大 韓放 射線 醫學 會 誌 第 27 卷 第1號 pp.39-44, 1991 Journal of Korean Radiological Society, 27(1) 39-44 , 1991

MR Features in Patients with Residual Paralysis

following Aseptic Meningitis

Dae Chul Suh, M.D. , Young Seo Park, M.D. *

첼

무 ι

국

/ / 、、

Department o[ Radiology, College o[ Medicine, Asan Medical Center, University o[ Ulsan

운동성 마비가 합병된 무균성 뇌막염 환자에서의

자기공명영상 소견

울산대학교 의 과대 학 진단방사선과학교실

서 대 철 • 박 영 서*

무균성 뇌막염 에 의한 운동성 마비는 드물게 보고되고 있는데 저 자들은 최 근 운동성마비 가 j합병된 무균성 뇌 막염 환자 3

명에서의 자기 공명영상 소견을 얻었다. 이 중 2명에서는 척수의 전각세 포 부위에서 괴사를 시사하는 조그만 두개의 동관 병

변이 관찰되었고 나머지 한명에서는 분절성의 위축이 관찰되었다- 이 들 중 2영의 혈청에서 는 enterovirus 71 의 항체가 상승

되어 있었다.

Index Words: Myelitis 30 ,206

Children , central nervous system

Spinal Cord , MR studies 30.1214

Introduction

Poliomyelitis-like paralysis can be caused by

neurovirulent strains of nonpolioenteroviruses.

Entervirus 71 (EV 71) is documented as one of the

potentially neurovirulent strains and a causative

agent of some epidemics (1-7). The clinical manifesta­

tions associated with the EV 71 infection include

aseptic meningitis. hand-food-mouth disease (HFMDJ,

acute respiratory illness and gastrointestinal

disease(6).Although rarely fata l,f1accidparalysis can

be followed by EV 71 induced aseptic meningitis.

Anterior horn cell necrosis was suggested on MR in

two patients with residual paralysis(7).MR features.

however. have not yet been described in detail. In this

report we present three cases ofpatients with clinical

evidence ofEV 71 induced aseptic meningitis whose

MR studies showed residual changes in spinal cord.

Materials and Methods

During four months from April to August. 1990,

201 patients of aseptic meningitis were diagnosed as

a aseptic meningitis in our hospital. Diagnosis of asep­

tic meningitis was based on clinical symptoms and

signs. cerebrospinal f1uid (CSF) findings. negative

CSF and blood culture. negative CSF latex agglutinin

test. negative CSF AFB and India ink staining

Among them actue onset of lower motor paralysis

was developed in four patients. The paralysis involv­

ed the lower extremities in three and the upper in one.

MR studies were performed in three patients with

paralysis in the lower extremities. The titrations of

neutralizing antibody against EV71 performed on

sera in three including a patient with paralysis In the

* 울산대학교 의 과대 학 소아과학교실

• Department of Pediatrics, College o[ Medicine, Asan Medical Center, University of Ulsan

이 논문은 1990년 12월 7일 접수하여 1991 년 1 월 1 0일에 채텍 되였음 Received December 7 , accepted January 10, 1991

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大햄‘放射練縣學셈잖 · 第 27 卷 第 l 號 1991

upper extremities showed initial high titer or fourfold

increase in antibody titer. The titrations for cox­

sackievirus A16 in three revealed antibody titers

within normal range. Viral culture was not per­

formed.

MR studies were performed on a 1.5T supercon­

ducting system (Signa. General Electric Medical

System . Milwaukee). T1-weighted images.

500-600/20/2 (TR/TE/excitations) . were obtained in

axial . sagittal and/or coronal planes. T2-weighted im­

ages (1.800-2.500/30. 80/1) were obtained in axial

planes in two patients and in sagital plane in a pa­

tien t. Sagittal gradient echo images (350/20/4) were

obtained in a patient

Results

Case 1

An 8 month-old boy presented with HFMD and

developed left lower extremity paralysis 4 days after

fever and rash . This was followed in a day by ascen­

ding paralysis. which eventually progressed to

quadriparesis. His initial neurologic examination

showed a weak motor response in the right leg a nd

no motor response in the left leg. Deep tendon reflexes

were diminished in both sides without sensory deficit.

