Population based mortality and quality of death certification in progressive supranuclear palsy (Steele-Richardson-Olszewski syndrome)

Relationships between regional burden of tau pathology and age at death and disease duration in PSP

BACKGROUND

A definitive diagnosis of progressive supranuclear palsy (PSP) can only be established through neuropathological evaluations where four cardinal tau lesions are identified. Relationships between regional tau burden and disease duration/age at death is unclear.

OBJECTIVE

To investigate relationships between tau burden in different brain regions and disease duration and age at death in PSP and determine whether association are influenced by PSP subtype (subcortical/cortical) or co-pathologies.

METHODS

We identified 45 patients with definite PSP who were evaluated at Mayo Clinic between 2009 and 2023, died and underwent histopathological evaluation. We performed semi-quantitative lesion count for each of four cardinal lesions (pretangles/globose neurofibrillary tangles, threads, tufted astrocytes, and coiled bodies) across 10 brain regions. We fit Bayesian linear hierarchical regression models to estimate the relationship between total pathological burden, and disease duration and age at death by region and the influence of subtype and co-pathologies.

RESULTS

Of the 45 patients, 18 (40 %) were female. Median age at death was 75 (56-87) years and median disease duration was 8 (3,15) years. Younger age at death was associated with greater total tau burden in the pallidum, red nucleus, striatum, and subthalamic nucleus (all p ≤ 0.01). Shorter disease duration was associated with greater total tau burden in the red nucleus (p = 0.05). There was no evidence for a difference in association between lesion types. PSP subtype and co-pathologies did not influence associations.

CONCLUSIONS

The findings from this study suggest that age and disease duration influence burden of tau pathology in subcortical regions in PSP.

Accuracy of routinely collected hospital administrative discharge data and death certificate ICD-10 diagnostic coding in progressive supranuclear palsy and corticobasal syndrome: a systematic review and validation study

BACKGROUND

We conducted a systematic review to identify existing ICD-10 coding validation studies in progressive supranuclear palsy and corticobasal syndrome [PSP/CBS]) and, in a new study, evaluated the accuracy of ICD-10 diagnostic codes for PSP/CBS in Scottish hospital inpatient and death certificate data.

METHODS

Original studies that assessed the accuracy of specific ICD-10 diagnostic codes in PSP/CBS were sought. Separately, we estimated the positive predictive value (PPV) of specific codes for PSP/CBS in inpatient hospital data (SMR01, SMR04) compared to clinical diagnosis in four regions. Sensitivity was assessed in one region due to a concurrent prevalence study. For PSP, the consistency of the G23.1 code in inpatient and death certificate coding was evaluated across Scotland.

RESULTS

No previous ICD-10 validation studies were identified. 14,767 records (SMR01) and 1497 records (SMR04) were assigned the candidate ICD-10 diagnostic codes between February 2011 and July 2019. The best PPV was achieved with G23.1 (1.00, 95% CI 0.93-1.00) in PSP and G23.9 in CBS (0.20, 95% CI 0.04-0.62). The sensitivity of G23.1 for PSP was 0.52 (95% CI 0.33-0.70) and G31.8 for CBS was 0.17 (95% CI 0.05-0.45). Only 38.1% of deceased G23.1 hospital-coded cases also had this coding on their death certificate: the majority (49.0%) erroneously assigned the G12.2 code.

DISCUSSION

The high G23.1 PPV in inpatient data shows it is a useful tool for PSP case ascertainment, but death certificate coding is inaccurate. The PPV and sensitivity of existing ICD-10 codes for CBS are poor due to a lack of a specific code.

Factors that impact dysphagia and discontinuance of oral intake in patients with progressive supranuclear palsy

Objective

To evaluate the swallowing function in the advanced stages of progressive supranuclear palsy (PSP) and clarify the factors that lead to adjustment of food consistency and discontinuation of oral intake.

