominant side (P=0.001, P<0.001, P=0.015, P<0.001, respectively) and non-dominant side (P=0.001, P<0.001, P=0.017, P<0.001 respectively) was observed in the ankylosing spondylitis group. There was an increase in the upward rotation of the scapula on the non-dominant side at 30, 60, and 90° humeral elevations in the ankylosing spondylitis group compared to the control group (P=0.018, P=0.003, P=0.001 respectively). The other parameters of the scapular motion did not differ between groups (P>0.05).

Conclusions

This study showed that shoulder muscle strength and active range of motion were lower, and the upward rotation of the scapula was greater in men with ankylosing spondylitis compared to typically healthy men. The kinetics and kinematics parameters of the shoulder and scapula should be considered when assessing the physical function of patients with ankylosing spondylitis.

Results of in situ fixation of Andersson lesion by posterior approach in 35 cases

STUDY OBJECTIVE

Due to the rarity of the Andersson lesion (AL), the literature is ambiguous regarding the type of surgical fixation, need for debridement and deformity correction. The purpose of this retrospective study is to evaluate the efficacy, feasibility and functional outcome of posterior fixation in AL.

MATERIALS AND METHODS

This study included 35 patients having thoracolumbar AL operated for in situ fixation and fusion with minimum of 24-month follow-up. VAS (Visual Analogue Score) back pain, ODI (Oswestry Disability Index), Frankel's grade were compared and analyzed. Union status was noted with complications.

RESULTS

The mean age of 35 patients was 56.34(± 11.3) years with average follow-up of 51.49 months. Two patients had AL at two levels. 27/37 AL were at discal level. Average estimated blood loss (EBL) was 276.43 ml and duration of surgery was 130.43 min. On an average, operated segments needed 7.77 screws. There were ten minor complications without long-term sequel. Neurological improvement was noted in 30 patients. Average preoperative VAS score improved from 8.69 to 3.14, ODI score improved from 68.76 to 18.77 at final follow-up which were significant (p < 0.05). There was significant improvement in Frankel's grading (Z = - 4.354, P = 0.00).

CONCLUSIONS

Surgical management of AL by posterior approach and posterior stabilization can give satisfactory results without the need of extensive anterior reconstruction, bone grafting or deformity correction procedures without added morbidity and complications.

Nöropatik ağrı aksiyal spondiloartritte gözden kaçan bir semptom mu?

Amaç: Aksiyal spondiloartitler (axSpA) kronik inflamatuar romatolojik hastalıklardan olup ağrı yaşam kalitelerini etkileyen en sık semptomdur. Literatürde ağrının her zaman inflamasyonla korele olmadığı gösterilmiştir. Bu çalışma ile aksiyal spondiloartrit hastalarında nöropatik ağrının frekansının gösterilmesi ve nöropatik ağrı ile hasta özelliklerinin arasındaki ilişkinin gösterilmesi amaçlanmıştır. Gereç ve Yöntem: Kliniğimizde Ocak- Mart 2019 ayları arasında takip edilen, Assessment of SpondyloArthritis International Society klasifikasyon kriterlerine göre axSpA kabul edilen hastalar çalışmaya dahil edilmiştir. Nöropatik ağrı Douleur Neuropathique en 4 Questions (DN4) ölçeği ile değerlendirildi. Bulgular: Seksen yedi axSpa hastası çalışmaya dahil edildi. Hastaların 30’unda DN4 ölçeğine göre (DN4 >4) nöropatik ağrı var kabul edildi. Nöropatik ağrı aktif hasta grubunda (ASDAS- CRP ve BASDAI’ ye göre) daha fazla saptandı. DN4 skoru ASDAS- CRP ve BASDAI skoru ile orta düzeyde korele saptandı. Hasta eğitim düzeyi ile DN4 skoru arasında hafif düzeyde korelasyon saptandı. Sonuç: Çalışmamızda axSpA hastalarında inflamatuvar ağrıya ek olarak nöropatik ağrının görülebileceği ve hastalık aktivitesi ile korele olabileceği gösterildi. Nöropatik ağrı hastaların yaşam kalitesini bozduğu, sosyal ve emosyonel bozukluklara yol açtığı literatürde gösterilmiştir. Hastalar standart anti inflamatuvar tedavi yaklaşımlarından fayda görmeyebilir. AxSpA hastalarında nöropatik ağrının değerlendirilmesi önem kazanmaktadır. AxSpA hastalarında nöropatik ağrının tanı ve tedavi sürecinde ileri çalışmalara gereksinim duyulmaktadır.

