New insights from a multi-ethnic Asian progressive supranuclear palsy cohort.

BACKGROUND: Progressive supranuclear palsy (PSP) is a rare, disabling, neurodegenerative disease, with few studies done in Asian populations. METHODS: We prospectively characterized the clinical features and disease burden in a consecutively-recruited multi-ethnic Asian PSP cohort. Patients were extensively phenotyped using the Movement Disorder Society (MDS-PSP) clinical diagnostic criteria and the PSP-Clinical Deficits Scale (PSP-CDS). Caregiver burden was measured using the modified Zarit Burden Interview (ZBI). Investigations (neuroimaging and genetic tests) were reviewed. RESULTS: There were 104 patients (64.4% male; 67.3% Chinese, 21.2% Indians, 9.6% Malays), consisting of 48.1% Richardson syndrome (PSP-RS), 37.5% parkinsonian phenotype (PSP-P), and 10.6% progressive gait freezing phenotype (PSP-PGF). Mean age at motor onset was 66.3 ± 7.7 years, with no significant differences between the PSP phenotypes. Interestingly, REM-sleep behaviour disorder (RBD) symptoms and visual hallucinations (considered rare in PSP) were reported in 23.5% and 22.8% of patients, respectively, and a family history of possible neurodegenerative or movement disorder in 20.4%. PSP-CDS scores were highest (worst) in PSP-RS; and correlated moderately with disease duration (rs = 0.45, P < 0.001) and weakly with caregiver burden (rs = 0.22, P = 0.029) in the overall cohort. Three of 48 (6.3%) patients who had whole-exome sequencing harboured pathogenic/likely pathogenic GBA variants. CONCLUSIONS: Significant heterogeneity in clinical features and disease burden, and high rates of RBD symptoms, visual hallucinations, and familial involvement were observed in this relatively large cohort. Our findings highlight important considerations when assessing Asian patients, and provide further support for the notion of overlapping neurobiology between PSP and Lewy body disorders.

Association between Appendectomy and Demyelinating Disorders in Subjects 40 Years and Older.

BACKGROUND: The association between appendectomy and multiple sclerosis (MS) is unknown. In this study, we explored the association between appendectomy and MS and neuromyelitis optica spectrum disorder (NMOSD). PATIENTS AND METHODS: MS and NMOSD patients older than 40 were identified from neurology records from hospitals in Malaysia. The diagnoses were based on the Revised McDonald (2010) and Wingerchuk (2015) criteria. Controls were sampled from Malaysia's normal population. Individuals were interviewed telephonically or face-to-face. The age inclusion criterion (over 40) differentiated high or low lifetime risk of appendicitis, as appendicitis incidence is rare after 40. RESULTS: 49 MS, 71 NMOSD, and 880 controls met the inclusion criteria. Seventy-two individuals (9 MS, 4 NMOSD, 59 control) had undergone appendectomy. Appendectomy rates were 18.37% in the MS group (95% CI 7.5-29.2%), 5.6% in the NMOSD group (0.3%, 11%), and 6.7% among controls (5.1%, 8.4%), (MS vs NMOSD P = 0.036, MS vs controls P = 0.007). Binary regression analysis showed that MS was an independent risk factor for appendectomy (OR 2.938, 95% CI 1.302, 6.633, P = 0.009). NMOSD showed no association with appendectomy. CONCLUSION: MS is positively associated with appendectomy, unlike ulcerative colitis, which is negatively associated. We hypothesize that there is a commonality in the microflora in persons who have had these two illnesses.

Eleven episodes of recurrent optic neuritis of the same eye for 22 years eventually diagnosed as neuromyelitis optica spectrum disorder.

It is difficult to predict whether a particular attack of neuromyelitis optica spectrum disorder (NMOSD) will affect the optic nerve [optic neuritis (ON): unilateral or bilateral], spinal cord (myelitis), brain or brainstem, or a combination of the above. We report an interesting case of recurrent ON of the same eye for a total of 11 episodes in a Chinese woman. Over a period of 22 years, the attacks only involved the left eye, and never the right eye and also no myelitis. For a prolonged duration, she was diagnosed as recurrent idiopathic ON. Only until she was tested positive for aquaporin 4 antibody that her diagnosis was revised to NMOSD. Optical coherence tomography revealed thinning of the retinal nerve fibre layer (RNFL) for the affected left eye, while the RNFL thickness was within normal range for the unaffected right eye. The disability accrual in NMOSD is generally considered to be attack-related - without a clinical attack of ON, there shall be no visual impairment, and no significant subclinical thinning of RNFL. Our case is in agreement with this notion. This is in contrast to multiple sclerosis where subclinical RNFL thinning does occur. This case highlights the importance of revisiting and questioning a diagnosis of recurrent idiopathic ON particularly when new diagnostic tools are available.