Tilt Table Testing.

This Diagnostic Test Interpretation uses a patient case to illustrate tilt table testing, useful for evaluating patients with syncope of unknown cause or postural orthostatic tachycardia syndrome (POTS).

Frequency of Comorbid Pathologies and Their Clinical Impact in Multiple System Atrophy.

BACKGROUND: Mixed pathology is common at autopsy for a number of age-associated neurodegenerative disorders; however, the frequency of comorbid pathologies in multiple system atrophy (MSA) and their clinical correlations are poorly understood. OBJECTIVE: We determined the frequency of comorbid pathologic processes in autopsy-confirmed MSA and assessed their clinical correlates. METHODS: This study included 160 neuropathologically established MSA from the Mayo Clinic brain bank. Clinical information, including age at onset or death, clinical subtype, initial symptoms, antemortem clinical diagnosis, and cognitive dysfunction was collected. We assessed comorbid pathologies including Alzheimer's disease neuropathologic change, Lewy-related pathology, argyrophilic grain disease, age-related τ astrogliopathy, transactive DNA-binding protein 43 pathology, cerebral amyloid angiopathy, and cerebrovascular small vessel disease and examined their clinical impact. RESULTS: The majority of MSA patients (62%) had no significant comorbid pathologies. There was a positive correlation between age at onset or death with the number of comorbid pathologies; however, even in the highest quartile group (average age at death 78 ± 6 years), the average number of comorbid pathologies was <2. Logistic regression analysis revealed that none of the assessed variables, including sex, age at onset, and the presence or absence of each comorbid pathology, were significantly associated with cognitive dysfunction. CONCLUSIONS: The majority of MSA patients do not have comorbid pathologies, even in advanced age, indicating that MSA is unique among neurodegenerative disorders in this regard. There was minimal clinical impact of comorbid pathologies in MSA. These findings warrant focusing on α-synuclein for the treatment strategy for MSA. © 2023 International Parkinson and Movement Disorder Society.

Diagnosing multiple system atrophy: current clinical guidance and emerging molecular biomarkers.

Multiple system atrophy (MSA) is a rare and progressive neurodegenerative disorder characterized by motor and autonomic dysfunction. Accurate and early diagnosis of MSA is challenging due to its clinical similarity with other neurodegenerative disorders, such as Parkinson's disease and atypical parkinsonian disorders. Currently, MSA diagnosis is based on clinical criteria drawing from the patient's symptoms, lack of response to levodopa therapy, neuroimaging studies, and exclusion of other diseases. However, these methods have limitations in sensitivity and specificity. Recent advances in molecular biomarker research, such as α-synuclein protein amplification assays (RT-QuIC) and other biomarkers in cerebrospinal fluid and blood, have shown promise in improving the diagnosis of MSA. Additionally, these biomarkers could also serve as targets for developing disease-modifying therapies and monitoring treatment response. In this review, we provide an overview of the clinical syndrome of MSA and discuss the current diagnostic criteria, limitations of current diagnostic methods, and emerging molecular biomarkers that offer hope for improving the accuracy and early detection of MSA.

Validation Study of the MDS Criteria for the Diagnosis of Multiple System Atrophy in the Mayo Clinic Brain Bank.

BACKGROUND AND OBJECTIVE: The second consensus criteria in 2008 have been used in diagnosing multiple system atrophy (MSA). The International Parkinson and Movement Disorder Society (MDS) proposed new diagnostic criteria for MSA in 2022. This study aimed to compare the diagnostic accuracy between these 2 criteria and validate the clinical utility of the newly proposed criteria for MSA. METHODS: We conducted a retrospective autopsy cohort study of consecutive patients with a clinical or pathologic diagnosis of MSA from the Mayo Clinic brain bank between 1998 and 2021. We studied 352 patients (250 pathologically diagnosed MSA and 102 non-MSA); MDS criteria and the second consensus criteria were applied. The sensitivity, specificity, and area under the curve (AUC) of receiver operating characteristic curves were compared between these criteria. Comparison was conducted between clinical subtypes and among clinically challenging cases (those with different clinical diagnoses or those with suspected but undiagnosed MSA before death). We also used machine learning algorithm, eXtreme Gradient Boosting, to identify clinical features contributing diagnostic performance. RESULTS: The sensitivity and specificity of clinically established and probable MSA by the MDS criteria were 16% and 99% and 64% and 74%, respectively. The sensitivity and specificity of probable MSA and possible MSA by the second consensus criteria were 72% and 52% and 93% and 21%, respectively. The AUC of MDS clinically probable MSA was the highest (0.69). The diagnostic performance did not differ between clinical subtypes. In clinically challenging cases, MDS clinically established MSA maintained high specificity and MDS clinically probable MSA demonstrated the highest AUC (0.62). MRI findings contributed to high specificity. In addition, combining core clinical features with 2 or more from any of the 13 supporting features and the absence of exclusion criteria also yielded high specificity. Among supporting features, rapid progression was most important for predicting MSA pathology. DISCUSSION: The MDS criteria showed high specificity with clinically established MSA and moderate sensitivity and specificity with clinically probable MSA. The observation that high specificity could be achieved with clinical features alone suggests that MSA diagnosis with high specificity is possible even in areas where MRI is not readily available.