CSF examination showed 210 white blood cells

(WBC)/mmJ with 88% mononuclear cells. and a pro­

tein and a glucose level of 27 and 68 mg/dl. respec­

tively. He slowly regained the activity ofhis right leg

14 days after onset. MR performed 20 days after onset

showed two small circ비ar lesions within the spinal

cord with signal intensities similar to CSF (Fig. 1). He

was discharged on the 16th hospital day. at which

time he was able to move his left big toe. Improve­

ment continued and by five months after discharge

he became to move his ankle but the weakness was

still present at that time.

Case 2

A 1 1O/12-year-old girl presented with a high fever.

vomiting and weakness in the left lower leg preced­

ed by mild fever and rash in hand. foot and mouth

three days ago . The neurologic examination showed

neck stiffness. The motor response was absent in the

left leg. The deep tendon refIexes were decreased in

left side. The pain responses were intact in both sides.

Spinal fIuid examination showed 360 WBC/mmJ with

32 % mononuclear cells and a protein content of 45.6

mg/dl and a glucose level of 6Omg/d l. MR performed

three weeks after onset revealed two small cavitary

lesions at the area of anterior horn cells (Fig. 2) . The

Fig. 1. Case 1: 8-month-old boy with residual paralysis preced­ed by HFMD and aseptic meningitis

a

a. A coronal T1-weighted image shows two parallellinear lesions of low signal intensities within the lower thoracic spinal cord. b. An axial T l-weighted image at the T 11 level reveals the circular cavities of low signal intensities forming the configuration Iike a pig nose

40

Dae Chul Suh , et al: MR Features in Patients with Residual Paralysis fo llowing Aseptic Meningitis

a

Fig. 2. Case 2: 1 lO/l2.year.old girl with residual paralysis. a. A sagittal T l-weighted image shows mild swelling of the lower thoracic spinal cord. Note the low signal in­tensities at anterior one-third of the spinal cord. b. An axial T l-weighted image demonstrates the small cavitary lesions. c. Axial T2-weighted image shows the same lesions of high signal intensities. larger on the left. The paralysis was more severe in the left extremities.

weakness was slowly improved but still present two

months after onset

Case 3

A 4 year-old girl was admitted because of URI-like

symptoms for four days and inability to bear weight

on her legs for one day. On admission. she was

afebrile. alert but irritable. Muscie power ofboth lower

extremities were decreased. The pain sense was ab­

sent 2cm below umbilicus. The deep tendon reflexes

were diminished. There was a loss of bladder control

CSF examination showed 360 WBCmmJ with 32%

mononuciear cells. and a protein content of 45mg/dl

c

culoneuropathy. MR performed 7 days after onset

revealed a mild enlargement of conus medullaris (Fig.

3A). A central syrinx-like cavity was noted within the

spinal cord on axial Tl and T2-weighted images (Fig.

3B) but regarded as a ~runcation artifact because the

images were acquired with 128 m atrix. Four month

later. the follow-up MR d emonstrated atrophic

changes of spin머 cord below T !O level (Fig. 3C). The

paralysis of lower extremities persisted after four

month follow-up .

Discussion

and a glucose level at 60 mg/dl. The result of elec- The occurrence of two hundred and one patients

tromyelography was consistent with polyradi- of aseptic meningitis during short period of four 41 -

大韓放射線團學會誌 : 第 27 卷 第 l 號 1991

a

b

months can be regarded as a epidemic outbreak.

