CaseReports

Bilateral Periodic Lateralized Epileptiform Discharges in Mycoplasma Encephalitis JosephF. Hulihan, MD*, Elizabeth M. Bebin, MDt, and Barbara F. Westmoreland, MD* Status epilepticus and prolonged coma developed in two patients with respi.ratory tract infections caused by Mycoplasma pneumoniae. Serial electroencephalography initially revealed bilateral, independent, periodic, lateralized epileptiform discharges. This pattern was replaced several days later by other electroencephalographic abnormalities. Hulihan IF, Bebin EM, Westmoreland BF. Bilateral periodic lateralized epileptiform discharges in Mycoplasma encephalitis. Pediatr Neurol 1992;8:292-4. Introduction Mycoplasma pneumcmiae is an important and potentially treatable cause of encephalitis in children [l]. The encephalitis may be severe and accompanied by prolonged seizures [2]. Reported electroencephalographic (EEG) findings in patients with M. pneumoniae-associated encephalitis are nonspecific and compatible with several central nervous system (CNS) infections [3-71. We describe two patients with M. pneumoniae-associated encephalitis in whom EEGs demonstrated bilateral, independent, periodic, lateralized epileptiform discharges (BIPLEDs).

Case Reports Patient 1. This J-year-old to the Mayo Clinic. During

boy with a history of asthma was admitted the preceding month, he had experienced

From the *Section of Electroencephalography Pediatric Neurology; Mayo Clinic and Mayo Mhesota.

292

PEDIATRIC

NEUROLOGY

and the +Section of Foundation; Rochester,

Vol. 8 No. 4

progressive lethargy and two exacerbations of asthma. On the day of admission, he had experienced a generalized tonic-clonic seizure that lasted 1 min; another generalized seizure occurred while he was in the ambulance. He was in status epilepticus on arrival at the emergency room. After resolution of his seizures, he was comatose for 3 days. Laboratory studies demonstrated that the titers for antibodies to M. pnerononiae were IgG I: 160 and IgM I:20 on the fourth day of illness and IgG I:40 and IgM I: IO on the 16th day of illness. Magnetic resonance imaging (MRI) scans did not reveal any abnormality. Other laboratory findings are summarized in Table I. EEG performed on the fourth hospital day revealed BlPLEDs of maximal voltage in the temporal regions (Fig 1). He was discharged on the eighth hospital day but was readmitted 24 hours later because of complex partial status epilepticus. EEG revealed multiple seizure discharges occurring independently over the left and right hemispheres, with persistent, generalized interictal delta activity. Seizures ceased abruptly on the fourth hospital day and the patient was less confused. Neurologic improvement continued for the next IO days and he was discharged. At follow-up I month after discharge, EEG demonstrated focal slowing and spike discharges over the right temporal region, improved background activity, and decreased generalized slow-wave abnormalities. These EEG abnormalities were still present in an EEG performed at a subsequent examination I year later, at which time the patient continued to have intractable complex partial seizures (3-4 monthly) and attentional deficits. Pafient 2. This ‘I-year-old comatose boy was transferred to the Mayo Clinic I week after an episode of status epilepticus. He had been well until 2 weeks previously, when cough, myalgias, and progressive fatigue had developed. On the morning of admission, he had experienced continuous convulsions that lasted 3 hours before being controlled with antiepileptic medication administered at another hospital. Laboratory studies revealed that the titers to M. pneunloniae were IgG 1:40 and IgM 1: 160 on days 6 and 16 of illness. MRI scans did not reveal any abnormality. The other laboratory findings are summarized in Table 1. EEG performed at admission revealed BIPLEDs, and one performed on hospital day 7 disclosed.generalized polymorphic delta activity, maximal over the temporal regions, with rare multifocal sharp waves. The patient was comatose for 4 weeks, after which time his level of consciousness gradually improved. At subsequent examination 5 months later, EEG demonstrated a background frequency of IO Hz and, with his eyes closed, transient rhythmic slow-wave activity. As with Patient I, Patient 2 had ongoing behavioral difficulties at examination 1 year later.

