Gender Differences in the Prevalence of Parkinson's Disease

Background

Parkinson's disease (PD) affects males more than females. The reasons for the gender differences in PD prevalence remain unclear.

Objective

The objective of this systematic review and meta-analysis was to update the overall male/female prevalence ratios (OPR).

Methods

We updated previous work by searching MEDLINE, SCOPUS, and OVID for articles reporting PD prevalence for both genders between 2011 and 2021. We calculated OPRs and investigated heterogeneity in effect estimates.

Results

We included 19 new articles and 13 articles from a previously published meta-analysis. The OPR was 1.18, 95% CI, [1.03, 1.36]. The OPR was lowest in Asia and appeared to be decreasing over time. Study design, national wealth, and participant age did not explain OPR heterogeneity.

Conclusion

Gender differences in PD prevalence may not be as stark as previously thought. Studies are needed to understand the role of other determinants of gender differences in PD prevalence.

104 Examining the sex differences in the prevalence and incidence of Parkinson disease

Background

Parkinson disease (PD) is a major cause of disability affecting >6 million people worldwide. The incidence/prevalence of PD is generally higher in males than females. It is unclear whether male predominance is observed in low- and middle-income countries, where the fastest apparent rate of increase of PD has been observed.

Methods

We searched MEDLINE, SCOPUS and OVID for articles published between 2014-2021 for incidence of PD, 2011-2021 for prevalence, and updated previously published systematic reviews for which the last date of inclusion had been 2014 and 2011. We included 32 articles for prevalence and 30 for incidence. We calculated male/female (M/F) prevalence and incidence ratios, and investigated heterogeneity in estimates.

Results

The combined M/F prevalence ratio was 1.18 (95% CI 1.03-1.36) and incidence ratio was

1.37 (95% CI 1.22-1.53), lowest in Asian populations. These were not influenced by study type, national economy or mean participant age. The female-to-male gap in life expectancy did partly account for data heterogeneity.

Conclusion

The sex gap for prevalence of PD was smaller than has previously been reported. More studies are needed to understand the determinants of sex imbalance in PD.

091 The East London Parkinson’s disease project – engaging a diverse population in research

Background

Parkinson disease (PD) is the second most common neurodegenerative disease and the burden appears to be growing fastest in middle-low and low income countries. In the majority of obser- vational studies of PD, White, well-educated and affluent participants are over-represented.

Aims

Our aim was to engage a diverse group of people with Parkinson disease (PwP) from East London and build a research platform for previously under-represented groups.

Methods

We created a register of PwP from the Royal London Hospital which includes approximately 400 patients. In parallel, we have recruited participants to the East London Parkinson’s disease (ELPD) project; a case-control study of phenotype, genotype and biomarker characteristics. Clinical manifes- tations, UPDRS scores, data on non-motor symptoms, as well as biospecimens (buccal and skin swabs, serum samples) have been obtained.

Results

145 patients and 80 controls have been recruited so far. The mean age of PwP was 67.81 (SD 10.4); 62% were male and 59% identified as being from South Asian or Black ethnicity. The most common presenting symptom was tremor (55.9%), followed by gait impairment (16.6%).

Conclusion

The ELPD project is a platform study for under-represented patients with PD which provides important opportunities for collaboration and research to improve health inequalities.

106 Inflammatory peripheral neuropathy in haematological malignancies

Background

We report the case of a 62-year-old female with demyelinating sensorimotor polyneuropathy in the context of lymphoplasmacytic lymphoma.

Case Presentation

62-year-old woman presenting with distal lower limb numbness bilaterally, with a 9-year progressive course. Over the next 3 years, foot drop developed with gradual lower and upper limb involvement.

Investigations showed raised IgM paraprotein, 20 g/dL. Bone marrow biopsy identified 2-B cell clonal populations with positive MYD88 mutation in keeping with lymphoplasmacytic lymphoma (LPL). Neuro- physiological studies showed very severe length-dependent, sensorimotor neuropathy. She was VEGF/anti-MAG negative, but anti-GM2 positive. Widely-spaced myelin and moderate axonal loss were seen on sural nerve biopsy.

She was diagnosed with a progressive demyelinating neuropathy in the context of LPL.

Initial IVIG treatment failed.

Second line treatment – cyclophosphamide/rituximab/dexamethasone, improved her lower limb weakness. Ibrutinib later stabilised her weakness in the lower but not upper limbs.

Plexus nerve biopsy showed general inflammation, excluding direct clonal infiltration and amyloid deposi- tion. This reconfirmed the diagnosis: inflammatory neuropathy driven by a haematological malignancy. She received further treatment with rituximab-bendamustine.

Conclusion

Understanding the pathological mechanism of polyneuropathies in haematological malignan- cies is of paramount importance for choosing the most effective therapy, as illustrated by the above cas8e7.

a.zirra@nhs.net

hiCLIP reveals the in vivo atlas of mRNA secondary structures recognized by Staufen 1

The structure of messenger RNA is important for post-transcriptional regulation, mainly because it affects binding of trans-acting factors. However, little is known about the in vivo structure of full-length mRNAs. Here we present hiCLIP, a biochemical technique for transcriptome-wide identification of RNA secondary structures interacting with RNA-binding proteins (RBPs). Using this technique to investigate RNA structures bound by Staufen 1 (STAU1) in human cells, we uncover a dominance of intra-molecular RNA duplexes, a depletion of duplexes from coding regions of highly translated mRNAs, an unexpected prevalence of long-range duplexes in 3' untranslated regions (UTRs), and a decreased incidence of single nucleotide polymorphisms in duplex-forming regions. We also discover a duplex spanning 858 nucleotides in the 3' UTR of the X-box binding protein 1 (XBP1) mRNA that regulates its cytoplasmic splicing and stability. Our study reveals the fundamental role of mRNA secondary structures in gene expression and introduces hiCLIP as a widely applicable method for discovering new, especially long-range, RNA duplexes.

Manual Aspiration Thrombectomy

Background and Purpose—

We evaluated recanalization rates, clinical outcomes, and safety when manual aspiration thrombectomy is used in conjunction with other thrombolytic modalities in a consecutive case series of patients with large vessel intracranial occlusion.

Methods—

We conducted a retrospective review of a prospectively acquired acute endovascular stroke database. Manual aspiration thrombectomy was carried out with Distal Access and Penumbra reperfusion catheters of different sizes placed in the thrombus and aspirated with a syringe.

Results—

We identified 191 patients: Occlusion locations were as follows: M1% to 50%, M2% to 10%, internal carotid artery terminus 25%, and vertebrobasilar 15%. Median treatment duration was 90 minutes. Recanalization results were Thrombolysis in Myocardial Ischemia 2/3 93%, Thrombolysis in Myocardial Ischemia 3 27%, Thrombolysis In Cerebral Infarction 2a/2b/3 91%, Thrombolysis In Cerebral Infarction 2b/3 71%, and Thrombolysis In Cerebral Infarction 3 25%. Larger catheters were associated with higher recanalization rates. Parenchymal hematoma rate was 13.6%. The favorable outcome (90-day modified Rankin Scale ≤2) rate was 54%. Mortality at 90 days was 25%.

Conclusions—

Manual aspiration thrombectomy is a useful addition to the armamentarium of endovascular treatment modalities for acute stroke.