Cancer in pathologically confirmed multiple system atrophy.

PURPOSE: The aim of this study was to assess whether cancer occurs with increased frequency in multiple system atrophy (MSA). The pathological hallmark of MSA is glial cytoplasmic inclusions containing aggregated α-synuclein, and the related protein γ-synuclein correlates with invasive cancer. We investigated whether these two disorders are associated clinically. METHODS: Medical records of 320 patients with pathologically confirmed MSA seen between 1998 and 2022 were reviewed. After excluding those with insufficient medical histories, the remaining 269 and an equal number of controls matched for age and sex were queried for personal and family histories of cancer recorded on standardized questionnaires and in clinical histories. Additionally, age-adjusted rates of breast cancer were compared with US population incidence data. RESULTS: Of 269 cases in each group, 37 with MSA versus 45 of controls had a personal history of cancer. Reported cases of cancer in parents were 97 versus 104 and in siblings 31 versus 44 for MSA and controls, respectively. Of 134 female cases in each group, 14 MSA versus 10 controls had a personal history of breast cancer. The age-adjusted rate of breast cancer in MSA was 0.83%, as compared with 0.67% in controls and 2.0% in the US population. All comparisons were nonsignificant. CONCLUSION: The evidence from this retrospective cohort found no significant clinical association of MSA with breast cancer or other cancers. These results do not exclude the possibility that knowledge about synuclein pathology at the molecular level in cancer may lead to future discoveries and potential therapeutic targets for MSA.

Current advances in the surgical treatment of glossopharyngeal neuralgia.

Glossopharyngeal neuralgia (GPN) is a neurological condition characterized by paroxysmal, stabbing-like pain along the distribution of the glossopharyngeal nerve that lasts from a couple of seconds to minutes. Pharmacological treatment with anticonvulsants is the first line of treatment; however, about 25% of patients remain symptomatic and require surgical intervention, which is usually done via microvascular decompression (MVD) with or without rhizotomy. More recently, the use of stereotactic radiosurgery (SRS) has been utilized as an alternative treatment method to relieve patient symptoms by causing nerve ablation. We conducted a systematic review to analyze whether MVD without rhizotomy is an equally effective treatment for GPN as MVD with the use of concurrent rhizotomy. Moreover, we sought to explore if SRS, a minimally invasive alternative surgical option, achieves comparable outcomes. We included retrospective studies and case reports in our search. We consulted PubMed and Medline, including articles from the year 2000 onwards. A total of 36 articles were included for review. Of all included patients with glossopharyngeal neuralgia, the most common offending artery compressing the glossopharyngeal nerve was the posterior inferior cerebellar artery (PICA). MVD alone was successful achieving pain relief immediately postoperatively in about 85% of patients, and also long term in 65-90% of patients. The most common complication found on MVD surgery was found to be transient hoarseness and transient dysphagia. Rhizotomy alone shows an instant pain relief in 85-100% of the patients, but rate of long-term pain relief was lower compared to MVD. The most common adverse effects observed after a rhizotomy were dysphagia and dysesthesia along the distribution of the glossopharyngeal nerve. SRS had promising results in pain reduction when using 75 Gy radiation or higher; however, long-term rates of pain relief were lower. MVD, rhizotomy, and SRS are effective methods to treat GPN as they help achieve instant pain relief and the decrease use of medication. Patients with MVD alone presented with less adverse effects than the group that underwent MVD plus rhizotomy. Although SRS may be a viable alternative treatment for GPN, further studies must be done to evaluate long-term treatment efficacy.

Common Variants Near ZIC1 and ZIC4 in Autopsy-Confirmed Multiple System Atrophy.

