William P. Cheshire

Consensus statement on the definition of orthostatic hypotension, neurally mediated syncope and the postural tachycardia syndrome

Roy Freeman • Wouter Wieling • Felicia B. Axelrod • David G. Benditt • Eduardo Benarroch • Italo Biaggioni • William P. Cheshire • Thomas Chelimsky • Pietro Cortelli • Christopher H. Gibbons • David S. Goldstein • Roger Hainsworth • Max J. Hilz • Giris Jacob • Horacio Kaufmann • Jens Jordan • Lewis A. Lipsitz • Benjamin D. Levine • Phillip A. Low • Christopher Mathias • Satish R. Raj • David Robertson • Paola Sandroni • Irwin Schatz • Ron Schondorff • Julian M. Stewart • J. Gert van Dijk

Spinal cord infarction Etiology and outcome

We reviewed 44 cases of ischemia and infarction of the spinal cord at two university hospitals.Three patients experienced transient ischemic attacks. Etiologies of completed strokes were diverse and included rupture and surgical repair of aortic aneurysms, aortic dissection, aortic rupture and thrombosis, global ischemia, anterior spinal artery embolism, repair and thrombosis of spinal arteriovenous malformations, hematomyelia, epidural hematoma, cervical osteophytosis, celiac plexus block, systemic lupus erythematosus, coagulopathy, and decompression sickness. Motor function improved in 12 patients, was substantial in only one, and occurred largely within the first 2 to 4 weeks. Favorable ambulatory outcome correlated with improving neurologic examinations and relatively preserved strength in hip abductors and knee extensors. More extensive deficits without initial improvement portended a more severe prognosis. Autonomic dysfunction, pain, paresthesia, and depression were common and impeded recovery in some patients. The mean level of deficit was at T-8 and in cases of global ischemia was at T-9, which leads us to dispute the classical view of a midthoracic watershed zone of ischemic vulnerability near T-4. NEUROLOGY 1996;47: 321-330

Consensus statement on the definition of orthostatic hypotension, neurally mediated syncope and the postural tachycardia syndrome.

Roy Freeman • Wouter Wieling • Felicia B. Axelrod • David G. Benditt • Eduardo Benarroch • Italo Biaggioni • William P. Cheshire • Thomas Chelimsky • Pietro Cortelli • Christopher H. Gibbons • David S. Goldstein • Roger Hainsworth • Max J. Hilz • Giris Jacob • Horacio Kaufmann • Jens Jordan • Lewis A. Lipsitz • Benjamin D. Levine • Phillip A. Low • Christopher Mathias • Satish R. Raj • David Robertson • Paola Sandroni • Irwin Schatz • Ron Schondorff • Julian M. Stewart • J. Gert van Dijk

Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17)

Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) is an autosomal dominant neurodegenerative disorder, which has three cardinal features: behavioral and personality changes, cognitive impairment, and motor symptoms. FTDP-17 was defined during the International Consensus Conference in Ann Arbor, Michigan, in 1996. The prevalence and incidence remain unknown but FTDP-17 is an extremely rare condition. It is caused by mutations in the tau gene, which encodes a microtubule-binding protein. Over 100 families with 38 different mutations in the tau gene have been identified worldwide. The phenotype of FTDP-17 varies not only between families carrying different mutations but also between and within families carrying the same mutations. The pathogenetic mechanisms underlying the disorder are thought to be related to the altered proportion of tau isoforms or to the ability of tau to bind microtubules and to promote microtubule assembly. Definitive diagnosis of FTDP-17 requires a combination of characteristic clinical and pathological features and molecular genetic analysis. Genetic counseling should be offered to affected and at-risk individuals; for most subtypes, penetrance is incomplete. Currently, treatment for FTDP-17 is only symptomatic and supportive. The prognosis and rate of the diseases progression vary considerably among individual patients and genetic kindreds, ranging from life expectancies of several months to several years, and, in exceptional cases, as long as two decades.

Myasthenia gravis with autoimmune autonomic neuropathy.

The autoantibodies that impair neuromuscular junction transmission in myasthenia gravis are specific for the nicotinic acetylcholine receptor (AChR) of muscle. Antibodies specific for AChRs in ganglionic neurons are found in a majority of patients with subacute autonomic neuropathy. Dysautonomia is not a recognized feature of myasthenia gravis, but there have been rare reports of myasthenia gravis coexisting with autonomic failure, usually in association with thymoma. Here we report seven patients who had myasthenia gravis with subacute autonomic failure. Their autonomic dysfunction ranged from isolated gastroparesis to severe panautonomic failure. Gastrointestinal dysmotility was a common feature. All had antibodies against muscle AChR, and three (all of whom had thymoma) had antibodies against neuronal ganglionic AChRs. In several patients, gastrointestinal function improved clinically after administration of an acetylcholinesterase inhibitor. These observations support a rare but definite clinical association between myasthenia gravis and autonomic failure and strengthen the concept that subacute autonomic neuropathy is an autoimmune disorder.

