Application of the international criteria for optic neuritis in the Acute Optic Neuritis Network.

OBJECTIVE: The first international consensus criteria for optic neuritis (ICON) were published in 2022. We applied these criteria to a prospective, global observational study of acute optic neuritis (ON). METHODS: We included 160 patients with a first-ever acute ON suggestive of a demyelinating CNS disease from the Acute Optic Neuritis Network (ACON). We applied the 2022 ICON to all participants and subsequently adjusted the ICON by replacing a missing relative afferent pupillary defect (RAPD) or dyschromatopsia if magnetic resonance imaging pathology of the optical nerve plus optical coherence tomography abnormalities or certain biomarkers are present. RESULTS: According to the 2022 ICON, 80 (50%) patients were classified as definite ON, 12 (7%) patients were classified as possible ON, and 68 (43%) as not ON (NON). The main reasons for classification as NON were absent RAPD (52 patients, 76%) or dyschromatopsia (49 patients, 72%). Distribution of underlying ON etiologies was as follows: 78 (49%) patients had a single isolated ON, 41 (26%) patients were diagnosed with multiple sclerosis, 25 (16%) patients with myelin oligodendrocyte glycoprotein antibody-associated disease, and 15 (9%) with neuromyelitis optica spectrum disorder. The application of the adjusted ON criteria yielded a higher proportion of patients classified as ON (126 patients, 79%). INTERPRETATION: According to the 2022 ICON, almost half of the included patients in ACON did not fulfill the requirements for classification of definite or possible ON, particularly due to missing RAPD and dyschromatopsia. Thorough RAPD examination and formal color vision testing are critical to the application of the 2022 ICON.

"Sitting-up vertigo as an expression of posterior semicircular canal heavy cupula and posterior semicircular canal short arm canalolithiasis".

Background: Vestibular symptoms on sitting-up are frequent on patients seen by vestibular specialists. Recently, a benign paroxysmal positional vertigo (BPPV) variant which elicits vestibular symptoms with oculomotor evidence of posterior semicircular canal (P-SCC) cupula stimulation on sitting-up was described and named sitting-up vertigo BPPV. A periampullar restricted P-SCC canalolithiasis was proposed as a causal mechanism. Objective: To describe new mechanisms of action for the sitting-up vertigo BPPV variant. Methods: Eighteen patients with sitting-up vertigo BPPV were examined with a pre-established set of positional maneuvers and follow-up until they resolved their symptoms and clinical findings. Results: All patients showed up-beating torsional nystagmus (UBTN) and vestibular symptoms on coming up from either Dix-Hallpike (DHM) or straight head-hanging maneuver. Sixteen out of 18 patients presented a sustained UBTN with an ipsitorsional component to the tested side on half-Hallpike maneuver (HH). A slower persistent contratorsional down-beating nystagmus was found in eleven out 18 patients tested on nose down position (ND). Conclusions: Persistent direction changing positional nystagmus on HH and ND positions indicative of P-SCC heavy cupula was found in 11 patients. A sustained UBTN on HH with the absence of findings on ND, which is suggestive of the presence of P-SCC short arm canalolithiasis, was found on 5 patients. All patients were treated with canalith repositioning maneuvers without success, but they resolved their findings by means of Brandt-Daroff exercises. We propose P-SCC heavy cupula and P-SCC short arm canalolithiasis as two new putative mechanisms for the sitting-up vertigo BPPV variant.

Sitting Up Vertigo. Proposed Variant of Posterior Canal Benign Paroxysmal Positional Vertigo.

