Sphincter EMG and differential diagnosis of multiple system atrophy

A Review on the Clinical Diagnosis of Multiple System Atrophy

Multiple system atrophy (MSA) is a rare, adult-onset, progressive neurodegenerative disorder with major diagnostic challenges. Aiming for a better diagnostic accuracy particularly at early disease stages, novel Movement Disorder Society criteria for the diagnosis of MSA (MDS MSA criteria) have been recently developed. They introduce a neuropathologically established MSA category and three levels of clinical diagnostic certainty including clinically established MSA, clinically probable MSA, and the research category of possible prodromal MSA. The diagnosis of clinically established and clinically probable MSA is based on the presence of cardiovascular or urological autonomic failure, parkinsonism (poorly L-Dopa-responsive for the diagnosis of clinically established MSA), and cerebellar syndrome. These core clinical features need to be associated with supportive motor and non-motor features (MSA red flags) and absence of any exclusion criteria. Characteristic brain MRI markers are required for a diagnosis of clinically established MSA. A research category of possible prodromal MSA is devised to capture patients manifesting with autonomic failure or REM sleep behavior disorder and only mild motor signs at the earliest disease stage. There is a number of promising laboratory markers for MSA that may help increase the overall clinical diagnostic accuracy. In this review, we will discuss the core and supportive clinical features for a diagnosis of MSA in light of the new MDS MSA criteria, which laboratory tools may assist in the clinical diagnosis and which major differential diagnostic challenges should be borne in mind.

Autonomic failure: Clinicopathologic, physiologic, and genetic aspects

Over the past century, generations of neuroscientists, pathologists, and clinicians have elucidated the underlying causes of autonomic failure found in neurodegenerative, inherited, and antibody-mediated autoimmune disorders, each with pathognomonic clinicopathologic features. Autonomic failure affects central autonomic nervous system components in the α-synucleinopathy, multiple system atrophy, characterized clinically by levodopa-unresponsive parkinsonism or cerebellar ataxia, and pathologically by argyrophilic glial cytoplasmic inclusions (GCIs). Two other central neurodegenerative disorders, pure autonomic failure characterized clinically by deficits in norepinephrine synthesis and release from peripheral sympathetic nerve terminals; and Parkinson's disease, with early and widespread autonomic deficits independent of the loss of striatal dopamine terminals, both express Lewy pathology. The rare congenital disorder, hereditary sensory, and autonomic neuropathy type III (or Riley-Day, familial dysautonomia) causes life-threatening autonomic failure due to a genetic mutation that results in loss of functioning baroreceptors, effectively separating afferent mechanosensing neurons from the brain. Autoimmune autonomic ganglionopathy caused by autoantibodies targeting ganglionic α3-acetylcholine receptors instead presents with subacute isolated autonomic failure affecting sympathetic, parasympathetic, and enteric nervous system function in various combinations. This chapter is an overview of these major autonomic disorders with an emphasis on their historical background, neuropathological features, etiopathogenesis, diagnosis, and treatment.

The Role of Pelvic Neurophysiology Testing in the Assessment of Patients with Voiding Dysfunction

Purpose of Review

The role of pelvic neurophysiology testing in the evaluation of patients with lower urinary tract (LUT) symptoms is explored in this review.

Recent Findings

Different neurophysiology tests such as sphincter EMG and pudendal somatosensory evoked potentials are useful in evaluating the sacral somatic afferent and efferent innervation. S2 and S3 dermatomal evoked potentials assess individual sacral roots and are feasible to perform using standard neurophysiology machines.

Summary

The innervation of the LUT has a substantial contribution from splanchnic and somatic nerves arising from the sacral segments. Pelvic neurophysiology tests, which assess somatic nerve functions, are therefore a useful tool in assessing sacral nerve functions in patients presenting with unexplained voiding dysfunction. In this review, the commonly performed neurophysiology studies that assess the S2, S3 and S4 sacral afferent and efferent pathways are outlined, and their clinical applications reviewed.