Seropositive Neuromyelitis Optica in a Case of Undiagnosed Ankylosing Spondylitis: A Neuro-Rheumatological Conundrum

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune astrocytopathy against foot processes of aquaporin-4 (AQP4) water channels. Patients with NMOSD tend to have other coexisting autoimmune/connective tissue diseases. However, AQP-4-antibody-positive NMOSD coexisting with ankylosing spondylitis (AS) is rare. AS is an immune-mediated disorder, a subset of axial spondyloarthropathies, which commonly manifests as chronic inflammatory back pain in young people, and it has a strong association with HLA-B27. In this study, a 35-year-old Indian man with an undiagnosed progressive axial spondyloarthropathy (i.e., AS) is reported presenting with acute-onset longitudinally extensive transverse myelitis, a clinical subset of NMOSD. Neuromyelitis optica spectrum disorder (NMOSD), a primary demyelinating disorder of the central nervous system (CNS), is an autoimmune astrocytopathy against foot processes of aquaporin-4 (AQP4) water channels, which manifests with optic neuritis, longitudinally extensive transverse myelitis (LETM), area-postrema syndrome, brainstem syndrome diencephalic syndrome, and cerebral syndrome.^1-4 Ankylosing spondylitis (AS) is an immune-mediated disorder, a subset of axial spondyloarthropathies, which commonly manifests as chronic inflammatory back pain in young people, and it has a strong association with HLA-B27.^5,6 AS characteristically targets the axial skeleton, peripheral joints, entheses (connective tissues between tendons/ligaments and bones), and gut.^5,6 Patients with NMOSD tend to have other coexisting autoimmune/connective tissue diseases.⁷ For example, cases with NMOSD and multiple sclerosis, which are other autoimmune primary demyelinating disorders of the CNS, have been reported.^8,9 However, concurrent existence of AS and NMOSD in the same patient even over years of disease course is rare.^10,11 In addition, studies describing neurological manifestations of AS are limited,¹² and they focus on joint inflammation and long-standing bony pathology (ankylosis) related to compressive myelopathy, myelo-radiculopathy, and cauda equina syndromes.^12,13 The authors present a case of a young Indian man with an undiagnosed progressive AS (misdiagnosed and mismanaged by an indigenous medical practitioner) presenting with acute-onset LETM variant of AQP4-positive NMOSD. A 35-year-old healthy, non-comorbid man from rural India came to the outpatient department with complaints of persistent tingling, numbness, and weakness of both lower limbs (right more than left) for 10 days. The clinical picture showed acute-onset urinary retention, which was relieved by urinary catheterization. An indigenous medical practitioner had prescribed drugs to treat a urinary tract infection. His weakness gradually progressed over the following week, causing him to become bedridden. During the removal of the catheter, he felt urgency, increased frequency of micturition, and overt urinary incontinence. He gave no history suggestive of any girdle-like sensations, root/radicular/tract pain, vertebral pain, trauma, recent vaccination, and diarrheal or febrile illness. For the last 8 months, he had a complaint of an insidious-onset, persistent, bilateral, dull aching pain in the gluteal region accompanied by low-back pain and morning stiffness up to 1 h, which markedly improved with activity and reoccurred following long periods of inactivity. He sometimes had to rise in the middle of the night because of excruciating pain, which could be relieved after moving around the room and corridors for half an hour. He was taking over-the-counter diclofenac tablets for pain relief prescribed by some indigenous medical practitioners who told him that it was due to overwork in agricultural fields, that is, mechanical back pain. He also had a normal X-ray of the lumbosacral spine. He had no addiction liabilities, and none of the family members had ever suffered from a similar kind of illness. He had never consulted any trained medical practitioner, as his previous back-pain-related symptoms responded well to the tablets prescribed by the indigenous medical practitioner(s). During examination, he was found to have recent-onset, asymmetric spastic paraparesis (right more than left) with upper motor neuron-type urinary bladder symptoms. Cognitive assessment (assessed by the Montreal cognitive assessment test) was normal, and posterior column sensations were preserved. Sensory system examination revealed no definite sensory level. Except for the paretic lower limbs, cerebellar functions were normal in other regions. Neuro-ophthalmological examinations were also normal, and no signs of meningeal irritation were observed. The history and course of the disease and clinical examinations were analyzed. Selective tractopathy (early and predominant motor and autonomic tract affection) was suggested for an intramedullary demyelinating pathology affecting the anterior central cord. This case was initially classified as acute-onset non-compressive myelopathy at the lower cervical/upper dorsal region level in a patient with a pre-existing axial spondyloarthropathy. Complete blood cell count; liver, kidney, and thyroid function tests; and plasma glucose and electrolytes were normal, except for an increased erythrocyte sedimentation rate (66 mm in the first hour). Magnetic resonance imaging (MRI) of the spinal cord revealed a demyelinating LETM from C5 to D4 level (Figure 1). Meanwhile, an MRI of the sacroiliac joints revealed bilateral sacroiliitis. Brain and orbital MRIs were devoid of any lesions. Anti-aquaporin 4 (AQP-4) antibodies were tested by cell-based assay in serum and cerebrospinal fluid (CSF), and both were positive. CSF further revealed lymphocytic pleocytosis and increased intrathecal protein production. Visually evoked potential recordings were also normal. In addition, anti-myelin oligodendrocyte glycoprotein antibodies were negative. Anti-nuclear antibody (ANA), ANA-profile, autoimmune vasculitis profile (c-ANCA, p-ANCA), neurovirus panel (i.e., polymerase chain reaction for adenovirus, Epstein-Barr virus, herpes simplex viruses 1 and 2, human herpesviruses 6 and 7, cytomegalovirus, enteroviruses, varicella-zoster virus, Japanese encephalitis, and dengue virus), CSF-polymerase chain reaction for Mycobacterium tuberculosis, angiotensin-converting