Low incidence of neurological recurrent side-effects following COVID-19 reimmunization.

BACKGROUND: Individuals who suffered a neurological adverse event after the Coronavirus disease (COVID-19) vaccine could hesitate and defer reimmunization. AIM: We examine the risk of recurrence following reimmunization among patients who developed a neurological event after the first dose of the COVID-19 mRNA vaccine. DESIGN: Observational study. METHODS: Individuals who developed an adjudicated neurological adverse event (based on Brighton Collaboration criteria) within 6 weeks of the first dose of the COVID-19 vaccine requiring hospitalization were enrolled into a multicenter national registry in Singapore. Neurological recurrence, defined by the development of another neurological event within 6 weeks of the second vaccine dose, was reviewed. Clinical characteristics were compared between patients who chose to proceed or withhold further vaccination, and between those who received timely (3-6 weeks) or delayed (>6 weeks) reimmunization. RESULTS: From 235 patients (median age, 67 years; 63% men) who developed an adjudicated neurological event after their first dose of mRNA vaccine between 30 December 2020 and 20 April 2021, 181 (77%) chose to undergo reimmunization. Those who decided against reimmunization were older (median age, 74 vs. 66 years) and had greater physical disability following their primary neurological event (46% vs. 20%, P < 0.001). Patients who suffered greater physical disability were three times more likely to delay their reimmunization (odds ratio 3.36, 95% confidence interval: 1.76-6.40). Neurological recurrence was observed in only four individuals (three with seizures and one with myasthenia gravis exacerbation). CONCLUSIONS: A prior neurological event should not necessarily preclude reimmunization and the decision to proceed with reimmunization should consider the overwhelming benefits conferred by vaccination toward ending this pandemic.

Targeted Anterior Cervical Epidural Blood Patch in a Patient with Spontaneous Intracranial Hypotension.

A 45-year-old male was admitted with severe orthostatic headache secondary to spontaneous intracranial hypotension. He had the site of cerebrospinal fluid (CSF) leakage identified at the anterolateral aspect of the C7-T1 spinal level. He first underwent a conventional posterior-approach cervical epidural blood patch (EBP) which provided immediate relief to the patient's symptoms; however, his symptoms recurred two days later. To better target the anterolateral leakage site, we employed an anterior-approach EBP under computed tomography (CT) guidance. After this attempt, the patient experienced complete relief of his symptoms, and the headache eventually resolved.

Incidence of Cerebral Venous Thrombosis Following SARS-CoV-2 Infection vs mRNA SARS-CoV-2 Vaccination in Singapore.

Importance: Reports of cerebral venous thrombosis (CVT) after messenger RNA (mRNA)-based SARS-CoV-2 vaccination has caused safety concerns, but CVT is also known to occur after SARS-CoV-2 infection. Comparing the relative incidence of CVT after infection vs vaccination may provide a better perspective of this complication. Objective: To compare the incidence rates and clinical characteristics of CVT following either SARS-CoV-2 infection or mRNA-based SARS-CoV-2 vaccines. Design, Setting, and Participants: Between January 23, 2020, and August 3, 2021, this observational cohort study was conducted at all public acute hospitals in Singapore, where patients hospitalized with CVT within 6 weeks of SARS-CoV-2 infection or after mRNA-based SARS-CoV-2 vaccination (BNT162b2 [Pfizer-BioNTech] or mRNA-1273 [Moderna]) were identified. Diagnosis of SARS-CoV-2 infection was based on quantitative reverse transcription-polymerase chain reaction or positive serology. National SARS-CoV-2 infection data were obtained from the National Centre for Infectious Disease, Singapore, and vaccination data were obtained from the National Immunisation Registry, Singapore. Exposures: SARS-CoV-2 infection or mRNA-based SARS-CoV-2 vaccines. Main Outcomes and Measures: Clinical characteristics, crude incidence rate (IR), and incidence rate ratio (IRR) of CVT after SARS-CoV-2 infection and after mRNA SARS-CoV-2 vaccination. Results: Among 62 447 individuals diagnosed with SARS-CoV-2 infections included in this study, 58 989 (94.5%) were male; the median (range) age was 34 (0-102) years; 6 CVT cases were identified (all were male; median [range] age was 33.5 [27-40] years). Among 3 006 662 individuals who received at least 1 dose of mRNA-based SARS-CoV-2 vaccine, 1 626 623 (54.1%) were male; the median (range) age was 50 (12-121) years; 9 CVT cases were identified (7 male individuals [77.8%]; median [range] age: 60 [46-76] years). The crude IR of CVT after SARS-CoV-2 infections was 83.3 per 100 000 person-years (95% CI, 30.6-181.2 per 100 000 person-years) and 2.59 per 100 000 person-years (95% CI, 1.19-4.92 per 100 000 person-years) after mRNA-based SARS-CoV-2 vaccination. Six (66.7%) received BNT162b2 (Pfizer-BioNTech) vaccine and 3 (33.3%) received mRNA-1273 (Moderna) vaccine. The crude IRR of CVT hospitalizations with SARS-CoV-2 infection compared with those who received mRNA SARS-CoV-2 vaccination was 32.1 (95% CI, 9.40-101; P < .001). Conclusions and Relevance: The incidence rate of CVT after SARS-CoV-2 infection was significantly higher compared with after mRNA-based SARS-CoV-2 vaccination. CVT remained rare after mRNA-based SARS-CoV-2 vaccines, reinforcing its safety.

