Original Studies
Fluctuation in Hearing Thresholds During Recovery From Childhood Bacterial Meningitis Irmeli Roine, MD, PhD,* Tuula Pelkonen, MD, PhD,†‡ Manuel Leite Cruzeiro, MD,‡ Matti Kataja, PhD,§ Antti Aarnisalo, MD, PhD,¶ Heikki Peltola, MD, PhD,† and Anne Pitkäranta, MD, PhD‖ Background: Hearing loss from childhood bacterial meningitis is believed to develop early and have little tendency for recovery. We performed serial hearing evaluations in a large number of children with bacterial meningitis in Luanda, Angola to clarify if, and how often, the result changed. Methods: Children with confirmed bacterial meningitis and hearing evaluations on admission, day 7 of treatment and the follow-up visit formed the study group. Hearing was tested by auditory brainstem response audiometry using stimuli of 40 dB, 60 dB and 80 dB. Threshold changes are described between the composite levels of 40/60 dB and 80/>80 dB. Results. In all, 235 ears were tested. While the ≤60 dB and ≥80 dB levels were maintained through all 3 examinations in 54% and 5% of ears, respectively, changes occurred in 41%. Deterioration from the ≤60 dB level to ≥80 dB was found in 10% of the ears transiently and in 7% permanently. Improvement from the ≥80 dB level to ≤60 dB occurred in 22% of the ears. Half of the ears with ≥80 dB impairment at the follow-up visit arrived with this finding; the others lost hearing later. Maintaining the ≤60 dB level throughout was associated with milder disease (P = 0.003), fewer convulsions (P < 0.0001) and older age (P = 0.009). Conclusions: Almost half of the ears showed threshold changes after admission during recovery from bacterial meningitis, most frequently improvement of initially severely impaired hearing, but some normal ears or with moderate impairment became severely impaired. Key Words: auditory brain stem response, hearing loss, bacterial meningitis, children, event-free survival (Pediatr Infect Dis J 2014;33:253–257)
H
earing impairment is 1 of the invalidating sequelae from childhood bacterial meningitis with an incidence of 10–30% in survivors.1,2 Sensorineural hearing loss is believed to develop early during the course of disease and, once established, to have little tendency for recovery,1,3 but data from serial hearing evaluations disagree. In small studies, 2 of 4 profound hearing impairments detected within 48 hours of admission recovered after 1 month,3
Accepted for publication August 26, 2013. From the *University Diego Portales, Santiago, Chile; †Children’s Hospital, Helsinki University Central Hospital, Helsinki University, Helsinki, Finland; ‡Pediatric Hospital David Bernardino, Luanda, Angola; §National Institute for Health and Welfare; ¶Department of Otorhinolaryngology, Audiology Section; and ‖Department of Otorhinolaryngology, Helsinki University Central Hospital, Helsinki University, Helsinki, Finland. This work was supported by grants from the Päivikki and Sakari Sohlberg Foundation, the Sigrid Jusélius Foundation, the Foundation for Pediatric Research and the daily newspaper Helsingin Sanomat, Helsinki, Finland. Heikki Peltola is a scientific consultant of the Serum Institute of India. The authors have no other funding or conflicts of interest to disclose. Address for correspondence: Irmeli Roine, Los Misioneros 2237, 7520179 Santiago, Chile. E-mail: [email protected]. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (www.pidj.com). Copyright © 2013 by Lippincott Williams & Wilkins ISSN: 0891-3668/14/3303-0253 DOI: 10.1097/INF.0000000000000218
11 of 16 cases of hearing abnormalities detected within 48 hours of admission reverted to normal at discharge4 and 13 of 16 cases of hearing loss apparent on admission recovered during hospital stay.5 We performed serial hearing evaluations by auditory brainstem response (ABR) audiometry in a large number of children with bacterial meningitis to clarify if, and how often, the result changed.
