Absence Of Other Neurological Symptoms Research Articles

Characterization of Anti-GAD65-Associated Neurological Syndromes: Clinical Features and Antibody Titers

Introduction: Anti-GAD65 antibodies are associated with several neurological phenotypes. Antibody titers are increasingly recognized as useful in diagnosis and prognosis. Objective: To describe a Portuguese cohort of patients with anti-GAD65-associated neurological syndromes. Methods: Retrospective analysis of all patients with positive anti-GAD65 antibodies and associated neurological syndromes followed in a tertiary referral center. Results: Nineteen anti-GAD65 antibody-positive neurological patients were identified, 62.3% female, with a mean age of onset of 56.0 (SD = 13.3) years. Comorbid autoimmune disorders were present in seven patients. Six patients had limbic encephalitis (31.6%), four had epilepsy (21.1%), four had cerebellar ataxia (21.1%), and three had stiff-person syndrome (15.8%). Two patients presented with isolated cognitive dysfunction (executive and mnesic) in the absence of other neurological symptoms. The mean follow-up time was 24.0 (14.0–42.0) months, at the end of which the mean modified Rankin Scale (mRS) value was 2.0 (1.0–4.0). Screening for malignancies was negative in all patients. Serum quantitative analysis was carried out in 18 patients, 10 of whom showed titers above previously defined cut-off points (>10,000 IU/L for ELISA and >20 mmol/L for RIA). Quantitative CSF analysis was performed in nine patients, with four showing above-threshold titers. There was no association between anti-GAD65 levels and clinical phenotype or the final mRS values. High-dose intravenous methylprednisolone and oral prednisolone were the most common acute and chronic treatment regimens, respectively. Conclusion: Anti-GAD65 antibodies are associated with varied neurological syndromes, and antibody titers alone should not be used to exclude a disease.

Diagnostic Yield of Investigations in Symmetric Optic Neuropathy.

Symmetric optic neuropathy (SON) is commonly seen in neuro-ophthalmic practice and is often discovered incidentally. Although multiple investigations might be performed to discover the underlying cause, they are not always indicated. The aim of this study was to report a clinically reasonable and cost-effective approach to investigating patients with SON. SON was defined as bilateral optic neuropathy with normal and/or symmetrically decreased central visual acuity, absence of relative afferent pupillary defect, presence of symmetric optic disc pallor, symmetric thinning of peripapillary retinal nerve fiber layer on optical coherence tomography, and absence of other identifiable causes of optic neuropathy. Records of all patients diagnosed with SON seen at a tertiary university-affiliated neuro-ophthalmology practice from 2016 to 2022 were reviewed to identify the yield of various investigations. Clinical data from the initial and last follow-up visit were obtained. Subgroup analysis was performed to ascertain whether diagnostic yield is higher in patients with severe visual loss (central acuity worse than 20/40) compared with those with mild visual loss (acuity 20/40 or better). One hundred thirty-six patients met inclusion criteria. Testing for OPA1 and OPA2 mutations had the highest diagnostic yield (16.0%), followed by mitochondrial genome sequencing (13.6%), serum vitamin B12 (6.1%), and serum folate (1.6%). MRI brain was performed in 54.4% of patients and had a diagnostic yield of only 5%. Both patients who had abnormal MRI had symptoms of demyelination at presentation. Patients were followed for a mean of 15.0 (SD 21.3) months. The most frequently identified etiologies of SON were Leber hereditary optic neuropathy (8.1%), alcohol/tobacco amblyopia (7.4%), vitamin B12 deficiency (5.9%), and dominant optic atrophy (2.9%). Patients with severe visual impairment were more likely to have a final diagnosis compared with those with milder visual impairment (63.9% vs 12.0%, P < 0.001). The diagnostic yield of investigating SON in patients with preserved visual function, normal diet, and absence of other neurological symptoms is very low. It is reasonable to observe patients with SON with mild visual impairment, reserving costly investigations for those with the visual acuity worse than 20/40 or progressive course.

A sabbath in the emergency room or a case of anticholinergic toxicity?