Results Both of our patients experienced status epilepticus and prolonged coma associated with M. pneumoniae infection (Table l), and both had behavioral impairments at subsequent examination at 1 year or longer. One patient continued to have intractable seizures. The initial EEG of each patient demonstrated BIPLEDs. In Patient 1, these discharges were apparent 4 days after resolution of status epilepticus, at which time the child was obtunded. They were maximal over the temporal regions and occurred at a frequency of approximately 1 Hz (Fig 1). The discharges from one hemisphere alternately preceded those from the opposite hemisphere. The initial EEG of Patient 2, performed on the same day as cessation of his

Communications should be addressed to: Dr. Westmoreland; Mayo Clinic; 200 First Street Southwest; Rochester, MN 55905. Received January 29, 1992; accepted April 21, 1992.

Fp1+7

+

-

-J--‘--

V

F7-T3

Ta-Ts /Jh& T5-01

w,nn

Fp2+8

F8-T4 TcT8 T8-02 Stuporous

Figure 1. Initial remporul regions.

of Porienr

EEG

I on dav

4 of hospitalization

1.

Patient NoJAge W-d l/5

Clinical

and laboratory

Seizure Type GSE NCSE CPS

findings

in 2 patients

with

Bilateral perihilar infiltrates

3-day coma, aphasia, impaired memory and concentration

maximal

in rhe

Seizures occurred in as many as 50% of the patients reported to have encephalitis associated with M. pneumoniae infection [2,5,8]. EEG abnormalities that were described in such patients included generalized polymorphic delta activity [3,5,6], focal or lateralized slow-wave abnormalities [3,5-71, and focal electrographic seizure discharges [4]. The largest reported series of patients with M. pneurnoniae-associated encephalitis that included EEG results was that of Lehtokoski-Lehtiniemi and Koskiniemi [2]. Of their 41 patients, 36 underwent EEG recordings during the first week of illness; 58% of these patients had pneumorriue-associated

Mycoplnsma

Chest X-ray Findings

Other Clinical Features

BIPLEDs

Discussion

seizures, revealed BIPLEDs that were maximal over the frontal regions. Subsequent EEGs demonstrated epileptiform abnormalities. In Patient 1, seizure discharges were maximal in the left and right temporal regions. In contrast to the BIPLEDs, these discharges were self-limited, changed in frequency and amplitude with time, and were associated with a change in the clinical state of the patient. EEG performed on Patient 2 on the eighth hospital day contained multifocal sharp waves. At subsequent examination, EEGs improved, but there were still slow-wave and epileptiform abnormalities. Table

reveuls

Hospital Day

Cerebrospinal Leukocyte5/mm3*

I 4

5 (35L,43M) 6 (50L,23M)

10

I8 (9lN.n.

encephalitis Fluid

Findings Erythro-

Cytes/mm3

1 2,130 0

Protein bngldl) 59 490

Mycoplasma Serology

IgG I:160 IgM I:20

29

2M)

IgG I:40

I6

IgM > I:10 2n

GSE

4-week coma, persistent cognitive

Bilateral, basilar bronchopneumonia

1

9 (IOOL)

6

58

7 (19L,67M)

0

31

6 8

I3

* Numbers

in parentheses

indicate

differential

Abbreviations: CPS = Complex partial seizures CSF = Cerebrospinal fluid GSE = Generalized status epilepticus L = Lymphocytes