MATERIALS AND METHODS This study was part of a previously reported clinical trial on 723 children with bacterial meningitis at the Pediatric Hospital of Luanda, Angola.6 The Hospital’s Ethics Committee approved the study protocol, and all patients at age 2 months to 13 years with presumed bacterial meningitis (Fig. 1) and their guardian’s informed consent were enrolled during July 2005 to June 2008. The children were often severely ill on admission, 272 (38%) died and all received cefotaxime as antimicrobial treatment. The present study included both ears of the children with confirmed bacterial meningitis (Fig. 1) with a hearing test by ABR within 24 hours of admission, on day 7 ± 1 of treatment and at a follow-up visit at least 1 month after admission. The ears with purulent discharge or with perforated tympanic membrane were excluded. After middle ear inspection by pneumatic otoscopy, specially trained research nurses performed ABR separately on each ear using Madsen™ (GN Otometrics A/S, Taastrup, Denmark) Octavus as described earlier with auditory click stimuli of 40, 60 and 80 dB.7 An independent expert (A.A.), blinded to all other aspects of the study evaluated the recordings. Hearing threshold was determined as the lowest dB level at which the register showed a clear 5th wave. A threshold of 40 dB was considered to indicate normal hearing, and impairments were classified as moderate for a threshold of 40 dB (= detectable 5th wave at 60 dB, but not at 40 dB), severe for 80 dB (= detectable 5th wave at 80 dB, but not at 40 dB, or 60 dB) and profound for the absence of the 5th wave at 40, 60 and 80 dB.7 To get an overview of the evolution of the thresholds, we describe the clinically most relevant changes between normal to moderately impaired hearing (threshold < 60 dB) and severely to profoundly impaired hearing (threshold ≥ 80 dB). This division stems from the practical consideration that a child whose hearing threshold is ≤60 dB understands spoken language, is within verbal social contact and able to hear and repeat words spoken in a raised voice at 1 m, whereas a child whose hearing threshold is ≥80 dB requires rehabilitation (hearing aids, cochlear implants, lip-reading and/or signing sometimes).8 The changes between the 4 threshold levels were so marked and variable that it was difficult to obtain an overview of the situation. To test for differences between the threshold changes and other variables, we used analysis of variance or the Kruskall-Wallis test (whichever was appropriate) and the contingency table. Quantitative variables with normal distribution are expressed as means ± standard deviation and without normal distribution as medians with interquartile range (IQR). Logistic regression model was used to examine which of the variables with a P < 0.05 in Table 1 remained significantly associated with the threshold changes when
The Pediatric Infectious Disease Journal • Volume 33, Number 3, March 2014
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The Pediatric Infectious Disease Journal • Volume 33, Number 3, March 2014
Roine et al
FIGURE 1. Formation of the study group. aSigns and symptoms of bacterial meningitis and cloudy CSF, or a CSF sample positive for Gram-staining, or CSF with >50 white cells (predominantly polymorphs)/mm3. bThe criteria for confirmed bacterial meningitis were positive CSF culture in 225, positive CSF antigen detection by polymerase chain reaction in 15 and having at least 2 of the following criteria: CSF leukocytes exceeding 100 (predominantly polymorphs)/mm3, positive Gramstain, positive latex agglutination test or serum C-reactive protein exceeding 40 mg/L, in addition to typical symptoms and signs of bacterial meningitis in 107.6 cTwo children were excluded from further analysis by the exclusion criteria of middle ear pathology in both ears. analyzed together, eg, were independent predictors of the changes. The results are expressed as odds ratio (OR) with 95% confidence interval (95% CI). If >1 variable measured the same phenomenon (for instance, severity of disease), only 1 was examined. P < 0.05 was taken as significant.