Hospital-based observational study of neurological disorders in patients recently vaccinated with COVID-19 mRNA vaccines.

PURPOSE: We describe the spectrum of acute neurological disorders among hospitalized patients who recently had COVID-19 mRNA vaccination. METHOD: We performed a prospective study at 7 acute hospitals in Singapore. Hospitalized patients who were referred for neurological complaints and had COVID-19 mRNA vaccines, BNT162b2 and mRNA-1273, in the last 6 weeks were classified into central nervous system (CNS) syndromes, cerebrovascular disorders, peripheral nervous system (PNS) disorders, autonomic nervous system (ANS) disorders and immunization stress-related responses (ISRR). RESULTS: From 30 December 2020 to 20 April 2021, 1,398,074 persons (median age 59 years, 54.5% males) received COVID-19 mRNA vaccine (86.7% BNT162b2, 13.3% mRNA-1273); 915,344(65.5%) completed 2 doses. Four hundred and fifty-seven(0.03%) patients were referred for neurological complaints [median age 67(20-97) years, 281(61.5%) males; 95.8% received BNT162b2 and 4.2% mRNA-1273], classified into 73(16.0%) CNS syndromes, 286(62.6%) cerebrovascular disorders, 59(12.9%) PNS disorders, 0 ANS disorders and 39(8.5%) ISRRs. Eleven of 27 patients with cranial mononeuropathy had Bell's palsy. Of 33 patients with seizures, only 4 were unprovoked and occurred within 2 weeks of vaccination. All strokes occurred among individuals with pre-existing cardiovascular risk factors. We recorded 2 cases of cerebral venous thrombosis; none were vaccine-induced thrombotic thrombocytopenia. Five had mild flares of immune-mediated diseases. CONCLUSION: Our observational study does not establish causality of the described disorders to vaccines. Though limited by the lack of baseline incidence data of several conditions, we observed no obvious signal of serious neurological morbidity associated with mRNA vaccination. The benefits of COVID-19 vaccination outweigh concerns over neurological adverse events.

Hereditary Transthyretin Amyloidosis- Clinical and Genetic Characteristics of a Multiracial South-East Asian Cohort in Singapore.

BACKGROUND AND AIMS: Studies of hereditary transthyretin amyloidosis (ATTRv amyloidosis) in South-East Asia are underrepresented in the literature. We report the unique phenotypic and genetic characteristics of this disorder in a multiracial South-East Asian cohort. METHODS: Patients with genetically proven ATTRv amyloidosis were identified over a 13-year period (2007-2020) at the National Neuroscience Institute, Singapore. Clinical, laboratory, genotypic and electrophysiological features were retrospectively reviewed. RESULTS: 29 patients comprising Chinese, Malay, Burmese, Vietnamese and Indonesians with ATTRv amyloidosis were identified. Somatic neuropathy was the most common initial presentation, followed by carpal tunnel syndrome, autonomic dysfunction and cardiac dysfunction. ATTR-A97S (p.Ala117Ser) was the most common variant found in 14 patients, constituting 66.7%of ethnic Chinese patients and 48.3%of the entire cohort. Five patients had early-onset disease (age < 50 years) with the following variants: ATTR-V30M (p.Val50Met), ATTR-G47A (p.Gly67Ala), ATTR-S50I (p.Ser70Ile) and ATTR-A97S (p.Ala117Ser); one patient with ATTR-A97S (p.Ala117Ser) had isolated unilateral carpal tunnel syndrome with amyloid deposits identified on histological examination of the transverse carpal ligament. All early-onset patients had a positive parental history; two patients, with ATTR-S50I (p.Ser70Ile) and ATTR-Ala97Ser (p.Ala117Ser) respectively, demonstrated anticipation with mother-to-daughter inheritance. Amongst the 24 patients with late-onset disease (age≥50 years), two patients had novel variants, ATTR-G66D (p.Glu86Asp) and ATTR-A81V (p.Ala101Val) that were confirmed to be pathogenic based on the histological identification of transthyretin amyloid. Other identified variants included ATTR-V30M (p.Val50Met), ATTR-R34T (p.Arg54Thr), ATTR-S50I (p.Ser70Ile), ATTR-H88R (p.His108Arg) and ATTR-A97S (p.Ala117Ser). CONCLUSION: Our study further expands the genotypic and phenotypic knowledge regarding ATTRv amyloidosis.

