British Journal of Radiology (2004) 77, 267-268
© 2004 British Institute of Radiology
doi: 10.1259/bjr/43021693
Multiple cerebral enhancing lesions in an acutely ill child
K M Hogarth, BSc, MBBS
1
W Jan, FRCR
2 and
J P Lin, MRCP, PhD
3
1 Guy's, Kings and St Thomas School of Medicine, 2 Radiology and 3 Paediatric Neurology Departments, Guy's and St Thomas Hospital, London, UK
Correspondence: Dr W Jan, Radiology Department, 2nd floor of Guy's Tower, Guy's Hospital, St Thomas Street, London SE1 9RT, UK
 |
Introduction
|
|---|
A 14-year-old girl presented to her local GP complaining of persistent headaches, nausea, vomiting and an episode of visual hallucination at school. She was intermittently unable to recognise people and she developed nocturnal enuresis. The GP investigated her for glandular fever, which was found to be negative. She presented to the Accident and Emergency Department 2 weeks later with increasing lethargy, drowsiness and confusion and she was admitted.
On examination, she was orientated in person but not in time or place and she responded to pain. Her core temperature was measured at 36°C and her oxygen saturation was 99% on air with a blood pressure of 99/49 mmHg and a sinus bradycardia of 55 bpm. Respiratory, abdominal and ENT examinations were all normal. An ophthalmologist assessed her and reported her to have swollen pale optic discs. On neurological examination, she had hypotonia, hyporeflexia and equivocal plantar reflexes. Her clinical condition initially deteriorated with loss of bladder control and gag reflex, requiring catheterization, intubation and ventilation.
Her blood sugar, renal and liver biochemical profiles were unremarkable. Blood cultures, urine cultures and throat swabs showed no growth. She was afebrile throughout her clinical course and the inflammatory markers were within normal ranges. She was tested for HIV, herpes simplex virus (HSV) and toxoplasma, all of which were negative. A lumbar puncture (LP) was also carried out from which a cytospin was performed. Immunohistochemistry was performed for CD3, CD4, B- and T-cell markers. No infective pathogen was isolated either serologically or immunologically, ruling out an infective cause. An MRI of the brain and cord (Figure 1
) was performed followed by a brain biopsy that excluded the diagnosis of lymphoma.
View larger version (114K):
[in this window]
[in a new window]
|
Figure 1. (a) Axial T2 weighted image. (b) Axial diffusion weighted image. (c) Coronal T1 weighted image. (d) Contrast enhanced coronal T1 weighted image.
|
|
How would you describe the MRI findings? What is the most likely diagnosis? Does the diffusion weighted imaging (DWI) help in narrowing the differential diagnosis in this case?
|
Answer
|
|---|
MRI showed multiple small enhancing lesions throughout the brain with little or no mass effect. The temporal lobes and cerebellum showed more involvement than other structures. There was no evidence of cord involvement. Most of the lesions were of high signal on the T1 weighted images (Figure 1c
), indicating a haemorrhagic component. The MRI findings were consistent with a differential diagnosis of many diseases including acute disseminated encephalomyelitis (ADEM), malignancy (e.g. lymphoma) and haemorrhagic encephalitis. DWI showed free diffusion, which was more in keeping with a diagnosis of ADEM. Based on the history, examination, laboratory findings and the MRI study, a clinical diagnosis of ADEM was made.
ADEM is a monophasic inflammatory condition of the central nervous system. It usually occurs following a viral prodrome or vaccination, presenting with multifocal neurological disturbance and altered state of consciousness [1]. Neurological symptoms typically follow the initial infectious illness between 1 and 20 days and include headaches and ataxia [2]. The disease course can progress to optic neuritis, seizures, myoclonus, transverse myelitis and coma. ADEM is more common in young adults and children [3]. In contrast to multiple sclerosis, ADEM usually has a fulminant presentation with markedly widespread neurological changes. Early studies found a mortality rate of up to 20%, with a high incidence of neurological sequelae in the survivors but more recent case reports have suggested a favourable prognosis [1]. Relapses of ADEM have been reported [4].