Methods

A total of 56 patients with PSP were recruited. Based on medical records, information about the basic attributes, clinical features (including axial rigidity and dementia), food intake, the results of a videofluoroscopic swallowing study (VFSS), and the timing of nasogastric tube transition and gastrostomy were extracted. From the VFSS images, the presence or absence of aspiration and retrocollis were assessed.

Results

The average age at the onset, diagnosis, and the final follow-up examination were 67.6 ± 6.4 years, 71.6 ± 5.8 years, and 75.4 ± 5.6 years, respectively. The average duration of illness was 64.6 ± 42.8 months. Twenty-four individuals (42.9%) were continuing oral intake, while 32 were tube-fed, among whom 16 (50.0%) underwent gastrostomy tube placement. There were significant differences in the duration from the disease onset to tube feeding between the patients with and without cognitive decline at the time of the diagnosis (p < 0.01) and in the duration from the initial VFSS to tube feeding between the patients with and without aspiration on the initial VFSS (p < 0.01). There were significant differences in the duration from the diagnosis to tube feeding and from the initial VFSS to tube feeding between patients with and without axial rigidity at the time of the diagnosis (p < 0.05 and p < 0.05, respectively). Additionally, there was a significant association between axial rigidity and retrocollis (p < 0.01).

Conclusion

Cognitive decline, axial rigidity and retrocollis, which are associated with the deterioration of dysphagia in PSP, are the highest risk factors for the discontinuation of oral intake. The early identification of these factors associated with the progression of dysphagia can contribute to the improvement of patient care and management.

[Dysphagia in Parkinsonian Syndromes]

Dysphagia is a clinically relevant problem in Parkinson's disease as well as in atypical Parkinsonian syndromes, such as multiple system atrophy and diseases from the spectrum of 4‑repeat tauopathies, which affect most patients to a varying degree in the course of their disease. This results in relevant restrictions in daily life due to impaired intake of food, fluids, and medication with a subsequent reduction in quality of life. This article not only gives an overview of the pathophysiological causes of dysphagia in the various Parkinson syndromes, but also presents screening, diagnostic and treatment procedures that have been investigated for the different diseases.

Diffusion tensor tractography of the corticobulbar tract in a dysphagic patient with progressive supranuclear palsy: A case report

RATIONALE

This paper reports the changes over time in the corticobulbar tract (CBT) analyzed using diffusion tensor tractography (DTT) in a dysphagic patient with progressive supranuclear palsy (PSP).

PATIENT CONCERNS

A 53-year-old man initially presented with dysarthria, gait disturbance, and bradykinesia, and approximately 1-year later, downward gaze paralysis appeared. Initially, there was no dysphagia; however, approximately 2 years after visiting the hospital, symptoms of dysphagia, including difficulty swallowing pills, aspiration, and oral movement impairments appeared. The symptoms gradually progressed, and finally, mouth opening was severely damaged to the extent that it was difficult to orally feed.

INTERVENTIONS

We performed diffusion tensor imaging 3 times; at 3-month, 20-month, and 41-month from onset.

OUTCOMES

On 3-month DTT, the left CBT was well reconstructed, whereas the right CBT showed partial tearing. In the 20-month DTT, both CBTs became thinner compared to the 3-month DTT. On 41-month DTT, both CBTs became much thinner than after 3-month and 20-month DTT.

LESSONS

We observed the degree of CBT injury over time in a dysphagic patient with PSP. These results suggest that the analysis of CBT using DTT is helpful in predicting the degree of dysphagia and prognosis in patients with PSP.