Immune checkpoint inhibitor-associated myositis and myasthenia gravis overlap: Understanding the diversity in a case series.

Immune checkpoint inhibitors (ICI) have improved survival across tumor types however they cause immune-related toxicities through removal of the inhibition of auto-reactive T cells. In this case review, we present 4 patients with metastatic cancer who developed de-novo neuromuscular side effects of myositis with overlapping seropositive myasthenia gravis after ICI treatment. Declaration: This study was performed in accordance to the ethical standards set by the SingHealth Institutional Review Board, with consent taken from living patients and waiver of consent from deceased patients (CIRB Ref 2019/2485). Supporting data were collected from our institution's digital medical records system.

Neurology of COVID-19 in Singapore.

PURPOSE: To describe the spectrum of COVID-19 neurology in Singapore. METHOD: We prospectively studied all microbiologically-confirmed COVID-19 patients in Singapore, who were referred for any neurological complaint within three months of COVID-19 onset. Neurological diagnoses and relationship to COVID-19 was made by consensus guided by contemporaneous literature, refined using recent case definitions. RESULTS: 47,572 patients (median age 34 years, 98% males) were diagnosed with COVID-19 in Singapore between 19 March to 19 July 2020. We identified 90 patients (median age 38, 98.9% males) with neurological disorders; 39 with varying certainty of relationship to COVID-19 categorised as: i) Central nervous system syndromes-4 acute disseminated encephalomyelitis (ADEM) and encephalitis, ii) Cerebrovascular disorders-19 acute ischaemic stroke and transient ischaemic attack (AIS/TIA), 4 cerebral venous thrombosis (CVT), 2 intracerebral haemorrhage, iii) Peripheral nervous system-7 mono/polyneuropathies, and a novel group, iv) Autonomic nervous system-4 limited dysautonomic syndromes. Fifty-one other patients had pre/co-existent neurological conditions unrelated to COVID-19. Encephalitis/ADEM is delayed, occurring in critical COVID-19, while CVT and dysautonomia occurred relatively early, and largely in mild infections. AIS/TIA was variable in onset, occurring in patients with differing COVID-19 severity; remarkably 63.2% were asymptomatic. CVT was more frequent than expected and occurred in mild/asymptomatic patients. There were no neurological complications in all 81 paediatric COVID-19 cases. CONCLUSION: COVID-19 neurology has a wide spectrum of dysimmune-thrombotic disorders. We encountered relatively few neurological complications, probably because our outbreak involved largely young men with mild/asymptomatic COVID-19. It is also widely perceived that the pandemic did not unduly affect the Singapore healthcare system.

A longitudinal study of non-motor symptom burden in Parkinson's disease after a transition to expert care.

BACKGROUND: Non-motor symptoms (NMS) are common among patients with Parkinson's disease (PD) however little is known about their progression in terms of severity or burden after referral to expert care. OBJECTIVE: This study was aimed to establish the progression of NMS burden in PD patients after referral to tertiary healthcare centre and factors affecting it. METHODS: Newly referred PD patients were prospectively enrolled and follow-up for up to 18 months. Non-motor symptoms scale (NMSS) was used to evaluate the burden of non-motor symptoms. RESULTS: There was a significant median reduction of total NMS burden over the follow-up period. Similarly all NMS domains except domains 2 (sleep/fatigue), 3 (mood/cognition), 6 (gastrointestinal) and 7 (urinary) showed significant median reduction of scores. In the univariate regression analysis, Hoehn & Yahr staging, disease duration, visit, Schwab & England Activities of Daily Living score and UPDRS motor scores were individually predictive of change in total NMS burden. However, in the multivariable regression analysis only the latter three were significantly predictive of change in the total NMS burden. CONCLUSION: There was a significant reduction of total NMS burden over the study period. The severity of motor and activity of daily living impairments as well as subsequent visit were the best predictors of NMS change.

Differentiating non-motor symptoms in Parkinson's disease from controls and hemifacial spasm.