Diagnosing multiple system atrophy at the prodromal stage

Identifying individuals at the earliest disease stage becomes crucial as we aim to develop disease-modifying treatments for neurodegenerative disorders. Prodromal diagnostic criteria were recently developed for Parkinson's disease (PD) and are forthcoming for dementia with Lewy bodies (DLB). The latest 2008 version of diagnostic criteria for multiple system atrophy (MSA) have improved diagnostic accuracy in early disease stages compared to previous criteria, but we do not yet have formal criteria for prodromal MSA. Building on similar approaches as for PD and DLB, we can identify features on history-taking, clinical examination, and ancillary clinical testing that can predict the likelihood of an individual developing MSA, while also distinguishing it from PD and DLB. The main clinical hallmarks of MSA are REM sleep behavior disorder (RBD) and autonomic dysfunction (particularly orthostatic hypotension and urogenital symptoms), and may be the primary means by which patients with potential prodromal MSA are identified. Preserved olfaction, absence of significant cognitive deficits, urinary retention, and respiratory symptoms such as stridor and respiratory insufficiency can be clinical features that help distinguish MSA from PD and DLB. Finally, ancillary test results including neuroimaging as well as serological and cerebrospinal fluid (CSF) biomarkers may lend further weight to quantifying the likelihood of phenoconversion into MSA. For prodromal criteria, the primary challenges are MSA's lower prevalence, shorter lead time to diagnosis, and strong overlap with other synucleinopathies. Future prodromal criteria may need to first embed the diagnosis into a general umbrella of prodromal alpha-synucleinopathies, followed by identification of features that suggest prodromal MSA as the specific cause.

Pure autonomic failure

In this chapter, we describe the history, presentation, diagnosis and treatment of pure autonomic failure (PAF). The pathology underlying this condition is thought to involve the deposition of alpha synuclein in the autonomic ganglia leading to diminished norepinephrine release and progressive autonomic dysfunction. We focus on various neurophysiological tests that may be used to evaluate the function of the peripheral autonomic nervous system including quantitative sudomotor axon reflex testing, thermoregulatory sweat testing, and others. These may help evaluate and diagnose various disorders of autonomic failure and neurogenic orthostatic hypotension including multiple system atrophy and Parkinson's disease dysautonomia. Management of PAF, including the therapeutic role of recent advances in pharmacologic treatment, is discussed.

Clinical neurophysiology of multiple system atrophy

Multiple system atrophy (MSA) is an adult-onset, rapidly progressive neurodegenerative syndrome. The diagnosis of MSA is primarily clinical. Neurophysiologic studies can provide important clues to the diagnosis of MSA and differentiate it from other neurodegenerative diseases especially when the clinical picture is unclear. This chapter reviews common and less common neurophysiological studies useful in the diagnosis of MSA.

Imaging the Autonomic Nervous System in Parkinson's Disease

PURPOSE OF REVIEW

Patients with Parkinson's disease (PD) often display gastrointestinal and genitourinary autonomic symptoms years or even decades prior to diagnosis. These symptoms are thought to be caused in part by pathological α-synuclein inclusions in the peripheral autonomic and enteric nervous systems. It has been proposed that the initial α-synuclein aggregation may in some PD patients originate in peripheral nerve terminals and then spread centripetally to the spinal cord and brainstem. In vivo imaging methods can directly quantify the degeneration of the autonomic nervous system as well as the functional consequences such as perturbed motility. Here, we review the methodological principles of these imaging techniques and the major findings in patients with PD and atypical parkinsonism.

RECENT FINDINGS

Loss of sympathetic and parasympathetic nerve terminals in PD can be visualized using radiotracer imaging, including ¹²³I-MIBG scintigraphy, and ¹⁸F-dopamine and ¹¹C-donepezil PET. Recently, ultrasonographical studies disclosed reduced diameter of the vagal nerves in PD patients. Radiological and radioisotope techniques have demonstrated dysmotility and prolonged transit time throughout all subdivisions of the gastrointestinal tract in PD. The prevalence of objective dysfunction as measured with these imaging methods is often considerably higher compared to the prevalence of subjective symptoms experienced by the patients. Degeneration of the autonomic nervous system may play a key role in the pathogenesis of PD. In vivo imaging techniques provide powerful and noninvasive tools to quantify the degree and extent of this degeneration and its functional consequences.

The value of the bulbocavernosus reflex and pudendal nerve somatosensory evoked potentials in distinguishing between multiple system atrophy and Parkinson's disease at an early stage

OBJECTIVES

This study was designed to investigate the clinical value of the bulbocavernosus reflex (BCR) and pudendal nerve somatosensory evoked potentials (PSEPs) in the differential diagnosis between multiple system atrophy (MSA) and Parkinson's disease (PD) in early stage.

MATERIALS AND METHODS

A total of 31 patients with MSA, 45 patients with PD, and 60 healthy participants were included in this study. A Keypoint EMG/EP system was used for BCR and PSEP measurements. Electrophysiological parameters were collected for statistical analysis.

RESULTS

The BCR elicitation rates were significantly lower in the patients with MSA than in the patients with PD (P<.05). Prolonged BCR latencies were found in the MSA group compared to the PD and control groups (P<.05). Bulbocavernosus reflex latencies were significantly prolonged in patients with MSA compared with PD patients showing early urogenital symptoms (P<.05). There was no significant difference in PSEP P41 latencies among the three groups (P=.434 in males, P=.948 in females). Both BCR and PSEP amplitudes were significantly lower in the MSA/PD group than in the control group (P<.001).