We report the case of a 32-year-old Italian man admitted to our emergency room for visual disturbances with blurred vision, anisocoria and temporal headache suddenly occurred in absence of other neurological symptoms. A diagnosis of Datura stramoniuminduced anticholinergic toxicity was done. With our work, we want to highlight the importance of a meticulous clinical examination, including papillary diameter and reflexes, combined with a detailed history of the patient in the emergency room. Anticholinergic toxicity is a medical emergency. The diagnosis is always clinical, and it can represent a challenge for the emergency clinicians because it can mimic several neurological diseases, including acute stroke and seizures, but early diagnosis is crucial to avoid severe complications and management errors.

Study of the Comorbidity Between Cases of Acute Peripheral Vestibulopathies and COVID-19.

An infective etiology of acute peripheral vestibulopathy (APV) has long been hypothesized. In the context of coronavirus disease 2019 (COVID-19), we examined the possible comorbidity between these two entities. APV is the second most common cause of vestibular disorders and results from a sudden and unilateral loss of vestibular inputs. The characteristic signs and symptoms include sudden and prolonged vertigo, absence of auditory symptoms, and absence of other neurological symptoms. An infective etiology of APV has long been hypothesized on the basis of its association with respiratory tract infections and its frequent occurrence in epidemics. Possible comorbidity with herpes simplex virus type 1 reactivation or influenza virus infection has also been proposed. This study was designed to assess the possible comorbidity between APV and COVID-19. Quantification of the number of hospital admissions for APV over the period from February to May 2020 was carried out in 5 French hospitals. A comparison with 2018 and 2019 entries over the same period was made. Comorbidity between APV and COVID-19 infection was investigated. No significant increase in admission for APV was noticed over the examination period. No significant difference was noticed among hospitals located in COVID-19 high- and low-risk zones for SARS-CoV-2. No significant increase in the severity of the APV cases was noticed. No case of comorbidity between APV and SARS-CoV-2 infection was reported. Based on our observations, no correlation was made between APV and COVID-19. Based on our observations, COVID-19 is not statistically correlated with APV.

Congenital Mirror Movements Due to RAD51: Cosegregation with a Nonsense Mutation in a Norwegian Pedigree and Review of the Literature.

BackgroundAutosomal dominant congenital mirror movements (CMM) is a neurodevelopmental disorder characterized by early onset involuntary movements of one side of the body that mirror intentional movements on the contralateral side; these persist throughout life in the absence of other neurological symptoms. The main culprit genes responsible for this condition are RAD51 and DCC. This condition has only been reported in a few families, and the molecular mechanisms linking RAD51 mutations and mirror movements (MM) are poorly understood.MethodsWe collected demographic, clinical, and genetic data of a new family with CMM due to a truncating mutation of RAD51. We reviewed the literature to identify all reported patients with CMM due to RAD51 mutations.ResultsWe identified a heterozygous nonsense mutation c.760C>T (p.Arg254*) in eight subjects: four with obvious and disabling MM, and four with a mild phenotype. Including our new family, we identified 32 patients from 6 families with CMM linked to RAD51 variants.DiscussionOur findings further support the involvement of RAD51 in CMM pathogenesis. Possible molecular mechanisms involved in CMM pathogenesis are discussed.

Chiari 1 Malformation Presenting as Central Sleep Apnea during Pregnancy: A Case Report, Treatment Considerations, and Review of the Literature.

Purpose: Chiari malformation (CM) type-1 frequently causes obstructive or central sleep-disordered breathing (SDB) in both adults and children, although SDB is relatively rare as a presenting manifestation in the absence of other neurological symptoms. The definitive treatment of symptomatic CM is surgical decompression. We report a case that is, to our knowledge, a novel manifestation of central sleep apnea (CSA) due to CM type-1 with severe exacerbation and initial clinical presentation during pregnancy.Methods: Case report from tertiary care comprehensive sleep medicine center with literature review of SDB manifestations associated with CM type-1. PubMed search was conducted between January 1982 and October 2013.Results: We report a 25-year-old woman with severe CSA initially presenting during her first pregnancy that eventually proved to be caused by CM type-1. The patient was successfully treated preoperatively by adaptive servoventilation (ASV), with effective resolution of SDB following surgical decompression, and without recurrence in a subsequent pregnancy. Our literature review found that 58% of CM patients with SDB had OSA alone, 28% had CSA alone, 8 (10%) had mixed OSA/CSA, and 6 (8%) had hypoventilation. Of CM patients presenting with SDB, 50% had OSA, 42% had CSA, 8% had mixed OSA/CSA, and 10.4% had hypoventilation. We speculate that CSA may develop in CM patients in whom brainstem compression results in excessive central chemoreflex sensitivity with consequent hypocapnic CSA.Conclusion: Chiari malformation type-1 may present with a diversity of SDB manifestations, and timely recognition and surgical referral are necessary to prevent further neurological deficits. ASV therapy can effectively manage CSA caused by CM type-1, which may initially present during pregnancy.

