Stroke and Stroke-like Episodes in Muscle Disease

Increased Rate of Complications Following Total Knee Arthroplasty in Patients Who Have Polymyositis

BACKGROUND

Polymyositis (PM) is a systemic connective tissue disorder that can lead to early onset degenerative joint disease and a need for total knee arthroplasty (TKA). Outcomes of TKA in patients who have PM are not well documented in the literature. The purpose of this study was to evaluate PM as a risk factor for complications after TKA.

METHODS

Using a national private payer insurance database from 2010 to 2022, PM patients undergoing primary TKA were compared to 10:1 matched controls based on age, sex, and comorbidities. Multivariable logistic regression analyses were done for medical complications up to 90 days and surgical complications up to 2 years. 90-day emergency department visits and inpatient readmissions were also documented. A total of 25,039 patients undergoing primary TKA were queried, of which 2,290 had PM.

RESULTS

Compared to the matched controls, patients who had PM demonstrated higher rates of medical and surgical complications, including pulmonary embolism (1.0% versus 0.5%, P = .001), cerebrovascular accident (1.3% versus 0.7%, P = .002), wound complications (3.4% versus 2.1%, P < .001), and periprosthetic joint infection at 1 year (1.7% versus 1.3%, P = .042) and 2 years (2.6% versus 1.9%, P = .006). Patients who had PM displayed elevated 90-day emergency department (14.9% versus 13.3%, P = .032) and hospital readmission rate (7.1% versus 4.8%, P < .001).

CONCLUSIONS

Patients who have PM are at higher risks of postoperative medical and surgical complications, including pulmonary embolism, cerebrovascular accident, wound complication, and periprosthetic joint infection. Given these results, it is helpful for orthopedic surgeons and patients to consider these risks when considering TKA for patients who have PM.

Whole exome/genome sequencing in cyclic vomiting syndrome reveals multiple candidate genes, suggesting a model of elevated intracellular cations and mitochondrial dysfunction

Objective

To utilize whole exome or genome sequencing and the scientific literature for identifying candidate genes for cyclic vomiting syndrome (CVS), an idiopathic migraine variant with paroxysmal nausea and vomiting.

Methods

A retrospective chart review of 80 unrelated participants, ascertained by a quaternary care CVS specialist, was conducted. Genes associated with paroxysmal symptoms were identified querying the literature for genes associated with dominant cases of intermittent vomiting or both discomfort and disability; among which the raw genetic sequence was reviewed. "Qualifying" variants were defined as coding, rare, and conserved. Additionally, "Key Qualifying" variants were Pathogenic/Likely Pathogenic, or "Clinical" based upon the presence of a corresponding diagnosis. Candidate association to CVS was based on a point system.

Results

Thirty-five paroxysmal genes were identified per the literature review. Among these, 12 genes were scored as "Highly likely" (SCN4A, CACNA1A, CACNA1S, RYR2, TRAP1, MEFV) or "Likely" (SCN9A, TNFRSF1A, POLG, SCN10A, POGZ, TRPA1) CVS related. Nine additional genes (OTC, ATP1A3, ATP1A2, GFAP, SLC2A1, TUBB3, PPM1D, CHAMP1, HMBS) had sufficient evidence in the literature but not from our study participants. Candidate status for mitochondrial DNA was confirmed by the literature and our study data. Among the above-listed 22 CVS candidate genes, a Key Qualifying variant was identified in 31/80 (34%), and any Qualifying variant was present in 61/80 (76%) of participants. These findings were highly statistically significant (p < 0.0001, p = 0.004, respectively) compared to an alternative hypothesis/control group regarding brain neurotransmitter receptor genes. Additional, post-analyses, less-intensive review of all genes (exome) outside our paroxysmal genes identified 13 additional genes as "Possibly" CVS related.

Conclusion

All 22 CVS candidate genes are associated with either cation transport or energy metabolism (14 directly, 8 indirectly). Our findings suggest a cellular model in which aberrant ion gradients lead to mitochondrial dysfunction, or vice versa, in a pathogenic vicious cycle of cellular hyperexcitability. Among the non-paroxysmal genes identified, 5 are known causes of peripheral neuropathy. Our model is consistent with multiple current hypotheses of CVS.

Cardiovascular events in adult polymyositis and dermatomyositis: a meta-analysis of observational studies

OBJECTIVES

We aimed to review whether polymyositis (PM) and dermatomyositis (DM) patients have an increased cardiovascular (CV) risk, including ischaemic heart disease (IHD), cerebrovascular accidents (CVA), and venous thromboembolism (VTE).