RESULTS Of the 451 survivors of the original study, 123 (27%) fulfilled the inclusion criteria (Fig. 1). Of their 246 ears, 9 were excluded for having purulent discharge and 2 for having a perforated tympanic membrane (both ears of 2 patients). Thus, 235 ears were studied, 2 from 114 patients and 1 from 7 patients. The patients’ median age was 11 months (range 2–157 months), 47% were females, and the median length of history of illness before admission was 4 days. Malaria thick film was positive in 31% (37/119), 58% (70/121) received antimalarial treatment, HIV serology was positive in 6% (7/110) and Mantoux test result ≥10 mm in 9% (8/89) of the studied children. The follow-up visit took place after 1 or 3 months in 95% of the patients (115/121) and after 6–24 months in 5% of the patients (6/121). The study group did not differ from the other survived patients with confirmed bacterial meningitis from the original trial,6 who did not attend a follow-up visit, nor from those who attended a follow-up visit but missed 1 or more of the serial hearing evaluations (P > 0.05, respectively, Fig. 1, Tables, Supplemental Digital Content 1 and 2, http:// links.lww.com/INF/B743 and http://links.lww.com/INF/B744). The admission hearing threshold was ≤60 dB in 71% of ears (168/235) and ≥80 dB in 29% (67/235). Thereafter, the levels oscillated in various ways, summarized as 6 types of evolutions (Table 2, Fig. 2). The first and most common type of evolution, comprising 128 ears (54%), showed no change from the ≤60 dB level during the 3 evaluations. In the second type, seen in 24 ears (10 %), a
254 | www.pidj.com
transient deterioration occurred from the ≤60 dB level to ≥80 dB on day 7, returning to ≤60 dB at the follow-up visit. In the third type, observed in 16 ears (7%), the initial threshold of ≤60 dB deteriorated to ≥80 dB, either already on day 7 (8/16 ears) or first at the follow-up visit (8/16 ears). The 4th type of evolution, observed in 51 ears (22%), consisted in improvement of the initial threshold of ≥80 dB to ≤60 dB, either already on day 7 (28/51 ears) or at the follow-up visit (23/51 ears). In the 5th type, seen in 4 ears (2%), both the admission and the follow-up visit threshold was ≥80 dB, but there was transient improvement to ≤60 dB on day 7. In the 6th and worst type of evolution, seen in 12 ears (5%), the threshold of ≥80 dB remained unchanged throughout the recordings. Only half of the ears (16/32), which at the follow-up visit had an ≥80 dB impairment, showed the same finding on admission; the other half (16/32 ears) deteriorated to this level after initially normal or only moderately impaired hearing.
Threshold Changes Compared With Other Data (Table 1) Compared with the ears that remained throughout at the ≤60 dB level, the ears that underwent other types of evolutions belonged to patients who were younger (P = 0.009), had more severe disease as measured by the Glasgow Coma Score (GCS; P = 0.0007), more seizures (P < 0.0001), slower recovery with the GCS under 15 for more days (P = 0.003) and a longer hospital stay (P = 0.007). In regard to management, they had received more frequently anticonvulsive medication (P < 0.0001) and intravenous quinine treatment (P = 0.009). They also had a lower Glasgow outcome score both on day 7 (P = 0.002) and at the 1-month, follow-up visit (P = 0.0003). Other differences between the groups were seen in cerebrospinal fluid (CSF) glucose concentration (P = 0.04) and malaria positivity, but not according to etiology (P > 0.05, Table 1). © 2013 Lippincott Williams & Wilkins
The Pediatric Infectious Disease Journal • Volume 33, Number 3, March 2014
Hearing Loss After Meningitis