SARS-CoV-2 Brain Regional Detection, Histopathology, Gene Expression, and Immunomodulatory Changes in Decedents with COVID-19

Brains of 42 COVID-19 decedents and 107 non-COVID-19 controls were studied. RT-PCR screening of 16 regions from 20 COVID-19 autopsies found SARS-CoV-2 E gene viral sequences in 7 regions (2.5% of 320 samples), concentrated in 4/20 subjects (20%). Additional screening of olfactory bulb (OB), amygdala (AMY) and entorhinal area for E, N1, N2, RNA-dependent RNA polymerase, and S gene sequences detected one or more of these in OB in 8/21 subjects (38%). It is uncertain whether these RNA sequences represent viable virus. Significant histopathology was limited to 2/42 cases (4.8%), one with a large acute cerebral infarct and one with hemorrhagic encephalitis. Case-control RNAseq in OB and AMY found more than 5000 and 700 differentially expressed genes, respectively, unrelated to RT-PCR results; these involved immune response, neuronal constituents, and olfactory/taste receptor genes. Olfactory marker protein-1 reduction indicated COVID-19-related loss of OB olfactory mucosa afferents. Iba-1-immunoreactive microglia had reduced area fractions in cerebellar cortex and AMY, and cytokine arrays showed generalized downregulation in AMY and upregulation in blood serum in COVID-19 cases. Although OB is a major brain portal for SARS-CoV-2, COVID-19 brain changes are more likely due to blood-borne immune mediators and trans-synaptic gene expression changes arising from OB deafferentation.

Gray and White Matter Correlates of Dysphagia in Progressive Supranuclear Palsy

BACKGROUND

Dysphagia is a common symptom of progressive supranuclear palsy often leading to aspiration pneumonia and death.

OBJECTIVE

The aim of this study was to examine how impairments of the oral and pharyngeal phases of the swallow and airway incursion during liquid swallows relate to gray and white matter integrity.

METHODS

Thirty-eight participants with progressive supranuclear palsy underwent videofluorographic swallowing assessment and structural and diffusion tensor head magnetic resonance imaging. Penalized linear regression models assessed relationships between swallowing metrics and regional gray matter volumes and white matter fractional anisotropy and mean diffusivity.

RESULTS

Oral phase impairments were associated with reduced superior parietal volumes and abnormal diffusivity in parietal and sensorimotor white matter, posterior limb of the internal capsule, and superior longitudinal fasciculus. Pharyngeal phase impairments were associated with disruption to medial frontal lobe, corticospinal tract, and cerebral peduncle. No regions were predictive of airway incursion.

CONCLUSIONS

Differential patterns of neuroanatomical impairment corresponded to oral and pharyngeal phase swallowing impairments. © 2021 International Parkinson and Movement Disorder Society.

Prognostic predictors relevant to end-of-life palliative care in Parkinson's disease and related disorders: a systematic review

Parkinson's disease and related disorders (PDRD) are the second most common neurodegenerative disease and a leading cause of death. However, patients with PDRD receive less end-of-life palliative care (hospice) than other illnesses, including other neurologic illnesses. Identification of predictors of PDRD mortality may aid in increasing appropriate and timely referrals. To systematically review the literature for causes of death and predictors of mortality in PDRD to provide guidance regarding hospice/end-of-life palliative care referrals. We searched MEDLINE, PubMed, EMBASE and CINAHL databases (1970-2020) of original quantitative research using patient-level, provider-level or caregiver-level data from medical records, administrative data or survey responses associated with mortality, prognosis or cause of death in PDRD. Findings were reviewed by an International Working Group on PD and Palliative Care supported by the Parkinson's Foundation. Of 1183 research articles, 42 studies met our inclusion criteria. We found four main domains of factors associated with mortality in PDRD: (1) demographic and clinical markers (age, sex, body mass index and comorbid illnesses), (2) motor dysfunction and global disability, (3) falls and infections and (4) non-motor symptoms. We provide suggestions for consideration of timing of hospice/end-of-life palliative care referrals. Several clinical features of advancing disease may be useful in triggering end-of-life palliative/hospice referral. Prognostic studies focused on identifying when people with PDRD are nearing their final months of life are limited. There is further need for research in this area as well as policies that support need-based palliative care for the duration of PDRD.

