Francisco Varela

Low familial risks for multiple sclerosis in Buenos Aires, Argentina.

BACKGROUND Multiple sclerosis is a complex disease in which genetic susceptibility plays a role and familial occurrence has long been recognized. To date, no studies of familial occurrence have been conducted in Argentina, a country with low to intermediate prevalence. METHODS As part of a cross-sectional study on multiple sclerosis in Buenos Aires, immediate and extended pedigree details were collected on 219 patients. Crude and age-adjusted recurrence risks for patient relatives were also assessed. RESULTS Details on age or age of death and disease status were obtained for 4227 relatives. Ten percent of patients reported at least one relative with MS diagnosis, the highest risk (1.54%) was observed in daughters of patients who presented 92-times greater risk than the general population. Sibling recurrence risk ratio was similar to that reported in other locations. CONCLUSIONS Relatives of patients with MS living in Argentina are at greater risk of developing the disease, although not as high as the risk reported for other geographic regions.

Autoimmune disease prevalence in a multiple sclerosis cohort in Argentina.

Background. Comorbid autoimmune diseases in MS patients have been studied extensively with controversial results. Moreover, no such data exists for Latin-American MS patients. Methods. We conducted a case-control study aimed to establish the prevalence of autoimmune disorders in a cohort of Argentinean MS patients. Results. There were no significant differences in autoimmune disease prevalence in MS patients with respect to controls. The presence of one or more autoimmune disorders did not increase risk of MS (OR 0.85, 95% CI 0.6–1.3). Discussion. Our results indicate absence of increased comorbid autoimmune disease prevalence in MS patients, as well as of increased risk of MS in patients suffering from other autoimmune disorders.

Cerebellar Ataxia With Extreme Photophobia Associated With Anti-SOX1 Antibodies

Anti-SOX1 antibodies are associated with diverse neurological syndromes, targeting both the central (paraneoplastic cerebellar degeneration) and peripheral nervous systems (Lambert Eaton myasthenic syndrome, paraneoplastic neuropathy). Although the pathogenic role of these antibodies remains unclear, their strong association with underlying neoplastic disease (mainly small-cell lung cancer) has designated them as onconeural antibodies. Here, we present a case of cerebellar ataxia with marked photophobia, with severe atrophy of the cerebellum and brain stem, associated with anti-SOX1 antibodies without evidence of an underlying malignancy. Although anti-SOX1-associated cerebellar syndrome is infrequent, investigation of these antibodies should be considered as a part of the diagnostic algorithm if more common causes have been ruled out. Extensive brain stem lesions causing disruption of the trigeminal pathway and its connections with the pretectal area might explain the underlying mechanism of the associated photophobia. Early recognition of anti-SOX1 antibodies, exclusion of underlying neoplasm, and prompt initiation of immunotherapy are essential to achieve a better outcome.

Pupillary Disorders in the Emergency Room: Lupinus mutabilis Intoxication

Lupinus mutabilis (LM) is a widespread species of lupin whose bean is consumed not only for its high caloric value but also as a homeopathic medicine, used for a diverse range of presumed clinical properties, including as an analgesic and an antidiabetic. The properties of lupine alkaloids are responsible for their anticholinergic toxicity in both the autonomic nervous system and the central nervous system (CNS). As this syndrome may vary in severity, lupinus toxicity should be suspected in patients with isolated symptoms as well, such as hyporeactive mydriasis. We present a case of a 48-year-old male patient presented to emergency department complaining about blurred vision, dizziness and palpitations. Physical examination only reveal hyporeactive mydriasis. Urine drug screening was negative and labs were otherwise within normal ranges. Brain Computed Tomography did not identify any abnormality. During the examination patient admitted that he was taking homeopathic medication for his osteoarthritis pain that contains high amounts of LM. He received hydration with parenteral saline while maintaining an adequate diuretic rhythm. Twelve hours later, his mydriasis had completely resolved. Clinicians should consider the possibility of LM toxicity in cases of pupillary abnormalities without any clear alternative explanation.