TABLE 1. Patient, Disease and Treatment Variables According to the Admission Threshold and the Type of Change in Serial Evaluations Admission Threshold ≤60 dB No Change Variable Age, months Females Days of illness prior to admission Prior antimicrobials GCS§ CSF glucose, mg/dL CSF white cells per μL Malaria thick film (+) Mantoux ≥10 mm HIV positive H. influenzae etiology S. pneumoniae etiology N. meningitidis etiology Seizures during stay Days with seizures Length of stay, days Any antimalarial treatment¶ Intravenous quinine Glasgow outcome score day 7║
Transient Deterioration
Admission Threshold ≥80 dB* Permanent Deterioration
Improved
No change
n = 128
n = 24
n = 16
n = 51
n = 12
P value
14 [34]† 58 (45)‡ 4 [4] 42/127 (33) 15 [4] 15 [16] 1072 [2640] 30/126 (24) 8/92 (9) 4/115 (3) 41 (32) 39 (30) 13 (10) 46/123 (37) 0 [1] 9 [6.5] 68 (53) 44 (34) 5 [0]
12 [13] 14 (58) 5 [4] 7 (29) 12 [5] 8 [13] 2500 [2480] 7/23 (30) 1/16 (6) 1/23 (4) 14 (58) 6 (25) 1 (4) 17/22 (77) 2 [4] 10.5 [8,5] 15 (63) 8 (33) 5 [2]
8.5 [6] 7 (44) 4 [3] 4 (25) 12.5 [8] 16 [13] 2020[3528] 6 (38) 0/14 (-) 0/16 (-) 8 (50) 5 (31) 2 (13) 12 (75) 3 [3,5] 11 [7.5] 9 (56) 8 (50) 4 [2]
9 [22] 25 (49) 4 [4] 32/50 (63) 12 [8] 10 [18] 1800 [2881] 25/50 (50) 4/38 (11) 4/47 (9) 17 (33) 18 (35) 3 (6) 28/48 (58) 1 [4] 11 [9.5] 35 (69) 32 (63) 5 [2]
6.5 [5] 4 (33) 4 [1] 6 (50) 7 [8.5] 14 [29] 1250 [1795] 4 (33) 0/10 (-) 3/12 (25) 3 (25) 8 (67) 1 (8) 12 (100) 4 [0,5] 14 [12] 6 (50) 6 (50) 3 [2]
0.009 0.66 0.88 0.001 0.0007 0.04 0.25 0.02 0.63 0.02 0.08 0.25 0.87 3 days during hospital stay (OR: 5.00; 95% CI: 1.73–14.49; P = 0.003 and OR: 3.87; 95% CI: 1.06–14.411; P = 0.04, respectively). Improvement of hearing threshold (Table 3) was associated with a history of preadmission antimicrobials (OR: 5.04; 95% CI: 2.16–11.79; P = 0.0002) and intravenous quinine treatment (OR: 4.03; 95% CI: 1.62–9.98; P = 0.003). Remaining at the ≥80 dB level throughout the 3 registrations was associated with having had convulsions for over 3 days during hospital stay (OR: 46.9; 95% CI: 4.81–457; P = 0.0009) and being HIV positive (OR: 86.6; 95% CI: 5.26–1424; P = 0.002).
Unilateral Versus Bilateral Threshold Changes Both ears showed the same evolution in hearing thresholds in 78/114 (68%) children, but in 36/114 (32%) children they differed. Having the same evolution in both ears versus different evolutions © 2013 Lippincott Williams & Wilkins
was associated with milder disease as assessed by median GCS at admission [15 (IQR 4) vs. 11.5 (IQR 7), P = 0.005] and a higher median Glasgow outcome score at day 7 [7 (IQR 0.3) vs. 5 (IQR 2), P = 0.04]. No differences (P > 0.05) were observed according to age, sex, head circumference, etiology or any of the other tested patient or disease characteristics (data not shown).
DISCUSSION Our results show that half of all ears with likely permanent severe/profound hearing loss after childhood bacterial meningitis had this finding already on admission, whereas the other half was admitted with normal or only moderately diminished hearing and became severely/profoundly impaired later. On the other hand, severely/profoundly impaired hearing on admission was often transitory and later improved. On the whole, considerable fluctuation in the hearing threshold occurred in no 3 days‡ Intravenous quinine§
Transient Deterioration* (n = 23)
Permanent Deterioration* (n = 14)
OR
95% CI
P
OR
0.059 0.89 0.71
0.12–0.29 0.34–2.31 0.25–2.00
0.0005 0.81 0.51
0.042 4.08 0.38
0.008–0.21 0.0001 1.02–16.32 0.05 0.05–2.56 0.18
0.103 0.69 5.04
3.69 2.08 5.00 0.71
0.79–17.22 0.19–22.43 1.73–14.49 0.26–1.96
0.10 0.55 0.003 0.51
0.85 — 3.87 1.76
0.23–3.15 0.81 — — 1.06–14.11 0.04 0.53–5.89 0.36
0.89 3.29 2.22 3.42
95% CI
P
Improvement* (n = 45) OR
95% CI
Remained at ≥80 dB* (n =11)† P
0.036–0.29
