Cerebral sparganosis diagnosed and treated with stereotactic techniques. Report of two cases

Epidemiology, Diagnosis, and Prevention of Sparganosis in Asia

Sparganosis is a zoonotic parasitic disease caused by the larvae (spargana) of the genus Spirometra, which is widely distributed globally and threatens human health. More than 60 species of Spirometra have already been identified, and over 2000 cases have been reported. This review summarizes the prevalence of humans, frogs, snakes, and other animals with spargana. Furthermore, the infection mode, distribution, and site are summarized and analyzed. We also describe the epidemiology, molecular diagnosis, and other aspects which are of considerable significance to preventing sparganum.

Surgical treatment of a patient with live intracranial sparganosis for 17 years

Background

The incidence of sparganosis, especially intracranial live sparganosis is very low in China. Due to the lack of typical clinical manifestations, it is difficult to make a clear preoperative diagnosis of the disease, which often leads to delays the disease and serious consequences.

Case presentation

A 23-year-old man presented with a 17-year history of intermittent seizures and right extremity numbness and weakness. Magnetic resonance imaging (MRI) showed patchy, nodular and line-like enhancement. Enzyme-linked immunosorbent assay (ELISA) detected positive antibodies to Spirometra mansoni in peripheral blood and cerebrospinal fluid (CSF). In addition, during the operation, an ivory-colored live sparganosis was removed under the precise positioning of neuronavigation, and the patient was diagnosed with cerebral sparganosis. The patient began praziquantel and sodium valproate treatment after the operation, and was followed up for 3 months. There was no recurrence of epilepsy, and the weakness and numbness of the right limb improved.

Conclusion

Nonspecific clinical manifestations often make the diagnosis of cerebral sparganosis difficult, and a comprehensive diagnosis should be made based on epidemiological history, clinical manifestations, ELISA results and imaging findings. Surgery is the preferred method for the treatment of cerebral sparganosis, and more satisfactory results can be achieved under the precise positioning of neuronavigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07293-7.

Diagnosis and stereotactic aspiration treatment of cerebral sparganosis: summary of 11 cases

Object

Cerebral sparganosis is a rare but underestimated parasitic disease caused by infestation by sparganum. It is difficult to make a confirmed preoperational diagnosis of this disease given the absence of characteristic clinical manifestations. A detailed protocol for the diagnosis and treatment of cerebral sparganosis is still lacking in the literature. In this article the authors set out comprehensive procedures for the diagnosis and treatment of cerebral sparganosis, describing the use of a stereotactic aspiration technique complemented by microsurgery based on experience gained from multiple cases.

Methods

The disease history, clinical manifestations, imaging features, and therapeutic procedures for 11 patients with cerebral sparganosis were retrospectively analyzed. Stereotactic aspiration procedures were performed in all 11 patients and were complemented by microsurgeries in 3 patients. The learning and experience gained from these treatments were summarized, and a comprehensive protocol for the diagnosis and treatment of cerebral sparganosis was reviewed.

Results

Larvae of Spirometra mansoni were taken from all 11 patients: completely removed in 10 cases and partially removed in 1 case (discovered later). After surgery, clinical symptoms in all 11 patients were significantly improved. All epileptic symptoms were successfully cured, although in 1 case occasional seizures still occurred because of the incomplete removal of the larva. Muscle strength in the 4 patients who had hemiparesis prior to surgery recovered to normal. Symptoms in the 1 patient who had presented with partial body sensory disturbance resolved after surgery. There were no complications or deaths.

Conclusions

The authors concluded that an effective preoperative diagnosis of cerebral sparganosis can be made by detailed inquiry into the possible infection history and disease symptoms as well as careful scrutiny of characteristic radiological features and immunological testing results. In stereotactic operations performed to remove the larva, priority should be given to image-guided stereotactic aspiration given that it causes the smallest wounds. In cases in which stereotactic aspiration fails, stereotactic microsurgery should be performed to remove the larva. The surgeon must carefully avoid breaking the larva and leaving behind any larva residue during surgery.

MR spectroscopy and MR perfusion character of cerebral sparganosis: a case report

The authors report the case of a 46-year-old woman with cerebral sparganosis resulting from infection with a larva of Spirometra. Computed tomography and magnetic resonance imaging revealed a mass lesion with prominent perifocal oedema in the left parietal lobe. Advanced imaging pulse sequences, including MR spectroscopy and MR perfusion, were performed. During surgery for the removal of a granuloma, the parasite was discovered and excised. Following treatment, the patient's neurological deficits markedly improved.

Difficulty in diagnosing a case with apparent sequel cerebral sparganosis

BACKGROUND

We report on a case of cerebral sparganosis that was correctly identified by a biopsy 10 years after the initial infection.

CASE DESCRIPTION

A 62-year-old man presented with an unusual case of cerebral sparganosis mansoni. He was admitted to our hospital for removal of a right frontal meningioma. Computed tomographic scan and MRI of the brain showed atrophy of the left cerebral hemisphere, enlargement of the lateral ventricle, and several small ring-enhanced lesions in the left frontal lobe. The patient had suffered from motor aphasia and right hemiparesis for 10 years; in addition, he had been treated for cerebral infarction. We performed a left frontal biopsy, during which we also removed the meningioma. The histologic diagnosis was cerebral sparganosis mansoni.

CONCLUSIONS

The follow-up CT findings after the patient's first attack were thought to be characteristic of cerebral sparganosis mansoni. However, the radiographic findings were difficult to differentiate from those of neoplasias.