enzyme, anti-phospholipid, and anti-thyroid antibodies were negative. Anti-CCP-antibody and rheumatoid factor were also negative, including creatine phosphokinase level and serum vitamin B12. Moreover, serologies for hepatitis B, C, human immunodeficiency virus, and scrub typhus were negative. However, HLA-B27 assay was positive. The final diagnosis was AQP4-positive NMOSD associated with AS. He was placed on pulse intravenous methylprednisolone (1 g/day for 5 days). Consequently, his lower limb power improved remarkably. Cyclical rituximab therapy was initiated to prevent relapses. At 3-month follow-up, he had no residual neurological deficit except for persistence of paresthesias. Neuroimaging and visually evoked potential studies revealed no active or new lesions. After 6 months of therapy, a subjective and objective improvement was observed in disease severity based on the Ankylosing Spondylitis Disease Activity Score. Our patient satisfied the new Assessment of SpondyloArthritis International Society diagnostic/classification criteria for AS and the Wingerchuk criteria for NMOSD,^4,14 an association that has been rarely reported.^10,11 Amid the extra-articular complications of long-standing AS, neurological manifestations are considered infrequent.¹⁵ However, subclinical neurological complications may be frequent in AS.¹² Common neurological manifestations result from bony (vertebral) ankylosis, subluxation of joints, ossification of anterior and posterior longitudinal ligaments, secondary spinal canal stenosis, bony (vertebral) fractures, and subsequent compressions over nerve radicles/roots/cauda equina, and inflammation-related (entrapment) peripheral neuropathies.^12,16,17 Acute transverse myelitis can occur as a subset of several primary demyelinating disorders of the CNS (i.e., multiple sclerosis, NMOSD, myelin oligodendrocyte glycoprotein antibody disease, and acute disseminated encephalomyelitis) and various systemic autoimmune connective tissue disorders (i.e., systemic lupus erythematosus, mixed connective tissue disease, Sjögren syndrome, inflammatory bowel disease, and neurosarcoidosis).¹⁸ Acute transverse myelitis (short or long segment) is an infrequent extra-articular complication of AS.¹⁸ It has been reported to evolve either as a distinct neurological complication of AS, or it may develop secondary to TNF-alpha-inhibitor therapy for the treatment of AS.^18,19 AS is a heritable inflammatory spondyloarthropathy that primarily affects the axial skeleton, which is mediated by T-cells; B-cells only play a minor role.⁵ On the contrary, the key for the pathogenesis of NMOSD is the production of autoantibodies against AQP-4 channels expressed on astrocytes, leading to complement-mediated damage, with ensuing demyelination. Myelitis usually shows high signal intensity on the tbl2-weighted image and contrast enhancement in the spinal cord.^1-4 Despite the difference in molecular mechanisms, the diagnosis of these diseases in the same individual may not be coincidental. Recent evidence has shown T-cell-mediated inflammatory responses in cases of NMOSD.²⁰ In particular, Th17 and Th2-related cytokines are elevated in the CSF of NMO patients.²⁰ Environmental factors such as Escherichia coli have also been proven to aggravate autoimmunity in AS and NMOSD (however, body fluid cultures for Escherichia coli, performed in our patient, showed similar association, and they were found negative two times).^21,22 Although large-scale epidemiological studies investigating the underlying pathogenesis related to these diseases are lacking, studies have demonstrated an increased incidence of optic neuritis among patients with AS.²³ Systemic sclerosis and mixed and undifferentiated connective tissue diseases were excluded after expert opinions (from two board-certified rheumatologists and two dermatologists) because of the lack of suggestive clinical findings (e.g., absence of skin thickening, salt-and-pepper appearance, nail changes, Mauskopf facies, sclerodactyly, calcinosis cutis, Raynaud's phenomenon, other cutaneous manifestations, pulmonary arterial hypertension/interstitial lung disease, dysphagia, muscular pain/weakness renal impairments, absence of ANA, anti-centromere antibodies, anti-Scl-70, PM-Scl antibodies, anti-ds DNA, PCNA, CENP-B, anti-nucleosomes, anti-Smith, anti-U1-RNP, anti-Jo1, anti-Mi2, anti-Ro52, anti-La antibodies, and normal C3 and C4 complement levels) (The European League Against Rheumatism and the American College of Rheumatology classification criteria 2019).²⁴ Finally, our patient was treated with intravenous steroids followed by rituximab infusions, a monoclonal anti-CD20 antibody directed against B-cells. In particular, this patient clinically and radiologically responded to immunomodulatory drugs, which might support a possible common pathogenic basis of the two processes. TNF-alpha inhibitors are commonly used as novel therapeutics in AS; however, they can potentially result in serious complications, that is, secondary demyelinating disorders.²⁵ However, such inhibitors in this patient were not used. When used in cases of AS, they show satisfactory results.^25,26 Therefore, it was decided to treat him with rituximab only without adding any second immunomodulatory. Other possible therapeutic options include cyclophosphamide and mycophenolate mofetil, but they were not used because of their low efficacy-safety balance. Moreover, plasmapheresis was not available in our specific setting, despite solid evidence that early treatment with therapeutic strategy (5-7 courses) provides good long-term outcomes in patients with NMOSD.²⁷ Therefore, when dealing with a case of acute non-compressive myelopathy, history and clinical examination are important to determine the potential underlying etiology and identify an undermined systemic disorder with apparently unrelated non-specific features. Connective tissue disorders should always be considered as a differential diagnosis and be ruled out in all cases of either seropositive or seronegative NMOSD. A diagnosis of AS should be considered in relevant circumstances when dealing with a case of isolated seronegative LETM. Moreover, early diagnosis and treatment of AS are quintessential to prevent lifelong distressing disabilities. However, whether patients with AS have any extra predilection to develop NMOSD throughout their life requires further studies.

