Síndrome de Sjögren primario que debuta con polimiositis mitocondrial, neuropatía axonal y parálisis hipopotasémica: reporte de caso / Onset of primary Sjögren syndrome with mitochondrial polymyositis, axonal neuropathy, and hypokalaemic paralysis: Case report

RESUMEN El síndrome de Sjögren es una entidad multisistémica de naturaleza autoinmune, clásicamente considerada una exocrinopatía debido a la alta frecuencia de síntomas secos (queratoconjuntivitis seca, xerostomía) como resultado de infiltración poliglandular por linfocitos autorreactivos. Sin embargo, menos del 10% de estos pacientes puede iniciar con manifestaciones extraglandulares severas, traducidas en peores desenlaces a largo plazo. Se presenta el caso de una gestante que inició con síndrome de debilidad aguda proximal relacionada con miositis con enfermedad mitocondrial e hipopotasemia severa, en el contexto de acidosis tubular renal distal, como manifestación extraglandular de síndrome de Sjögren primario. Se discuten brevemente manifestaciones neurológicas de esta entidad, incluyendo aquellas secundarias a trastornos metabólicos precipitados por compromiso autoinmune.

ABSTRACT Sjögren's syndrome is a multisystemic autoimmune disorder. It is classically considered as an exocrine disease, given the high frequency of dry symptoms (keratoconjunctivitis sicca, xerostomia) as a result of poly-glandular infiltration by autoreactive lymphocytes. However, less than 10% of these patients can onset with severe extra-glandular manifestations, resulting in worse long-term outcomes. The case of a pregnant woman is presented, who debuted with acute proximal weakness syndrome related to myositis with mitochondrial pathology and severe hypokalaemia in the context of distal renal tubular acidosis, as an extra-glandular manifestation of primary Sjögren's syndrome. Neurological manifestations of this condition are briefly discussed, including those secondary to metabolic disorders precipitated by autoimmune compromise.

[Hypokalemic periodic paralysis. A case report]. / Parálisis periódica hipopotasémica. A propósito de un caso.

Periodic paralysis is a rare disorder that causes episodes of severe muscle weakness that can be confused with other diseases, including epilepsy or myasthenia gravis. Hyperkalemic and hypokalemic paralysis are included within these diseases, the latter being divided into periodic paralysis (familial, thyrotoxic or sporadic) and non-periodic paralysis. In this regard, we present a case of familial hypokalemic periodic paralysis in an eighteen year-old female who was diagnosed with epilepsy in childhood, as well as a subclinical hypothyroidism (for which she received replacement therapy) months ago. The diagnosis was made by the anamnesis and the confirmation of hypokalemia.