METHODS

We searched PubMed, Embase, and the Cochrane database for relevant studies from inception to February 2021.

RESULTS

Twenty-two studies comprising 25,433 patients were included. With PM/DM versus general populations, the risk was significantly increased for CV events (relative risk (RR)=2.37, 95%CI:1.86-3.02). The RR of CV events for males with PM/DM was higher than for females (RR = 1.43; 95%CI:1.17-1.74). PM/DM patients followed for one to five years had a significantly higher CV risk than those followed for five to ten years (RR = 3.51, 95%CI:1.95-6.32). The risk was increased for North Americans (RR = 4.28, 95%CI:2.57-7.11), Europeans (RR = 2.29, 95%CI:1.58-3.31), and Asians (RR = 2.03, 95%CI:1.41-2.90). Our meta-analysis found that the elevated CV event risk was related to PM (RR = 2.35, 95%CI:1.51-3.66) and DM (RR = 2.55, 95%CI:1.66-3.93). Subgroup analyses showed that the risk was significantly increased for IHD (RR = 1.76, 95%CI:1.40-2.21), CVA morbidity (RR = 1.31, 95%CI:1.03-1.67), and ischaemic stroke (IS) (RR = 1.47, 95%CI:1.26-1.73), with no statistically significant increased risk of haemorrhagic stroke mortality (RR = 1.43, 95%CI:0.92-2.21). The CV event risk was increased for VTE (RR = 4.60, 95%CI:3.17-6.66), deep venous thrombosis (DVT) (RR = 5.53, 95%CI:3.25-9.39), and pulmonary embolism (PE) (RR = 5.26, 95%CI:2.62-10.55).

CONCLUSION

This meta-analysis found that PM/DM patients had a ∼2.37 times increased CV risk, particularly males diagnosed in the previous five years. PM/DM may be an independent risk factor for developing IHD, IS, DVT, and PE.

Cardiac complications in inherited mitochondrial diseases

Maternally mitochondrial dysfunction includes a heterogeneous group of genetic disorders which leads to the impairment of the final common pathway of energy metabolism. Coronary heart disease and coronary venous disease are two important clinical manifestations of mitochondrial dysfunction due to abnormality in the setting of underlying pathways. Mitochondrial dysfunction can lead to cardiomyopathy, which is involved in the onset of acute cardiac and pulmonary failure. Mitochondrial diseases present other cardiac manifestations such as left ventricular noncompaction and cardiac conduction disease. Different clinical findings from mitochondrial dysfunction originate from different mtDNA mutations, and this variety of clinical symptoms poses a diagnostic challenge for cardiologists. Heart transplantation may be a good treatment, but it is not always possible, and other complications of the disease, such as mitochondrial encephalopathy, lactic acidosis, and stroke-like syndrome, should be considered. To diagnose and treat most mitochondrial disorders, careful cardiac, neurological, and molecular studies are needed. In this study, we looked at molecular genetics of MIDs and cardiac manifestations in patients with mitochondrial dysfunction.

Similar risk of cardiovascular events in idiopathic inflammatory myopathy and rheumatoid arthritis in the first 5 years after diagnosis

OBJECTIVES

To estimate the incidence of cardiovascular (CV) events in idiopathic inflammatory myopathy (IIM) compared to patients with rheumatoid arthritis (RA) and the general population. To explore the contribution of traditional CV risk factors to any difference observed.

METHODS

A retrospective matched population-based cohort study was conducted using UK Clinical Practice Research Datalink (CPRD) from 1987 to 2013. The incidence of CV events was calculated for each cohort over time and compared using Cox proportional hazards models. Multivariable analyses were used to adjust for traditional CV risk factors.

RESULTS

A total of 603 patients with IIM 4047 RA and 4061 healthy controls were included. The rate of CV events in IIM was significantly greater than healthy controls [hazard ratio (HR) 1.47 (95% confidence interval (CI) 1.18-1.83)] and remained significant after adjustment for CV risk factors [HR 1.38 (95% CI 1.11-1.72)]. Risk was similar between IIM and RA [HR 1.01 (95% CI 0.78-1.31)]. The rate of myocardial infarction [HR 1.61 (95% CI 1.27-2.04)] but not stroke [HR 0.92 (95% CI 0.59-1.44)] was significantly greater in IIM compared to healthy controls. After the first 5 years, the rate of CV events for RA remained significantly greater compared to the control group, but appeared to return to that of the healthy controls in the IIM group.

