Toxocara Canis Myelitis

Abstract

Toxocara myelitis is a rare disease. Few cases have been reported in the literature. Patients present with myelopathy, occasional eosinophilia in blood and cerebrospinal fluid (CSF), with abnormal signals on magnetic resonance imaging (MRI). In the current study we report 17 cases of isolated Toxocara myelitis from a single tertiary referral center in Lebanon, with description of the clinical presentation, laboratory data, MRI findings, and response to antihelminthic treatment. Clinical and laboratory data were collected for 17 patients who presented with evidence of spinal cord disease. The clinical presentation included sensory, motor, and autonomic dysfunction, predominantly in the lower extremities. Patients exhibited a subacute or chronic course; this was either slowly progressive or remitting-relapsing with mild to moderate disability. The patients underwent extensive blood and CSF workup as well as MRI of the spinal cord and brain. Only 2 patients had a high eosinophil count in the CSF, although blood eosinophilia was seen in 6 patients. All patients tested positive for Toxocara canis antibodies in the blood and CSF. MRI of the spinal cord revealed a single characteristic lesion in the spinal cord with fusiform enlargement that was isointense on T1-weighted images and hyperintense on T2-weighted images. Nodular enhancement was seen after gadolinium injection. Treatment with albendazole, with or without steroids, resulted in marked neurologic improvement and normalization of the MRI in all patients.The finding of a single inflammatory MRI lesion in the spinal cord with positive Toxocara canis serology in the blood and CSF in cases of subacute or chronic myelitis suggests the diagnosis of Toxocara myelitis, irrespective of the presence of eosinophilia. Antihelminthic treatment is associated with a good outcome.

Cerebral Toxocariasis: Silent Progression to Neurodegenerative Disorders?

“…larvae in neural tissues, thus supporting a tentative diagnosis of NT (134)(135)(136)(137). In fact, the more sensitive MRI method can reveal granulomas as hyperintensities on T2-weighted MRI sequences, located mainly cortically or subcortically in brain areas (134,137,138).…”

“…larvae in neural tissues (134)(135)(136)(137)(138). MRI images of the brain may show clearly defined, multifocal lesions with strong contrast enhancement or, for persistent infections, both diffuse and circumscribed changes, but these are nonspecific findings.…”

“…It was noted that the center of one occipital lobe lesion was hyperattenuating on computed tomography scans and hyperintense on both T1-and T2-weighted MRI images, which was suggestive of microhemorrhages or cortical necrosis due to cerebral infarction. Granulomas on the initial MRI also showed strong homogeneous enhancement, possibly due to a localized disruption of the blood-brain barrier (BBB) as a result of inflammation (118,135,138).…”

CLINICAL, IMAGING, AND PATHOLOGIC CHARACTERISTICS OF GURLTIA PARALYSANS MYELOPATHY IN DOMESTIC CATS FROM CHILE

“…Probably, the addition of other MRI sequences will improve the sensitivity. Characteristics of neurohelminthiasis in previous canine and human case studies also included focal to generalized enlargement of the spinal cord and diffuse to nodular T2W hyperintense lesions consistent with areas of edema, hemorrhage, slow venous flow, thrombosed veins, gliosis, and parasitic migration tracts . Myelitis resulting from toxoplasma in cats has also manifested as segmental enlargement of the spinal cord and irregular hyperintensity in T2‐weighted images of the spinal cord .…”

Signal Transducer and Activator of Transcription Factor 6 Signaling Contributes to Control Host Lung Pathology but Favors Susceptibility againstToxocara canisInfection

“…Toxocariasis in humans results from accidental ingestion of Toxocara- embryonated eggs from excreta in the environment or by direct dog-to-person contact [6, 7]. Although larvae in muscle may be relatively symptom less, those in brain may cause serious neurological disorders [8]; these symptoms are believed to result from inflammation following degeneration of the parasite [9]. …”