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.

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.

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.

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.