CONCLUSIONS

Pudendal nerve damage is more severe in MSA than in PD. Prolonged BCR latency may be valuable for distinguishing between MSA and PD in the early stages. BCR and PSEP testing may also contribute to localized and qualitative diagnosis of the distribution of neurodegenerative pathologies in these two disorders.

Diagnosis and differential diagnosis of MSA: boundary issues

Because the progression of multiple system atrophy (MSA) is usually rapid and there still is no effective cause-related therapy, early and accurate diagnosis is important for the proper management of patients as well as the development of neuroprotective agents. However, despite the progression in the field of MSA research in the past few years, the diagnosis of MSA in clinical practice still relies largely on clinical features and there are limitations in terms of sensitivity and specificity, especially in the early course of the disease. Furthermore, recent pathological, clinical, and neuroimaging studies have shown that (1) MSA can present with a wider range of clinical and pathological features than previously thought, including features considered atypical for MSA; thus, MSA can be misdiagnosed as other diseases, and conversely, disorders with other etiologies and pathologies can be clinically misdiagnosed as MSA; and (2) several investigations may help to improve the diagnosis of MSA in clinical practice. These aspects should be taken into consideration when revising the current diagnostic criteria. This is especially true given that disease-modifying treatments for MSA are under investigation.

An update on the cerebellar subtype of multiple system atrophy

Multiple system atrophy is a rare and fatal neurodegenerative disorder characterized by progressive autonomic failure, ataxia and parkinsonism in any combination. The clinical manifestations reflect central autonomic and striatonigral degeneration as well as olivopontocerebellar atrophy. Glial cytoplasmic inclusions, composed of α-synuclein and other proteins are considered the cellular hallmark lesion. The cerebellar variant of MSA (MSA-C) denotes a distinctive motor subtype characterized by progressive adult onset sporadic gait ataxia, scanning dysarthria, limb ataxia and cerebellar oculomotor dysfunction. In addition, there is autonomic failure and variable degrees of parkinsonism. A range of other disorders may present with MSA-C like features and therefore the differential diagnosis of MSA-C is not always straightforward. Here we review key aspects of MSA-C including pathology, pathogenesis, diagnosis, clinical features and treatment, paying special attention to differential diagnosis in late onset sporadic cerebellar ataxias.

Multiple system atrophy of the cerebellar type: clinical state of the art

Multiple system atrophy (MSA) is a late-onset, sporadic neurodegenerative disorder clinically characterized by autonomic failure and either poorly levodopa-responsive parkinsonism or cerebellar ataxia. It is neuropathologically defined by widespread and abundant central nervous system α-synuclein-positive glial cytoplasmic inclusions and striatonigral and/or olivopontocerebellar neurodegeneration. There are two clinical subtypes of MSA distinguished by the predominant motor features: the parkinsonian variant (MSA-P) and the cerebellar variant (MSA-C). Despite recent progress in understanding the pathobiology of MSA, investigations into the symptomatology and natural history of the cerebellar variant of the disease have been limited. MSA-C presents a unique challenge to both clinicians and researchers alike. A key question is how to distinguish early in the disease course between MSA-C and other causes of adult-onset cerebellar ataxia. This is a particularly difficult question, because the clinical framework for conceptualizing and studying sporadic adult-onset ataxias continues to undergo flux. To date, several investigations have attempted to identify clinical features, imaging, and other biomarkers that may be predictive of MSA-C. This review presents a clinically oriented overview of our current understanding of MSA-C with a focus on evidence for distinguishing MSA-C from other sporadic, adult-onset ataxias.

Anal sphincter electromyography in patients with newly diagnosed idiopathic parkinsonism

OBJECTIVES

The differential diagnosis of patients with idiopathic parkinsonism is difficult, especially early in the course of the disease. External anal sphincter electromyography (EAS-EMG) has been reported to be of value in the differential diagnosis between Parkinson's disease (PD) and multiple system atrophy (MSA). Patients with MSA are reported to have pathological EAS-EMG and patients with PD are reported to have significantly less pathological EAS-EMG results. Comparisons between patients with parkinsonian disorders have usually been made many years into the disease, and thus it is largely unknown if the results of EAS-EMG can be used to distinguish the different diagnoses in the early phase of the disease.

