Susceptibility-weighted imaging is helpful in diagnosis of cerebral gnathostomiasis.

PURPOSE: To describe the role of SWI compared with other MR imaging sequences and CT in diagnosis of cerebral gnathostomiasis. MATERIALS AND METHODS: CTs and MRIs of patients with cerebral gnathostomiasis were retrospectively reviewed. The types of intracranial hemorrhage, including intraparenchymal hemorrhage (IPH), subdural hemorrhage (SDH), subarachnoid hemorrhage (SAH), and their locations were recorded. RESULTS: Four patients proven as cerebral gnathostomiasis were included. Intracranial hemorrhage was detected in all patients. There was IPH in all patients, SAH in 2 patients, and SDH in 2 patients. All patients (4/4) revealed hemorrhagic tracts which were very conspicuously seen on SWI. Other imaging sequences could also reveal hemorrhagic tracts in 3 patients (3/4) but are less conspicuously seen than SWI. None of the CT brains could detect hemorrhagic tracts. CONCLUSIONS: Intracranial hemorrhage associated with hemorrhagic tract, best demonstrated by SWI, is the key imaging characteristic in diagnosis of cerebral gnathostomiasis.

An Unusual Case of Gastric Gnathostomiasis Caused by Gnathostoma spinigerum Confirmed by Video Gastroscopy and Morphological and Molecular Identification.

Human gnathostomiasis is a harmful foodborne parasitic infection caused by nematodes of the genus Gnathostoma. Here, we report an unusual case of gastric gnathostomiasis seen in a hospital in Thailand along with the clinical characteristics, treatment, and outcome. A 39-year-old man presented with complaints of epigastric pain, dizziness, and history of passing dark, tarry stools for 2 days. The patient had a history of consuming raw freshwater fish. Supplementary differential diagnosis was performed via rapid serological testing, and presence of the causative agent was confirmed based on video gastroscopy, morphology of the removed parasite, and molecular identification. After its surgical removal from the stomach, the parasite was morphologically identified as Gnathostoma species. Molecular identification was performed via DNA extraction from the recovered worm, and amplification and sequencing of the second internal transcribed spacer (ITS2) region and partial cytochrome c oxidase subunit I (cox1) gene. The ITS2 and cox1 sequences were consistent with those of Gnathostoma spinigerum. Clinicians in endemic areas should therefore be aware of the rare clinical manifestations and use of supplementary serological tests to facilitate early diagnosis and treatment of gastric gnathostomiasis.

Case Report: The First Direct Evidence of Gnathostoma spinigerum Migration through Human Lung.

Gnathostomiasis is a helminthic infection caused by the third-stage larvae of nematodes of the genus Gnathostoma. The life cycle in humans starts with an enteric phase, with the worm perforating the gastric or intestinal mucosa to reach the peritoneal cavity and migrating through the human body. Subsequent penetration through the diaphragm may produce pleuropulmonary symptoms. We herein present a previously healthy 56-year-old Thai man from Southern Thailand who was an ex-smoker presented with chronic dry cough progressing to hemoptysis after consuming grilled swamp eels and freshwater fish. Chest computed tomography showed consolidation at the lingular segment, and the differential diagnosis was primary lung cancer and pulmonary tuberculosis. The lung tissue biopsied during bronchoscopy displayed segments of organisms with the phenotypic characteristics of Gnathostoma spp., and abundant eosinophils were seen in the alveolar tissue. Gnathostoma spinigerum infection was confirmed by a Western blot assay for G. spinigerum-specific 24-kDa reactive band. The patient received albendazole, and a follow-up chest radiograph revealed improvement in the consolidation in the lung and reduction in hemoptysis. We report the first direct evidence including pathology and immunohistochemistry of Gnathostoma invasion via the human lung, with clinical and radiographic presentations mimicking either malignancy or chronic infection.

Case Report: Ocular Gnathostomiasis in Venezuela Most Likely Acquired in Texas.

A 69-year-old male dentist in Caracas, Venezuela, was referred to our Cornea Clinic with a history of pain, photophobia, and blurred vision on his left eye. Routine biomicroscopic examination with a slit lamp showed a worm in the corneal stroma of his left eye. The worm was surgically removed and was identified morphologically as Gnathostoma binucleatum.

Thoracic Myelopathy Due to Gnathostomiasis Acquired in New Zealand.

Gnathostomiasis is a zoonotic disease endemic in Asia. It most commonly manifests as gastrointestinal and cutaneous disease. Central nervous system involvement is a rare but feared complication, often leaving patients with permanent neurologic deficits. Clinicians outside of Asia and Latin America may have little experience with this illness, causing delays in diagnosis and treatment. We describe a 40-year-old woman who developed a progressive myelopathy over 18 months. She had never traveled outside of New Zealand. Cerebrospinal fluid (CSF) showed marked eosinophilia and Gnathostoma serology was positive in both serum and CSF. This is the first report of gnathostomiasis acquired in New Zealand, and the first case of neurognathostomiasis reported outside Asia. Clinicians should include neurognathostomiasis in the differential diagnosis of myelopathy and CSF eosinophilia, even if there is no history of travel to endemic areas.

Spinal Gnathostomiasis: A Case Report with Magnetic Resonance Imaging and Electrophysiological Findings.

Background: Spinal gnathostomiasis results in serious multiorgan impairments. Magnetic resonance imaging (MRI) and serology help in diagnosis, and assessing the severity and extent of the disease. However, the physiology of neural pathway could not be demonstrated. Electrodiagnosis may have a role in demonstrating the functions of the central and peripheral neural pathways and prognostic assessment of the disease. Material and Method: An 18-year-old man presented with radicular pain and rapid progressive weakness of lower extremities, leading to paraplegia in three days. A clinical evaluation and laboratory tests, including serology, MRI, and electrodiagnosis, were performed. Results: The investigation showed L1 paraplegia with urinary retention. The serial MRI of T-spine showed longitudinal T2 hypointense lesion along the lower thoracic spinal cord, representing track-like hemorrhage with spinal cord edema at the onset of symptoms, nodular enhancement of T11-T12 spinal cord, and enhancing and clumping of cauda equina nerve roots in the MRI at two months after the first MRI. The CSF and serum for Gnathostoma antibody were positive. Intravenous corticosteroid and oral albendazole were given. Three months after treatment, the symptoms improved in sensation but not in motor function. The electrodiagnosis was performed. There were very small amplitudes and no response in bilateral tibial and peroneal motor nerve conduction studies (NCS) respectively. The bilateral sural sensory NCS were normal. Neither tibial somato-sensory evoke potentials (SSEP) nor motor evoke potential (MEP) was recorded. No further improvement of patient's clinical status at eight months after onset was observed. Conclusion: Electrophysiological findings demonstrated the function of spinal cord and peripheral nerves in the patient with spinal gnathostomiasis. There were correlations between MRI and electrophysiological findings that confirmed pathophysiology of the disease. Absence of SSEP and MEP response correlated with poor neurological outcomes in radiculomyelitis caused by Gnathostoma spp. infection.