Intradural-extramedullary spinal cysticercosis with brain involvement: a case report and literature review

Abstracts

Relato de um caso raro de apresentação de infestação por cisticercose do espaço subaracnóide cerebral e intra-raquiano nas regiões cervical e torácica em mulher de 59 anos de idade, com náuseas, sinais de ataxia cerebelar e perda gradual da sensibilidade nas pernas. O diagnóstico foi feito por meio de imagens por ressonância magnética do cérebro e da coluna cérvico-torácica, que evidenciaram a presença de cistos nos espaços subaracnóides. O exame do líquido cefalorraquiano revelou teste imunológico ELISA positivo e elevado nível de proteína (420 mg/dl), indicativo de atividade da doença. Os parasitos foram removidos cirurgicamente pela necessidade de descompressão da medula espinhal torácica. Breve comentário sobre a patogênese da forma cística da cisticercose espinhal intradural-extramedular, aspectos das imagens de ressonância magnética e tratamento foram feitos com base nos achados de revisão da literatura.

Cisticercose; Cérebro; Coluna; Ressonância magnética

CASE REPORT

Intradural-extramedullary spinal cysticercosis with brain involvement: a case report and literature review^*

Luiz Antonio Rossi^I; Adalberto Sestari^II; Modesto Cerioni Jr.^III

^IAssistant Professor of the Discipline Radiology Principles at Center of Medical and Biological Sciences, Pontifícia Universidade Católica de São Paulo

^IIAssistant Professor at Universidade da Cidade de São Paulo, Neuroradiologist at Hospital do Servidor Público Estadual "Francisco Morato de Oliveira"

^IIINeurosurgeon at Hospital do Servidor Público Estadual "Francisco Morato de Oliveira"

^{Mailing Address}

ABSTRACT

Report on a rare case of infestation by cysticercosis involving the cerebral subarachnoid space and the epidural space in the cervical and thoracic regions of a 59-year old female patient who presented nausea, signs of cerebelar ataxia and gradual loss of the sensibility in both legs. The diagnosis was based on magnetic resonance imaging of brain and cervical-thoracic spine demonstrating the presence of cysts in the subarachnoid spaces. An enzyme-linked immunosorbent assay (ELISA) performed on cerebrospinal fluid resulted positive and demonstrated a protein level of 420 mg/dl indicating the disease activity. Parasites were surgically removed for the necessity of thoracic spinal cord decompression. Based on findings of literature review, brief comments were made on the pathogenesis of the intradural-extramedullary spinal cysticercosis cystic form, magnetic resonance imaging findings and treatment.

Keywords: Cysticercosis; Brain; Spine; Magnetic resonance imaging.

INTRODUCTION

Human cysticercosis is the most common parasitic disease to affect the central nervous system, caused by the larval stage of Taenia solium (cysticercus), especially in countries where the sanitary infrastructure is deficient, particularly in Latin America, Africa and Asia and yet, with relative frequency, in Portugal, Spain and European Eastern countries and endemic in developed countries with high rates of immigration from endemic areas^(1–3).

The adult worm develops in humans after ingestion of pork, rare, infected meat containing encysted larvae. The human cysticercosis is acquired through oral-fecal pathway after contact with member of the family or community with the adult worm, as well as by auto-infestation in patient with the intestinal adult worm. After ova ingestion, the shells of ova are digested and the larvae develops and lodge in soft-tissues, primarily in brain, spinal cord, heart/extra-ocular/skeletal muscle, eyeball, fat tissue and skin^(1–3).

Cerebral and spinal-medullary intraparenchymatous cysticercosis is caused by cysts and/or granulomatous, inflammatory nodules, whereas extraparenchymatous cysticercosis like those located inside periencephalic liquoric spaces (including the subarachnoid space in the region of cortical sulci and encephalic cisterns), cerebral ventricles and intradural-extramedullary space of the vertebral column, is typically cystic.

The case report includes clinical-radiological-pathologic aspects of cerebral and spinal intradural-extramedullary cysticercosis in cystic form, with a brief literature review.

CASE REPORT

A 59-year old, white woman was admitted for evaluation, presenting nausea, cerebelar ataxia, a gradual loss of sensibility in both legs, micturition and evacuation disorders. At general physical and neurological examination decreased reflexes in lower extremities and hyperesthesia at the T6 dermatome where characterized.

