A case report of thrombocytopenic COVID-19 and Miller-Fisher syndrome on a concurrent chronic immune neuropathy.

RATIONALE: Miller-Fisher syndrome (MFS) is a rare subtype of Guillain-Barre syndrome with classic features of ataxia, areflexia, and ophthalmoplegia that can be caused by a preceding infection including COVID-19. We present a current, asymptomatic thrombocytopenic COVID-19 infection as a cause of MFS in a 60-year-old male with a concurrent chronic immune neuropathy. PATIENT CONCERNS: A 60-year-old male presenting with acute symptoms of MFS including ataxia, areflexia, and ophthalmoplegia on a chronic immune neuropathy for at least 1 year and concurrent asymptomatic COVID-19 positive infection. DIAGNOSIS: MFS suspected secondary to a current thrombocytopenic COVID-19 infection. INTERVENTIONS: Five days of intravenous immune globulin with continued monthly intravenous immune globulin as an outpatient, follow-up long-term in a neuromuscular clinic, electromyography as an outpatient, and continued physical therapy. OUTCOMES: The patient significantly improved after initial treatment. LESSONS: The full effect of COVID-19 on the various Guillain-Barre syndrome subtypes is unknown, although it clearly can be a cause of the various variants including being caused by a current, asymptomatic infection.

COVID-19 and MOG-IgG-associated acquired demyelinating polyneuropathy compatible with chronic inflammatory demyelinating polyneuropathy in a previously healthy girl.

Neurological manifestations of COVID-19 in the pediatric population are not as well described as those in the adult population. We describe a case of myelin oligodendrocyte glycoprotein immunoglobulin G (MOG-IgG)-associated disorder in a 9-year-old girl, who experienced complete recovery. This rare disorder is a demyelinating disease that often relapses and has the potential to cause severe morbidity. The case highlights the need for early recognition of asymptomatic and subacute presentations of demyelinating disorders and testing for MOG-IgG antibodies, as the management of presumed monophasic demyelinating disorders vs MOG-IgG-positive demyelinating disorder is different.

Postinfectious SARS-CoV-2 Opsoclonus-Myoclonus-Ataxia Syndrome.

BACKGROUND: The opsoclonus-myoclonus-ataxia syndrome (OMAS) represents a pathophysiology and diagnostic challenge. Although the diverse etiologies likely share a common mechanism to generate ocular, trunk, and limb movements, the underlying cause may be a paraneoplastic syndrome, as the first sign of cancer, or may be a postinfectious complication, and thus, the outcome depends on identifying the trigger mechanism. A recent hypothesis suggests increased GABAA receptor sensitivity in the olivary-oculomotor vermis-fastigial nucleus-premotor saccade burst neuron circuit in the brainstem. Therefore, OMAS management will focus on immunosuppression and modulation of GABAA hypersensitivity with benzodiazepines. METHODS: We serially video recorded the eye movements at the bedside of 1 patient with SARS-CoV-2-specific Immunoglobulin G (IgG) serum antibodies, but twice-negative nasopharyngeal reverse transcription polymerase chain reaction (RT-PCR). We tested cerebrospinal fluid (CSF), serum, and nasopharyngeal samples. After brain MRI and chest, abdomen, and pelvis CT scans, we treated our patient with clonazepam and high-dose Solu-MEDROL, followed by a rituximab infusion after her formal eye movement analysis 10 days later. RESULTS: The recordings throughout her acute illness demonstrated different eye movement abnormalities. While on high-dose steroids and clonazepam, she initially had macrosaccadic oscillations, followed by brief ocular flutter during convergence the next day; after 10 days, she had bursts of opsoclonus during scotopic conditions with fixation block but otherwise normal eye movements. Concern for a suboptimal response to high-dose Solu-MEDROL motivated an infusion of rituximab, which induced remission. An investigation for a paraneoplastic etiology was negative. CSF testing showed elevated neuron-specific enolase. Serum IgG to Serum SARS-CoV2 IgG was elevated with negative RT-PCR nasopharyngeal testing. CONCLUSION: A recent simulation model of macrosaccadic oscillations and OMAS proposes a combined pathology of brainstem and cerebellar because of increased GABAA receptor sensitivity. In this case report, we report 1 patient with elevated CSF neuronal specific enolase, macrosaccadic oscillations, ocular flutter, and OMAS as a SARS-CoV-2 postinfectious complication. Opsoclonus emerged predominantly with fixation block and suppressed with fixation, providing support to modern theories on the mechanism responsible for these ocular oscillations involving cerebellar-brainstem pathogenesis.

Visual, Ocular Motor, and Cochleo-Vestibular Loss in Patients With Heteroplasmic, Maternally-Inherited Diabetes Mellitus and Deafness (MIDD), 3243 Transfer RNA Mutation.

BACKGROUND: Mitochondrial encephalopathy, lactic acidosis, and stroke-like symptoms (MELAS) and MIDD (maternally-inherited diabetes mellitus and deafness) are caused by A3243G transfer RNA mutations that affect mitochondrial function. Hearing loss and early onset diabetes mellitus constitute the main MIDD phenotype. Regarding the ophthalmologic manifestations of MIDD, we hypothesized that decreased vestibulo-ocular reflex (VOR) gain in patients with MIDD may contribute to impaired dynamic visual acuity. METHODS: Neuro-ophthalmologic, neuroimaging, and neuro-otologic evaluations were performed in 2 nonrelated patients with MIDD who complained of oscillopsia with head movement. We obtained quantitative recording of the horizontal and the vertical VOR, using the video head impulse test device. RESULTS: In the 2 patients, we detected visual, ocular motor, and vestibular abnormalities. Decreased VOR gain in the planes of all 3 semicircular canals and impaired dynamic visual acuity was demonstrated in both cases. CONCLUSIONS: MIDD patients are primarily recognized by their advanced hearing loss or deafness, early onset diabetes mellitus, and lactic acidosis. Decreased vision in these patients relates primarily to peri-macular retinal atrophy. In addition, loss of vestibular function causes poor dynamic visual acuity. Both patients, in their late fifties, had evidence of progressive central and peripheral nervous system dysfunction.