CONCLUSION

IIM is associated with an increased risk of CV events in the first 5 years after diagnosis similar to that of RA. Beyond 5 years, the risk appears to return to that of the general population in IIM but not RA. Key Points • The excess risk of cardiovascular events in IIM is similar to that found in RA. • The excess risk of cardiovascular events is greatest in the first 5 years after diagnosis.

Mitochondrial metabolic stroke: Phenotype and genetics of stroke-like episodes

Stroke-like episodes (SLEs) are the hallmark of mitochondrial encephalopathy with lactic acidosis and stroke-like episode (MELAS) syndrome but rarely occur also in other specific or nonspecific mitochondrial disorders. Pathophysiologically, SLLs are most likely due to a regional disruption of the blood-brain barrier triggered by the underlying metabolic defect, epileptic activity, drugs, or other factors. SLEs manifest clinically with a plethora of cerebral manifestations, which not only include features typically seen in ischemic stroke, but also headache, epilepsy, ataxia, visual impairment, vomiting, and psychiatric abnormalities. The morphological correlate of a SLE is the stroke-like lesion (SLL), best visualised on multimodal MRI. In the acute stages, a SLL presents as vasogenic edema but may be mixed up with cytotoxic components. Additionally, SLLs are characterized by hyperperfusion on perfusion studies. In the chronic stage, SLLs present with a colorful picture before they completely disappear, or end up as white matter lesion, cyst, laminar cortical necrosis, focal atrophy, or as toenail sign. Treatment of SLLs is symptomatic and relies on recommendations by experts. Beneficial effects have been reported with nitric-oxide precursors, antiepileptic drugs, antioxidants, the ketogenic diet, and steroids. Lot of research is still needed to uncover the enigma SLE/SLL.

Mitochondrial diseases caused by mtDNA mutations: a mini-review

There are several types of mitochondrial cytopathies, which cause a set of disorders, arise as a result of mitochondria’s failure. Mitochondria’s functional disruption leads to development of physical, growing and cognitive disabilities and includes multiple organ pathologies, essentially disturbing the nervous and muscular systems. The origins of mitochondrial cytopathies are mutations in genes of nuclear DNA encoding mitochondrial proteins or in mitochondrial DNA. Nowadays, numerous mtDNA mutations significant to the appearance and progress of pathologies in humans are detected. In this mini-review, we accent on the mitochondrial cytopathies related to mutations of mtDNA. As well known, there are definite set of symptoms of mitochondrial cytopathies distinguishing or similar for different syndromes. The present article contains data about mutations linked with cytopathies that facilitate diagnosis of different syndromes by using genetic analysis methods. In addition, for every individual, more effective therapeutic approach could be developed after wide-range mutant background analysis of mitochondrial genome.

Mechanical thrombectomy in a young stroke patient with Duchenne muscular dystrophy

Background:

Duchenne muscular dystrophy (DMD) is an X-linked recessive skeletal muscle myopathy which is caused by mutations in the dystrophin gene. Lack of dystrophin also results to cardiomyopathy, which raises significantly the stroke risk in DMD-patients. However, data about therapeutic opportunities in the acute setting are scarce in literature. So far, only two cases receiving IV thrombolysis are described, one of them with fatal outcome.

Method:

Case report of a case of successful mechanical thrombectomy (MTE) in an acute ischemic stroke (AIS) patient with DMD and associated dilatative cardiomyopathy.

Results:

A 20-year old DMD-patient was transferred at 08:56 h to our department due to wake up stroke with severe right-sided hemiparesis and aphasia (NIHSS=20). Last-seen-normal was at 03:00 h. Cerebral CT-scan revealed only slight early ischemic changes (ASPECT-Score=8). CT-angiography detected occlusion of left middle cerebral artery (LMCA). MTE started rapidly at 9:23 h and using direct thrombus aspiration (Penumbra System®) complete recanalization was achieved 20 min later (TICI-grade 3). Considering the specific risks of general anesthesia in DMD, the procedure was performed with propofol, remifentanil and rocuronium. The patient recovered quickly from the acute symptoms, due to preexisting hypotonic tetraparesis his NIHSS-score at discharge was 12 points.

Conclusions:

To the best of our knowledge, this is the first report on MTE in a patient with DMD related cardioembolic stroke. In contrast to the few reports with IV thrombolysis, MTE seems to represent an optimal treatment option. Specific characteristics of DMD-patients like anesthetic regimen should be taken into account.

