Neurological manifestations of phaeochromocytomas and secretory paragangliomas: a reappraisal.

OBJECTIVE: To determine the frequency and range of neurological manifestations of phaeochromocytomas and secretory paragangliomas. METHODS: A retrospective review of case notes of patients admitted to Auckland Hospital from 1985 to 2011 with a discharge diagnosis of phaeochromocytoma or secretory paraganglioma. RESULTS: Ninety-three patients were admitted with a phaeochromocytoma or secretory paraganglioma. Sixty-eight patients (73%) had neurological symptoms, but only 15 patients (16%) received a neurological consultation. Neurological manifestations occurred in three main clinical contexts. First, paroxysmal symptoms occurred in 66 of 93 patients (71%). Neurological symptoms were common features of these attacks and included headache (47 patients), anxiety (24 patients), tremulousness (15 patients) and dizziness (12 patients). The headaches typically had an explosive onset. Delay in diagnosis was common. Second, 28 patients (30%) had an acute crisis, which was associated with neurological symptoms in 11 (39%) of the episodes: headache (10 patients); seizures (five patients); strokes (three patients); delirium (three patients) and subarachnoid haemorrhage (one patient). Third, five of six patients with a head and neck secretory paraganglioma had neurological symptoms related to infiltration of the middle ear or compression of cranial nerves. Reversible cerebral vasoconstriction syndrome (RCVS) was documented in three patients. CONCLUSIONS: Neurological manifestations of phaeochromocytomas and secretory paragangliomas were common, and these tumours can present with various neurological manifestations. The paroxysmal symptoms can be incorrectly attributed to other headache syndromes, panic attacks or cerebral vasculitis. RCVS may play a role in the pathogenesis of the neurological symptoms associated with acute crises and paroxysmal attacks.

Assessing possible selection bias in a national voluntary MS longitudinal study in Australia.

BACKGROUND: Surveying volunteer members of a multiple sclerosis registry is a very cost-effective way of assessing the impact of the disease on life outcomes. However, whether the data from such a study can be generalised to the whole population of persons living with MS in a country or region is unclear. METHODS: Here we compare the demographic and disease characteristics of participants in one such study, the Australian Multiple Sclerosis Longitudinal Study (AMSLS), with two well-characterised MS prevalence studies with near-complete ascertainment of MS in their study regions. RESULTS: Although some differences were found, these largely represented the effects of geography (sex ratios) and local factors (national immunomodulatory therapy prescribing requirements), and the cohorts were otherwise comparable. Overall, despite comprising only 12-16% of MS cases in Australia, the AMSLS is highly representative of the MS population. CONCLUSIONS: Therefore with some minor caveats, the AMSLS data can be generalised to the whole Australasian MS population. Volunteer disease registries such as this can be highly representative and provide an excellent convenience sample when studying rare conditions such as MS.

Sustained improvement in Expanded Disability Status Scale as a new efficacy measure of neurological change in multiple sclerosis: treatment effects with natalizumab in patients with relapsing multiple sclerosis.

BACKGROUND: Validated measures of sustained improvements in neurological function have not been established for multiple sclerosis (MS) clinical studies. OBJECTIVE: To evaluate sustained Expanded Disability Status Scale (EDSS) change as a potential indicator of neurological improvement and as an outcome measure in MS clinical studies. METHODS: Analyses were performed on patients (n = 620) from the pivotal natalizumab study AFFIRM with baseline EDSS scores ≥2.0. Cumulative probabilities of neurological improvement, defined as a 1.0-point decrease in EDSS score sustained for ≥12 weeks, were estimated by Kaplan-Meier analysis. A Cox proportional hazards model identified associated baseline factors and examined treatment effects. RESULTS: Sustained improvement (as well as sustained worsening) in neurological disability was seen in AFFIRM patients. Sustained EDSS changes correlated well with quality of life measurements (SF36 and VAS). Natalizumab increased the cumulative probability of improvement over 2 years by 69% versus placebo (HR = 1.69; 95% CI 1.16-2.45; p = 0.006). Sensitivity analyses showed consistent benefits of natalizumab with variations in improvement magnitude and duration, and baseline disease activity. CONCLUSION: These analyses demonstrate that sustained EDSS improvement is an additional measure that is sensitive to treatment effects over 2 years and correlates with quality of life. Further research is warranted to validate its use as an MS study clinical outcome.

MS prevalence in New Zealand, an ethnically and latitudinally diverse country.

BACKGROUND: The prevalence of multiple sclerosis (MS) is not uniform, with a latitudinal gradient of prevalence present in most studies. Understanding the drivers of this gradient may allow a better understanding of the environmental factors involved in MS pathogenesis. METHOD: The New Zealand national MS prevalence study (NZMSPS) is a cross-sectional study of people with definite MS (DMS) (McDonald criteria 2005) resident in New Zealand on census night, 7 March 2006, utilizing multiple sources of notification. Capture-recapture analysis (CRA) was used to estimate missing cases. RESULTS: Of 2917 people with DMS identified, the crude prevalence was 72.4 per 100,000 population, and 73.1 per 100,000 when age-standardized to the European population. CRA estimated that 96.7% of cases were identified. A latitudinal gradient was seen with MS prevalence increasing three-fold from the North (35°S) to the South (48°S). The gradient was non-uniform; females with relapsing-remitting/secondary-progressive (RRMS/SPMS) disease have a gradient 11 times greater than males with primary-progressive MS (p < 1 × 10(-7)). DMS was significantly less common among those of Maori ethnicity. CONCLUSIONS: This study confirms the presence of a robust latitudinal gradient of MS prevalence in New Zealand. This gradient is largely driven by European females with the RRMS/SPMS phenotype. These results indicate that the environmental factors that underlie the latitudinal gradient act differentially by gender, ethnicity and MS phenotype. A better understanding of these factors may allow more targeted MS therapies aimed at modifiable environmental triggers at the population level.

Disability profile of multiple sclerosis in New Zealand.

New Zealand is a high risk region for multiple sclerosis (MS). The aim of this study was to investigate demographic, clinical and temporal factors associated with disability status in the New Zealand National Multiple Sclerosis Prevalence Study (NZNMSPS) cohort. Data were obtained from the 2006 NZNMSPS with MS diagnosis based on the 2005 McDonald criteria. Disability was assessed using the Expanded Disability Status Scale (EDSS). Disability profiles were generated using multiple linear regression analysis. A total of 2917 persons with MS was identified, of whom disability data were available for 2422 (75% females). The overall disability was EDSS 4.4±standard deviation 2.6. Higher disability was associated with older age, longer disease duration, older and younger ages of onset, spinal cord syndromes with motor involvement at onset, and a progressive onset type. Lower disability was associated with sensory symptoms at onset and a relapsing onset type. Overall, the factors studied explained about one-third of the variation in disability, and of this, about two-thirds was accounted for by age, age of onset and disease duration and one-third by the nature of first symptoms and type of disease onset (progressive or relapsing). Current age, age at onset and disease duration all had independent associations with disability and their effects also interacted in contributing to higher disability levels over the course of the disease.