MATERIALS AND METHODS

We investigated 148 newly diagnosed patients with idiopathic parkinsonism from a population-based incidence cohort (100 definite PD, 21 probable PD, 16 MSA, 11 progressive supranuclear palsy, and 40 controls) with EAS-EMG within 3 months of their first visit and, in the majority of patients, before start of treatment with dopaminergic drugs. The clinical diagnoses were made using established clinical diagnostic criteria after a median follow-up of 3 years.

RESULTS

All patient groups had more pathological EAS-EMG results than controls. No EAS-EMG differences were found between the patient groups, especially not between PD and MSA.

CONCLUSIONS

External anal sphincter electromyography examination cannot separate the different parkinsonian subgroups from each other in early course of the diseases.

Premotor signs and symptoms of multiple system atrophy

Diagnostic criteria for multiple system atrophy are focused on motor manifestations of the disease, in particular ataxia and parkinsonism, but these criteria often cannot detect the early stages. Non-motor symptoms and signs of multiple system atrophy often precede the onset of classic motor manifestations, and this prodromal phase is estimated to last from several months to years. Autonomic failure, sleep problems, and respiratory disturbances are well known symptoms of established multiple system atrophy and, when presenting early and preceding ataxia or parkinsonism, should be regarded as evidence of premotor multiple system atrophy. An early and accurate diagnosis is becoming increasingly important as new neuroprotective agents are developed.

Anesthesia implications in emergency oncologic surgery in a case of untreated Parkinsonism

Oncologic surgery has made tremendous advancements in the last two decades. The prognosis of once thought to be irreversible and incurable diseases has improved dramatically with these advancements, which have given a fresh lease of hope to the general population. But there are certain factors that are still unfavorable for achieving improved outcome of surgery in various cancers. The associated comorbid diseases do determine to a large extent the actual outcome of all the interventions to treat oncologic disease. The untreated coexisting disease makes the task of the attending anesthesiologist very challenging as numerous complications are anticipated, especially during emergency surgery. We are describing a case of a patient with endometrial carcinoma who presented with unstoppable bleeding per-vaginum and was suffering from Parkinson disease since 1½ years, for which no treatment was ever sought. Vaginal hysterectomy was performed under graded epidural anesthesia; and after a smooth and uneventful postoperative period of 8 days, she was referred to radiotherapy unit for further management.

The search for biomarkers in Parkinson's disease: a critical review

Parkinson's disease (PD) is a progressive neurodegenerative disorder that primarily presents with features of bradykinesia, rigidity and tremor, and has, as part of its core pathology, the degeneration of dopaminergic neurons in the substantia nigra pars compacta. There is a great need for the development of a reliable diagnostic tool to improve promptness of diagnosis, definition of disease subtypes, and to monitor disease progression and demonstrate treatment efficacy in the case of disease modifying therapies. Current biomarkers range from objective clinical tools, to neuroimaging, to 'wet' markers involving blood and cerebrospinal fluid. To date, all candidate biomarkers for PD have failed to be developed into a clinically useful tool. Ideally, a combination of sensitive markers will be needed, not only to predict the onset of PD, but also to help in subtype classification and to follow progression. Here, we critically review various PD biomarker studies.

Multiple system atrophy

BACKGROUND

It has been almost 4 decades since the descriptions of the 3 parts of multiple system atrophy (MSA) have taken place, characterized clinically by dysautonomia, parkinsonism, and cerebellar dysfunction. The discovery of a distinctive pathologic maker has finally provided the conceptual synthesis of these 3 entities into the universal designation of MSA as a distinct disease process with a complex combination of clinical presentations. Although advances have been made in terms of awareness and knowledge concerning the clinical features and pathophysiology of MSA, it remains challenging for neurologists who treat these patients to differentiate MSA from its mimics as well as providing them with effective treatment.

REVIEW SUMMARY

The aim of this review is to provide an overview of the advances in the knowledge of the disease, to highlight typical features useful for the recognition of its entity, and to enlist different treatment options.

CONCLUSION

Despite the fact that there is still no treatment modality that can alter the disease progression, a number of useful symptomatic treatment measures are available and should be offered to patients to ameliorate the nonmotor features of MSA and even the motor features that may at least transiently respond to treatment.

Continuous urinary incontinence presenting as the initial symptoms demonstrating acontractile detrusor and intrinsic sphincter deficiency in multiple system atrophy

Severe stress incontinence due to intrinsic sphincter deficiency may be common in aged women. However stress urinary incontinence could be the initial symptom of severe neurogenic bladder even if no neurological signs have previously been recognized. Urodynamic study is necessary in such a case. Tension-free vaginal tape surgery and intermittent self-catheterization may be one option, but self catheterization might become difficult when the neurological disorders develop. In this case report, we highlight the need for caution in identifying the presence of an occult neurogenic bladder when intending to carry out surgery for patients with severe stress incontinence.