Symptomatic thoracic ossification of the ligamentum flavum in a patient with ankylosing spondylitis: Report of a case and review

Background:

Thoracic spinal cord compression due to both ankylosing spondylitis (AS) and ossification of the ligamentum flavum (OLF) is rare.

Case Description:

A 33-year-old male with AS presented with a paraparesis attributed to MR documented T9-T10 OLF/stenosis. He was successfully managed with a decompressive laminectomy; this resulted in marked improvement of his deficit.

Conclusion:

Thoracic OLF and AS rarely contribute T9-T10 spinal cord compression that may be readily relieved with a decompressive laminectomy.

Atraumatic thoracic spinal fracture mimicking herpes zoster neuralgia: a case report

Background

Intercostal neuralgia is most common in patients with herpes zoster, but it might be the initial symptom of serious diseases, such as atraumatic spinal fracture, which may lead to serious consequences if not diagnosed and treated early. Severe intercostal neuralgia is rarely reported as the first symptom of ankylosing spondylitis with atraumatic vertebral fractures.

Case presentation

A 70-year-old Chinese Han man previously diagnosed with ankylosing spondylitis presented to the hospital with intense intercostal pain without trauma. The patient was initially suspected of having herpes zoster neuralgia; however, he subsequently experienced numbness and weakness of both lower limbs as well as constipation. Thoracic vertebral fracture and compression of the spinal cord were detected with magnetic resonance imaging, and he underwent emergency posterior thoracic spinal canal decompression, and intercostal neuralgia was relieved after surgery. Spinal tuberculosis and tumors were later excluded by pathological examination and follow-up results. A 6-month postoperative follow-up showed that the weakness and numbness of the left lower limb had significantly improved, and his urinary function had recovered.

Conclusions

Patients with ankylosing spondylitis could develop atraumatic spinal fractures. Severe intercostal neuralgia is an early indicator of spinal fractures, and spinal magnetic resonance imaging is crucial for the diagnosis.

The structural, functional and electrophysiological assessment of paraspinal musculature of patients with ankylosing spondylitis and non-radiographic axial spondyloarthropathy

Paravertebral muscles are affected in spondyloarthritis. Decreased mobility of spine may lead to atrophy and fatty degeneration of these muscles. The objective of this study was to compare the sonographic, electrophysiological and magnetic resonance imaging (MRI) features of paraspinal muscles between patients with ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA). The patients who were diagnosed as AS with modified New York criteria and those as nr-axSpA with ASAS 2009 criteria were enrolled. Clinical evaluation, electrophysiological examination including nerve conduction studies and needle electromyography (EMG) for lower extremities and paraspinal mapping (PSM) were performed by the first examiner. The second examiner measured lumbar multifidus areas, graded the fatty degeneration of the muscle at different levels in T2 weighted axial MRI and also performed the ultrasonographic evaluation. A total of 19 patients with AS and 14 patients with nr-axSpA were evaluated. MRI of 2 patients with AS could not be obtained. Right lumbar multifidus area/vertebra area (MV ratio) was smaller in AS patients at L3 level (p 0,029); there were no significant differences in other levels. Fatty degeneration was also higher in AS patients in left multifidus at L5-S1 disc level (p 0,015). PSM scores that demonstrate the extent of denervation in paraspinal muscles were significantly higher in AS patients than in nr-axSpA patients (p < 0,001). Patients with AS have more fatty degeneration and denervation in paraspinal muscles. These processes may also contribute the severity of pain and disability. The relationship between paraspinal muscle denervation and progression of fatty degeneration should further be revealed.