Magnetic resonance imaging (MRI) has revealed cystic lesions in brain, cervical-thoracic spine subarachnoid spaces with signs of compression on the thoracic spinal cord (Figures 1 and 2).

Laboratory tests on cerebrospinal fluid collected by means of lumbar puncture have indicated a high protein level (420 mg/dl) and the research of antibodies for cysticercus, ELISA test, was positive.

Because of the cysts compressive effect on the thoracic spinal cord, surgical treatment was indicated, which has evidenced several cystic lesions in subarachnoid spaces immediately after dura mater incision, such lesion being removed (Figure 3).

DISCUSSION

A case of vesicles in the corpus callosum was first described by Paranoli in 1550. Paracelso correlated cerebral vesicles and convulsive attacks in 1650, while Ridi and Malpighi characterized these parasitic lesions in 1686. The first reference to intra-rachidian cysticercosis is attributed to Rokitansky in 1856⁽⁴⁾.

The neurocysticercosis intra-rachidian form is quite rare, the intradural-extramed-ullary presentation being the most frequent and the intramedullary, the less frequent. Among 205 inpatients at Hospital Vera Cruz de Campinas, SP, Neurology Service, in the period between 1961 and 1987, only 18 (9.0%) had a definite diagnosis of neurocysticercosis, and only three (1.4%) presented intradural-extramedullary spinal infestation by cysticercosis⁽⁵⁾.

In the literature, we have found an excellent review study analyzing 95 cases of spinal cysticercosis published since 1865 (Chart 1), 61 (66.0%) of them presenting intradural-extramedullary localization, and 33 (34.0%) presenting intramedullary localization⁽⁴⁾. Many studies included in this review and other more recent studies^(1,3,6), likewise the present case, have shown the simultaneous involvement of liquoric, intradural-extramedullary spinal spaces in different segments and cerebral spaces.

The cysticerci larvae dissemination into the intradural-extramedullary spinal space has been explained by the accumulation of a great volume of blood originating from valveless epidural venous plexus, with extremely thin-walled veins, which may conduct the blood towards any direction, under the influence of intra-abdominal and intrathoracic pressure variations. Two surgically-confirmed cases of primary cysticerci larvae dissemination into the intradural-extramedullary spinal canal without cerebral involvement corroborate the hypothesis of retrograde flow of those larvae through the veins of the above mentioned epidural venous plexus, differently from the Isamat de La Riva's postulate on the parasites descending migration from the cerebral subarachnoid space into the spinal space⁽⁷⁾.

The term racemose cysticercosis (cysticercus racemosus) has been utilized by several authors and characterizes the development of large translucent vesicles, with big tails, multiloculated or branched off, absent scolex, subarachnoid space-occupying^(1,3,5,6,8).

The intra-rachidian intradural-extramedullary cysticercosis may be asymptomatic or presenting few symptoms over long periods of time. Symptoms may vary, depending on the vertebral column segment (cervical, dorsal, lumbar or sacral) were cysts are lodged^(1–3,6). When the cyst is localized in the spine cervical-thoracic segment, the symptoms are more apparent and usually cause medullary compression syndrome, as described in this case: gradual loss of sensibility in both legs, hyperestesia at the corresponding dermatome and micturition and evacuation physiological disorders. However, in the spine lumbosacral segment, frequently the clinical picture evidences localized radiculopathy that may be confounded with discopathy^(1–3,6).

Before the MRI advent, computed mielotomography, notwithstanding its invasive nature, was the imaging method employed for investigating lesions producing medullary and/or radicular compression symptoms. This procedure showed intra-rachidian, round, hypodense lesions marginated by intrathecally-injected iodine contrast^(2,5,6).

Presently, the imaging method of choice for intradural-extramedullary cysticercosis diagnosis is the MRI, that accurately demonstrates cystic lesions in subarachnoid liquoric spaces of periencephalic or spinal regions and, principally because is a non-invasive procedure^(1,3,8,9).

MRI images indicate the precise localization and contours of these cysts whose signal intensity is similar to CSF, hyposignal in T1-weighted sequences and hypersignal in T2-weighted sequences^(1,3,8,9) , identical to those demonstrated in this patient studies.