Chapitre I - Troubles vésico-sphintériens des syndromes parkinsoniens

Lower urinary tract dysfunction is frequent in Parkinson's disease and other Parkinsonian syndromes and can cause urinary incontinence complicating a urgency-frequency syndrome or on the contrary, dysuria. These disorders are a frequent urological presenting complaint due to their impact on the patient's quality of life. Urologists must be aware of the different natural histories of diseases such as Parkinson's disease and Parkinsonian syndromes such as multisystem atrophy, which often have a severe course and are marked by resistance to neuropharmacological treatments. These various diseases can also directly induce urinary symptoms, independently of urological complications. Inversely, the development of urinary disorders, especially obstructive symptoms, in a patient with Parkinsonian syndrome may require review of the neurological diagnosis. Finally, therapeutic management is complex due to the difficulty of using pharmacological treatments, and the risk of deterioration after surgical treatment of obstructive uropathy.

Neurophysiological testing in anorectal disorders

The neurophysiological techniques currently available to evaluate anorectal disorders include concentric needle electromyography (EMG) of the external anal sphincter, anal nerve terminal motor latency (TML) measurement in response to transrectal electrical stimulation or sacral magnetic stimulation, motor evoked potentials (MEPs) of the anal sphincter to transcranial magnetic cortical stimulation, cortical recording of somatosensory evoked potentials (SEPs) to anal nerve stimulation, quantification of electrical or thermal sensory thresholds (QSTs) within the anal canal, sacral anal reflex (SAR) latency measurement in response to pudendal nerve or perianal stimulation, and perianal recording of sympathetic skin responses (SSRs). In most cases, a comprehensive approach using several tests is helpful for diagnosis: needle EMG signs of sphincter denervation or prolonged TML give evidence for anal motor nerve lesion; SEP/QST or SSR abnormalities can suggest sensory or autonomic neuropathy; and in the absence of peripheral nerve disorder, MEPs, SEPs, SSRs, and SARs can assist in demonstrating and localizing spinal or supraspinal disease. Such techniques are complementary to other methods of investigation, such as pelvic floor imaging and anorectal manometry, to establish the diagnosis and guide therapeutic management of neurogenic anorectal disorders.

Incomplete emptying and urinary retention in multiple-system atrophy: When does it occur and how do we manage it?

Neurogenic urinary retention can be a major cause of morbidity in multiple-system atrophy (MSA). However, the timing of its appearance has not been entirely clear, and neither have the medical and surgical modalities for managing patients. We present the data obtained from our uroneurological assessment and therapeutic interventions at various stages of MSA. We recruited 245 patients with probable MSA. We measured postvoid residuals (PVR) and performed EMG cystometry in all patients. The grand average volume of PVR was 140 mL (range, 0-760) in our patients. The average PVR volume was 71 mL in the first year, increasing to 129 mL in the second year and 170 mL by the fifth year. The percentages of patients with complete urinary retention, acontractile detrusor, and detrusor-sphincter dyssynergia (DSD) also increased. The increase in PVR resulted in a decrease in functional bladder capacity, together with an increase in detrusor overactivity and neurogenic sphincter EMG. Clean intermittent self-catheterization (CISC) was introduced in most patients. Bladder-oriented therapy (cholinergic agents) had a limited value, whereas urethra-oriented therapy benefited patients with DSD (surgery) for up to 2 years, but syncope occurred in a subset of patients (alpha-blockers). MSA patients present with large PVR by the second year of illness, and that large PVR secondarily causes urinary frequency. CISC is the recommended treatment for most patients. Urethra-oriented medication and surgery benefit patients who would have difficulty performing CISC, although careful consideration of the short-term efficacy and potential adverse effects of these alternatives is mandatory.

Is sphincter electromyography a helpful investigation in the diagnosis of multiple system atrophy? A retrospective study with pathological diagnosis