Acute Brain Ischemia, Infarction and Hemorrhage in Subjects Dying with or Without Autopsy-Proven Acute Pneumonia

Stroke is one of the most serious complications of Covid-19 disease but it is still unclear whether stroke is more common with Covid-19 pneumonia as compared to non-Covid-19 pneumonia. We investigated the concurrence rate of autopsy-confirmed acute brain ischemia, acute brain infarction and acute brain hemorrhage with autopsy-proven acute non-Covid pneumonia in consecutive autopsies in the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND), a longitudinal clinicopathological study of normal aging and neurodegenerative diseases. Of 691 subjects with a mean age of 83.4 years, acute pneumonia was histopathologically diagnosed in 343 (49.6%); the concurrence rates for histopathologically-confirmed acute ischemia, acute infarction or subacute infarction was 14% and did not differ between pneumonia and non-pneumonia groups while the rates of acute brain hemorrhage were 1.4% and 2.0% of those with or without acute pneumonia, respectively. In comparison, in reviews of Covid-19 publications, reported clinically-determined rates of acute brain infarction range from 0.5% to 20% while rates of acute brain hemorrhage range from 0.13% to 2%. In reviews of Covid-19 autopsy studies, concurrence rates for both acute brain infarction and acute brain hemorrhage average about 10%. Covid-19 pneumonia and non-Covid-19 pneumonia may have similar risks tor concurrent acute brain infarction and acute brain hemorrhage when pneumonia is severe enough to cause death. Additionally, acute brain ischemia, infarction or hemorrhage may not be more common in subjects dying of acute pneumonia than in subjects dying without acute pneumonia.

Increased Risk of Autopsy-Proven Pneumonia with Sex, Season and Neurodegenerative Disease

There has been a markedly renewed interest in factors associated with pneumonia, a leading cause of death worldwide, due to its frequent concurrence with pandemics of influenza and Covid-19 disease. Reported predisposing factors to both bacterial pneumonia and pandemic viral lower respiratory infections are wintertime occurrence, older age, obesity, pre-existing cardiopulmonary conditions and diabetes. Also implicated are age-related neurodegenerative diseases that cause parkinsonism and dementia. We investigated the prevalence of autopsy-proven pneumonia in the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND), a longitudinal clinicopathological study, between the years 2006 and 2019 and before the beginning of the Covid-19 pandemic. Of 691 subjects dying at advanced ages (mean 83.4), pneumonia was diagnosed postmortem in 343 (49.6%). There were 185 subjects without dementia or parkinsonism while clinicopathological diagnoses for the other subjects included 319 with Alzheimer's disease dementia, 127 with idiopathic Parkinson's disease, 72 with dementia with Lewy bodies, 49 with progressive supranuclear palsy and 78 with vascular dementia. Subjects with one or more of these neurodegenerative diseases all had higher pneumonia rates, ranging between 50 and 61%, as compared to those without dementia or parkinsonism (40%). In multivariable logistic regression models, male sex and a non-summer death both had independent contributions (ORs of 1.67 and 1.53) towards the presence of pneumonia at autopsy while the absence of parkinsonism or dementia was a significant negative predictor of pneumonia (OR 0.54). Male sex, dementia and parkinsonism may also be risk factors for Covid-19 pneumonia. The apolipoprotein E4 allele, as well as obesity, chronic obstructive pulmonary disease, diabetes, hypertension, congestive heart failure, cardiomegaly and cigarette smoking history, were not significantly associated with pneumonia, in contradistinction to what has been reported for Covid-19 disease.

Accuracy of death certificates for recording parkinsonian syndromes and associated dementia

INTRODUCTION

Death certification is often used to identify patients with certain diseases in epidemiologic research. There have been few studies looking at the accuracy of recording of parkinsonian diagnoses, any associated dementia and the cause of death on death certificates in people with parkinsonian conditions. This study aimed to assess this.