Cerebral Manifestations of Mitochondrial Disorders

This review aims at summarizing and discussing previous and recent findings concerning the cerebral manifestations of mitochondrial disorders (MIDs). MIDs frequently present as mitochondrial multiorgan disorder syndrome (MIMODS) either already at onset or later in the course. After the muscle, the brain is the organ second most frequently affected in MIMODS. Cerebral manifestations of MIDs are variable and may present with or without a lesion on imaging or functional studies, but there can be imaging/functional lesions without clinical manifestations. The most well-known cerebral manifestations of MIDs include stroke-like episodes, epilepsy, headache, ataxia, movement disorders, hypopituitarism, muscle weakness, psychiatric abnormalities, nystagmus, white and gray matter lesions, atrophy, basal ganglia calcification, and hypometabolism on 2-deoxy-2-[fluorine-18]fluoro-D-glucose positron-emission tomography. For most MIDs, only symptomatic therapy is currently available. Symptomatic treatment should be supplemented by vitamins, cofactors, and antioxidants. In conclusion, cerebral manifestations of MIDs need to be recognized and appropriately managed because they strongly determine the outcome of MID patients.

Stroke-like episodes, peri-episodic seizures, and MELAS mutations

PURPOSE

Stroke-like episodes (SLEs) are a hallmark of various mitochondrial disorders, in particular MELAS syndrome. SLEs manifest with vasogenic oedema (DWI and ADC hyperintensity) or partial cytotoxic oedema (DWI hyperintensity, ADC hypointensity) in the acute and subacute stage, and with gyriform T1-hyperintensity (cortical necrosis) in the chronic stage.

PRINCIPAL RESULTS

SLEs must be clearly distinguished from ischaemic stroke, since management of these two entities is different. SLEs may go along with or without seizures or epileptiform discharges on EEG. However, in MELAS syndrome seizures may also occur in the absence of SLEs. Focal and generalised seizures have been reported but it is currently unknown if the one or the other prevail. SLEs with and without seizures may respond to NO-precursors l-arginine, succinate, or citrulline. As a supportive measure a ketogenic diet should be initiated. Seizures prior to or during a SLE or paroxysmal EEG-activity during a SLE should be initially treated with antiepileptic drugs (AEDs) with low mitochondrion-toxicity. Only in case these AEDs are ineffective, AEDs with higher mitochondrion-toxicity should be added.

MAJOR CONCLUSIONS

All patients with SLEs need to have an EEG recorded irrespective if they have manifesting seizures or not. There are no mtDNA or nDNA mutations which predispose for SLEs with seizures.

Stroke in Duchenne Muscular Dystrophy: A Retrospective Longitudinal Study in 54 Patients

BACKGROUND AND PURPOSE

Duchenne muscular dystrophy (DMD) is the most frequent skeletal muscle myopathy. Nearly all patients develop cardiomyopathy in their second decade of life. The purpose of this study was to evaluate the frequency, cause, and outcome of stroke in a German cohort of patients with DMD.

METHODS

Retrospective analysis of medical records of 54 DMD patients, who lived in a regional facility for handicapped people (Wichernhaus Altdorf, Germany) between 1963 and 2013.

RESULTS

Fifty-four DMD patients were followed up for 7.4 years on average. Mean age at admission and discharge from the long-term care facility or death were 11.4 and 18.8 years, respectively. Covering a total observation period of 400 patient-years, we identified 4 DMD patients with juvenile arterial ischemic strokes. Off-label systemic thrombolysis in 2 patients resulted in a nearly complete regression of stroke-related symptoms, but 1 patient died of septic pneumonia and cardiac failure 24 days after thrombolysis therapy. In the other 2 patients, who had their ischemic strokes in 1994 and 1998, severe infarction-related symptoms persisted, and 1 patient died 13 days later. DMD-associated cardiomyopathy without evidence of atrial fibrillation was the only risk factor for ischemic stroke in all patients.

CONCLUSIONS

This study indicates an increased risk for ischemic strokes in DMD patients. Regular cardiological assessment of all DMD patients is mandatory to evaluate the individual risk profile for cardioembolic events and to adapt therapeutic strategies.

Mitochondrial vasculopathy

Mitochondrial disorders (MIDs) are usually multisystem disorders (mitochondrial multiorgan disorder syndrome) either on from onset or starting at a point during the disease course. Most frequently affected tissues are those with a high oxygen demand such as the central nervous system, the muscle, endocrine glands, or the myocardium. Recently, it has been shown that rarely also the arteries may be affected (mitochondrial arteriopathy). This review focuses on the type, diagnosis, and treatment of mitochondrial vasculopathy in MID patients. A literature search using appropriate search terms was carried out. Mitochondrial vasculopathy manifests as either microangiopathy or macroangiopathy. Clinical manifestations of mitochondrial microangiopathy include leukoencephalopathy, migraine-like headache, stroke-like episodes, or peripheral retinopathy. Mitochondrial macroangiopathy manifests as atherosclerosis, ectasia of arteries, aneurysm formation, dissection, or spontaneous rupture of arteries. The diagnosis relies on the documentation and confirmation of the mitochondrial metabolic defect or the genetic cause after exclusion of non-MID causes. Treatment is not at variance compared to treatment of vasculopathy due to non-MID causes. Mitochondrial vasculopathy exists and manifests as micro- or macroangiopathy. Diagnosing mitochondrial vasculopathy is crucial since appropriate treatment may prevent from severe complications.