IgM > I:64 (cold agglutinins l:128) IgG I:40 IgM 1:160

IgG I:40 IgM I:160

cell count in percentages. M N NCSE

= Monocytes = Neutrophils = Nonconvulsive

status epilepticus

Hulihan

et al: Mycoplasma

Encephalitis293

evidence of a severe, generalized disturbance. Specific EEG findings were not described, but the authors reported that there was improvement after 4 additional weeks. To our knowledge, periodic discharges have not been reported in association with M. pneumoniae infection. Brenner and Schaul reviewed the types of periodic EEG patterns [9]. Periodic, lateralized epileptiform discharges (PLEDs) are sharp wave, spike, or polyspike discharges recurring every 1-2 s over one hemisphere and are observed most often in association with such acute, unilateral lesions &s cerebral infarction [9-l 11. PLEDs also occur in herpes simplex encephalitis [ 121 and in some patients with meningitis or encephalitis [lo]. BIPLEDs are less common and the discharges are asynchronous and may differ in distribution and waveform between the two hemispheres [9]. In a series of 18 patients with BIPLEDs, the most common causes were anoxic encephalopathy (5 patients), CNS infection (5 patients), and chronic seizure disorders (4 patients) [ 131. Two of the 5 patients with CNS infection had herpes simplex encephalitis, 2 had bacterial meningitis (one due to Klebsiella and the other to Haemophilus injluenzae), and one had an encephalitis of unknown cause (other than herpes simplex). Smith et al. reported 2 patients with herpes simplex encephalitis and BIPLEDs [14] and Mizrahi and Tharp repoited multifocal periodic discharges in association with neonatal herpes simplex encephalitis [15]. Our 2 patients demonstrated that Mycoplasma encephalitis also can be associated with BIPLEDs. References [l] Koskiniemi M, RautonenJ, Lehtokoski-Lehtiniemi E, VaheriA. Epidemiologyof encephalitisin children-A 20-year survey. Ann Neural

1991;29:492-7.

294 PEDIATRICNEUROLOGY Vol. 8 No. 4

[2] Lehtokaski-Lehtiniemi E, KoskiniemiM-L. Mycoplasma pneumoniae encephalitis:A severe entity in children. Pediatr Infect Dis J 1989;8:65 I-3. [3] Carstensen H, Nilsson K-O. Neurological complications associated with Mycoplasma pnewnoniae infection in children. Neuropediatrics 1987;18:57-8. [4] Scully RE, Mark EJ, McNeely sachusetts General Hospital. Weekly

BU. Case records clinicopathological

of the Masexercises.

Case 35-198 I. N Engl J Med 1981;305:507-14. [S] Connolly JH, Hawkins SA. Neurological illness associated with Mycoplasma pneumoniae infection: A study of eight cases. Ir J Med Sci 1980;149:95-101. [6] Hely MA, Williamson PM, Terenty TR. Neurological complications of Mycoplasma pneumoniae infection. Clin Exp Neural 1984;20: 153-60. [7] Ong

ELC,

Ellis

ME,

Yuill

GM.

Neurological

complications

of

Mycoplasma pneumoniae infection. RespirMed 1989;83:441-2. [8] PSnkii A. Central nervous system manifestations associated with serologically verified Mycoplasma pneumoniae infection. Stand J Infect Dis 1980;12:175-84. [9] Bt%Mer RP, &haul N. Periodic clinical correlation, and pathophysiology.

EEG patterns: Classification, J Clin Neurophysiol 1990;7:

249-67.

[lo] Chatrian GE, Shaw C-M, Leffman H. The riodic lateralized epileptiform discharges in EEG: clinical, and pathological study. Electroencephalogr

significance of peAn electrographic, Clin Neurophysiol

1964;17:177-93.

[11]

Kuroiwa

patterns.

Arch

Y. Celesia GG. Clinical Neural 1980;37: 15-20.

significance

of periodic

EEG

[12] Elian M. Herpes simplex encephalitis: Prognosis and longterm follow-up.Arch Neurol 1975;32:39-43. [13] de la Paz D, Brenner RP. Bilateral independent periodic lateralized epileptiform discharges: Clinical significance. Arch Neural 1981;38:713-5. [14] Smith tinctive clinical

JB, Westmoreland BF, Reagan EEG profile iv herpes simplex

TJ, Sandok encephalitis.

BA. A disMayo Clin

Proc 1975;50:469-74. [15] Mizrahi EM, Tharp BR. A characteristic EEG pattern natal herpes simplex encephalitis. Neurology 1982;32: 1215-20.

in neo-