METHODS

Data for these analyses were derived from a prospective incident cohort of degenerative/vascular parkinsonian syndromes with lifelong follow-up from Scotland, UK (the PINE study). In those who died, the available research and clinical care records were reviewed to establish the cause for each patient's death. The sensitivity of death certificates was calculated to detect any parkinsonian diagnosis mentioned on the death certificate, the correct specific diagnosis and the presence of dementia. The causes of death were compared between clinical records and death certificates.

RESULTS

Two hundred and seventy-seven patients had died (180 men), mean age at diagnosis and death 76.9 years and 81.9 years respectively. 66.8% of death certificates mentioned any parkinsonian syndrome but only 49.5% had the correct diagnosis. Sensitivity was highest for Parkinson's disease, those who had parkinsonian-related deaths, had longer disease durations and died out of hospital. Death certificates detected 51.2% of those with dementia. The commonest causes of death were pneumonia, end-stage Parkinsonism and vascular disease with moderate agreement between case-note review and death certification.

CONCLUSION

Deaths certificates often do not mention underlying Parkinsonism or associated dementia and so epidemiological studies should not rely on this as a sole method of identifying cases or studying mortality.

Management of Dysphagia in Patients with Parkinson's Disease and Related Disorders

Various methods of rehabilitation for dysphagia have been suggested through the experience of treating stroke patients. Although most of these patients recover their swallowing function in a short period, dysphagia in Parkinson's disease (PD) and Parkinson-related disorder (PRD) degenerates with disease progression. Muscle rigidity and bradykinesia are recognized as causes of swallowing dysfunction, and it is difficult to easily apply the strategies for stroke to the rehabilitation of dysphagia in PD patients. Disease severity, weight loss, drooling, and dementia are important clinical predictors. Silent aspiration is a pathognomonic sign that may lead to aspiration pneumonia. Severe PD patients need routine video fluoroscopy or video endoscopy to adjust their food and liquid consistency. Patients with PRD experience rapid progression of swallowing dysfunction. Nutrition combined with nasogastric tube feeding or percutaneous endoscopic gastrostomy feeding should be considered owing to the increased risk of aspiration and difficulty administrating oral nutrition.

A case of spinal anesthesia in a patient with progressive supranuclear palsy

Progressive supranuclear palsy (PSP) is one of the rare diseases. PSP is characterized by oculomotor dysfunction, postural instability, akinesia, dysarthria, and dysphagia. The major cause of death in patients with PSP is aspiration pneumonia. Considering these complications, spinal anesthesia is useful in patients with PSP. However, the potential harmful effects of spinal anesthesia including neurotoxicity of local anesthetics and neurologic complications for patients with PSP are unclear, because there has been no report. Here, we present spinal anesthesia for a patient with PSP. An 80-year-old man with progressive oculomotor dysfunction, dysphagia, and history of repeated aspiration pneumonia was scheduled for inguinal hernia surgery. Acutely concerning about perioperative pulmonary complications, we performed spinal anesthesia. Fortunately, there was no complication associated with respiration or neural system during perioperative period. We hope our experience and case report will be helpful in specific perioperative anesthetic care for patients with PSP.

Impact of Aspiration Pneumonia on the Clinical Course of Progressive Supranuclear Palsy: A Retrospective Cohort Study

Introduction

Although aspiration pneumonia is the most common complication of progressive supranuclear palsy (PSP), the clinical impact of aspiration pneumonia on disease course and survival has not been fully estimated. Thus, we retrospectively analyzed the prognostic factors and clinical consequences of pneumonia in PSP.

Methods

The clinical course of patients with aspiration pneumonia was surveyed. The association between baseline clinical features (2 years from disease onset) and latency to the initial development of pneumonia was investigated using survival time and Cox regression analyses.