When DLB, PD, and PSP masquerade as MSA An autopsy study of 134 patients

Objective: To determine ways to improve diagnostic accuracy of multiple system atrophy (MSA), we assessed the diagnostic process in patients who came to autopsy with antemortem diagnosis of MSA by comparing clinical and pathologic features between those who proved to have MSA and those who did not. We focus on likely explanations for misdiagnosis. Methods: This is a retrospective review of 134 consecutive patients with an antemortem clinical diagnosis of MSA who came to autopsy with neuropathologic evaluation of the brain. Of the 134 patients, 125 had adequate medical records for review. Clinical and pathologic features were compared between patients with autopsy-confirmed MSA and those with other pathologic diagnoses, including dementia with Lewy bodies (DLB), Parkinson disease (PD), and progressive supranuclear palsy (PSP). Results: Of the 134 patients with clinically diagnosed MSA, 83 (62%) had the correct diagnosis at autopsy. Pathologically confirmed DLB was the most common misdiagnosis, followed by PSP and PD. Despite meeting pathologic criteria for intermediate to high likelihood of DLB, several patients with DLB did not have dementia and none had significant Alzheimer-type pathology. Autonomic failure was the leading cause of misdiagnosis in DLB and PD, and cerebellar ataxia was the leading cause of misdiagnosis in PSP. Conclusions: The diagnostic accuracy for MSA was suboptimal in this autopsy study. Pathologically confirmed DLB, PD, and PSP were the most common diseases to masquerade as MSA. This has significant implications not only for patient care, but also for research studies in MSA cases that do not have pathologic confirmation.

Efficacy and safety of rifampicin for multiple system atrophy: a randomised, double-blind, placebo-controlled trial

BACKGROUND No available treatments slow or halt progression of multiple system atrophy, which is a rare, progressive, fatal neurological disorder. In a mouse model of multiple system atrophy, rifampicin inhibited formation of α-synuclein fibrils, the neuropathological hallmark of the disease. We aimed to assess the safety and efficacy of rifampicin in patients with multiple system atrophy. METHODS In this randomised, double-blind, placebo-controlled trial we recruited participants aged 30-80 years with possible or probable multiple system atrophy from ten US medical centres. Eligible participants were randomly assigned (1:1) via computer-generated permuted block randomisation to rifampicin 300 mg twice daily or matching placebo (50 mg riboflavin capsules), stratified by subtype (parkinsonian vs cerebellar), with a block size of four. The primary outcome was rate of change (slope analysis) from baseline to 12 months in Unified Multiple System Atrophy Rating Scale (UMSARS) I score, analysed in all participants with at least one post-baseline measurement. This study is registered with ClinicalTrials.gov, number NCT01287221. FINDINGS Between April 22, 2011, and April 19, 2012, we randomly assigned 100 participants (50 to rifampicin and 50 to placebo). Four participants in the rifampicin group and five in the placebo group withdrew from study prematurely. Results of the preplanned interim analysis (n=15 in each group) of the primary endpoint showed that futility criteria had been met, and the trial was stopped (the mean rate of change [slope analysis] of UMSARS I score was 0.62 points [SD 0.85] per month in the rifampicin group vs 0.47 points [0.48] per month in the placebo group; futility p=0.032; efficacy p=0.76). At the time of study termination, 49 participants in the rifampicin group and 50 in the placebo group had follow-up data and were included in the final analysis. The primary endpoint was 0.5 points (SD 0.7) per month for rifampicin and 0.5 points (0.5) per month for placebo (difference 0.0, 95% CI -0.24 to 0.24; p=0.82). Three (6%) of 50 participants in the rifampicin group and 12 (24%) of 50 in the placebo group had one or more serious adverse events; none was thought to be related to treatment. INTERPRETATION Our results show that rifampicin does not slow or halt progression of multiple system atrophy. Despite the negative result, the trial does provide information that could be useful in the design of future studies assessing potential disease modifying therapies in patients with multiple system atrophy. FUNDING National Institutes of Health, Mayo Clinic Center for Translational Science Activities, and Mayo Funds.

