A 39-year-old man suffered from lumbago for 4 years without any known causes. On February 15, 2020, he was hospitalized with aggravated lumbago, accompanied by numbness and weakness in both lower limbs. At the local hospital, A multiphase and contrast-enhanced magnetic resonance imaging (MRI) of the lumbar spine showed lesions in the lumbar spinal canal and the sacral canal, and the intervertebral discs between the fourth and fifth lumbar vertebrae (L4/5) had degenerative changes. Head multiphase and contrast-enhanced MRI showed multiple lesions of the brain parenchyma, cerebromalacia in the near-midline area of the bilateral cerebellar hemispheres, and proliferation of the peripheral glial cells. The local hospital performed posterior lumbar spinal canal exploration and spinal canal decompression surgery. Pathological examination of the spinal tissue suggested cysticercosis. After receiving five courses of praziquantel anthelmintic treatment, the patient felt a worsening of the lower back pain, numbness, and fatigue of both lower limbs, and attended our hospital on October 14, 2020.
On admission, the patient was unable to walk. Physical examination showed that there were no subcutaneous nodules throughout the whole body, mild depressed edemas of the right lower limb, muscle atrophy of both lower limbs, hypoesthesia of the skin, and the extensor muscle strength was grade 1. The deep and shallow reflexes could be induced, and the pathological sign and meningeal irritation sign were negative. All other physical examinations were normal.
To render a definite diagnosis, we performed a series of biochemical and immunological examinations after admission, and enzyme-linked immunosorbent assays (ELISAs) showed that antibodies of cysticercosis and Clonorchis hepatica were weakly positive. No parasite eggs were found in the patient's feces, and no tapeworm segments were previously observed. After performing a detailed medical history inquiry, we learned that the patient had a history of eating raw pork, raw snake gall, drinking wine, and catching frogs.
On the second day after admission, we performed a lumbar puncture, hoping to observe pathogenic evidence in the cerebrospinal fluid to assist in diagnosis. However, there was no cerebrospinal fluid outflow when the puncture needle entered the spinal canal. Similar findings were also observed following the puncture of different lumbar intervertebral spaces. This abnormal phenomenon made us consider the abnormality of the anatomical structure of the patient’s spinal canal. We immediately examined the patient's brain and entire spine using multiphase and contrast-enhanced MRI. The results revealed that the patient had abnormal changes in the posterior horn of the left lateral ventricle, the semi-oval center and the parietal lobe, softened foci in the midline area of the cerebellum on both sides, spinal cord changes from the 11th thoracic vertebra (T11) to the 2nd sacral vertebra (S2), and spinal meningeal enhancement was found in the thoracic, lumbar, and sacral vertebrae. Spinal cord edema was observed from the 8th to 10th thoracic vertebrae (T8-T10), and intervertebral discs between the fourth and fifth lumbar spine (L4/5) and the fifth lumbar spine and the first sacral vertebra (L5/S1) had degenerative changes (Fig. 1&2).
As the patient felt that the numbness of both lower limbs was gradually aggravated, physical examination found that the sensation of both lower limbs decreased and spread below the navel. The muscle strength of both lower limbs was reduced to grade 0, and the muscle tension was increased, resulting in foot drop. We immediately ordered a spinal orthopedic consultation. The spinal orthopedist reviewed the MRI images and concluded that the patient's symptoms were likely caused by a tumor in the spine. After fully assessing the patient’s condition, the spine orthopedist performed an operation of posterior intraspinal lesion resection and spinal decompression on October 30, 2020 to solve the existing problems and make a diagnosis. During the operation, the thoracic and lumbar spinal canals were found to be full of solid lesions, which were sent for pathological examination. Under the microscope, an unidentified parasite could be seen in the pathological section. Chronic inflammation and fibrous tissue wrapping were observed around the parasite, and no special staining results were observed (Fig. 3). Because the parasite’s scolex was not observed in the pathological section, the identity of the parasite could not be determined. Although there are cases of cysticercus colonization in the spinal canal, the macroscopic appearance and the microscopic pathological findings did not support that it was cysticercosis. Thus, the patient was deemed to have been infected by a different parasite.
To make a diagnosis, we carried out PMseq pathogenic microbial next generation sequencing (NGS) testing on the remaining specimens on November 12, 2020 (BGI Genomics, BGI-Shenzhen, Shenzhen, China). The results showed that 1,228,955 sequences mapped to Spirometra erinaceieuropaei, while 106 sequences mapped to Dibothriocephalus latus. Therefore, the final diagnosis was intraspinal sparganosis.
After posterior intraspinal lesion resection and spinal decompression, the patient's lumbago improved slightly, but the lower limb fatigue and hypoesthesia did not improve, and progressively worsened, which may have been related to a series of inflammatory reactions caused by insect death after anthelmintic treatment. To explore the follow-up treatment, we invited radiologists, pathologists, spine orthopedists, and neurosurgeons for multidisciplinary consultations. After discussion, it was considered that there were too many lesions in the cone and cauda equina of the patient, and we had to consider the fact that the surgical removal of the worm in the spinal canal may put the patient at a great risk of paralysis. Injury to the sacral plexus nerve during surgery would result in paralysis of both lower limbs and incontinence of urine and feces. Therefore, surgical treatment was not recommended, and we chose the conservative treatment plan. In order to achieve the therapeutic objective, we increased the dose of praziquantel and extended the treatment time. Considering that killing the worm with drugs can cause allergic reactions and inflammatory reactions, which in turn can lead to edema in the spinal canal and pressure on the spinal cord, the use of hormones and dehydrating agents would be a good solution to this thorny problem. In addition, neurotrophic drugs can promote the regeneration and repair of nerve cells. Rehabilitation exercises and follow-up evaluations will be performed.