Results

Ninety patients with a clinical diagnosis of PSP were observed for 5.1±3.8 years (mean±SD), and 22 had aspiration pneumonia. Subsequently, 20 patients (91%) had to discontinue oral feeding entirely and 13 (59%) died, whereas, of 68 patients without pneumonia, only three patients (4%) died. Time to initial development of pneumonia was strongly correlated with survival time (Spearman R = 0.92, P<0.001), with a mean latency of 2.3 years to death. Among baseline clinical features, early fall episodes and cognitive decline were significant predictors of pneumonia (P = 0.001 and P<0.001, respectively, log rank test). Cox regression analysis demonstrated that early fall episodes (adjusted hazard ratio: 3.9, 95% confidence interval: 1.2–12.5, P = 0.03) and cognitive decline (adjusted hazard ratio: 5.2, 95% confidence interval: 1.4–19.3, P = 0.02) independently predicted pneumonia. By contrast, dysphagia was not associated with pneumonia (P = 0.2, log rank test).

Conclusion

Initial development of pneumonia indicates an unfavorable clinical course and predicts survival time (mean survival time 2.3 years). Patients with early falls and cognitive decline were at high risk of early development of pneumonia.

Communication impairments in people with progressive supranuclear palsy: A tutorial

Progressive supranuclear palsy (PSP) is a progressive neurological condition, whose main features include supranuclear gaze palsy, frequent falls, bradykinesia, axial rigidity, cognitive decline and communication impairments. Even though communication impairments are early and prominent manifestations, there is a significant lack of research on the nature of these impairments in PSP and the role of speech-language pathologists (SLPs). This tutorial article aims to describe the communication impairments observed in people with PSP; provide clinical guidelines for SLPs when assessing motor speech, language and other communication impairments; and to present facilitation and compensation approaches to treatment for people with PSP. The predominant motor speech impairment is mixed dysarthria, but there is a lack of consensus about the classification of language impairments. The involvement of SLPs in the assessment and treatment of people with PSP should be early, on-going and in collaboration with other health professionals, with the primary focus of maintaining quality of life for these patients and their family members.

Multiple system atrophy: prognostic indicators of survival

Neurological and autonomic presentation in multiple system atrophy (MSA) may predict early mortality. Quantification of early autonomic failure as a mortality predictor is lacking. Early neurological and autonomic clinical features were retrospectively reviewed in 49 MSA cases (median age at onset, 56.1 years; 16 women) confirmed by autopsy at Mayo Clinic. When available, the 10-point composite autonomic severity score derived from the autonomic reflex screen provided quantification of the degree of autonomic failure and thermoregulatory sweat test quantitated body surface anhidrosis. Symptoms at onset were autonomic in 50%, parkinsonian in 30%, and cerebellar in 20% of cases. Survival (median [95% confidence interval]) was 8.6 [6.7-10.2] years. Survival was shorter in patients with early laboratory evidence of generalized (composite autonomic severity score ≥ 6) autonomic failure (7.0 [3.9-9.8] vs. 9.8 [4.6-13.8] years; P = 0.036), and early requirement of bladder catheterization (7.3 [3.1-10.2] vs. 13.7 [8.5-14.9] years; P = 0.003) compared with those without these clinical features. On Cox proportional analysis, prognostic indicators of shorter survival were older age at onset (hazard ratio [95% confidence interval], 1.04 [1.01-1.08]; P = 0.03), early requirement of bladder catheterization (7.9 [1.88-38.63]; P = 0.004), and early generalized (composite autonomic severity score ≥ 6) autonomic failure (2.8 [1.01-9.26]; P = 0.047). Gender, phenotype, and early development of gait instability, aid-requiring ambulation, orthostatic symptoms, neurogenic bladder, or significant anhidrosis (thermoregulatory sweat test ≥ 40%) were not indicators of shorter survival. Our data suggest that early development of severe generalized autonomic failure more than triples the risk of shorter survival in patients with MSA.

Sepsis-associated mortality in England: an analysis of multiple cause of death data from 2001 to 2010

OBJECTIVES

To quantify mortality associated with sepsis in the whole population of England.

DESIGN

Descriptive statistics of multiple cause of death data.

