A 59-year-old man suffered numbness in his left upper limb for 4 years and weakness in his left upper and lower limb for 2 months. Physical examination showed his muscle power was grade 4 in the left upper and lower limb, and his sensation to pinprick was slightly decreased on his ulnar side of the upper limb. His left tendon jerks were brisk and the left Hoffmann’s sign was positive. His blood eosinophilic granulocyte value was higher than normal. Five years previously he suffered a fall related injury, and was diagnosed as having mild cervical vertebral fracture. He was discharged from a local hospital after medical treatment. On the basis of his history and physical examination, we originally considered his condition was due to chronic cervical spinal cord injury. Moreover, cervical spondylotic myelopathy was also considered, which often occurs in middle aged and older individuals.
Based on the patient’s clinical presentation, the lesion was easily localised on a cervical segment. Magnetic resonance imaging (MRI) was performed for detection of the putative spinal cord lesion. C6 vertebral body misalignments and C7 vertebral body mild compression were revealed on MRI. At the C6/7 level an intramedullary cystic lesion could be seen. The cystic lesion seemed traumatic, causative or congenital in nature. However, a suspicious nodule inside the cyst could not be interpreted as chronic spinal cord injury. The cord was also focally enlarged with mild oedema. The lesion appeared to be cystic and the scolex inside the cyst was visualised. The scolex appeared isointense with the spinal intramedullary cord on T1 weighted MRI (arrows in fig 1A).
The cystic lesion was located in the intramedullary spinal cord, which had resulted in the patient’s sensory and motor deficit. Owing to his history of cervical spinal injury, a misdiagnosis of an injury related cyst was made preoperatively. We undertook surgical exploration of the cervical spinal cord and tried to resect the cystic lesion; fortunately the total cystic lesion could be easily removed by suction. A confirmed diagnosis was made on the preoperative MRI manifestations and intraoperative findings. Retrospectively, the unique manifestation on MRI had indicated an intramedullary cysticercosis. Cystic lesions showing the scolex on computed tomography or MRI were proposed as sufficient criteria for a diagnosis of neurocysticercosis.1
During the operation a 2 mm long midline myelotomy was made, and the lesion was found immediately. A cleavage plane between the spinal cord and cystic lesion was defined. Circumferentially the cyst wall was then totally removed by suction. Neuropathological analysis showed cyst wall remnants from intramedullary cysticercosis. A Taenia solium scolex was identified. Dexamethasone was administered together with praziquantel to attenuate the oedema and associated inflammation.2,3 The dexamethasone was slowly tapered, while the praziquantel was continued for a full 2 week course.
Postoperatively, the patient’s limb strength and sensation to pinprick recovered, and he experienced only mild numbness on the ulnar side of the left hand and forearm. A further MRI confirmed complete resolution of the cystic lesion (arrows in fig 1B) before the patient was discharged. At 2 years follow-up the patient was very well and able to participate in activities of moderate intensity.