Sphincter electromyography (spEMG) is often used as an ancillary test when multiple system atrophy (MSA) is suspected. Our aim was to determine the clinical features associated with spEMG being performed, the influence of the result on the final clinical diagnosis, and its utility as a clinical investigation. A retrospective audit of all cases in the Queen Square Brain Bank between 1989 and 2002 was performed. The clinical features and diagnostic accuracy were compared between patients in whom spEMG was performed and those in whom it was not. From 845 sets of complete clinical records, we identified 37 (4.4%) cases that had been investigated with spEMG. Thirty of these cases had a pathological diagnosis of MSA. Of these 30, 24 had abnormal spEMGs, 5 had a borderline result, and only 1 had a normal spEMG. Sixty-six cases had pathologically proven MSA but no spEMG. Those investigated with spEMG were younger at disease onset (P < 0.001), more frequently male (P = 0.03), and more likely to have had other investigations performed. They had a greater incidence of pyramidal tract signs at final clinical diagnosis, and the final clinical diagnostic accuracy was higher (P = 0.04). Due to the retrospective nature of the study, balanced populations for calculation of sensitivity and specificity were not available. In this selected series of pathologically confirmed cases, investigation with spEMG was one of several factors associated with improved clinical diagnostic accuracy. A normal spEMG is unlikely in pathologically proven MSA, at least in cases with a mean symptom duration of more than 5 years when the test is performed.

Update on the neurology of Parkinson's disease

The differential diagnosis of a patient with apparent Parkinson's Disease (PD) and bladder symptoms is considered and the bladder dysfunction of Multiple System Atrophy (MSA) is reviewed. Recent insights into the progression of the neuropathology of PD have enabled thinking about the stage of the disease at which bladder dysfunction is likely to occur and the expected clinical context of the problem. Bladder symptoms of neurological origin are likely in a patient who has had treated motor symptoms for some years and in whom the ongoing neuropathology has progressed beyond involvement of the basal ganglia, so that symptoms due to cortical dysfunction as well as the adverse effects of dopaminergic medication are also confounding factors. Bladder symptoms in a man with lesser neurological disability should be investigated to exclude underlying outflow obstruction. Possible management options are considered.

When is Onuf's nucleus involved in multiple system atrophy? A sphincter electromyography study

BACKGROUND

External anal sphincter (EAS) electromyography (EMG) abnormalities can distinguish multiple system atrophy (MSA) from Parkinson's disease in the first five years after disease onset. However, the prevalence of the abnormalities in the early stages of MSA is unknown.

OBJECTIVES

To present EAS-EMG data in the various stages of MSA.

METHODS

84 patients with "probable" MSA were recruited (42 men, 42 women; mean age 62 years (range 47 to 78); mean disease duration 3.2 years (0.5 to 8.0; <1 year in 25%); 50 cerebellar form (MSA-C), 34 parkinsonian form (MSA-P)). EAS motor unit potential (MUP) analysis and EMG cystometry were carried out in all patients.

RESULTS

The overall prevalence of neurogenic change of the EAS MUP was 62%-52% in the first year after disease onset, increasing to 83% by the fifth year (p<0.05); it also increased with severity of gait disturbance (p<0.05), storage and voiding disorders, and detrusor sphincter dyssynergy (NS). The neurogenic change was not correlated with sex, age, MSA-P/C, postural hypotension, constipation, erectile dysfunction in men, underactive or acontractile detrusor, or detrusor overactivity. In 17 incontinent patients without detrusor overactivity or low compliance, urinary incontinence was more severe in those with neurogenic change than in those without (p<0.05).

CONCLUSIONS

Involvement of Onuf's nucleus in MSA is time dependent. Before the fifth year of illness, the prevalence of neurogenic change does not seem to be high, so a negative result cannot exclude the diagnosis of MSA.

Sonographic assessment of urinary retention in multiple system atrophy and idiopathic Parkinson's disease

Sonography of the bladder was performed before and after voluntary voiding in 20 subjects with possible/probable multiple system atrophy (MSA), 20 patients with idiopathic Parkinson's disease (PD), and 20 healthy controls. Mean residual volume was 173 ml (SD, 194) in MSA and significantly increased compared to both PD (21 ml; SD, 49) and controls (13 ml; SD, 12). Incomplete voiding (>100 ml of residual volume) was found in 11 subjects with MSA but only in 1 patient with PD. Positive predictive value of increased residual volume for MSA was 91.6% in this study, whereas negative predictive value was only 67.8. Bladder sonography is an objective, simple, and safe tool that allows one to screen for urinary retention, which is highly suggestive but incompletely sensitive for MSA. Because sonography is easily accessible and rapidly performed, it is feasible for routine assessment of atypical Parkinsonism.

How to diagnose multiple system atrophy

The diagnosis of multiple system atrophy (MSA) in life remains entirely clinical. Consensus diagnostic criteria have been developed, but their use does not particularly render a diagnosis of MSA more accurate than are clinicians' diagnoses. Some patients may not fulfill the stipulated core diagnostic criteria, yet display many so-called red flags pointing toward MSA. The additional usefulness of these red flags and of a variety of investigations currently is being investigated, with a view to some of them being incorporated in future sets of diagnostic criteria.