BACKGROUND: Multiple System Atrophy is a rare neurodegenerative disease with alpha-synuclein aggregation in glial cytoplasmic inclusions and either predominant olivopontocerebellar atrophy or striatonigral degeneration, leading to dysautonomia, parkinsonism, and cerebellar ataxia. One prior genome-wide association study in mainly clinically diagnosed patients with Multiple System Atrophy failed to identify genetic variants predisposing for the disease. OBJECTIVE: Since the clinical diagnosis of Multiple System Atrophy yields a high rate of misdiagnosis when compared to the neuropathological gold standard, we studied only autopsy-confirmed cases. METHODS: We studied common genetic variations in Multiple System Atrophy cases (N = 731) and controls (N = 2898). RESULTS: The most strongly disease-associated markers were rs16859966 on chromosome 3, rs7013955 on chromosome 8, and rs116607983 on chromosome 4 with P-values below 5 × 10-6 , all of which were supported by at least one additional genotyped and several imputed single nucleotide polymorphisms. The genes closest to the chromosome 3 locus are ZIC1 and ZIC4 encoding the zinc finger proteins of cerebellum 1 and 4 (ZIC1 and ZIC4). INTERPRETATION: Since mutations of ZIC1 and ZIC4 and paraneoplastic autoantibodies directed against ZIC4 are associated with severe cerebellar dysfunction, we conducted immunohistochemical analyses in brain tissue of the frontal cortex and the cerebellum from 24 Multiple System Atrophy patients. Strong immunohistochemical expression of ZIC4 was detected in a subset of neurons of the dentate nucleus in all healthy controls and in patients with striatonigral degeneration, whereas ZIC4-immunoreactive neurons were significantly reduced inpatients with olivopontocerebellar atrophy. These findings point to a potential ZIC4-mediated vulnerability of neurons in Multiple System Atrophy. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Motor Cortex Stimulation for Pain: A Narrative Review of Indications, Techniques, and Outcomes.

BACKGROUND: Motor cortex stimulation (MCS) was introduced in 1985 and has been tested extensively for different types of peripheral and central neuropathic pain syndromes (eg, central poststroke pain, phantom limb pain, trigeminal neuropathic pain, migraines, etc). The motor cortex can be stimulated through different routes, including subdural, epidural, and transcranial. OBJECTIVES: In this review, we discuss the current uses, surgical techniques, localization techniques, stimulation parameters, and clinical outcomes of patients who underwent chronic MCS for treatment-resistant pain syndromes. MATERIALS AND METHODS: A broad literature search was conducted through PubMed to include all articles focusing on MCS for pain relief (keywords: subdural, epidural, repetitive transcranial magnetic stimulation, transcranial direct current stimulation, motor cortex stimulation, pain). LITERATURE REVIEW: Epidural MCS was the most widely used technique and had varying response rates across studies. Long-term efficacy was limited, and pain relief tended to decrease over time. Subdural MCS using similar stimulation parameters demonstrated similar efficacy to epidural stimulation and less invasive methods, such as repetitive transcranial magnetic stimulation (rTMS), which have been shown to provide adequate pain relief. rTMS and certain medications (ketamine and morphine) have been shown to predict the long-term response to epidural MCS. Complications tend to be rare, the most reported being seizures during subdural or epidural stimulation or hardware infection. CONCLUSIONS: Scientific evidence supports the use of MCS for treatment of refractory neuropathic pain syndromes. Further studies are warranted to elucidate the specific indications and stimulation protocols that are most amenable to the different types of MCS.

Oral and intravenous hydration in the treatment of orthostatic hypotension and postural tachycardia syndrome.

Hydration with water and salt is the mainstay of treatment for autonomic nervous system disorders that impair orthostatic tolerance. The goal is to expand intravascular volume to compensate for the downward displacement of blood volume that occurs when standing and thereby sustain cerebral perfusion and restore quality of life. Despite strong consensus recommendations for salt supplementation as standard treatment of these disorders, published evidence of benefit is relatively weak, and no randomized clinical trials have occurred. This review summarizes the physiological rationale for hydration and evaluates the literature on oral and intravenous hydration in the treatment of neurogenic orthostatic hypotension, postural tachycardia syndrome, and recurrent vasovagal syncope. We conclude that oral salt replacement is indicated for treatment of neurogenic orthostatic hypotension because these patients have excessive renal sodium excretion, and for treatment of chronic orthostatic intolerance because these patients are often hypovolemic. As not all patients are able to tolerate sufficient oral hydration, there is also a role for intravenous volume-loading in severe cases of postural tachycardia syndrome. We offer guidance, based on review of the literature and the clinical judgment of a cardiologist and neurologist with experience treating autonomic disorders, regarding the option of ongoing intravenous hydration for treatment of severe, refractory cases of postural tachycardia syndrome.