Neuroimaging and pathological findings in a child with cerebral sparganosis

The authors report the case of a 6-year-old boy with cerebral sparganosis due to infection with a plerocercoid tapeworm larva of Spirometra mansoni. Magnetic resonance imaging revealed an area of irregular long T2 signal in the right frontal lobe. When compared with images obtained 2 years earlier, the lesion appeared to have migrated into the parietal lobe. During surgery for the removal of a granuloma, the parasite was discovered and excised. Following surgery, the patient's neurological deficits markedly improved. The authors review the pathological and imaging features of cerebral sparganosis.

Surgical removal of a live worm by stereotactic targeting in cerebral sparganosis. Case report

A 64-year-old man presented with generalized tonic clonic convulsion followed by weakness of the right lower extremity. He had a medical history of hypertension, hyperlipidemia, and right cerebellar infarction. Computed tomography (CT) showed a small high density nodule with an enhanced perifocal low density area in the left occipital lobe. T1-weighted magnetic resonance (MR) imaging showed a ring-shaped and partial string-like nodule with enhancement by gadolinium. T2-weighted MR imaging showed the white matter of the left occipital lobe as high intensity. CT and MR imaging seemed to indicate metastatic brain tumors, although cortical atrophy and ventricular dilation were recognized. Left parietal craniotomy was performed under stereotactic targeting to obtain a definitive diagnosis. During manipulation at the center of the targeted lesion, a white, tape-like body was found and recognized to be a live worm. Serological testing revealed strong immunopositivity against Spirometra mansoni. The infection route in the present case was probably through eating raw chicken meat. Cerebral sparganosis is extremely rare but should be considered in the differential diagnosis of metastatic brain tumors, especially in endemic areas.

Tapeworms

Tapeworms are among the oldest afflictions of humans. They continue, even today, to be an important cause of morbidity and mortality, worldwide. Taenia saginata and Taenia solium infections are still common in many developing countries. Diphyllobothrium latum infections, are decreasing, but this tapeworm, transmitted to humans through the eating of raw salmon, can cause severe anemia. Hymenolepis and Dipylidium infections may occur to children. Hydatid disease is a common cause of morbidity, especially among immigrant groups from endemic areas of the Mediterranean; the liver is the most common site of a hydatid cyst. Although surgery has been the mainstay of therapy, drug therapy and percutaneous aspiration have been used more frequently in recent years. praziquantel and albendazole are the two most useful drugs against various tapeworm infections.

Survey of Spirometra erinaceieuropaei in frogs in Taiwan and its experimental infection in cats

Eighteen of 56 (32.1%) wild Rana limnocharis from central and south Taiwan were found to contain plerocercoids of Spirometra erinaceieuropaei. This is the first report of S. erinaceieuropaei infections in frogs in Taiwan, with the plerocercoids being recovered from the thigh and back muscles or under the skin. Other species of frogs examined, including nine wild R. latouchii, one wild Buergeria robustus and 110 cultured R. rugulosa were free of infection. The plerocercoids were orally inoculated into four cats; three of which were each given a single plerocercoid and one a dose of three plerocercoids. Daily faecal examination showed that two cats started shedding eggs of S. erinaceieuropaei on day 8 postinfection (PI) and the other two on day 10 PI. The highest eggs per gram and eggs per day for a single worm was found to be 428,000 and 14,416,000 respectively. Only the cat inoculated with three plerocercoids shed proglottids in its faeces during the 2 month observation period.

Current views on geographic distribution and modes of infection of neurohelminthic diseases

Neurohelminthiases are more prevalent in geographic areas where environmental factors and poor sanitary conditions favor the parasitism between man and animals. In recent years, population shifts and rapid transport have facilitated the spread of certain helminthic diseases from endemic to non-endemic areas. Although many helminthic parasites are known to cause various human diseases afflicting many millions of people in the world, neurohelminthiases are often not diagnosed because they have been unrecognized by clinicians or confirmatory diagnostic tests are not easily available. Paragonimiasis and schistosomiasis (fluke diseases) are endemic in Asia, Africa and Central America; lesions in the central nervous system (CNS) due to ectopic parasitism of the preadult and adult flukes produce various clinical features that often mimic other diseases. In most cestodiasis (tapeworm disease), the adult worm that lodges in the alimentary tract does not involve the CNS; however, the larvae often enter the nervous system by migration or by metastasis via the systemic circulation, where they cause cystic lesions. Cysticercosis is the most common CNS helminthic infection especially in endemic areas where the parasitism between man and pigs is maintained. In other cestodiases, infections to man are often caused by ingestion of food or water contaminated with feces of the definitive hosts (mammals or man). Nematodes (roundworms) generally enter the CNS by ectopic migration of the infective larvae (larva migrans); the routes of infection to man vary with species of the nematodes, and the animal hosts they infest. Angiostrongylus cantonensis is a neurotropic nematode that requires the CNS of mammalian hosts for its growth; the third-stage larvae frequently invade skeletal muscles and the nervous system. Strongyloides, a gastrointestinal nematode, is known to cause CNS involvement in immunosuppressed patients. Recently, some nematodes heretofore unknown to cause human parasitism have been recognized as the causative agents of CNS infections.

Intraventricular haemorrhage and hydrocephalus caused by intraventricular parasitic granuloma suggesting cerebral sparganosis

A 67-year-old female farmer presented with acute loss of consciousness. Computed tomograms showed a calcified mass in the cavum septi pellucidi with intraventricular haemorrhage and obstructive hydrocephalus. The patient became fully conscious after urgent external ventriculostomy and subsequently underwent craniotomy for the excision of the mass. Pathological examination of the mass demonstrated a granuloma surrounding a degenerating larva compatible with Spirometra mansonoides whose mimicking an intraventricular tumour has not been reported before.