There are no consistent laboratory findings in ADEM. Cerebrospinal fluid (CSF) often shows mild protein elevation or lymphocytic pleocytosis [2]. Viral serology may be positive for HSV, HIV, varicella-zoster virus, Epstein-Barr virus and others but it is difficult to establish a causal effect. MRI is very sensitive in detecting white matter pathology and is considered the imaging study of choice in diagnosing ADEM [5, 6]. T2 weighted images reveal high signal intensity lesions in the subcortical white matter, brainstem, middle cerebellar peduncles and periventricular white matter [6]. The lesions are typically bilateral, asymmetrical and highly variable in size and number [7]. Enhancement is due to disruption of the blood–brain barrier in the early stages of demyelination and so in theory all lesions should enhance in the early stage and none should enhance in the late stage. In practice, however, a mixture of enhancing and non-enhancing lesions is seen in both early and late stages [8]. Optic neuritis is common in ADEM and can be seen on short tau inversion recovery (STIR) orbital imaging [9].
MRI is not only the imaging modality of choice for the diagnosis of ADEM but it is also used to monitor the disease progression and response to treatment with serial imaging studies. As MRI technology evolves, its ability to detect and diagnose pathology will increase. Novel MR techniques such as DWI and diffusion tensor imaging (DTI) are now being applied to the investigation of ADEM [10, 11].
The patient in this case was initially treated with intravenous ceftriaxone, aciclovir and clarithromycin to cover infectious causes. These were discontinued when laboratory findings were negative for infectious agents. She responded well to high dose intravenous methylprednisolone (10–20 mg kg-1 d-1), with good recovery of her neurological function. Although the prognosis is usually good and it is usually expected that a full recovery will eventually be made, this teenager continues to exhibit mild cerebellar ataxia on the left and profound cognitive and emotional disturbance consistent with the scattered frontal lobe haemorrhages on neuroimaging (Figure 2).
View larger version (154K):
[in this window]
[in a new window]
|
Figure 2. Axial T1 weighted scan performed 6 weeks after the initial presentation. Most of the lesions are now obvious on the non-contrast scans and there was complete lack of lesion enhancement after contrast injection.
|
|
Received for publication July 11, 2003.
Accepted for publication August 20, 2003.
|
References
|
|---|
- Hynson JL, Kornberg AJ, Coleman LT, Shield L, Harvey AS, Kean MJ. Clinical and neuroradiological features of acute disseminated encephalomyelitis in children. Neurology 2001;56:1308–18.[Abstract/Free Full Text]
- Stüve O, Zamvil SS. Pathogenesis, diagnosis, and treatment of acute disseminated encephalomyelitis. Curr Opin Neurol 1999;12:395–401.[CrossRef][Medline]
- Epperson LW, Whitaker JN, Kapila A. Cranial MRI in acute disseminated encephalomyelitis. Neurology 1988;38:332–3.[Free Full Text]
- Schwarz S, Mohr A, Knauth M, Wildemann B, Storch-Hagenlocher B. Acute disseminated encephalomyelitis: a follow-up study of 40 adult patients. Neurology 2001;56:1313–8.[Abstract/Free Full Text]
- Kesselring J, Miller DH, Robb SA, Kendall BE, Moseley IF, Kingsley D, et al. Acute disseminated encephalomyelitis: MRI findings and the distinction from multiple sclerosis. Brain 1990;113:291–302.[Abstract/Free Full Text]
- Singh S, Alexander M, Korah IP. Acute disseminated encephalomyelitis: MR imaging features. AJR Am J Roentgenol 1999;173:1101–7.[Free Full Text]
- Allen IV. Demyelinating diseases. In: Adams JH, Corsellis JAN, Duchen LW, editors. Greenfield's neuropathology, 4th edn. London: Edward Arnold, 1984; 338–84.
- Van Der Meyden CH, De Villiers JFK, Middlecot BD, Terblanchè J. Gadolinium ring enhancement and mass effect in acute disseminated encephalomyelitis. Neuroradiol 1994;36:221–3.[CrossRef][Medline]
- Tolly TL, Wells RG, Sty JR. MR features of fleeting CNS lesions associated with Epstein-Barr virus infection. J Comput Assist Tomogr 1989;13:665–8.[Medline]
- Honkaniemi J, Dastidar P, Kähärä V, Haapasolo H. Delayed MR imaging changes in acute disseminated encephalomyelitis. AJNR Am J Neuroradiol 2001;22:1117–24.[Abstract/Free Full Text]
- Inglese M, Salvi F, Iannucci G, Mancardi GL, Mascalchi M, Filippi M. Magnetization transfer and diffusion tensor MR imaging of acute disseminated encephalomyelitis. AJNR Am J Neuroradiol 2002;23:267–72.[Abstract/Free Full Text]
Top
Introduction
Answer