Trigeminal neuralgia: for one nerve a multitude of treatments

Trigeminal neuralgia (TN) is reputed to be one of the most painful conditions in human experience. Thus, many treatments, both medical and surgical, have been developed for this relapsing and remitting, paroxysmal stabbing or electrical, facial pain syndrome. The likely etiology in many cases is vascular compression of the trigeminal nerve root entry zone, leading to focal demyelination and aberrant neural discharges. MRI may disclose neurovascular contact, although not with sufficient sensitivity or specificity to substitute for careful clinical diagnosis. In treating TN, antiepileptic drugs are superior to traditional analgesics. Carbamazepine is the first choice drug. Additional drugs for which there is evidence of efficacy include oxcarbazepine, baclofen, gabapentin, lamotrigine and phenytoin. Many patients eventually experience tachyphylaxis or may not tolerate effective doses. Surgical options include: microvascular decompression; balloon compression; radiofrequency thermocoagulation or glycerol rhizotomies; and subcutaneous alcohol branch blockade. Stereotactic gamma knife radiosurgery is a further option. Motor cortex stimulation and transcranial magnetic stimulation, although having shown initial promise for trigeminal neuropathic pain, seem to be ineffective for classical TN. The choice of drug, whether or when to operate, and which procedure to choose should be individualized to the particular needs and conditions of the patient.

Drug-Induced Hyperhidrosis and Hypohidrosis Incidence, Prevention and Management

The human sweating response is subject to the influence of diverse classes of drugs. Some act centrally at the hypothalamus or at spinal thermoregulatory centres, while others act at sympathetic ganglia or at the eccrine-neuroeffector junction. Pharmacological disturbances of sweating have broad clinical implications. Drugs that induce hyperhidrosis, or sweating in excess of that needed to maintain thermoregulation, can cause patient discomfort and embarrassment, and include cholinesterase inhibitors, selective serotonin reuptake inhibitors, opioids and tricyclic antidepressants. Drugs that induce hypohidrosis, or deficient sweating, can increase the risk of heat exhaustion or heat stroke and include antimuscarinic anticholinergic agents, carbonic anhydrase inhibitors and tricyclic antidepressants. As acetylcholine is the principal neuroeccrine mediator, anhidrosis is one of the clinical hallmarks by which acute anticholinergic toxicity may be recognized. The symptom of dry mouth often accompanies the less apparent symptom of hypohidrosis because the muscarinic M3 acetylcholine receptor type predominates at both sweat and salivary glands. Management options include dose reduction, drug substitution or discontinuation. When compelling medical indications require continuation of a drug causing hyperhidrosis, the addition of a pharmacological agent to suppress sweating can help to reduce symptoms. When hypohidrotic drugs must be continued, deficient sweating can be managed by avoiding situations of heat stress and cooling the skin with externally applied water. The availability of clinical tests for the assessment of sudomotor dysfunction in neurological disease has enhanced recognition of the complex effects of drugs on sweating. Advances in the understanding of drug-induced anhidrosis have also enlarged the therapeutic repertoire of effective treatments for hyperhidrosis.

Analysis of COQ2

BackgroundLoss of function COQ2 mutations results in primary CoQ10 deficiency. Recently, recessive mutations of the COQ2 gene have been identified in two unrelated Japanese families with multiple system atrophy (MSA). It has also been proposed that specific heterozygous variants in the COQ2 gene may confer susceptibility to sporadic MSA. To assess the frequency of COQ2 variants in patients with MSA, we sequenced the entire coding region and investigated all exonic copy number variants of the COQ2 gene in 97 pathologically-confirmed and 58 clinically-diagnosed MSA patients from the United States.ResultsWe did not find any homozygous or compound heterozygous pathogenic COQ2 mutations including deletion or multiplication within our series of MSA patients. In two patients, we identified two heterozygous COQ2 variants (p.S54W and c.403 + 10G > T) of unknown significance, which were not observed in 360 control subjects. We also identified one heterozygous carrier of a known loss of function p.S146N substitution in a severe MSA-C pathologically-confirmed patient.ConclusionsThe COQ2 p.S146N substitution has been previously reported as a pathogenic mutation in primary CoQ10 deficiency (including infantile multisystem disorder) in a recessive manner. This variant is the third primary CoQ10 deficiency mutation observed in an MSA case (p.R387X and p.R197H). Therefore it is possible that in the heterozygous state it may increase susceptibility to MSA. Further studies, including reassessing family history in patients of primary CoQ10 deficiency for the possible occurrence of MSA, are now warranted to resolve the role of COQ2 variation in MSA.