Among the 201 patients with aseptic meningitis. four

patients including a referred patient developed fiac­

cid para1ysis (2%). The paralysis mainly involved the

lower extremitis except one patient who showed the

weakness of upper extremities and did not have MR

examination. Three ofthem revealed elevated titers

against EV 71 in serologic test. Although vira1 culture

was not done we assume that EV 71 is incriminated

c

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Fig. 3. Case 3: 4-year-old girl with transverse myelitis. a . ME performed seven days after onset shows m i1d swell­ing of conus medullaris on sagittal Tl-weighted image. b. An axial T l-weighted image shows a centrallow signal intensity caused by truncation artifact c. MR performed four months later reveals atrophic changes in the lower thoracic spinal cord on sagittal Tl-weighted image.

as the cause of the epidemic.

Since the first outbreak was reported in the United

States. EV 71 has been associated with rare outbreaks

in worldwide distribution as well as sporadic cases

of flaccid paralysis (1-7). The spectrum of the illness

observed in the outbreaks were variable (6). Rash is

a common clinical findings in EV 71 infection.

Mac비opap비ar. generalized vesicular. and diffuse

erythematous exanthems have been obseπed. but

Dae Chul Suh, et al: MR Features in Patients with Residual Paralysis following Aseptic Meningitis

the most frequen t1y noted pattern of rash in all out­

breaks was HFMD. The simultaneous occurrence of

HFMD and CNS disease may suggest EV 71 infection

as a common cause ofHFMD. In our cases, HFMD was

the initial symptomatic manifestation in three offour

patients. Coxsackie A-16 is seldom associated with

CNS disease and the serologic test for coxsackie A-16

was negative in three offour patients. The c1inical pat­

tern of the CNS disease associated with EV 71 in­

c1udes aseptic meningitis. meningoencephalitis and

myelitis causing motoparesis. The striking feature of

our outbreak is the occurrence of paralytic disease ,

since paralysis was not common feature for reported

outbreaks. However. the epidemic of EV 71 disease

in Bulgaria (1 975) differed considerably from

epidemics in other country because of the high in­

cidence of paralytic cases (2) . A large portion of case

had severe poliomyelitis-like paralytic disease with

a bulbar form of poliomyelitis and encephalomyelitis.

High mortality (64.7%) among the bulbar cases was

noted. Except Bulgarian outbreaks. only ten cases of

flaccid paralysis were reported upto now: a case of

infective polyneuritis in Australia (1972). two cases

in Japan (1978). fives cases in Philadelphia (1987).

MR findings were first reported in two of five cases

in Philadelphia (7). A MR in a patient with weakness

in upper extremities showed an enlarged cervial cord

Repeated MRI five months later revealed a circular

hypointensity in the left ventral aspect ofthe cervical

cord. A MR p~rformed in another patient 7 month

later was only described as two small hyperintensities

on T2-weighted image in the ventral horns of the

lower thoracic spinal cord. larger on the right. cor­

responding to side and distribution of residual

weakness. In our cases. the cord lesions occupying

the areas of anterior horn cells were well

demonstrated on axial Tl and T2-weighted images.

The small circ비ar cavities of low signal intensities

formed .a configuration shaped like a pig nose on ax­

ial Tl-weighted images. The size of the cavity cor­

responded to the severity of the residual paralysis.

Swelling of conus medullaris was noted on sagittal

Tl weighted image at acute phase. The involvement

of anterior horn cells can be idenfit1ed at anterior one

third of swollen spinal cord as in case 2 (Fig. 2).

is not previously documented in other outbreaks. The

clinical menifestation of the patient were also sug­

gestive of transverse myelitis instead of poliomyelitis­

like paralysis which characteristically involved the

anterior born cells. In spite of the fourfold elevation

of antibody titer for EV 71 in that patient. we can not

completely exc1ude the possibility of aseptic men­

ingitis induced by other viral infection.