Olfaction and Parkinson's syndromes: its role in differential diagnosis

PURPOSE OF REVIEW

Marked olfactory dysfunction (hyposmia) is a frequent and early abnormality in Parkinson's disease. We review recent advances related to its cause and its clinical relevance with respect to the differential diagnosis of Parkinsonian syndromes.

RECENT FINDINGS

Marked olfactory dysfunction occurs in Parkinson's disease and dementia with Lewy bodies but is not found in progressive supranuclear palsy and corticobasal degeneration. In multiple system atrophy, the deficit is mild and indistinguishable from cerebellar syndromes of other aetiologies, including the spino-cerebllar ataxias. This is in keeping with evidence of cerebellar involvement in olfactory processing, which may also help to explain recent findings of mild olfactory dysfunction in essential tremor. Smell testing remains, however, a clinically relevant tool in the differential diagnosis of indeterminate tremors. Intact olfaction has also been reported recently in Parkin disease (PARK 2) and vascular Parkinsonism. The relevance of sniffing ability to olfaction and a possible role of increased tyrosine hydroxylase and dopamine in parts of the olfactory bulb are issues of current interest with respect to pathophysiology. The early or 'pre-clinical' detection of Parkinson's disease is increasingly recognized as an area in which olfactory testing may be of value.

SUMMARY

Research findings have confirmed a role for olfactory testing in the differential diagnosis of movement disorders, and suggest that this approach is currently underused in clinical practice. Validated test batteries are now available that may prove to be of practical use in the differential diagnosis of Parkinsonian syndromes and indeterminate tremors.

Caribbean parkinsonism and other atypical Parkinsonian disorders

Atypical parkinsonism (AP) is a term applied to disorders characterized by parkinsonism that evolves rapidly, with poor or transient response to levodopa, or has other associated features such as early falls and postural instability, early autonomic failure, supranuclear gaze palsy, pyramidal or cerebellar signs, alien hand syndrome or severe ideomotor apraxia. The most common AP are multiple system atrophy, progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). Other APs include Caribbean parkinsonism (CP) and parkinsonism-dementia complex of Guam (PDC). In this review we provide an update in etiology, neuropathology, diagnosis and treatment of atypical parkinsonian disorders associated with protein tau deposit, also known as tauopathies.

Multiple system atrophy

Multiple system atrophy (MSA) is a sporadic neurodegenerative disorder characterised clinically by any combination of parkinsonian, autonomic, cerebellar, or pyramidal signs and pathologically by cell loss, gliosis, and glial cytoplasmic inclusions in several CNS structures. Owing to the recent advances in its molecular pathogenesis, MSA has been firmly established as an alpha-synucleinopathy along with other neurodegenerative diseases. In parallel, the clinical recognition of MSA has improved and the recent consensus diagnostic criteria have been widely established in the research community as well as movement disorders clinics. Although the diagnosis of this disorder is largely based on clinical expertise, several investigations have been proposed in the past decade to assist in early differential diagnosis. Symptomatic therapeutic strategies are still limited; however, several candidate neuroprotective agents have entered phase II and phase III clinical trials.

Erectile and urinary dysfunction may be the presenting features in patients with multiple system atrophy: a retrospective study

Multiple system atrophy (MSA) is a progressive neurodegenerative disease characterized by parkinsonism and cerebellar, autonomic, urinary, and/or pyramidal dysfunction. Urinary and erectile dysfunction (ED) symptoms are prominent early features in men with MSA. Autonomic failure, considered until recently to be the cause of ED in these men, is commonly expressed through symptoms of orthostatic hypotension (OH). The aim of this retrospective study is to examine the chronological relationship between the development of urogenital symptoms and those of OH in patients diagnosed with MSA and discuss its significance in the aetiology of ED in these patients. A total of 71 male patients, referred to a Uro-Neurology department with a diagnosis of 'probable MSA', were reviewed in terms of 'autonomic' symptoms only--OH and lower urinary tract symptoms, accompanied by ED--present at the time of their referral. Laboratory investigations including anal sphincter EMG and/or autonomic function tests (AFTs) were performed in 75 and 90% of the patients, respectively. At presentation, urinary complaints were recorded in 96% of patients and ED in all patients that this was inquired about. The onset of ED had preceded the onset of bladder symptoms in 58% and the onset of OH symptoms in 91% of these men. Bladder symptoms also preceded symptoms of OH in 76% of patients. Sphincter EMG was abnormal in 91% and AFTs in 77% of the patients tested. Almost all patients with abnormal EMG had troublesome urinary symptoms. AFTs showed similar sensitivity relating to symptoms. At presentation, urogenital symptoms are common in patients with probable MSA and are often not accompanied by symptoms of OH. The earlier occurrence of ED in men with MSA suggests a lack of a causal relationship to hypotension. The notion that MSA possibly affects the dopaminergic mechanism of erectile function is discussed.