Fluctuation in Hearing Thresholds During Recovery From Childhood Bacterial Meningitis Irmeli Roine, MD, PhD,* Tuula Pelkonen, MD, PhD,†‡ Manuel Leite Cruzeiro, MD,‡ Matti Kataja, PhD,§ Antti Aarnisalo, MD, PhD,¶ Heikki Peltola, MD, PhD,† and Anne Pitkäranta, MD, PhD‖ Background: Hearing loss from childhood bacterial meningitis is believed to develop early and have little tendency for recovery. We performed serial hearing evaluations in a large number of children with bacterial meningitis in Luanda, Angola to clarify if, and how often, the result changed. Methods: Children with confirmed bacterial meningitis and hearing evaluations on admission, day 7 of treatment and the follow-up visit formed the study group. Hearing was tested by auditory brainstem response audiometry using stimuli of 40 dB, 60 dB and 80 dB. Threshold changes are described between the composite levels of 40/60 dB and 80/>80 dB. Results. In all, 235 ears were tested. While the ≤60 dB and ≥80 dB levels were maintained through all 3 examinations in 54% and 5% of ears, respectively, changes occurred in 41%. Deterioration from the ≤60 dB level to ≥80 dB was found in 10% of the ears transiently and in 7% permanently. Improvement from the ≥80 dB level to ≤60 dB occurred in 22% of the ears. Half of the ears with ≥80 dB impairment at the follow-up visit arrived with this finding; the others lost hearing later. Maintaining the ≤60 dB level throughout was associated with milder disease (P = 0.003), fewer convulsions (P < 0.0001) and older age (P = 0.009). Conclusions: Almost half of the ears showed threshold changes after admission during recovery from bacterial meningitis, most frequently improvement of initially severely impaired hearing, but some normal ears or with moderate impairment became severely impaired. Key Words: auditory brain stem response, hearing loss, bacterial meningitis, children, event-free survival (Pediatr Infect Dis J 2014;33:253–257)
H
earing impairment is 1 of the invalidating sequelae from childhood bacterial meningitis with an incidence of 10–30% in survivors.1,2 Sensorineural hearing loss is believed to develop early during the course of disease and, once established, to have little tendency for recovery,1,3 but data from serial hearing evaluations disagree. In small studies, 2 of 4 profound hearing impairments detected within 48 hours of admission recovered after 1 month,3
Accepted for publication August 26, 2013. From the *University Diego Portales, Santiago, Chile; †Children’s Hospital, Helsinki University Central Hospital, Helsinki University, Helsinki, Finland; ‡Pediatric Hospital David Bernardino, Luanda, Angola; §National Institute for Health and Welfare; ¶Department of Otorhinolaryngology, Audiology Section; and ‖Department of Otorhinolaryngology, Helsinki University Central Hospital, Helsinki University, Helsinki, Finland. This work was supported by grants from the Päivikki and Sakari Sohlberg Foundation, the Sigrid Jusélius Foundation, the Foundation for Pediatric Research and the daily newspaper Helsingin Sanomat, Helsinki, Finland. Heikki Peltola is a scientific consultant of the Serum Institute of India. The authors have no other funding or conflicts of interest to disclose. Address for correspondence: Irmeli Roine, Los Misioneros 2237, 7520179 Santiago, Chile. E-mail: [email protected]. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (www.pidj.com). Copyright © 2013 by Lippincott Williams & Wilkins ISSN: 0891-3668/14/3303-0253 DOI: 10.1097/INF.0000000000000218
11 of 16 cases of hearing abnormalities detected within 48 hours of admission reverted to normal at discharge4 and 13 of 16 cases of hearing loss apparent on admission recovered during hospital stay.5 We performed serial hearing evaluations by auditory brainstem response (ABR) audiometry in a large number of children with bacterial meningitis to clarify if, and how often, the result changed.