Cerebral functional deficits in patients with ankylosing spondylitis- an fMRI study

Neurological impairment plays an important role in the development of Ankylosing spondylitis (AS). Early diagnosis and detection of it may stop the progress of neurological complications and improve the quality of patients' lives greatly. Somatosensory evoked potential (SSEP) and magnetic motor evoked potentials (MEP) have been proved useful to detect neurological impairments of AS. This study aimed to investigate the cerebral function deficits of AS using functional MRI technology. Twenty seven patients with AS and 28 control subjects were included in this study. All of them underwent structural MRI and resting state-functional MRI (rs-fMRI) scanning. Comparisons of amplitude of low frequency fluctuations (ALFF) of rs-fMRI signals between AS patients and normal controls were performed using two sample t-tests. To examine functional connectivity within the groups, one-sample t tests were performed on the individual z-value maps. The z values were compared between the two groups using two-sample t test. Partial correlations between rs-fMRI measures (ALFF and functional connectivity) of the brain regions which showed group difference and clinical results including the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score, the serum high-sensitivity C-reactive protein (hsCRP), and the erythrocyte sedimentation rate (ESR) were analyzed for AS patients. Compared with normal controls, the AS patients exhibited significant lower ALFF in the left medial frontal gyrus, the right precentral gyrus and the right posterior cingulate, while higher ALFF in the left cerebellum anterior lobe, the left middle temporal gyrus, the left superior occipital gyrus, the left postcentral gyrus and the right precuneus. AS patients showed widespread brain connectivity alterations. Functional connectivity strength of the left precuneus and the left middle temporal gyrus were closely correlated with the the BASDAI scores, ESR and hsCRP in AS patients. Our results enhance the understanding of the pathomechanism of AS and suggest that Rs-fMRI may be a helpful tool in the clinical detection and evaluation of neurological impairment in AS.

Medial olivocochlear reflex in ankylosing spondylitis patients

OBJECTIVE

Ankylosing spondylitis (AS) is a chronic systemic inflammatory disease. Via autoimmune mediators, AS can damage the auditory system similar to other systems. Otoacoustic emission studies in AS patients showed that the damage that causes hearing loss was in the outer hair cells. The medial olivocochlear (MOC) reflex is used to evaluate the MOC efferent system (MOES), which includes the outer hair cells. The aim of this study was to evaluate the presence of subclinical damage in the inner ear with the aid of the MOC reflex test in AS patients with no hearing complaints.

PATIENTS AND METHODS

Thirty-four patients with AS and a control group of 30 healthy volunteers with similar demographic characteristics were evaluated in the study. Otoacoustic emission responses, MOC reflex results, and frequency-specific and total suppression findings were compared between the groups. The relationship between clinical and laboratory findings for the AS patients, and the MOC reflex data were also investigated.

RESULTS

Reduced MOC reflex response (p = 0.04) and suppression (p = 0.019) were detected in AS patients. When the clinical and laboratory findings for the AS patients and the MOC reflex test results were compared, a significant correlation was found only between the MOC reflex and the erythrocyte sedimentation rate.

CONCLUSION

The results showed that AS can damage the inner ear, especially the MOES, and can reduce the MOC reflex response without clinical hearing loss.

Correlation of blood bone turnover biomarkers and Wnt signaling antagonists with AS, DISH, OPLL, and OYL

Background

Wnt signaling plays an important role in development and maintenance of many organs and tissues. The most-studied secreted Wnt inhibitors are sclerostin (SOST), Dickkopf-related protein 1 (DKK-1), and secreted frizzled related protein 1 (SFRP-1) which play important roles in bone turnover. The present study investigated the relationship between serum Wnt inhibitors and diseases with excessive ossification structures, such as ossification of posterior longitudinal ligament (OPLL), ankylosing spondylitis (AS), diffuse idiopathic skeletal hyperostosis (DISH), and ossification of yellow ligament (OYL).

Methods

Twenty-five patients with AS, DISH, OPLL, or OYL were recruited in this study. Fasting peripheral blood samples were collected from all patients and nine controls. Various biomarkers of bone turnover including osteocalcin (OSC), osteoprotegerin (OPG), SFRP-1, DKK-1, and SOST were investigated.

Results

Our data showed that serum levels of OSC were higher, but Dkk-1 levels were lower in AS, DISH, OPLL, and OYL patients than those in the controls. Serum levels of SFRP-1 were significantly higher in DISH patients than those in the controls. Serum levels of SOST were significantly higher in DISH and OPLL patients than both levels in the controls. Serum levels of OPG were lower in AS patients than those in the controls. Serum levels of OSC were higher in the OPLL patients than those in the AS patients. Serum levels of DKK-1, SFRP-1, SOST, and OPG were not significantly different between the different disease groups.

Conclusions

In this exploratory study, both OSC and DKK-1 levels are correlated with the clinical conditions associated with excessive ossification, indicating that blood OSC and DKK-1 levels may serve as diagnostic biomarkers for AS, DISH, OPLL, and OYL. These findings may also help discover potential drug therapies for management of these diseases in the future.

