Somatosensory evoked potentials and auditory brain-stem responses in congenital hypothyroidism. I. A longitudinal study before and after treatment in six infants detected in the neonatal period

Laureau, E; Vanasse, Michel; Hébert, Réal; Letarte, Jacques; Glorieux, Jacqueline; Desjardins, Michèle; Dussault, Jean H.

doi:10.1016/0013-4694(86)90186-0

Cited by 26 publications

(13 citation statements)

References 34 publications

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“…SEP abnormalities such as were found in CHT patients at the onset of treatment could therefore be expected. Other evoked potential studies on the somesthetic and visual pathways showed similar results (12,13). A study on the peripheral nerves (22) demonstrated depressed nerve conduction velocities at initiation of therapy.…”

Section: Discussionmentioning

confidence: 74%

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Influence of Treatment on the Maturation of the Somesthetic Pathway in Infants with Primary Congenital Hypothyroidism during the First Year of Life

Bongers-Schokking

Colon²,

Mulder

et al. 1993

Pediatr Res

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ABSTRACT. To assess the influence of treatment on the development of the somesthetic pathway in infants with congenital hypothyroidism receiving early treatment, median nerve somatosensory evoked potentials were measured during the 1st y of life.Twenty-nine infants were studied with six to seven somatosensory evoked potential tests per infant. The cervical latency (N13) divided by arm length and the first (N19) and second (N32) cephalic latencies as well as N13-N32 latency were measured. At diagnosis, all components showed a small but significant delay, which was not related to thyroxine (T4) levels before treatment. During treatment, T4 ranged from 50 to 290 nmol/L. At 12 mo, the cervical latency divided by arm length had normalized, whereas N19 and N13-N32 were more abnormal than at diagnosis. For N19, these abnormalities were related to a slow initial rise of T4 (1100 nmol/L after 1 wk of treatment) and the initial N19 values. Abnormal N13-N32 values were associated with high T4 values during treatment (>200 nmol/L) and the type of congenital hypothyroidism (partial or total deficiency in T4 production). Induction of therapy with I-triiodothyronine rather than I-thyroxine and the occurrence of low T4 values ( e l 0 0 nmol/L) after the 4th wk of therapy had no such effect. Our data suggest that, for normal CNS development, euthyroidism should be reached as soon as possible by adequate induction therapy. Thereafter, T4 supplementation should be strictly dosed, keeping the serum T4 values within narrow limits around the mean normal for age, because overtreatment, like initial undertreatment, may lead to CNS abnormalities at the end of the first year. (Pediatr Res 34: 73-78,1993) Abbreviations CHT, congenital hypothyroidism I-T4, levo-thyroxine 1-T3, levo-triiodothyronine I-T4/f, fast initial serum T4 rise on I-T4 induction I-T4/s, slow initial serum T4 rise on I-T4 induction PD, partial deficiency in T4 production TD, total deficiency in T4 production PMA, postmenstrual age SEP, somatosensory evoked potentials N13/AL, latency to first negative peak in cervical lead divided by arm length N19, latency to first negativity in cephalic lead N32, latency to second negativity in cephalic lead N60, latency to third negativity in cephalic lead P22, latency to first positivity after N19 T4>200, group with serum T4 >200 nmol/L on all occasions T 4~2 0 0 , group with serum T4 ~2 0 0 nmol/L on all occasions bl, slope for period T4 ~2 0 0 nmol/L b2, slope for period T4 >200 nmol/L The major objective of the national screening programs for CHT is the prevention of neurologic damage. On the whole, the results of the screening seem gratifying, but there are still unsatisfying aspects. Several studies (1-3) report CHT infants displaying minor neurologic dysfunctions and subnormal IQ at later age despite early diagnosis and treatment. Other studies report normal findings (4-6).Generally, the neurologic deficits are ascribed to perinatal thyroid hormone deficiency, because they were found to be related to very low initial T4 val...

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Section: Discussionmentioning

confidence: 74%

“…We followed longitudinally 29 CHT patients with median nerve SEP. SEP abnormalities were expected on the basis of earlier evoked potential studies in CHT infants (10)(11)(12)(13). SEP results were related to treatment factors such as induction of therapy with I-T4 or I-T3, slow or fast rise of T4 during induction of therapy, and subsequent T4 IKKING ET AL.…”

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confidence: 91%

Influence of Treatment on the Maturation of the Somesthetic Pathway in Infants with Primary Congenital Hypothyroidism during the First Year of Life

Bongers-Schokking

Colon²,

Mulder

et al. 1993

Pediatr Res

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“…Saito et al 9 , in an experimental study carried out in dogs, found a reduction in the number of neuronal cells in the cerebral cortex and structural changes in the membranous labyrinth and in the petrous portion of the temporal bone. Thus, similarly to what happens in diabetes mellitus, the hypothyroidism-related hearing impairment seems to involve numerous structures [10][11][12] . Tonal threshold audiometry, Immittance tests and electrophysiological methods such as brainstem auditory evoked potentials (BAEP) and otoacoustic emissions (EAE) have been used to assess patients with hypothyroidism.…”

Section: Introductionmentioning

confidence: 77%

Avaliação audiológica em pacientes portadores de hipotireoidismo

Santos¹,

Dias²,

Mazeto³

et al. 2010

Braz. j. otorhinolaryngol. (Impr.)

