Parálisis de Bell y dolor facial asociados con infección por Toxocara sp / Bell's palsy and facial pain associated with toxocara infection

Objectives: Toxocarosis involving cranial nerves is extremely rare and almost exclusively concerns the optic nerve. Toxocarosis involving the seventh cranial nerve has not been reported. Case report: A 33y male developed left-sided Bell's palsy two days after left-sided otalgia 6y before. Despite extensive diagnostic work-up at that time the cause of Bell's palsy remained unknown. During the following years Bell's palsy slightly improved but retromandibular pain remained almost unchanged and he developed enlarged lymph nodes along the jugular veins, submandibularly, and in the trigonum caroticum. Re-evaluation 6y later revealed an increased titer of serum antibodies against Toxocara canis and a positive Westernblot for Toxocara canis ES-antigen. Despite absent eosinophilia in the serum, toxocarosis was diagnosed and a therapy with albendazole initiated, with benefit for retromandibular pain, but hardly for Bell's palsy or enlarged lymph nodes. CSF investigations after albendazole revealed a positive Westernblot for antibodies against toxocara but absent pleocytosis or eosinophilia, and negative PCR for Toxocara canis. Conclusions: Visceral larva migrans due to Toxocara canis may be associated with Bell's palsy, retromandibular pain, and lymphadenopathy. A causal relation between Bell's palsy and the helminthosis remains speculative. Adequate therapy years after onset of the infestation may be of limited benefit.

Objetivos: La toxocarosis que compromete los nervios craneales es extremadamente infrecuente y afecta casi exclusivamente al nervio óptico. No ha sido comunicada la toxocarosis que afecte al séptimo nervio cranial por lo que se expone un caso clínico. Caso clínico: Varón de 33 años que había presentado seis años antes, una otalgia izquierda seguida dos días más tarde de una parálisis de Bell ipsilateral. A pesar de un exhaustivo estudio, la causa de esta parálisis quedó sin etiología. En los años siguientes la parálisis mejoró moderadamente pero persistió un dolor retromandibular casi sin variaciones y el paciente desarrolló adenopatías en la cadena yugular, submandi-bulares y en el triángulo carotídeo. Una re-evaluación efectuada seis años más tarde detectó un título elevado de anticuerpos contra Toxocara canis y un antígeno ES de T. canis positivo mediante Westernblot. A pesar de no haber eosinofilia en la sangre, se diagnosticó una toxoca-rosis iniciándose terapia con albendazol, con lo cual se observó una reducción del dolor retro-mandibular aunque escaso beneficio sobre la parálisis de Bell y los ganglios comprometidos. El líquido cefalorraquídeo analizado después de haberse efectuado la cura con albendazol reveló un test de Westernblot positivo para anticuerpos anti-toxocara, en ausencia de pleocitosis o eosinofilia, y una RPC para Toxocara canis negativa. Conclusiones: El síndrome de larva migrans visceral debido a T. canis puede asociarse con parálisis de Bell, dolor retroman-dibular y linfoadenopatías. La relación causal entre la parálisis de Bell y la helmintosis permanece en el plano especulativo. La terapia anti-parasitaria realizada años tras la instalación de una infestación puede tener un beneficio aunque limitado.

Neurotoxocariasis associated with lower motor neuron disease: report of one case / Neurotoxocariasis asociada a enfermedad de motoneurona inferior: presentación de un caso

We report a 51-year-old male with a history of palpitations, hepatopathy and hypercholesterolemia, who habitually ate raw goat meat, and developed general fasciculations, muscle cramps in the lower limbs, distal muscle weakness and wasting, without upper motor neuron signs or sensory abnormalities. Diagnostic workup revealed positive antibodies against Toxocara canis in the serum and cerebrospinal fuid. Nerve conduction studies revealed a proximal and distal axonal lesion of motor nerves and needle electromyography was indicative of acute and chronic denervation with giant motor unit action potentials. Despite a therapy with albendazole and riluzole, muscle weakness and wasting further progressed and affected also the respiratory muscles. Followup nerve conduction studies and electromyography confrmed progression of the axonal degeneration. Whether lower motor neuron disease was causally related to neurotoxocariasis or due to a general metabolic defect, remains speculative.

Presentamos un hombre de 51 años con una historia de palpitaciones, hepatopatía e hipercolesterolemia que comía habitualmente carne de cabra cruda, que desarrolló un cuadro caracterizado por fasciculaciones generalizadas, calambres musculares en las extremidades inferiores, pérdida de fuerza y atrofa muscular distal, sin signos de lesión de motoneurona superior o alteraciones sensitivas. El laboratorio mostró anticuerpos anti Toxocara canis en suero y líquido cefalorraquídeo. La electromiografía mostró una lesión axonal proximal y distal de nervios motores y denervación con potenciales de acción gigantes en las unidades motoras. A pesar de tratarse con albendazol y riluzona, la debilidad muscular y atrofa continuaron progresando. Una nueva electromiografía confrmó la progresión de la degeneración axonal. La asociación entre esta enfermedad de motoneurona inferior y la neurotoxocariasis, es especulativa.

Neurotoxocarosis

Infection of humans with embryonated eggs of Toxocara canis (larva migrans) remains asymptomatic, or results in covert or common toxocarosis, visceral larva migrans syndrome, or ophthalmologic and neurologic impairment. Though neurological manifestations of Toxocara canis larvae are rare, toxocarosis remains an important differential diagnosis of various neurological disorders. Manifestations of the central nervous system are dementia, meningo-encephalitis, myelitis, cerebral vasculitis, epilepsy, or optic neuritis. Manifestations of the peripheral nervous system comprise radiculitis, affection of cranial nerves, or musculo-skeletal involvement. If toxocarosis is neglected, ignored, or refused as a differential of these abnormalities, it may be easily overlooked for years. Early recognition and treatment of the infection is, however, of paramount importance since it reduces morbidity and mortality and the risk of secondary superinfection. Like the visceral manifestations, neurological manifestations of toxocarosis are treated by benzimidazole components, most frequently albendazole, corticosteroids, or diethylcarbamazine. If detected and treated early, the prognosis of neurological manifestations of toxocarosis is favourable.

Infecção humana com ovos embrionados de Toxocara canis (larva migrans) pode permanecer assintomática ou resultar em toxocaríase acentuada ou comum, síndrome da larva migrans visceral ou manifestações neurológicas ou oftalmológicas. Embora manifestações neurológicas das larvas de Toxocara canis sejam raras, a toxocaríase permanece como importante diagnóstico diferencial de várias manifestações neurológicas. Manifestações do sistema nervoso central são demência, meningoencefalite, mielite, vasculite cerebral, epilepsia, ou neurite ótica. Manifestações do sistema nervoso periférico compreendem radiculite, agressão de nervos cranianos ou envolvimento músculo-esquelético. Se a toxocaríase é negligenciada, ignorada, ou recusada como diferencial destas anormalidades, ela pode ser facilmente desapercebida por anos. Reconhecimento precoce de tratamento da infecção é portanto de fundamental importância uma vez que reduz sua morbidade e mortalidade e o risco de superinfecção secundária. Da mesma maneira que as manifestações viscerais, as neurológicas são tratadas por benzimidazólicos, mais freqüentemente albendazole, corticosteróides ou dietilcarbamazine. Se detectado e tratado precocemente, o prognóstico das manifestações neurológicas da toxocaríase é favorável.