OBJECTIVE: To describe a variant of posterior canal benign paroxysmal positional vertigo (BPPV). STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Fifteen patients with symptoms of BPPV and oculomotor evidence of activation of posterior semicircular canal (P-SCC) cupula that arises when sitting up from Dix-Hallpike maneuver (DH). INTERVENTION: All patients were examined with videonystagmography and underwent brain magnetic resonance imaging (MRI). RESULTS: All patients showed up-beating nystagmus with ipsilateral torsional component when coming up from right or left side DH. Most patients described vertiginous symptoms when sitting up from bed and many described severe non-positional disequilibrium. Eight patients had been treated with Epley canalith repositioning maneuver (CRM) at our clinic for posterior canal BPPV. Four of them were re-tested within an hour for CRM effectiveness and the rest, a week later. Three patients had been diagnosed with BPPV and were being treated with CRM in other institutions. Four patients showed these findings but they had not previously undergone CRM. All patients were treated with CRM without success, but they resolved their positional vertigo by means of Brandt Daroff exercises. No patient showed evidence of central vestibular disorder. CONCLUSION: We propose a P-SCC canalolithiasis limited to the periampullar portion by means of an anatomical restriction of distal movement of the otoconial debris. This syndrome seems to be more frequent early after CRM of classical P-SCC canalolithiasis. Close attention to ocular movement on sitting up after DH on patients is warranted.

Subjective visual vertical in Pisa syndrome.

BACKGROUND: Parkinson's Disease (PD) alters perception and somatosensory information integration, including visual dependency and judgment of body position in space. PD may be associated with Pisa syndrome (PS), a lateral deviation of the longitudinal body axis (LBA) of unknown origin. We tested whether this inclination is associated with an altered perception of the subjective visual vertical (SVV) and if these alterations are secondary effects of the LBA deviation or of a primary perceptual dysfunction. Furthermore, we investigated the contribution of different sensory modalities and dopaminergic medication. METHODS: Seventeen PD patients (8 with PS, 9 without PS) and 18 healthy controls were tested. The SVV was assessed in a seated, in a lateral horizontal and - in PS patients - in a seated manually rectified position. Frame and moving-stimulus-patterns were used to test visual dependency. In PD and PS patients all trials were conducted in dopaminergic "on" and "off". RESULTS: When seated, SVV values on PD in "on" and PS in "on" and "off" differed significantly from controls. This difference remained in PS patients after manual rectification in "off". The SVV in a lateral horizontal position was not significantly different between the three groups. When inclined, visual dependency was higher in PD "off" than in controls. DISCUSSION: Both PS and PD patients showed SVV deviations compared to healthy controls. These cannot be explained by their intrinsic lateral deviation in PS patients. They must be secondary to either a primary perceptual dysfunction or alterations of internal models of verticality due to re-weighting of perceptual afferences.

Atypical imaging findings in a renal transplant patient with reversible posterior leukoencephalopathy syndrome: a case report.

BACKGROUND: Atypical clinical and imaging findings in Reversible Posterior Leukoencephalopathy Syndrome are recognized with increasing frequency. CASE REPORT: We report a case of an adult in his 5(th )decade immunosupressed with methilprednisolone, tacrolimus and micophenolate who two months after renal transplantation, multiple infections and an episode of humoral rejection became hypertensive with severe headaches, visual field abnormalities, seizures, left hemiparesis and hemineglect. Computed Tomography scan of the brain showed a hypo dense lesion in the left occipital lobe. Ischemic stroke was diagnosed and aspirin and permissive hypertension were indicated. Twelve hours later he developed left sided motor seizures and cortical blindness. Magnetic Resonance Image showed hyper intensity in T2 and FLAIR in both occipital lobes and a small area of cortical restricted diffusion in Diffuson Weighted Images in the left occipital lobe. With a diagnosis of Reversible Posterior Leukoencephalopathy Syndrome his blood pressure was controlled with intravenous labetalol, and two days later the neurologic findings returned to baseline and most Computed tomography findings resolved. CONCLUSION: This case underscores that in the appropriate setting Reversible Posterior Leukoencephalopathy Syndrome should be suspected and the clinician should not be misled by atypical clinical or imaging findings. In contrast to other pathologies that resemble Reversible Posterior Leukoencephalopathy Syndrome, with the right and timely treatment, signs, symptoms and images can be completely reversible.