MATERIALS AND METHODS This study was part of a previously reported clinical trial on 723 children with bacterial meningitis at the Pediatric Hospital of Luanda, Angola.6 The Hospital’s Ethics Committee approved the study protocol, and all patients at age 2 months to 13 years with presumed bacterial meningitis (Fig. 1) and their guardian’s informed consent were enrolled during July 2005 to June 2008. The children were often severely ill on admission, 272 (38%) died and all received cefotaxime as antimicrobial treatment. The present study included both ears of the children with confirmed bacterial meningitis (Fig. 1) with a hearing test by ABR within 24 hours of admission, on day 7 ± 1 of treatment and at a follow-up visit at least 1 month after admission. The ears with purulent discharge or with perforated tympanic membrane were excluded. After middle ear inspection by pneumatic otoscopy, specially trained research nurses performed ABR separately on each ear using Madsen™ (GN Otometrics A/S, Taastrup, Denmark) Octavus as described earlier with auditory click stimuli of 40, 60 and 80 dB.7 An independent expert (A.A.), blinded to all other aspects of the study evaluated the recordings. Hearing threshold was determined as the lowest dB level at which the register showed a clear 5th wave. A threshold of 40 dB was considered to indicate normal hearing, and impairments were classified as moderate for a threshold of 40 dB (= detectable 5th wave at 60 dB, but not at 40 dB), severe for 80 dB (= detectable 5th wave at 80 dB, but not at 40 dB, or 60 dB) and profound for the absence of the 5th wave at 40, 60 and 80 dB.7 To get an overview of the evolution of the thresholds, we describe the clinically most relevant changes between normal to moderately impaired hearing (threshold < 60 dB) and severely to profoundly impaired hearing (threshold ≥ 80 dB). This division stems from the practical consideration that a child whose hearing threshold is ≤60 dB understands spoken language, is within verbal social contact and able to hear and repeat words spoken in a raised voice at 1 m, whereas a child whose hearing threshold is ≥80 dB requires rehabilitation (hearing aids, cochlear implants, lip-reading and/or signing sometimes).8 The changes between the 4 threshold levels were so marked and variable that it was difficult to obtain an overview of the situation. To test for differences between the threshold changes and other variables, we used analysis of variance or the Kruskall-Wallis test (whichever was appropriate) and the contingency table. Quantitative variables with normal distribution are expressed as means ± standard deviation and without normal distribution as medians with interquartile range (IQR). Logistic regression model was used to examine which of the variables with a P < 0.05 in Table 1 remained significantly associated with the threshold changes when
The Pediatric Infectious Disease Journal • Volume 33, Number 3, March 2014
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The Pediatric Infectious Disease Journal • Volume 33, Number 3, March 2014
Roine et al
FIGURE 1. Formation of the study group. aSigns and symptoms of bacterial meningitis and cloudy CSF, or a CSF sample positive for Gram-staining, or CSF with >50 white cells (predominantly polymorphs)/mm3. bThe criteria for confirmed bacterial meningitis were positive CSF culture in 225, positive CSF antigen detection by polymerase chain reaction in 15 and having at least 2 of the following criteria: CSF leukocytes exceeding 100 (predominantly polymorphs)/mm3, positive Gramstain, positive latex agglutination test or serum C-reactive protein exceeding 40 mg/L, in addition to typical symptoms and signs of bacterial meningitis in 107.6 cTwo children were excluded from further analysis by the exclusion criteria of middle ear pathology in both ears. analyzed together, eg, were independent predictors of the changes. The results are expressed as odds ratio (OR) with 95% confidence interval (95% CI). If >1 variable measured the same phenomenon (for instance, severity of disease), only 1 was examined. P < 0.05 was taken as significant.
