Obstructive sleep apnea in those with idiopathic intracranial hypertension undergoing diagnostic in-laboratory polysomnography.

RATIONALE: The association of obstructive sleep apnea (OSA) with idiopathic intracranial hypertension (IIH) remains unclear, and few studies have used objective in-laboratory polysomnography (PSG) data. Thus, we used PSG data to examine the: 1) association between OSA, and its severity, with IIH and 2) sex differences in OSA severity in those with and without IIH. METHODS: We retrospectively analyzed diagnostic PSG data from January 2015 to August 2023 for patients who were diagnosed with IIH by a neuro-ophthalmologist using the modified Dandy criteria. We selected three age, sex, and body mass index (BMI) matched controls for each IIH patient. We examined potential associations of IIH with OSA using regression. Sex differences were analyzed using ANOVA. RESULTS: Of 3482 patients who underwent PSG, we analyzed 78 IIH patients (16 males) and 234 matched controls (48 males). Five (6.4 %) IIH and 39 (16.7 %) control patients had OSA, defined as AHI≥15. After adjusting for age, sex, BMI, and comorbidities, IIH was negatively associated with the presence of OSA (OR 0.29, 95%CI 0.10-0.87, p = 0.03). However, models that adjusted for acetazolamide use, with or without comorbidities, showed no significant relationship with OSA (OR 0.31, p = 0.20). Males with IIH had a significantly higher age (p = 0.020), OSA severity (p = 0.032), and arousal index (p = 0.046) compared to females with IIH. CONCLUSIONS: IIH treated with acetazolamide was not an independent risk factor for OSA presence or severity. The presence of IIH treated with acetazolamide likely does not warrant routine screening for OSA, but related risk factors may identify appropriate patients.

Neurovascular Compression in the Anterior Visual Pathway: A Case Series.

A retrospective review of 29 patients with neurovascular compression syndrome (NVCS) involving the anterior visual pathway was conducted. Various patterns of NVCS and visual defects were identified, most commonly involving the optic nerve and internal carotid artery. Most patients were stable, except one with progressive visual field defects. Although mostly asymptomatic, NVCS can rarely cause compressive optic neuropathy. NVCS should be kept in the differential diagnosis of normal tension glaucoma, especially with progressive visual loss despite treatment. Patients with progressive visual loss may require decompression surgery. Non-contrast computed tomography scan may miss NVCS, and magnetic resonance imaging is diagnostic.

Abducens Nerve Palsy as a Presenting Symptom of Multiple Sclerosis.

Multiple sclerosis (MS) is a chronic disorder characterized by demyelination of the central nervous system. It often presents in women aged 18-35 with neurological symptoms such as visual loss, paresthesia, focal weakness, and ataxia. Demyelination in the brainstem can result in internuclear ophthalmoplegia causing binocular horizontal diplopia. Our report details a patient with horizontal diplopia from an isolated abducens (sixth) nerve palsy as the initial symptom of MS. While rare, this demonstrates the importance of including MS in the differential diagnosis for an isolated abducens nerve palsy, especially in younger patients with no known vascular risk factors.

Idiopathic Intracranial Hypertension: A Case Study of Patient Engagement in the Treatment of a Chronic Disease.

Idiopathic intracranial hypertension is a rare neurological disorder characterized by increased intracranial pressure, which can lead to visual loss and headaches. While medical therapy exists, weight loss is the only disease-modifying treatment. Weight loss is the only therapy that leads to sustained resolution of papilledema. Involving the patient in their disease management through patient engagement is a way to improve disease outcomes, and strengthen the therapeutic relationship. This feature discusses an overview of the disease, a patient's experience, and a physician's perspective.

SLEAP SMART (Sleep Apnea Screening Using Mobile Ambulatory Recorders After TIA/Stroke): A Randomized Controlled Trial.