Vestibular evoked myogenic potentials in patients with ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic systemic inflammatory disease with unknown etiology. Although sacroiliac joint involvement is the classic sign along with the formed immune mediators, it may result in immune-mediated inner ear disease and may cause damage to the audiovestibular system. Vestibular evoked myogenic potentials (VEMP) is a clinical reflex test used in the diagnosis of vestibular diseases and is performed by recording and evaluating the muscle potentials resulting from the stimulation of the vestibular system with different stimuli. The aim of this study is to evaluate the cervical VEMP test results in AS patients without vestibular symptoms. Thirty-three patients with AS and a control group of 30 healthy volunteers with similar demographic characteristics were evaluated in the study. VEMP wave latency, P13-N23 wave amplitude, and VEMP asymmetry ratio (VAR) values were compared between the groups. The relationship between clinical and laboratory findings of the AS patients and VEMP data were also investigated. Compared with healthy people, this study shows the response rate of patients with ankylosing spondylitis was reduced in the VEMP test, and P13-N23 wave amplitude showed a decrease in AS patients who had VEMP response (p < 0.001). There was no correlation between the clinical and laboratory findings and VEMP findings in patients with ankylosing spondylitis. The data obtained from this study suggest that AS may lead to decreased sensitivity of the vestibular system.

Somatosensory evoked potential findings in ankylosing spondylitis

OBJECTIVE

Somatosensory evoked potential (SSEP) abnormalities were reported in patients with ankylosing spondylitis (AS). This study aimed to investigate SSEP abnormalities and its relation with clinical findings in AS patients.

MATERIALS AND METHODS

The study included 26 patients with AS and 17 age-matched health volunteers (Control for SSEP). Median nerve SSEP findings were normal in all AS cases.

RESULTS

However, delayed latency and/or very low amplitude of tibial nerve SSEP was found in 20 (76.9%) AS patients. There were significant correlations between tibial SSEP latency and disease duration (R=0.433 to 0.635). There was also an inverse correlation between tibial SSEP amplitude and disease duration (R=-0.429, p=0.047). Serum estradiol level, hip total bone mineral density, The Bath Ankylosing Spondylitis Functional Index (BASFI) score and Beck depression score were significantly lower in AS patients with SSEP abnormalities (37.3±10.8 pg/mL, 0.916±0.123 g/cm(2), 35.0±27.9, 12.8±8.4, respectively) than in AS patients without SSEP abnormalities (53.7±12.3 pg/mL, 1.103±0.197 g/cm(2), 64.8±15.5, 24.8±10.1, respectively).

CONCLUSION

Significant inverse correlations between SSEP latencies and dehydroepiandrosterone sulphate (DHEAS) levels were found (R=-0.400 to -0.713). There were also significant inverse correlation between SSEP latencies and DHEAS/oestrogen index (R=-0.596 to -0.868), and between SSEP latencies and DHEAS/Progesterone index (R=-0.467 to -0.685). As a conclusion, this study indicates that tibial nerve SSEP abnormalities are common in patients with AS and there are significant correlations between clinical findings of AS and SSEP abnormalities.

Ankylosing spondylitis confers substantially increased risk of clinical spine fractures: a nationwide case-control study

Ankylosing spondylitis (AS) leads to osteopenia/osteoporosis and spine rigidity. We conducted a case-control study and found that AS-affected patients have a 5-fold and 50% increased risk of clinical spine and all clinical fractures, respectively. Excess risk of both is highest in the first years and warrants an early bone health assessment after diagnosis.

INTRODUCTION

Ankylosing spondylitis (AS) is related to spine rigidity and reduced bone mass, but data on its impact on fracture risk are scarce. We aimed to study the association between AS and clinical fractures using a case-control design.

METHODS

From the Danish Health Registries, we identified all subjects who sustained a fracture in the year 2000 (cases) and matched up to three controls by year of birth, gender and region. Clinically diagnosed AS was identified using International Classification of Diseases, 8th revision (ICD-8; 71249), and International Classification of Diseases, 10th revision (ICD-10; M45) codes. We also studied the impact of AS duration. Conditional logistic regression was used to estimate crude and adjusted odds ratios (ORs) for non-traumatic fractures (any site, clinical spine and non-vertebral) according to AS status and time since AS diagnosis. Multivariate models were adjusted for fracture history, socio-economic status, previous medical consultations, alcoholism and use of oral glucocorticoids.

RESULTS

We identified 139/124,655 (0.11%) AS fracture cases, compared to 271/373,962 (0.07%) AS controls. Unadjusted (age- and gender-matched) odds ratio (OR) were 1.54 [95% confidence interval (95%CI) 1.26-1.89] for any fracture, 5.42 [2.50-11.70] for spine and 1.39 [1.12-1.73] for non-vertebral fracture. The risk peaked in the first 2.5 years following AS diagnosis: OR 2.69 [1.84-3.92] for any fracture.

CONCLUSIONS

Patients with AS have a 5-fold higher risk of clinical spine fracture and a 35% increased risk of non-vertebral fracture. This excess risk peaks early, in the first 2.5 years of AS disease. Patients should be assessed for fracture risk early after AS diagnosis.