However, these characteristics may differ when cysts present inflammatory alterations, resulting in hyperintense images both in T1-weighted and T2-weighted sequences, as a consequence of the high protein content⁽³⁾. After paramagnetic contrast agent endovenous infusion, both the cyst and the meninges surrounding the adjacent medulla may be enhanced (arachnoiditis)^(1–3,8), which has not occurred in this case report.

A differential diagnosis spectrum should be considered when cystic, intra-rachidian lesions are detected in MRI images: congenital lesions (simple or complex arachnoid cysts, dermoid cysts), cysts of other parasitary etiology (hydatid), tuberculosis, sarcoidosis or subarachnoid metastatic neoplasm^(1,3).

A positive ELISA serological test and high rates of protein in CSF may be of help in the diagnosis, indicate the disease activity and serve as a follow-up and control of medicamentous treatment⁽⁶⁾. In the present case, CSF laboratory tests reveal high protein levels (420 mg/dl) and positive for ELISA.

Usually, treatment is conservative, presenting good results with administration of cysticidal drugs like praziquantel or albendazole, the later demonstrating higher treatment efficacy^(8,9). In cases where signs of medullary and/or radicular compression are detected, surgical indication becomes necessary, likewise in the case of our patient. An interesting aspect of the decompressive surgery in this case was the photographic register of a careful and individual surgical removal of cysts, allowing the radiological-surgical-pathological correlation.

Concluding, cysticercosis is a severe global public health problem, including developed countries because of the high rates of immigration from endemic areas. The disease severity is determined when cystic cysticerci involve subarachnoid spaces, producing medullary symptoms when located in the cervico-thoracic segment and radicular symptoms, when located in the lumbosacral segment, demanding surgery due to frequent unsuccessful conservative clinical treatments. The diagnosis may be completed by a findings combination: epidemiological history, classical clinical signs and symptoms, MRI images, laboratory tests and CSF serological tests.

REFERENCES

Received June 24, 2004.

Accepted after revision December 15, 2004.

References

• 1. Leite CC, Jinkins JR, Escobar BE, et al MR imaging of intramedullary and intradural-extramedullary spinal cysticercosis. AJR Am J Roentgenol 1997;169:17131717.
• 2. Bandres JC, White AC Jr, Samo T, Murphy EC, Harris RL. Extraparenchymal neurocysticercosis: report of five cases and review of management. Clin Infect Dis 1992;15:799811.
• 3. Çiftçi E, Diaz-Marchan PJ, Hayman LA. Intradural-extramedullary spinal cysticercosis: MR imaging findings. Comput Med Imaging Graph 1999;23:161164.
• 4. Gallani NR, Zambelli HJ, Roth-Vargas AA, Limoli Junior C. Spinal cord cysticercosis: report of 2 cases, review of the literature, and comments on its pathogeny. Arq Neuropsiquiatr 1992; 50:343350.
• 5. Rossitti SL, Roth-Vargas AA, Moreira AR, Sperlescu A, Araújo JF, Balbo RJ. Pure spinal leptomeningeal cysticercosis. Arq Neuropsiquiatr 1990; 48:366370.
• 6. Parker F, Hladky JP, Breton JO, Mignard C, Laporte JP, Bousquet C. Cysticercose racemeuse de la queue de cheval et arachnoidite kystique. Neurochirurgie 1988;34:280285.
• 7. Sperlescu A, Balbo RJ, Rossitti SL. Brief comments on the pathogenesis of spinal cysticercosis. Arq Neuropsiquiatr 1989;47:105109.
• 8. Martinez HR, Rangel-Guerra R, Arredondo-Estrada JH, Marfil A, Onofre J. Medical and surgical treatment in neurocysticercosis: a magnetic resonance study of 161 cases. J Neurol Sci 1995; 130:2534.
• 9. Corral I, Quereda C, Moreno A, et al Intramedullary cysticercosis cured with drug treatment. A case report. Spine 1996;21:22842287.

*

Study developed at Hospital do Servidor Público Estadual "Francisco Morato de Oliveira", São Paulo, SP, Brazil.

Publication Dates

• Publication in this collection
  21 Nov 2006
• Date of issue
  Oct 2006

History

• Accepted
  15 Dec 2004
• Received
  24 June 2004