BACKGROUND AND PURPOSE: Poststroke/transient ischemic attack obstructive sleep apnea (OSA) is prevalent, linked with numerous unfavorable health consequences, but remains underdiagnosed. Reasons include patient inconvenience and costs associated with use of in-laboratory polysomnography (iPSG), the current standard tool. Fortunately, home sleep apnea testing (HSAT) can accurately diagnose OSA and is potentially more convenient and cost-effective compared with iPSG. Our objective was to assess whether screening for OSA in patients with stroke/transient ischemic attack using HSAT, compared with standard of care using iPSG, increased diagnosis and treatment of OSA, improved clinical outcomes and patient experiences with sleep testing, and was a cost-effective approach. METHODS: We consecutively recruited 250 patients who had sustained a stroke/transient ischemic attack within the past 6 months. Patients were randomized (1:1) to use of (1) HSAT versus (2) iPSG. Patients completed assessments and questionnaires at baseline and 6-month follow-up appointments. Patients diagnosed with OSA were offered continuous positive airway pressure. The primary outcome was compared between study arms via an intention-to-treat analysis. RESULTS: At 6 months, 94 patients completed HSAT and 71 patients completed iPSG. A significantly greater proportion of patients in the HSAT arm were diagnosed with OSA (48.8% versus 35.2%, P=0.04) compared with the iPSG arm. Furthermore, patients assigned to HSAT, compared with iPSG, were more likely to be prescribed continuous positive airway pressure (40.0% versus 27.2%), report significantly reduced sleepiness, and a greater ability to perform daily activities. Moreover, a significantly greater proportion of patients reported a positive experience with sleep testing in the HSAT arm compared with the iPSG arm (89.4% versus 31.1%). Finally, a cost-effectiveness analysis revealed that HSAT was economically attractive for the detection of OSA compared with iPSG. CONCLUSIONS: In patients with stroke/transient ischemic attack, use of HSAT compared with iPSG increases the rate of OSA diagnosis and treatment, reduces daytime sleepiness, improves functional outcomes and experiences with sleep testing, and could be an economically attractive approach. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02454023.

Unilateral Papilledema in Idiopathic Intracranial Hypertension: A Case Series.

Idiopathic intracranial hypertension (IIH) typically presents with bilateral papilledema; however, highly asymmetric and rare unilateral cases have been reported. We report three cases of IIH meeting modified Dandy criteria presenting with unilateral papilledema. Magnetic resonance imaging (MRI) demonstrated bilateral distention of the optic nerve sheaths and computed tomography (CT) of the orbits demonstrated a smaller diameter of the optic canal in the unaffected eye in two cases. Papilledema fully resolved in all with acetazolamide. Of postulated mechanisms, we suspect that differences in bony optic canal diameter, compliance of the lamina cribrosa, and optic nerve sheath anatomy may contribute to asymmetry.

Congenital Herniation of the Gyrus Rectus Resulting in Compressive Optic Neuropathy.

We report a 34-year-old male with a previously uninvestigated lifelong blindness of the right eye from compressive optic neuropathy secondary to congenital herniation of the gyrus rectus (HGR). His past medical history was otherwise unremarkable, with no history of prior head or ocular trauma. On examination, he had no light perception in the right eye, right relative afferent pupillary defect (RAPD), and primary optic atrophy. His left eye had normal visual acuity, color vision, and a healthy optic disc. There was a sensory exotropia in the right eye; however, extraocular movements were intact and the remainder of his neurological exam was normal. MRI revealed compression of the prechiasmatic right optic nerve from HGR and atrophy of the right optic nerve and optic chiasm (Figures 1 and 2), without any parenchymal mass lesions. There were no signal abnormalities in the optic nerves or the chiasm.

Homonymous Retinal Ganglion Cell Layer Atrophy With Asymptomatic Optic Tract Glioma in Neurofibromatosis Type I.