The differential diagnosis of an acute onset of ex­

tremity weakness in children inc1udes three impor­

tant viral syndromes of the caudal central nervous

system(9) Poliomyelitis refers to the primary involve­

ment of the gray matter of the spinal cord and usually

the anterior horn cell. Although poliovirus infections

has been controlled by vaccine. poliomyelitis may be

caused by neurovirulent strains of enterovirus. The

lack of sensory involvement in two patients (case 1

and 2) and MRI defect in the ventral horns of the

spinal cords with persistent weakness support the

anterior horn cell as target of involvement. The se­

cond type is a transverse myelitis in which there is

less predilection for cell type . The entire spinal cord

at one level is usually involved as in case 3 . Acute

transverse myelitis has been described in association

with mumps. measles. varicellar-zoster. infectious

mononuc1eosis. enterovirus. and herpes simplex in­

fections . The cord swelling in acute transverse

myelitis is also reported in AIDS patients (10.11). A

third. viral syndrome is polyradiculitis which is com­

monly associated with infectious mononucleosis but

MR findings have not been described

Identification of the lesion within the spinal cord

is important for determination of the extent and

prediction of the progrnosis. MR is highly sensitive

in depicting spinal cord lesion. Because the paralysis

was noticed in three to five days after symptom onset.

MR studies must be included in workups when the

weakness is noted during the course of viral men­

ingitis. MR images should be obtained in mu1tiple

planes. Axial Tl and T2-weighted images are

necessary to find small cavitary lesions within the

spinal cord. Sagittal Tl and T2-weighted or gradient

echo images are also useful in evaluation of the cord

swelling and the extent ofthe lesion involved. Trun­

cation artifact can mimic a syrinx-like artifact as in

Atrophic changes shown in case 3. to our knowledge. case 3. By increasing the number of phase encoding

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大韓放射線醫學會끓‘ : 第 27 卷 第 l 號 1991

s teps . d ecreasing th e fie1d of view. and switching

phas e-and frequency-encoding axes. syrinx like ar­

tifact can be elim inate d(8).

REFERENCES

1. Schmidt NJ . Lennette EH. Ho HH. An apparantly

new enterovirus iso1ated from patients with disease

of the centra1 nervous system. J Infect Dis 1974;

129:304-309

2 . Chumakov M. Voroshilova M. Shindarov L. et a l.

Enterovirus 71 iso1ated from cases of epidemic

poliomyelitis-like diseases in Bu1garia. Arch Viro1

1979; 60:329-340

3. Ishimaru Y. Nakano S. Yamaoka. et a l. Outbreaks

of hand. foot . and mouth disease by enterovirus 7 1.

Archives ofDisease in Childhood 1980; 55:583-588

4 . Chonmaitree T. Menegus MA. Schervish-Swierkosz

EM. et a l. Enterovirus 71 infection: report of an out­

break with two cases of para1ysis and a review of the

literature. Pediatrics 1981; 67 :489-493

5 . Grist NR. Bell EJ. Para1ytic p이iomyelitis and non­

polioenteroviruses: studies in Scotland. Rev of In­

fect Dis 1984; 6:S 385-386

6. Me1nick J L. Enterovirus type 71 infections: a varied

clinica1 pattern sometimes mimicking para1ytic

poliomyelitis. Rev of Infect Dis 1984; 6:S387-390

7 . Hayward JC. Gillespie SM. Kap1없1 KM. et a l. Out­

breakofp이iomyelitis-like para1ysis associated with

enterovirus 7 1. Pediatr Infect DisJ 1989: 8 :611-616

8 . Bronskill MJ. McVeigh ER. Kucharczyk W. et a l.

Syrinx-like artifacts on MR images of the spin외 cord.

Radio1ogy 1988; 166:485-488

9 . Feigin DR. Cherry JD. Textbook of pediatric infec­

tious diseases. 2nd ed. Philade1phia. W.B. Sounders

Company 1987; 475-515

10. Merine D. Wang H. Kumar AJ. et a l. CT

mye10graphy and MR imaging of acute transverse

myelitis. 1987: 11:606-608

11. Barakos JA. Mark AS. Dillon WP. et a l. MR imag­

ing of acute transverse myelitis and AIDS

mye1opathy. J Comput Assit Tomogr 1990: 45-50

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