Salt: The paradoxical philosopher's stone of autonomic medicine.

Sodium chloride, or common table salt, for millennia has played a prominent role in human affairs. Salt is also a key molecule for regulating intravascular fluid volume in patients with orthostatic disorders. In this first article of a special issue of the journal focusing on salt and the autonomic nervous system, the historical and physiologic significance of salt is reviewed, highlighting its importance to society and to medicine. The relevance of salt both for civilization and for autonomic physiology penetrates into nearly every aspect of life and health. Replacing salt that has been depleted or administering salt to expand intravascular volume is considered standard treatment for patients with orthostatic hypotension and syndromes of orthostatic intolerance. The potential longterm effects of added salt, including effects unrelated to intravascular volume, have been insufficiently studied in patients with autonomic disorders. A salient concern is the potential increased risk of developing hypertension. Underappreciated aspects of salt include its ability to increase anxiety and through nonosmotic mechanisms to contribute to local tissue inflammation. Salt may be either salubrious or detrimental, or possibly both at the same time, depending on the clinical conditions. Reconciling these opposite effects in clinical practice requires weighing benefits against potential risks, assessing what is known alongside what is uncertain, and titrating treatment decisions to the particular needs of each individual patient.

Diagnostic criteria for initial orthostatic hypotension: a narrative review.

Abnormalities in orthostatic blood pressure changes upon active standing are associated with morbidity, mortality, and reduced quality of life. However, over the last decade, several population-based cohort studies have reported a remarkably high prevalence (between 25 and 70%) of initial orthostatic hypotension (IOH) among elderly individuals. This has raised the question as to whether the orthostatic blood pressure patterns in these community-dwelling elderly should truly be considered as pathological. If not, redefining of the systolic cutoff values for IOH (i.e., a value ≥ 40 mmHg in systolic blood pressure in the first 15 s after standing up) might be necessary to differ between normal aging and true pathology. Therefore, in this narrative review, we provide a critical analysis of the current reference values for the changes in systolic BP in the first 60 s after standing up and discuss how these values should be applied to large population studies. We will address factors that influence the magnitude of the systolic blood pressure changes following active standing and the importance of standardization of the stand-up test, which is a prerequisite for quantitative, between-subject comparisons of the postural hemodynamic response.

Religion in the US during the time of a Pandemic: A Medical Perspective.

Approximately 80% of Americans identify as religious. As physicians caring for patients with COVID-19, we have seen both positive and negative effects of religious activity during the pandemic. Religious worship generally supports close social interaction, which provides many benefits, especially in mental health, but it can also contradict infection control measures. These forces do not necessarily have to be in opposition to each other. Herein, we present three case vignettes of religious patients who were infected with and recovered from COVID-19. We review the potential benefits and risks of religious activity in the current pandemic, as supported by the medical literature. Finally, we offer some thoughts on how to engage with patients so that the benefits of both religious activity and public health measures are optimized.

Clinical features of autopsy-confirmed multiple system atrophy in the Mayo Clinic Florida brain bank.

BACKGROUND: Multiple system atrophy (MSA) presents with various combinations of autonomic dysfunction, parkinsonism, and cerebellar ataxia. Although clinical diagnostic criteria have been widely used, the sensitivity and specificity are suboptimal. This study aims to provide evidence supporting the revision of the current diagnostic criteria for MSA. METHODS: Medical records of 171 patients with autopsy-confirmed MSA in the Mayo Clinic brain bank were reviewed with regard to their clinical features and diagnoses. Pathologic features, including concomitant pathologies (i.e., Alzheimer-related and Lewy-related pathologies), were also assessed. RESULTS: The cohort included 133 MSA-parkinsonian type, 36 MSA-cerebellar type, and 2 unclassified MSA patients who did not show significant motor symptoms. Twenty-three patients (13%) were not clinically diagnosed with MSA, but instead with progressive supranuclear palsy, Parkinson's disease (PD), PD with dementia (PDD), or dementia with Lewy bodies (DLB). Three patients with PDD and DLB also had concomitant Lewy body pathology. Six patients had late-onset MSA, with an age of onset greater than 75 years. Erectile dysfunction was frequent in male patients (60/63; 95%) in all age ranges. REM sleep behavior disorder (RBD) was present in 82 patients (48%) and was the initial symptom in 13 patients. Cognitive impairment was present in 60 patients (35%), but was an initial symptom in only two patients. CONCLUSIONS: Our findings support the conclusion that late-onset presentation should not exclude MSA. The findings of this large autopsy-based cohort provides valuable insights for improving clinical criteria for MSA.

