Main article
Pyridoxine-dependent epilepsy: EEG investigations and long-term follow-up

https://doi.org/10.1016/0013-4694(91)90035-3Get rights and content

Abstract

The EEG features and clinical correlates were investigated before, directly after, and on long-term follow-up after initiation of pyridoxine therapy in 6 patients with B6-dependent epilepsy. At each phase, the EEG provided important diagnostic and prognostic information. Pre-B6 3 neonates manifested a unique EEG pattern of generalized bursts of 1–4 Hz sharp and slow activity. This pattern has not been previously described in neonates with B6 dependency and in this age group appears to be highly suggestive of the diagnosis. Five patients experienced an apparent initial response to traditional antiepileptics. The parenteral pyridoxine test, performed in all 5, and repeated in 3, proved to be a highly reliable and reproducible diagnostic test. After 50–100 mg of B6 there was cessation of clinical seizures within minutes and of paroxysmal discharges within hours. On long-term follow-up (3–28 years) all 6 patients were seizure free on B6 (10–100 mg/day) monotherapy. Recurrences of seizures and of specific sequential EEG changes (background slowing, photoparoxysmal response, spontaneous discharges, stimulus-induced myoclonus, generalized seizures) occurred upon B6 withdrawal. Long-term prognosis correlated with the EEG. Two patients had persistently abnormal EEG backgrounds and were moderately to severely retarded, while 4 had normal EEGs with normal or near normal development.

References (36)

  • G.W. Frimpter et al.

    Vitamin B6-dependency syndromes

    Int. J. Clin. Nutr. Res.

    (1969)
  • Y.S. Shin et al.

    Pyridoxal-5′-phosphate concentration as a marker for vitamin-B6-dependent seizures in the newborn

    Lancet

    (1984)
  • D.S. Bachman

    Late-onset pyridoxine dependency convulsions

    Ann. Neurol.

    (1983)
  • A. Bankier et al.

    Pyridoxine dependent seizures - a wider clinical spectrum

    Arch. Dis. Child.

    (1983)
  • M. Bejsovec et al.

    Familial intrauterine convulsions in pyridoxine dependency

    Arch. Dis. Child.

    (1967)
  • P.D. Blanchard et al.

    Isoniazid overdose in the Cambodian population of Olmsted County, Minnesota

    JAMA

    (1986)
  • G. Blennow et al.

    High dose B6 treatment in infantile spasms

    Neuropediatrics

    (1986)
  • T.A. Clarke et al.

    Pyridoxine-dependent seizures requiring high doses of pyridoxine for control

    Am. J. Dis. Child.

    (1979)
  • D.B. Coursin

    Convulsive seizures in infants with pyridoxine-deficient diet

    JAMA

    (1954)
  • G.F. Crowell et al.

    Pyridoxine-dependent seizures

    Am. Fam. Physcn.

    (1983)
  • A. Fois et al.

    Frequency of relative pyridoxine dependency in epileptic children

    Helv. Paediat. Acta

    (1966)
  • J.H. French et al.

    Pyridoxine and infantile myoclonic seizures

    Neurology

    (1967)
  • R. Garty et al.

    Pyridoxine-dependent convulsions in an infant

    Arch. Dis. Child.

    (1962)
  • J. Gentz et al.

    Vitamin B6 metabolism in pyridoxine dependency with seizures

    Acta Paediat. Scand.

    (1967)
  • F.H. Gilles et al.

    Myelinated tracts: growth patterns

  • F. Goutières et al.

    Atypical presentations of pyridoxine-dependent seizures: a treatable cause of intractable epilepsy in infants

    Ann. Neurol.

    (1985)
  • A. Heeley et al.

    Pyridoxol metabolism in vitamin B6 responsive convulsions of early infancy

    Arch. Dis. Child.

    (1978)
  • A.D. Hunt et al.

    Pyridoxine dependency: report of a case of intractable convulsions in an infant controlled by pyridoxine

    Pediatrics

    (1954)
  • Cited by (0)

    Presented in part at the American Epilepsy Society Meeting, 1987, Baltimore, MD.

    View full text