Sphincter electromyography and multiple system atrophy

Electromyographic studies of the sphincter in patients with multiple system atrophy have shown increased duration and polyphasia of motor unit potentials. These electrophysiological markers have been used to argue for the selective degeneration of sacral motor neurons in Onuf's nucleus in patients with multiple system atrophy. Studies comparing sphincter electromyographic changes in patients with multiple system atrophy and Parkinson's disease have shown significant differences between these two patient populations. Despite the controversy surrounding this claim, recent studies using quantitative electromyographic techniques support the view that reinnervation of the anal sphincter muscles may be a useful diagnostic marker for distinguishing multiple system atrophy from Parkinson's disease. A critical review of these data is needed to assess the validity and reliability of electromyographic changes in multiple system atrophy.

Parkinson's disease and anaesthesia

Parkinson's disease is an increasingly common disease of elderly patients who present a particular anaesthetic challenge. This review explores the epidemiology, aetiology, pathogenesis, and pathophysiology of the condition, particularly the possible role of genetic factors. The clinical features are described in detail and recent advances in medical management are highlighted. Controversies surrounding the use of the newer drugs and possible advances in neurosurgical interventions are discussed. Particular anaesthetic problems in patients with Parkinson's disease are respiratory, cardiovascular, and neurological. Potential drug interactions are described and recommendations are made about suitable anaesthetic techniques.

Progressive supranuclear palsy: where are we now?

This review provides an update on progressive supranuclear palsy (PSP, or Steele-Richardson-Olszewski disease), an adult-onset neurodegenerative disorder characterised by early postural instability, which leads to falls, and a vertical supranuclear-gaze palsy. Recent epidemiological studies have shown that the disorder is more common than previously recognised, that it is commonly misdiagnosed, and that it may present to a wide range of hospital specialists. The diagnosis of PSP hinges on clinical acumen. Attempts to identify a suitable biomarker in the CSF or a specific and sensitive imaging or neurophysiological technique have so far failed to have a significant effect on the diagnostic process. Better understanding of the molecular pathology of PSP has highlighted the importance of tau-protein accumulation and tau-genotype susceptibility in its pathogenesis. No drug treatment significantly and consistently benefits patients, and novel therapies are urgently required.

Parkinsonian syndromes and differential diagnosis

PURPOSE OF REVIEW

Physicians are becoming more astute at diagnosing the various parkinsonian syndromes but in clinical practice it is still often difficult to make the correct diagnosis. This review discusses new evidence that may aid physicians in correctly identifying parkinsonian syndromes.

RECENT FINDINGS

We will review the newest developments in the areas of clinical features, electrophysiologic tests, autonomic tests, neuropsychologic tests, imaging, and biochemical markers which may be of value in differentiating these syndromes.

SUMMARY

Accurate diagnosis of the parkinsonian syndromes has important implications for patients, in terms of both prognosis and management. Investigations reported during the last year provide new insight into the distinguishing features of these syndromes and may help clinicians and researchers define these disorders more precisely.

Shy-Drager syndrome and severe unexplained intraoperative hypotension responsive to vasopressin

IMPLICATIONS

We describe the first case of Shy-Drager syndrome diagnosed on the basis of intraoperative hemodynamic changes. The initial hypertension in the supine position followed by severe hypotension after hydralazine administration, ultimately responsive to vasopressin, led to a diagnosis of Shy-Drager syndrome. We suggest that vasopressin may be the drug of choice in patients with Shy-Drager syndrome with refractory hypotension.

Neurophysiological correlate of clinical signs in Parkinson's disease

Clinical diagnosis of Parkinson's disease (PD) is not always coincident with pathological findings. A better characterization of the disease from the results of studies in various areas of neuroscience can help in improving the rate of diagnostic certainty. Neurophysiology is among the techniques with better chances to furnish specific diagnostic cues on motor aspects of the disease. Neurophysiology provides quantifiable data using non-invasive, relatively inexpensive, methods. Neurophysiological tests can be applied with no previous preparation, and repeated many times without dangerous consequences. To be rewarding, however, neurophysiological examination should be done in close cooperation between the clinician who detects relevant specific signs, and the neurophysiologist who devises the most demonstrative methods to document those signs. In this review, we describe the neurophysiological correlate of symptoms and signs in patients with PD, and particularly their pathophysiological meaning, with special focus on those that could be more helpful to the neurologists in establishing differences with respect to other diseases presenting with parkinsonism.