Dilemma of shadows

Mahesh1, Abinaya1, Suresh Chelliah2,*

1Department of Pediatrics, Child Jesus Hospital, Trichy, India

2Department of Pediatrics, Kauvery Hospital, Trichy, India

*Correspondence: chelliah.suresh@yahoo.in

Background

Multiple ring-enhancing lesions in the brain have various differential diagnoses including neoplastic and non-neoplastic diseases. Infectious, vascular and inflammatory are non-neoplastic causes and primary brain tumour and metastasis are important etiologies for neoplastic disorders.

Neurocysticercosis and tuberculoma are endemic diseases in India. Both diseases may have similar kinds of clinical manifestations and radiological appearances. This case is an example of the ever-present dilemma that a clinician faces.

Case Presentation

A 14-years-old adolescent girl was brought with low grade fever, headache and diplopia for four days, vomiting and diarrhoea for two days. There was no history of seizure or weakness of limbs.

She was admitted a week earlier for initiating treatment for Neurocysticercosis. She was an immunocompetent girl who presented with two episodes of generalised seizures, vomiting and headache for two days. MRI brain showed, multifocal ring enhancing lesions, diffusely scattered in bilateral cerebral hemispheres, cerebellum and superior midline vermis with perilesional oedema. Small multiple regular lesions and scolex noticed within were suggestive of NCC. She was given dexamethasone and albendazole and discharged in three days with advice to continue treatment for two weeks.

On re-admission, she was irritable and afebrile. Vitals: HR, 74/min; RR, 22/min; BP, 100/60 mmHg. Her systemic examination revealed bilateral lateral rectus palsy, equal pupils and normal tone and power in all four limbs.

Fundus showed bilateral florid papilledema. MRI brain had the same findings with some reduction in the number of lesions. Neurologist and neurosurgeon were consulted, steroids and antiepileptics were continued. Anti-oedema measures were added.

Improvement in MRI findings with worsening clinical status prompted a relook. Lumbar puncture was done using a narrow-gauge needle. CSF analysis was suggestive of meningitis. Cell count, 325; N, 37%; Sugar, 15 mg%; Protein, 200 mg%. CBNAAT was confirmatory of tuberculosis. LFT was normal. ATT was started after reassuring the family members.

The next major concern was depression, which worsened her symptoms. Psychiatrist was consulted, relative was counselled about emotional support and the need of antidepressants. Her symptoms abated and, sensorium improved. She showed interest in surroundings. Lateral Rectus palsy resolved fully. Mannitol was stopped and oral steroids was continued with appropriate ATT.

Discussion

Central nervous system (CNS) tuberculosis (TB) is a serious form of TB, due to haematogenous spread of Mycobacterium tuberculosis (MT). Manifesting as meningitis, cerebritis and tuberculous abscesses or tuberculomas, it occurs in approximately 1% of all patients with TB, affecting disproportionately children and immunosuppressed patients. Intracranial tuberculomas are the least common presentation of CNS TB, found in 1% of these patients. They are multiple in only 15%–33% of the cases [1]

It is presumed that multiple IC tuberculomas are mostly secondary to hematogenous spread, while the solitary IC ones evolve from CSF infection into the adjacent parenchyma [2].

Neurocysticercosis (NCC) caused by the larval stage of Taenia solium, is the most common and serious parasitic disease of the CNS in many developing countries. The usual mode of presentation is focal seizures with or without secondary generalization, in a previously healthy individual, reported in up to 79% of neurocysticercosis cases. Other complaints are related to space occupying lesions including headache, vomiting and features of raised intracranial pressure. The characteristic appearance of neurocysticercosis in MRI include single, which is more common, or multiple enhancing lesions with diameter range between 5–20mm in any part of cerebral hemispheres. A 44% of patients have punctuated eccentric high-density structure suggestive of scolex. Another minor characteristic finding of neurocysticercosis is rounded hypotenuse non-enhancing lesions. The radiological appearance of IC tuberculoma in MRI is hypointensity with ring-shaped contrast enhancement on T1-weighted images, and hyperintensity with a central hypo intensity on T2-weighted images

A large survey of 50,617 people in Vellore showed that NCC is the cause of nearly one-third of all cases of active epilepsy (AE) in both the urban and rural regions. Extrapolating the results to the country as a whole lead to an estimated disease burden of 1 million patients in India with AE attributable to NCC.

Enzyme linked immunosorbent blot for cysticercal antibodies (EITB) is the best serological test available for the diagnosis of NCC. This assay tests for antibodies to seven larval specific antigens. It has a sensitivity of 98% and specificity of 100% in patients with more than one live cyst or subarachnoid disease. However, it only detects the presence of antibodies to the larval antigen and does not necessarily indicate the presence of active disease. Seroprevalence (those with positive EITB) was over 15% in a large sample of asymptomatic persons residing in Vellore district [3].

In a recent RCT, 10 days combined therapy with albendazole (15 mg/kg/day) and praziquantel (50 mg/kg/day) was found to be superior to either albendazole alone or high dose albendazole (22 mg/kg/day) in clearing cysts from the brain [4].

Conclusions

The dilemma will persist as long as the diseases exist. NCC can be eradicated if clean water is available and food and hand hygiene improves. Review and revision of diagnosis when the expected course is not seen is necessary always.

Author contribution

Dr. Mahesh, Consultant Pediatrician, Child Jesus Hospital, and our Neurology, Radiology, Psychiatry teams played a significant role in the management of the child. Dr. Abinaya helped to prepare the manuscript. Dr. Suresh Chelliah will be the guarantor.

References

  1. https://path.upmc.edu/cases/case968/dx.html
  2. Diagnosis and Discussion – Case 968 (upmc.edu). https://path.upmc.edu/cases/case968/dx.html
  3. Rajshekhar V. Neurocysticercosis: Diagnostic problems & current therapeutic strategies. Indian J Med Res. 2016;144:319-26
  4. Garcia HH, Gonzales I, Lescano AG et al. Efficacy of combined antiparasitic therapy with praziquantel and albendazole for neurocysticercosis: a double-blind, randomised controlled trial. Lancet Infect Dis. 2014;14(8):687-95.
Dr-Suresh-chelliah

Dr. Suresh Chelliah
Senior Consultant Paediatrician