RESULTS Of the 451 survivors of the original study, 123 (27%) fulfilled the inclusion criteria (Fig. 1). Of their 246 ears, 9 were excluded for having purulent discharge and 2 for having a perforated tympanic membrane (both ears of 2 patients). Thus, 235 ears were studied, 2 from 114 patients and 1 from 7 patients. The patients’ median age was 11 months (range 2–157 months), 47% were females, and the median length of history of illness before admission was 4 days. Malaria thick film was positive in 31% (37/119), 58% (70/121) received antimalarial treatment, HIV serology was positive in 6% (7/110) and Mantoux test result ≥10 mm in 9% (8/89) of the studied children. The follow-up visit took place after 1 or 3 months in 95% of the patients (115/121) and after 6–24 months in 5% of the patients (6/121). The study group did not differ from the other survived patients with confirmed bacterial meningitis from the original trial,6 who did not attend a follow-up visit, nor from those who attended a follow-up visit but missed 1 or more of the serial hearing evaluations (P > 0.05, respectively, Fig. 1, Tables, Supplemental Digital Content 1 and 2, http:// links.lww.com/INF/B743 and http://links.lww.com/INF/B744). The admission hearing threshold was ≤60 dB in 71% of ears (168/235) and ≥80 dB in 29% (67/235). Thereafter, the levels oscillated in various ways, summarized as 6 types of evolutions (Table 2, Fig. 2). The first and most common type of evolution, comprising 128 ears (54%), showed no change from the ≤60 dB level during the 3 evaluations. In the second type, seen in 24 ears (10 %), a
254 | www.pidj.com
transient deterioration occurred from the ≤60 dB level to ≥80 dB on day 7, returning to ≤60 dB at the follow-up visit. In the third type, observed in 16 ears (7%), the initial threshold of ≤60 dB deteriorated to ≥80 dB, either already on day 7 (8/16 ears) or first at the follow-up visit (8/16 ears). The 4th type of evolution, observed in 51 ears (22%), consisted in improvement of the initial threshold of ≥80 dB to ≤60 dB, either already on day 7 (28/51 ears) or at the follow-up visit (23/51 ears). In the 5th type, seen in 4 ears (2%), both the admission and the follow-up visit threshold was ≥80 dB, but there was transient improvement to ≤60 dB on day 7. In the 6th and worst type of evolution, seen in 12 ears (5%), the threshold of ≥80 dB remained unchanged throughout the recordings. Only half of the ears (16/32), which at the follow-up visit had an ≥80 dB impairment, showed the same finding on admission; the other half (16/32 ears) deteriorated to this level after initially normal or only moderately impaired hearing.
Threshold Changes Compared With Other Data (Table 1) Compared with the ears that remained throughout at the ≤60 dB level, the ears that underwent other types of evolutions belonged to patients who were younger (P = 0.009), had more severe disease as measured by the Glasgow Coma Score (GCS; P = 0.0007), more seizures (P < 0.0001), slower recovery with the GCS under 15 for more days (P = 0.003) and a longer hospital stay (P = 0.007). In regard to management, they had received more frequently anticonvulsive medication (P < 0.0001) and intravenous quinine treatment (P = 0.009). They also had a lower Glasgow outcome score both on day 7 (P = 0.002) and at the 1-month, follow-up visit (P = 0.0003). Other differences between the groups were seen in cerebrospinal fluid (CSF) glucose concentration (P = 0.04) and malaria positivity, but not according to etiology (P > 0.05, Table 1). © 2013 Lippincott Williams & Wilkins
The Pediatric Infectious Disease Journal • Volume 33, Number 3, March 2014
Hearing Loss After Meningitis
