MRI findings of eosinophilic myelomeningoencephalitis due to Angiostrongylus cantonensis.
OBJECTIVE
To study the imaging characteristics of eosinophilic myelomeningoencephalitis due to Angiostrongylus cantonensis using magnetic resonance imaging (MRI).


METHODS
Seventeen MRI examinations of the brain and spinal cord in five patients with angiostrongyliasis cantonensis of the central nervous system were performed. The final diagnosis was based on typical clinical symptoms, results of blood and cerebrospinal fluid (CSF) tests, and the presence of nematode larvae in the CSF. The sequential MRI follow-up examinations were carried out at a different stage for every patient from 1 to 28 weeks after the onset of symptoms. The features of the lesions in the brain, spinal cord, meninges and nerve roots on MRI were studied, moreover, the development of the lesions was analysed on follow-up MRI.


RESULTS
Abnormalities were demonstrated on MRI in all five cases. They included three cases of meningoencephalitis, one case of encephalitis and one myelomeningitis. The locations and appearances of the lesions were as follows: (1) brain involvement in four cases (including cerebrum in four, cerebellum in two and brain stem in three), and spinal cord involvement in one case. These lesions were diffuse or scattered and appeared as similar or slightly reduced signal intensity on T1-weighted images (T1WI), high signal intensity on T2-weighted images (T2WI) and turbo fluid attenuated inversion recovery pulse sequence (FLAIR) images. After administration of gadolinium chelate (Gd-DTPA), multiple round or oval enhancing nodules, with diameters ranging from 3 to 10 mm, were seen on T1WI, a few lesions appeared as stick-shaped enhancement whose longest measurement was 14 mm. Diffuse or local oedema around the lesion could be seen. (2) Meningeal involvement in four cases, a case of ependymal involvement and a case of nerve root involvement were among them. These lesions appeared as linear or nodular enhancement of the leptomeninges and ependyma, as well as nerve root enhancement. (3) There was a mild ventricular enlargement in two cases. On follow-up MRI lesions were most severe from the 5th week to the 8th week and it took at least 4-8 weeks (1-2 months) for a lesion to resolve completely, the resolution of larger lesion needed more than 22 weeks.


CONCLUSIONS
Multiple enhancing nodules in the brain and linear enhancement in the leptomeninges were the main features; stick-shaped enhancement was the characteristic sign of the disease on Gd-DTPA enhanced-T1 weighted images.
Jin
E
E
Department of Radiology, Beijing Friendship Hospital affiliate of Capital University of Medical Sciences, 95 Yong-An Road, Beijing 100050, China. erhujin@hotmail.com
Ma
D
D
Liang
Y
Y
Ji
A
A
Gan
S
S
D000328:Adult; D017185:Angiostrongylus cantonensis; D000818:Animals; D001921:Brain / Q000469:parasitology; D003287:Contrast Media; D004802:Eosinophilia / Q000175:diagnosis* / Q000469:parasitology; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008590:Meningoencephalitis / Q000175:diagnosis* / Q000469:parasitology; D008875:Middle Aged; D013116:Spinal Cord / Q000469:parasitology; D017206:Strongylida Infections / Q000175:diagnosis*
D003287:Contrast Media; D019786:Gadolinium DTPA