Approximately 20% of patients with Neurofibromatosis type 1 (NF1) develop optic pathway gliomas (OPGs). Not all OPGs in NF1 necessarily become vision compromising and predicting which patients might develop visual decline is difficult at present time. Optical coherence tomography (OCT) has emerged as a useful tool able to directly assess the morphology and thickness of individual retinal layers. The ganglion cell layer (GCL) is composed of the retinal ganglion cells which receive information from photoreceptors via interneurons, while the retinal nerve fiber layer (RNFL) contains the retinal ganglion cell unmyelinated axons that merge to form the optic nerve. Lesions of the anterior visual pathway result in retrograde axonal degeneration from ganglion cell death and ultimately manifest as thinning of the RNFL and/or GCL. In this report we highlight a case of a 38 year-old woman with an NF1 associated left chiasmal and optic tract glioma who had normal visual fields and visual acuity. However, using OCT we demonstrate a homonymous pattern of GCL atrophy that corresponds with her left optic tract glioma. Given this homonymous pattern of atrophy in the GCL and the left optic tract lesion, one would expect a right homonymous hemianopia. To our knowledge this is the first reported case of a homonymous pattern of GCL-IPL atrophy in an adult with an NF1 related OPG involving the optic chiasm and optic tract, but without objective visual field or acuity deficits. This case is important because, mechanistically, it suggests that a necessary threshold of GCL atrophy may be needed before visual concerns can be detected and, secondly, it invites future studies to evaluate whether OCT may serve as a potential screening tool for those with NF1 related OPGs.

An evaluation of genetic causes and environmental risks for bilateral optic atrophy.

PURPOSE: To assess the clinical utility of next-generation sequencing (NGS) for the diagnosis of patients with optic atrophy (OA). DESIGN: Retrospective cohort study. METHODS: 97 patients were referred to the McMaster University Medical Center (Hamilton, Ontario) for evaluation of bilateral OA. All patients were sent for NGS including a 22 nuclear gene panel and/or complete mitochondrial DNA (mtDNA) sequencing. Positive genetic test results and abnormal vibration sensation were compared in patients +/- environmental exposures or a family history. RESULTS: 19/94 (20.2%) had a positive nuclear variant, of which 15/19 (78.9%) were in the OPA1 gene. No positive mtDNA variants were identified. The detection of a positive genetic variant was significantly different in patients who reported excessive ethanol use, but not in patients who smoke (0/19 (0%) vs. 19/78 (24.4%), P = 0.0164 and 4/22 (18.2%) vs. 15/74 (20.3%), P = 0.829, respectively). Patients with a positive family history were more likely to have a positive genetic variant compared to patients with a negative family history (P = 0.0112). There were significantly more excessive drinkers with an abnormal vibration sensation (P = 0.026), and with a similar trend in smokers (P = 0.074). CONCLUSIONS: All positive genetic variants were identified in nuclear genes. We identified a potential independent pathophysiological link between a history of excessive ethanol consumption and bilateral OA. Further investigations should evaluate and identify potential environmental risk factors for OA.

Silent Post Cataract Bilateral Sequential Nonarteritic Anterior Ischaemic Optic Neuropathy.

Nonarteritic anterior ischaemic optic neuropathy (NAION) has been reported as a rare occurrence following cataract surgery. Bilateral sequential NAION following cataract surgery is extremely rare. We report an 83-year-old male who developed bilateral sequential NAION within 5 and 3 weeks of undergoing uneventful cataract surgeries in each eye. A brief review of the literature on this topic is provided. This case serves to add to the ongoing debate about the association between cataract surgery and NAION.

Cortical Ribbon Sign in Acute Hepatic Encephalopathy with Sequential Atrophy.

A 59-year-old man presented with confusion, decreased level of consciousness, and generalized tonic-clonic seizures. He was intubated and promptly stabilized on antiepileptic medications. He was not in status epilepticus. He improved after seizure control, though he remained confused. He was neither acutely intoxicated nor were there any substance withdrawal concerns prior to his presentation. Furthermore, no metabolic, electrolyte, or nutritional perturbations were identified. He did, however, have a history of alcoholic hepatitis and was awaiting a liver transplant, but his blood work did not reveal evidence of fulminant hepatic failure at presentation (international normalized ratio - 1.17, platelet count 161,000/µL, ammonia 18 µmol/L, blood urea nitrogen 4.5 mmol/L, and his liver enzymes were only remarkable for an elevated alkaline phosphatase of 143 U/L).