TABLE 1. Patient, Disease and Treatment Variables According to the Admission Threshold and the Type of Change in Serial Evaluations Admission Threshold ≤60 dB No Change Variable Age, months Females Days of illness prior to admission Prior antimicrobials GCS§ CSF glucose, mg/dL CSF white cells per μL Malaria thick film (+) Mantoux ≥10 mm HIV positive H. influenzae etiology S. pneumoniae etiology N. meningitidis etiology Seizures during stay Days with seizures Length of stay, days Any antimalarial treatment¶ Intravenous quinine Glasgow outcome score day 7║
Transient Deterioration
Admission Threshold ≥80 dB* Permanent Deterioration
Improved
No change
n = 128
n = 24
n = 16
n = 51
n = 12
P value
14 [34]† 58 (45)‡ 4 [4] 42/127 (33) 15 [4] 15 [16] 1072 [2640] 30/126 (24) 8/92 (9) 4/115 (3) 41 (32) 39 (30) 13 (10) 46/123 (37) 0 [1] 9 [6.5] 68 (53) 44 (34) 5 [0]
12 [13] 14 (58) 5 [4] 7 (29) 12 [5] 8 [13] 2500 [2480] 7/23 (30) 1/16 (6) 1/23 (4) 14 (58) 6 (25) 1 (4) 17/22 (77) 2 [4] 10.5 [8,5] 15 (63) 8 (33) 5 [2]
8.5 [6] 7 (44) 4 [3] 4 (25) 12.5 [8] 16 [13] 2020[3528] 6 (38) 0/14 (-) 0/16 (-) 8 (50) 5 (31) 2 (13) 12 (75) 3 [3,5] 11 [7.5] 9 (56) 8 (50) 4 [2]
9 [22] 25 (49) 4 [4] 32/50 (63) 12 [8] 10 [18] 1800 [2881] 25/50 (50) 4/38 (11) 4/47 (9) 17 (33) 18 (35) 3 (6) 28/48 (58) 1 [4] 11 [9.5] 35 (69) 32 (63) 5 [2]
6.5 [5] 4 (33) 4 [1] 6 (50) 7 [8.5] 14 [29] 1250 [1795] 4 (33) 0/10 (-) 3/12 (25) 3 (25) 8 (67) 1 (8) 12 (100) 4 [0,5] 14 [12] 6 (50) 6 (50) 3 [2]
0.009 0.66 0.88 0.001 0.0007 0.04 0.25 0.02 0.63 0.02 0.08 0.25 0.87 3 days during hospital stay (OR: 5.00; 95% CI: 1.73–14.49; P = 0.003 and OR: 3.87; 95% CI: 1.06–14.411; P = 0.04, respectively). Improvement of hearing threshold (Table 3) was associated with a history of preadmission antimicrobials (OR: 5.04; 95% CI: 2.16–11.79; P = 0.0002) and intravenous quinine treatment (OR: 4.03; 95% CI: 1.62–9.98; P = 0.003). Remaining at the ≥80 dB level throughout the 3 registrations was associated with having had convulsions for over 3 days during hospital stay (OR: 46.9; 95% CI: 4.81–457; P = 0.0009) and being HIV positive (OR: 86.6; 95% CI: 5.26–1424; P = 0.002).
Unilateral Versus Bilateral Threshold Changes Both ears showed the same evolution in hearing thresholds in 78/114 (68%) children, but in 36/114 (32%) children they differed. Having the same evolution in both ears versus different evolutions © 2013 Lippincott Williams & Wilkins
was associated with milder disease as assessed by median GCS at admission [15 (IQR 4) vs. 11.5 (IQR 7), P = 0.005] and a higher median Glasgow outcome score at day 7 [7 (IQR 0.3) vs. 5 (IQR 2), P = 0.04]. No differences (P > 0.05) were observed according to age, sex, head circumference, etiology or any of the other tested patient or disease characteristics (data not shown).
DISCUSSION Our results show that half of all ears with likely permanent severe/profound hearing loss after childhood bacterial meningitis had this finding already on admission, whereas the other half was admitted with normal or only moderately diminished hearing and became severely/profoundly impaired later. On the other hand, severely/profoundly impaired hearing on admission was often transitory and later improved. On the whole, considerable fluctuation in the hearing threshold occurred in no 3 days‡ Intravenous quinine§
Transient Deterioration* (n = 23)
Permanent Deterioration* (n = 14)
OR
95% CI
P
OR
0.059 0.89 0.71
0.12–0.29 0.34–2.31 0.25–2.00
0.0005 0.81 0.51
0.042 4.08 0.38
0.008–0.21 0.0001 1.02–16.32 0.05 0.05–2.56 0.18
0.103 0.69 5.04
3.69 2.08 5.00 0.71
0.79–17.22 0.19–22.43 1.73–14.49 0.26–1.96
0.10 0.55 0.003 0.51
0.85 — 3.87 1.76
0.23–3.15 0.81 — — 1.06–14.11 0.04 0.53–5.89 0.36
0.89 3.29 2.22 3.42
95% CI
P
Improvement* (n = 45) OR
95% CI
Remained at ≥80 dB* (n =11)† P
0.036–0.29