When should MELAS (Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes) be the diagnosis?

Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes (MELAS) is a rare mitochondrial disorder. Diagnostic criteria for MELAS include typical manifestations of the disease: stroke-like episodes, encephalopathy, evidence of mitochondrial dysfunction (laboratorial or histological) and known mitochondrial DNA gene mutations. Clinical features of MELAS are not necessarily uniform in the early stages of the disease, and correlations between clinical manifestations and physiopathology have not been fully elucidated. It is estimated that point mutations in the tRNALeu(UUR) gene of the DNAmt, mainly A3243G, are responsible for more of 80% of MELAS cases. Morphological changes seen upon muscle biopsy in MELAS include a substantive proportion of ragged red fibers (RRF) and the presence of vessels with a strong reaction for succinate dehydrogenase. In this review, we discuss mainly diagnostic criterion, clinical and laboratory manifestations, brain images, histology and molecular findings as well as some differential diagnoses and current treatments.

MR screening of candidates for thrombolysis: How to identify stroke mimics?

Stroke mimics account for up to a third of suspected strokes. The main causes are epileptic deficit, migraine aura, hypoglycemia, and functional disorders. Accurate recognition of stroke mimics is important for adequate identification of candidates for thrombolysis. This decreases the number of unnecessary treatments and invasive vascular investigations. Correctly identifying the cause of symptoms also avoids delaying proper care. Therefore, this pictorial review focuses on what the radiologist should know about the most common MRI patterns of stroke mimics in the first hours after onset of symptoms. The issues linked to the accurate diagnosis of stroke mimics in the management of candidates for thrombolysis will be discussed.

Skeletal muscle microvasculature in the diagnosis of neuromuscular disease

Blood vessels are often overlooked in analyses of skeletal muscle biopsies. However, there are many vascular features in skeletal muscle biopsies that, when interpreted in the context of other histologic patterns and clinical history, provide useful information that allows muscle pathologists to narrow their differential diagnoses and provide more accurate guidance to treating physicians. Here, we provide a review of normal skeletal muscle vasculature with details of the ultrastructure of vessel walls. We discuss the vascular effects of factors common to many patients undergoing muscle biopsy, for example, diabetes mellitus, hypertension, and aging. We then discuss vascular findings relevant to diagnostic muscle biopsy evaluation, with current theories of pathogenesis and detailed descriptions of the important features.

The broadening spectrum of mitochondrial disease: shifts in the diagnostic paradigm

BACKGROUND

The diagnosis of mitochondrial disease requires a complex synthesis of clinical, biochemical, histological, and genetic investigations. An expanding number of mitochondrial diseases are being recognized, despite their phenotypic diversity, largely due to improvements in methods to detect mutations in affected individuals and the discovery of genes contributing to mitochondrial function. Improved understanding of the investigational pitfalls and the development of new laboratory methodologies that lead to a molecular diagnosis have necessitated the field to rapidly adopt changes to its diagnostic approach.

SCOPE OF REVIEW

We review the clinical, investigational and genetic challenges that have resulted in shifts to the way we define and diagnose mitochondrial disease. Incorporation of changes, including the use of fibroblast growth factor 21 (FGF-21) and next generation sequencing techniques, may allow affected patients access to earlier molecular diagnosis and management.

MAJOR CONCLUSIONS

There have been important shifts in the diagnostic paradigm for mitochondrial disease. Diagnosis of mitochondrial disease is no longer reliant on muscle biopsy alone, but should include clinical assessment accompanied by the use of serological biomarkers and genetic analysis. Because affected patients will be defined on a molecular basis, oligosymptomatic mutation carriers should be included in the spectrum of mitochondrial disease. Use of new techniques such as the measurement of serum FGF-21 levels and next-generation-sequencing protocols should simplify the diagnosis of mitochondrial disease.

GENERAL SIGNIFICANCE

Improvements in the diagnostic pathway for mitochondrial disease will result in earlier, cheaper and more accurate methods to identify patients with mitochondrial disease. This article is part of a Special Issue entitled Frontiers of Mitochondrial Research.