Posted by Dr. Bijoykumar Barik on Thursday, 22nd July 2010INTRODUCTION:-
Neurocysticercosis is most common parasitic infestation of CNS1. The incidence of spinal involvement is 1.5-3%4.Spinal neurocysticercosis usually appear due to mass effect. Most cases occur in subarachnoid space but intra medullary location is extremely rare1. Here we report a case of intramedullary neurocysticercosis (reported about 50 cases sofar) 4 and discuss the disease.
Neurocysticercosis (NCC), Spinal neurocysticercosis (SNCC), intra medullary, Tinea Solium, MRI.
A 26 year named BC , from Salepur presented to this hospital in June 2008 with c/o of head ache & neck pain(1 month), numbness of right side of face(15 days),inability to hold objects properly in right hand (15days).He was alright 1 month back. Started with continuous headache relieved with analgesics, without associated vomiting, nasal stuffiness or blurring of vision. After 15 days he developed numbness of right side of face & noticed weakness of right hand which gradually progressed so that he could not hold any object properly. There was no history of fever, root pain, or convulsion. There was no bladder or bowel involvement. There was no h/o Diabetes, trauma, hypertension or tuberculosis. Family history was not suggestive. He was not habituated to alcohol or smoking. There was no contact history& he was unmarried.
On examination he was of average built having BP- 130/80 mm of Hg; pulse 68/ min, regular; without pallor, jaundice or lymphadenopathy.
CNS examination revealed patient to be conscious with normal higher functions including speech. All the cranial nerves were intact except diminished pain sensation on right side of face. Motor system showed normal bulk with increased tone of muscles in legs & arms. Power was grade V in both lower limbs but grade IV in both upper limbs. Hand grip was weak on both sides, right >left. Bicep & triceps reflexes were exaggerated on both sides with normal supinators. Knee & ankle jerks on both sides were exaggerated. Plantar was extensor on right but flexor on left. Sensory system was normal. Skull & spine was normal without any meningeal or cerebellar signs. Fundus was normal.
Other systems like CVS, GIT, respiratory did not reveal any abnormalities.
Routine investigations like Hb%, DC, TLC, FBS, urea, creatinine serum K+, Na+ were normal. ESR was 25/1st hour & Mx was negative. Chest X-ray & cervical spine X’ray were normal. CSF study was normal. MRI of brain & spinal cord showed ring enhancing tiny lesions at cervico medullary junction inside the medullary central canal with consequent syrinx formation..(Figure-1,Figure-2) Anticystocercal antibody was positive.
A young male presenting with gradual onset of assymetrical weakness of upper & lower limbs, with headache & diminished pain sensation of right side of face without significant involvement of lower limbs with features of UMN involvement in the form of hypertonia & hyper reflexia of all limbs below C4 without sensory level a provisional diagnosis of high cervical cord compression ( intramedullary) was thought of, probably involving trigeminothalamic tract(right) & corticospinal tract below pyramid (right). With the investigations the patient was diagnosed as a case of SNCC with obstructive syringomyelia.
The patient was treated with Albendazole 400 mg twice daily for 28 days with oral prednisolone in tapering dose.In the next followup after one month he complained of progressive weakness of upper limbs with no response to Albendazole.Hence he was advised for neurosurgical consultation for excision of the cyst.
Neurocysticerosis is the most common parasitic infestation of CNS caused by ingestion of eggs of Taenia Solium3.T.Solium has its definite host in human being where adult worm stays in intestine laying eggs which are taken by pigs who are intermediate hosts. The embryo cross the intestine and reside in CNS, muscles, eyes and skin as cysticerci.Human beings have the disease when they ingest the eggs instead of Pigs. The eggs hatch in the intestine and develop into cysticerci in the above mentioned organs.
Usual organs involved in Neurocysticerosis are brain, eye, subcutaneous tissues.Common presentation of cysticerosis of brain are headache, seizure and focal neurological deficit.
Spinal neurocysticerosis is a rare presentation; the incidence ranging from 0.7-5.85%1,3.Spinal forms have been identified in vertebral, extradural, intradural, intramedullary regions.Intramedullary cysticerosis is very uncommon1. Migration of the cysticercus through the ventriculo-ependyal pathway and haematogeneous dissemination has been identified as pathogenic mechanism1,4.
In absence of previous history or subcutaneous nodule it may be difficult to suspect clinically intramedullary cysticerosis.High eosinophil count with soft tissue calcification though suggestive is rare.Result of surgery has not been encouraging due to parenchymal gliosis as a result of toxic waste from larva, pachymeningitis and vascular insufficiency.
But in the era of microsurgery good outcome has been reported. Medical treatment of intramedullary lesions can be considered in patients of stable neurological status but impossible in acute or progressive cases.Post operative anticerceal drugs should be given as it is a generalized disease with focal manifestation1.
SNCC is rare compared to intracranial as cysticerci do not pass through subarachnoid space at cervical level due to its size(sieve effect).Besides CSF reflux at craniovertebral junction propels floating cysts back into intracranial space than spinal canal.
Several possible mechanisms of spinal invasion are:-
(a)Ventricular cysticerci pass through Magendie or Luschka foramen, migrate by gravity through subarachnoid space to inoculate spinal cord commonly cervical region.
(b)Haematogeneous spread explain intramedullary lesion,commonly thoracic area due to increased blood flow.(c) Intraventricular hypertension enables migration through a dilated ependymal canal into spinal cord explaining intramedullary invasion.Other favorable conditions favoring spinal invasion may be due to NCC-related hydrocephalus and/or meningitis, use of antiepileptic drugs like Carbamazepine or Phenytoin which can after immune function leading to parasitic infestation3.
The location of mass lesion, its size, the inflammatory response generated by cyst breakdown are important factors for management.Brain blood flow is 100fold greater than spinal explaining more intraventricular lesion.In spinal form thoracic region having more blood flow explains high incidence.The location of cysticerci is cervical - 34%,thoracic -44.5%, lumbar -15.5% and sacral- 6%.MRI is the investigation of choice.
Concurrent intracranial lesion are seen in spinal involvement. As long as cysticercus is viable there is relative host immune tolerance. Massive antigen response occurs with death of parasite with intensification of immune/inflammatory response.Surgery is required for diagnosis and treatment though outcome is mixed. Albendazole or Praziquantel with or without steroid are used. Albendazole is preferred as blood level are increased with steroid.Spinal intramedullary cysticercosis represents a challenge for diagnosis & surgery. Patient recovery is variable. Despite promising reports the safety and efficacy of medical treatment remains unproved4.
1. Singh P, Sahai K.-Intramedullary cysticercosis.Neurol India 2004;52:264-5
2. Mohanty A.Venkatrama SK, Das BS,Rao BR,Vasudev MK -Spinal Intramedullary cysticercosis-Neurosurgery.1997; Jan 40(1):82-7
3.Dong Ah Shin & Hyun Chul Shin-Yonsei Med.J.2009,Aug 31;50(4):582-584.
A case of extensive spinal cysticercosis involving whole spinal canal with a h/o cerebral cysticercosis.
4.Agarwal R,Chauhan SPS, Mishra V, Singh PA,Gopal NN-Acta biomed 2008;79,39-41
Focal spinal intramedullary cysticercosis.