Neurological events with tumour necrosis factor alpha inhibitors reported to the Food and Drug Administration Adverse Event Reporting System

BACKGROUND

The association between inhibition of tumour necrosis factor alpha (TNF-α) and new onset of neurological adverse events (AEs) is unclear.

AIMS

To evaluate neurological AEs with TNF-α inhibitors reported to the Food and Drug Administration Adverse Event Reporting System (FAERS) utilising a standardised scoring tool for drug-induced AEs.

METHODS

A search of FAERS for neurological AEs (January 1, 2000 to December 31, 2009) reported with infliximab, adalimumab, certolizumab and etanercept was performed. Full-text reports were accessed using the Freedom of Information Act and scored using Naranjo score, while accounting for temporal association, previous conclusive reports of the neurological AE with any TNF-α inhibitor, and alternate explanations including underlying disease, concomitant medications and comorbidities, such as diabetes mellitus.

RESULTS

There were 772 reports. Most were in patients who had rheumatoid arthritis (393, 50.9%) followed by inflammatory bowel disease (140, 18.1%). No significant differences in age or gender were seen between IBD patients compared with rheumatological diseases (P = 0.584 and P = 0.055 respectively). Etanercept was reported most (327, 42.4%) followed by infliximab (276, 35.8%) (P = 0.008). Peripheral neuropathy was the most common neurological AE (296 reports, 38.3%) followed by central nervous system and/or spinal cord demyelination (153 reports, 19.8%). Majority (551, 71.4%) of the reports were of 'possible' AE with the remaining 'probable' AE and none identified as 'definite' AE.

CONCLUSION

While several neurological AEs have been described, definite association between de novo development of these AEs and exposure to TNF-α inhibitors was not established using the Naranjo score.

Multiple sclerosis during adalimumab treatment in a case with ankylosing spondylitis

Ankylosing spondylitis is a chronic and progressive inflammatory disease involving the sacroiliac joints with HLA-B27 positivity in 85% of the patients and radiologically evidence of sacroiliitis. It is associated with several extraarticular manifestations, but neurological complications are rare. Occurrence of multiple sclerosis in patients with ankylosing spondylitis has been reported in limited cases. Adalimumab, a TNF-α antagonist, offers a significant improvement in ankylosing spondylitis and is considered to be less immunogenic and more tolerable than other TNF-α blockers. A case of multiple sclerosis coexisted with HLA-B27 positive ankylosing spondylitis after treated with adalimumab was reported.

MR-defined fat infiltration of the lumbar paravertebral muscles differs between non-radiographic axial spondyloarthritis and established ankylosing spondylitis

OBJECTIVE

The aim of our study was to compare the magnetic resonance imaging (MRI)-defined cross-sectional area and semi-quantitative grading of fatty degeneration of lumbar paravertebral muscles in patients with non-radiographic axial spondyloarthritis (nr-axSpA) and established ankylosing spondylitis (AS).

METHODS

Cross-sectional area (CSA) of lumbar paravertebral muscles, including the right and left multifidus (MF), erector spina (ES), psoas (PS), vertebral body and muscle:vertebra ratio (MVr), was measured. Fat infiltration of the paravertebral muscles was graded semi-quantitatively.

RESULTS

The CSA of the MF, ES and PS muscles and the MVr (at the L2, L3, L4 and L5 levels) were quite similar between patients with nr-axSpA (n = 14) and AS (n = 22). However, patients with AS had higher grades of fat infiltration than those with nr-axSpA (Right L4 grading of MF + ES muscles: 1.4 ± 0.73 vs. 0.51 ± 0.52, respectively, p = 0.001; left L4 grading: 1.36 ± 0.65 vs. 0.38 ± 0.50, respectively, p < 0.0001). This difference remained significant after adjusting for age and symptom duration. The inter-rater reliability was good (intraclass correlation coefficient 0.75 and 0.85).

CONCLUSIONS

This is first study demonstrating that MRI-defined fatty degeneration differs between patients with nr-axSpA and established AS. Semi-quantitative grading is reliable, and fatty degeneration of paravertebral muscles seems to be related to chronicity and spinal functions in patients with nr-axSpA and AS.

Conservative management of ossification of the posterior longitudinal ligament. A review

OBJECT

Ossification of the posterior longitudinal ligament (OPLL) can result in significant myelopathy. Surgical treatment for OPLL has been extensively documented in the literature, but less data exist on conservative management of this condition.

METHODS

The authors conducted a systematic review to identify all reported cases of OPLL that were conservatively managed without surgery.

RESULTS

The review yielded 11 published studies reporting on a total of 480 patients (range per study 1-359 patients) over a mean follow-up period of 14.6 years (range 0.4-26 years). Of these 480 patients, 348 (72.5%) were without myelopathy on initial presentation, whereas 76 patients (15.8%) had signs of myelopathy; in 56 cases (15.8%), the presence of myelopathy was not specified. The mean aggregate Japanese Orthopaedic Association score on presentation for 111 patients was 15.3. Data available for 330 patients who initially presented without myelopathy showed progression to myelopathy in 55 (16.7%), whereas the other 275 (83.3%) remained progression free. In the 76 patients presenting with myelopathy, 37 (48.7%) showed clinical progression, whereas 39 (51.5%) remained clinically unchanged or improved.