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Heari ng loss in hypothyroidism has been reported by many authors but its pathophysiology is unclear.Aims: to study the audiological evaluation of patients with acquired hypothyroidism.Materials and Methods: two groups were included: a hypothyroidism group (HG,, and a control group (CG, n-30). Parameters studied: gender, time of hypothyroidism, comorbidities, cochleovestibular symptoms, biochemistry and hormonal exams (TSH, T4), tonal audiometry, TOAEs and BERA.Results: all participants were women, 70% of the HG had Hashimoto thyroiditis, 60% of the HG had had the diagnostic of the hypothyroidism for at least five years. Depression and hypertension were frequent in HG. All HG patients had altered TSH values and 50% had diminished T4 values. Sensorineural hearing loss was detected in 22 ears from the HG and in seven from the CG. BERA was normal in the CG and altered in 10 ears from the HG, showing L-V increase. TOAEs were absent in 12 ears from the HG and in four from the CG. Conclusions:HG patients had more cochleovestibular symptoms, higher audiometric thresholds, increase in L-V in the BERA and absence or reduction in TOAEs amplitudes. Such alterations were not associated with THS and free T4 levels. Braz J Otorhinolaryngol. 2010;76(4):478-84. ORIGINAL ARTICLE BJORL

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“…These data agree with earlier studies on untreated CHT infants of comparable age. In a SEP study, prolonged central conduction times were found after median nerve stimulation (12). A study on peripheral nerves of the lower limb revealed reduced peripheral nerve conduction velocities as well as prolonged Hoffmann's reflexes (21).…”

Section: Discussionmentioning

confidence: 97%

“…At this age, dSEP was on the order of hormone levels directly, but within a time interval of at least 1 2-3 wk for all variables (Table 2). wk (10)(11)(12). Before each test informed consent was obtained BA score of the CHT infants was 8.3 _+ 2.4, whereas 11.6 + from the Parents.…”

Section: Methodsmentioning

confidence: 99%

Somatosensory Evoked Potentials in Neonates with Primary Congenital Hypothyroidism during the First Week of Therapy

et al. 1991

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ABSTRACT. At the present, the influence of intrauterine hypothyroidism on the fetus is estimated by bone age (BA). BA is also used as a predictor of later neuropsychologic development. The aim of this study was to investigate whether the neurophysiologic maturation of neonates with congenital hypothyroidism (CHT) is delayed at the start of therapy and, if so, whether this delay is comparable to that in BA. Twenty-seven infants with CHT were examined with median nerve somatosensory evoked potentials (SEP) before or within 1 wk after initiation of therapy. The effect of neonatal jaundice, a potential confounder of neonatal SEP, was also evaluated. Cervical (N13), first cephalic (N19), and second cephalic (N32) peak latencies were measured, as well as N13-N19 interval (central conduction time) and N13 latency divided by arm length. The SEP data of 103 normal infants were used as reference values. In the CHT newborns, a maturational delay was found for all SEP parameters. Preterm infants (n = 3) were conspicuously less affected than term patients. In term CHT infants, jaundice during the first postnatal week, but not late jaundice, had an additional adverse effect. SEP delay was not related to initial or actual T4 levels. BA delay exceeded SEP delay by several weeks. Our data suggest that the depressed T4 levels of the hypothyroid fetus and neonate affect the nervous tissue to a lesser degree than bone tissue and, further, that SEP is superior to BA as parameter for the evaluation of neurologic maturation of infants with CHT. (Pediatr Res 30: 34-39, 1991)

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Somatosensory evoked potentials and auditory brain-stem responses in congenital hypothyroidism. I. A longitudinal study before and after treatment in six infants detected in the neonatal period

Cited by 26 publications

References 34 publications

Influence of Treatment on the Maturation of the Somesthetic Pathway in Infants with Primary Congenital Hypothyroidism during the First Year of Life

Influence of Treatment on the Maturation of the Somesthetic Pathway in Infants with Primary Congenital Hypothyroidism during the First Year of Life

Avaliação audiológica em pacientes portadores de hipotireoidismo

Somatosensory Evoked Potentials in Neonates with Primary Congenital Hypothyroidism during the First Week of Therapy

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