Autonomic dysfunction following COVID-19 infection: an early experience.

PURPOSE: Post-COVID-19 syndrome is a poorly understood aspect of the current pandemic, with clinical features that overlap with symptoms of autonomic/small fiber dysfunction. An early systematic analysis of autonomic dysfunction following COVID-19 is lacking and may provide initial insights into the spectrum of this condition. METHODS: We conducted a retrospective review of all patients with confirmed history of COVID-19 infection referred for autonomic testing for symptoms concerning for para-/postinfectious autonomic dysfunction at Mayo Clinic Rochester or Jacksonville between March 2020 and January 2021. RESULTS: We identified 27 patients fulfilling the search criteria. Symptoms developed between 0 and 122 days following the acute infection and included lightheadedness (93%), orthostatic headache (22%), syncope (11%), hyperhidrosis (11%), and burning pain (11%). Sudomotor function was abnormal in 36%, cardiovagal function in 27%, and cardiovascular adrenergic function in 7%. The most common clinical scenario was orthostatic symptoms without tachycardia or hypotension (41%); 22% of patients fulfilled the criteria for postural tachycardia syndrome (POTS), and 11% had borderline findings to support orthostatic intolerance. One patient each was diagnosed with autoimmune autonomic ganglionopathy, inappropriate sinus tachycardia, vasodepressor syncope, cough/vasovagal syncope, exacerbation of preexisting orthostatic hypotension, exacerbation of sensory and autonomic neuropathy, and exacerbation of small fiber neuropathy. CONCLUSION: Abnormalities on autonomic testing were seen in the majority of patients but were mild in most cases. The most common finding was orthostatic intolerance, often without objective hemodynamic abnormalities on testing. Unmasking/exacerbation of preexisting conditions was seen. The temporal association between infection and autonomic symptoms implies a causal relationship, which however cannot be proven by this study.

Investigating ELOVL7 coding variants in multiple system atrophy.

Multiple system atrophy (MSA) is a rare sporadic, progressive parkinsonism characterised by autonomic dysfunction. A recent genome-wide association study reported an association at the Elongation of Very Long Fatty Acids Protein 7 (ELOVL7) locus with MSA risk. In the current study four independent and unrelated cohorts were assessed, consisting of pathologically confirmed MSA cases, Parkinson's disease (PD) cases, and two unrelated, healthy control groups. All exons of ELOVL7 were sequenced in pathologically confirmed MSA cases; data for PPMI samples and Biobank controls was extracted from whole genome sequence. Coding variants in ELOVL7 were extremely rare, and we observed no significant association of ELOVL7 coding variants with risk of MSA.

Electrodiagnostic assessment of the autonomic nervous system: A consensus statement endorsed by the American Autonomic Society, American Academy of Neurology, and the International Federation of Clinical Neurophysiology.

Evaluation of disorders of the autonomic nervous system is both an art and a science, calling upon the physician's most astute clinical skills as well as knowledge of autonomic neurology and physiology. Over the last three decades, the development of noninvasive clinical tests that assess the function of autonomic nerves, the validation and standardization of these tests, and the growth of a large body of literature characterizing test results in patients with autonomic disorders have equipped clinical practice further with a valuable set of objective tools to assist diagnosis and prognosis. This review, based on current evidence, outlines an international expert consensus set of recommendations to guide clinical electrodiagnostic autonomic testing. Grading and localization of autonomic deficits incorporates scores from sympathetic cardiovascular adrenergic, parasympathetic cardiovagal, and sudomotor testing, as no single test alone is sufficient to diagnose the degree or distribution of autonomic failure. The composite autonomic severity score (CASS) is a useful score of autonomic failure that is normalized for age and gender. Valid indications for autonomic testing include generalized autonomic failure, regional or selective system syndromes of autonomic impairment, peripheral autonomic neuropathy and ganglionopathy, small fiber neuropathy, orthostatic hypotension, orthostatic intolerance, syncope, neurodegenerative disorders, autonomic hyperactivity, and anhidrosis.