Abstract T P89: Unilateral Cerebral Atrophy Secondary to Extracranial Carotid Stenosis

Background: Moderate to severe or bilateral carotid stenosis is associated with cerebral atrophy and cognitive decline. Prior studies have evaluated global atrophy and its correlation with the degree of stenosis. It is unclear whether carotid stenosis can lead to unilateral cerebral changes. Objective: To evaluate for unilateral cerebral atrophy in asymptomatic patients with moderated to severe extracranial unilateral carotid stenosis. Methods: Subjects were selected from patients who had undergone carotid vascular imaging and MRI of the brain, from January 2007 to January 2013 at our institution. Patients with history of TIA or ischemic stroke were excluded. Carotid stenosis (CS) group consisted of patients with unilateral moderate to severe carotid stenosis (n=9). Patients without any stenosis (n=5) were used as controls. T1-weighted brain images (FOV 256 x 256 x128, resolution 1.5 x 1.5 x 5 mm) were registered to Talairach space using FSL software. Non-brain tissue was removed using the BET module. Segmentation into gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) was done with the FAST tool. Total brain volume (TBV) was calculated as the sum of three tissue types (GM + WM + CSF). Total number of voxels in each hemisphere was calculated for GM, WM and CSF. Index of Asymmetry (IoA), was defined as the absolute value of inter-hemispheric voxel difference divided by TBV. IoA for each tissue type was compared between subjects and controls using Student’s t-test. Results: Mean age was 63.7±7.8 and 57.4 ±6.0 for the CS and control groups, respectively. Average gray matter IoA for CS was significantly increased compared to controls (1.4% v. 0.7, p &lt; 0.02). Average white matter IoA was similar between the groups (0.6% v. 0.7%, p&lt; 0.36). There was a trend for increased CSF IoA in the CS group compared to controls, but it did not reach statistical significance (1.8% v. 0.9%, p &lt; 0.10). Conclusion: Moderate to severe carotid stenosis can lead to unilateral cerebral atrophy in the absence of other neurological symptoms. Further prospective studies with larger cohorts of the patients are required.

Is vestibular neuritis an immune related vestibular neuropathy inducing vertigo?

Objectives. To review the current knowledge of the aetiology of vestibular neuritis including viral infections, vascular occlusion, and immunomediated mechanisms and to discuss the pathogenesis with relevance to pharmacotherapy. Systematic Review Methodology. Relevant publications on the aetiology and treatment of vestibular neuritis from 1909 to 2013 were analysed. Results and Conclusions. Vestibular neuritis is the second most common cause of peripheral vestibular vertigo and is due to a sudden unilateral loss of vestibular function. Vestibular neuronitis is a disorder thought to represent the vestibular-nerve equivalent of sudden sensorineural hearing loss. Histopathological studies of patients who died from unrelated clinical problems have demonstrated degeneration of the superior vestibular nerve. The characteristic signs and symptoms include sudden and prolonged vertigo, the absence of auditory symptoms, and the absence of other neurological symptoms. The aetiology and pathogenesis of the condition remain unknown. Proposed theories of causation include viral infections, vascular occlusion, and immunomediated mechanisms. The management of vestibular neuritis involves symptomatic treatment with antivertiginous drugs, causal treatment with corticosteroids, and physical therapy. Antiviral agents did not improve the outcomes.

Memory lost, memory regained: neuropsychological findings and neuroimaging in two cases of paraneoplastic limbic encephalitis with radically different outcomes

OBJECTIVETo report two cases of paraneoplastic limbic encephalitis (PNLE) with similar clinical presentation, but dramatically different outcome and to highlight the role of neuropsychological and radiological evaluation in PNLE.METHODSBoth patients...