BACKGROUND AND AIMS: Non-motor symptoms (NMS) are important manifestations of Parkinson's disease (PD) that reduce patients' health-related quality of life. Some NMS may also be caused by age-related changes, or manifested as a psychological reaction to a chronic neurological condition. This case-control study compared the NMS burden among PD patients, healthy controls and hemifacial spasm (HFS) patients. In addition, we determined the NMS that discriminated between PD and non-PD subjects. METHODS: 425 subjects were recruited from a tertiary hospital in Singapore (200 PD patients, 150 healthy controls and 75 HFS patients). NMS burden in subjects was measured using the Non-Motor Symptoms Scale (NMSS). RESULTS: NMSS total score was significantly higher in PD patients (37.9±2.6) compared to healthy controls (11.2±0.9) (p<0.0001) and HFS patients (18.0±2.1) (p<0.0001). In addition, NMSS total score was significantly higher in HFS patients compared to healthy controls (p = 0.003). PD patients experienced a higher NMS burden than healthy controls in all domains, and a higher NMS burden than HFS patients in all but attention/memory and urinary domains. NMS burden for HFS and healthy controls differed only in the sleep/fatigue and urinary domains. Using stepwise logistic regression, problems of 'constipation', 'restless legs', 'dribbling saliva', 'altered interest in sex' and 'change in taste or smell' were found to have significant discriminative power in differentiating between PD patients and healthy controls and between PD patients and HFS patients. CONCLUSION: PD patients experienced a greater overall NMS burden compared to both healthy controls and HFS patients. HFS patients demonstrated a higher NMS burden than controls, and some NMS may be common to chronic neurological conditions while others are more specific to PD. Differentiating patients using NMS domains may help refine the clinical management of NMS in PD patients.

Sleep and Parkinson's disease: a review of case-control polysomnography studies.

The link between Parkinson's disease (PD) and certain primary sleep disorders has yet to be clarified. We performed a systematic review of case-control polysomnography studies to evaluate the relationship between PD and sleep disorders. A PubMed literature search and bibliography review yielded 15 case-control polysomnography studies in patients with PD. Studies differed by recruitment methods, duration of polysomnography monitoring, and sleep parameters measured. Subjective sleepiness was greater in patients than controls (50%-66% vs 2.9%-12%) despite lack of objective increase in daytime sleepiness by mean sleep latency testing. The 4 case-control polysomnography studies investigating rapid eye movement behavior disorder support a higher prevalence in PD (0%-47% vs 0%-1.8% in controls), although differences in diagnostic criteria hamper interpretation. The preponderance of evidence did not support an increased incidence of obstructive sleep apnea (27%-60% vs 13%-65%) or periodic leg movements of sleep in patients compared to controls. Adequately powered, prospective studies with uniform methodology and healthy controls are needed to further address the association and pathophysiological significance between PD and sleep problems.

Case control polysomnographic studies of sleep disorders in Parkinson's disease.

BACKGROUND: The relationship between a number of primary sleep disorders and Parkinson's disease (PD) is still debated. There are limited case control polysomnographic studies in PD and most of these study sample sizes are small. METHODOLOGY/FINDINGS: We conducted one of the largest case-control studies involving overnight polysomnographic evaluation, with prospective recruitment of unselected Parkinson's disease patients and healthy controls from an Asian population. The cases were recruited from the specialized movement disorder outpatient clinics in a tertiary referral center, and controls from the same geographical locations. All subjects underwent an overnight polysomnographic study and a multiple sleep latency test. A total of 124 subjects including 56 patients and 68 controls frequency-matched for age and sex were included. Multivariate analysis revealed that patients had significantly shorter total sleep time than controls (p = 0.01), lower sleep efficiency (p = 0.001) and increased REM latency (p = 0.007). In patients, multivariate analysis showed that reduced total sleep time was significantly associated with increased age (p = 0.001) and increased levodopa dose (p = 0.032). The mean Insomnia Severity Index was higher in PD patients (9.0±7.1) compared to controls (3.3±3.9, p<0.001). The mean Epworth Sleepiness Scale score was higher in PD patients (9.3±5.9 vs. 5.7±4.8, p<0.001). Nocturnal arousals, obstructive sleep apnea, periodic leg movements and objective abnormal sleepiness were not increased in our patients. CONCLUSIONS/SIGNIFICANCE: Our case-control polysomnographic study, the first-ever performed in an Asian population, revealed altered sleep architecture and reduced sleep in PD patients compared to controls. Reduced total sleep time was associated with increased age and levodopa dose. However, nocturnal arousals, primary sleep disorders and abnormal sleepiness were not increased in our PD patients suggesting that ethnic/genetic differences may be a factor in the pathophysiology of these conditions.