CONCLUSIONS

Patients who present without myelopathy have a high chance of remaining progression free. Those who already have signs of myelopathy at presentation may benefit from surgery due to a higher rate of progression over continued follow-up.

Ossification of the posterior longitudinal ligament: a review of literature

Ossification of the posterior longitudinal ligament (OPLL) is most commonly found in men, in the elderly, and in Asian patients. The disease can start with mild or no symptoms, but some patients progress slowly to develop symptoms of myelopathy. An accurate diagnosis through the use plain radiograph, computed tomography, and magnetic resonance imaging findings is very important to monitor the development of symptoms and to make decisions regarding a treatment plan. When symptoms are mild and non-progressive, conservative treatments and periodic observations are good enough, but once symptoms of myelopathy are present and neurologic symptoms are progressive, the treatment of choice is surgery to relieve spinal cord compression. Surgical management of OPLL continues to be controversial. Each surgical technique has some advantages and disadvantages, and the choice of operation should be decided carefully with various considerations. The patient's neurological condition, location and extent of pathology, cervical kyphosis, presence or absence of accompanied instability, and the individual surgeon's experience must be an important factors that should be considered before surgery.

Ossification of the posterior longitudinal ligament: a review

Ossification of the posterior longitudinal ligament (OPLL) is most commonly found in men, the elderly, and Asian patients. There are many diseases associated with OPLL, such as diffuse idiopathic skeletal hyperostosis, ankylosing spondylitis, and other spondyloarthropathies. Several factors have been reported to be associated with OPLL formation and progression, including genetic, hormonal, environmental, and lifestyle factors. However, the pathogenesis of OPLL is still unclear. Most symptomatic patients with OPLL present with neurological deficits such as myelopathy, radiculopathy, and/or bowel and bladder symptoms. There are some reports of asymptomatic OPLL. Both static and dynamic factors are related to the development of myelopathy. Plain radiography, CT, and MR imaging are used to evaluate OPLL extension and the area of spinal cord compression. Management of OPLL continues to be controversial. Each surgical technique has some advantages and disadvantages, and the choice of operation should be made case by case, depending on the patient's condition, level of pathology, type of OPLL, and the surgeon's experience. In this paper, the authors attempt to review the incidence, pathology, pathogenesis, natural history, clinical presentation, classification, radiological evaluation, and management of OPLL.

Symptomatic noncompressive motoromyelopathy presents as early manifestation in ankylosing spondylitis

Ankylosing spondylitis (AS) is an autoimmune spondyloarthropathy involving principally the sacroiliac joint and axial skeleton. Spinal cord involvement is an infrequent and late complication. It mostly results from compressive myelopathy due to skeletal osteopathy and usually presents with radiculomyelopathic sensory and motor deficits. To report three patients who suffered a progressive paraparesis/tetraparesis compatible with motor myelopathy without typical skeletal symptom. Myelopathy of unknown origin was initially interpreted in these patients. Radiography did not show typical change at sacroiliac joint or vertebrate. Spinal magnetic resonance image revealed cord atrophy at cervical and thoracic segment. A positivity of B27 antigen was found afterward. Their spondyloarthropathic symptoms developed within six months later with radiographic sacroiliitis. Seropositive AS with noncompressive myelopathy was finally established. Patients showed a reverse of motor impairment when their pain was well undercontrolled. Motor myelopathy may be neglected or underestimated in AS, in especially when typical skeletal symptom is absent or minimal. It may progress surreptitiously to harm spinal function or superimpose to crippling disability in compressive spinal cord injury. Therefore, a careful evaluation and monitor of spinal cord function is important for AS patient despite spinal deformity is not observed.

Thoracic spinal cord herniation in a patient with long-standing ankylosing spondylitis

The objective of this study was to describe an adult male patient with ankylosing spondylitis (AS) associated with thoracic spinal cord herniation (TSCH). TSCH is a scarce entity presented as a displacement of thoracic cord through an anterior or anterolateral dural defect. More importantly, the co-occurrence of AS and thoracic spinal cord herniation is exceptional. To date, only one case of SCH in association with AS has been reported in the literature. A 56-year-old male patient presented with the progressive difficulty in walking and numbness of both lower limbs for the past 18 months. The patient was diagnosed as AS when he was 30 years old. Sagittal MRI of thoracic spine showed dural defect of the posterior aspect of T11 and 12 vertebral bodies. Axial T2-weighted MRI demonstrated that spinal cord was displaced ventrally and to the right. The diagnosis of TSCH with AS was established. The prognosis was explained to the patient. We recommended duraplasty for dural repair to the patient, but he refused surgery. The results demonstrated that TSCH associated with long-standing AS was very uncommon, and MRI is recommended to rule out SCH in the long-standing AS patients with neurologic symptoms. The SCH in AS might be caused by inflammation, and thoracolumbar hyperkyphosis results from AS might be associated with the development of SCH.