SETTING

England between 2001 and 2010.

PARTICIPANTS

All people whose death was registered in England between 2001 and 2010 and whose certificate contained a sepsis-associated International Classification of Diseases, 10th Revision (ICD-10) code.

DATA SOURCES

Multiple cause of death data extracted from Office for National Statistics mortality database.

STATISTICAL METHODS

Age-specific and sex-specific death rates and direct age-standardised death rates.

RESULTS

In 2010, 5.1% of deaths in England were definitely associated with sepsis. Adding those that may be associated with sepsis increases this figure to 7.7% of all deaths. Only 8.6% of deaths definitely associated with sepsis in 2010 had a sepsis-related condition as the underlying cause of death. 99% of deaths definitely associated with sepsis have one of the three ICD-10 codes-A40, A41 and P36-in at least one position on the death certificate. 7% of deaths definitely associated with sepsis in 2001-2010 did not occur in hospital.

CONCLUSIONS

Sepsis is a major public health problem in England. In attempting to tackle the problem of sepsis, it is not sufficient to rely on hospital-based statistics, or methods of intervention, alone. A robust estimate of the burden of sepsis-associated mortality in England can be made by identifying deaths with one of the three ICD-10 codes in multiple cause of death data. These three codes could be used for future monitoring of the burden of sepsis-associated mortality.

Clinical features and criteria for the diagnosis of progressive supranuclear palsy

SUMMARY The neurofibrillary tau pathology of progressive supranuclear palsy (PSP) has been associated with a number of different clinical syndromes that all ultimately lead to death and disability within 6–10 years. In 1964, Steele, Richardson and Olszewski predicted that the classic clinical syndrome they had described was specific to the topographic distribution of PSP–tau neurodegeneration and that other clinical syndromes may occur if other brain regions were affected. The spectrum of clinical disease related to PSP–tau pathology is indeed broader than 40 years ago. In addition to the classic form of PSP (Richardson’s syndrome), a number of clinical variants caused by the same neurodegenerative process have been identified. These include PSP–Parkinsonism, PSP–corticobasal syndrome, PSP–pure akinesia with gait freezing and PSP–progressive nonfluent aphasia. Here we review the clinical pictures of these syndromes and propose practical diagnostic guidelines to aid the clinician in tackling the challenges presented by the multifaceted condition of PSP–tau pathology.

The effect of onset age on the clinical features of Parkinson's disease

Many clinicians view age at onset as an important determinant of clinical phenotype in Parkinson's disease (PD) and this has been reinforced by the identification of Mendelian genes that account for some cases of younger onset PD. A systematic review of OVID Medline for articles relevant to the relationship between clinical features and age at onset in PD published in English between 1950-2007 was performed. There are very few prospective community based studies which focus on the relationship between age at onset and the features of PD and a variety of case definitions are used in the literature. Most studies of young onset PD are based on specialist clinic referral series. The available evidence suggests that PD patients with a younger age at onset have: (i) a slower disease progression, (ii) an increased rate of dystonia at onset and during treatment, (iii) a lower rate of dementia and (iv) an increased rate of dyskinesias in response to L-DOPA treatment. The majority of the available studies do not report patient genotype data, but it is probably that the clinical heterogeneity of PD will be further refined with detailed clinico-genetic studies.

Survival in multiple system atrophy

We here report survival in patients with multiple system atrophy (MSA) in a large, prospectively studied group of patients with MSA. Eighty-five of 100 patients were known to have died. Three patients were rediagnosed as having PD. Twenty-four patients came to autopsy, which showed MSA in 22 and idiopathic Parkinson's disease in 2. The median survival time was 8.6 and 7.3 years for men and women, respectively (hazard ratio for women was 1.49, 95% CI 0.97-2.31, P = 0.07). Except for rediagnosis as PD, no predictive factors for better survival could be identified. These data confirm the relatively poor prognosis of MSA of less than 9 years on average.