Investigations for neonatal seizures

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Summary

Seizures during the neonatal period are always medical emergencies. Apart from the need for rapid anticonvulsive treatment, the underlying condition is often not immediately obvious. In the search for the correct diagnosis, a thorough history, clinical examination, laboratory work-up, neurophysiological and neuroradiological investigations are all essential. A close collaboration between neonatologists, neuropaediatricians, laboratory specialists, neurophysiologists and radiologists facilitates the adequate care of the infant.

Introduction

Neonatal seizures are medical emergencies that need evaluating and treating promptly. The majority of neonatal seizures are reactive, secondary to an underlying condition and a diverse range of disorders have to be considered, searched for and treated. The investigative work-up should follow a hierarchy to identify disorders that require specific treatment of the underlying cause.

The spectrum of disorders causing neonatal seizures varies with gestational age, with intracranial haemorrhage dominating in the extremely preterm infant.1 Towards term, the most common cause is hypoxic–ischaemic encephalopathy and perinatal arterial stroke. Further, the emergence of signs can also depend on the exposure to external stimuli (e.g. initiation of feeds for some metabolic disorders, incubation time for some infections). Hence, it is important to modify the investigative plan in accordance with the gestational and postnatal age of the infant.2, 3, 4, 5

Section snippets

Clinical history

The presentation of neonatal seizures differs from seizures later in life. In the individual infant with seizures, seizures with and without clinical manifestations usually co-exist.6 Interviews with the parents and midwives, and scrutiny of the maternal medical charts, can reveal important information (Table 1).

Clinical manifestations

The presentation of seizures in the neonatal period differs considerably from that which is seen in older children and in adults. A thorough description of the signs often gives important clues to the aetiology. Today with the general availability of smart-phones with video-function, it is not uncommon that the neonatologist is actually first approached with a video showing the movements that initiated the anxiety of the parents or the nurses/midwives. We now encourage parents to document

Clinical examination

A detailed clinical examination should be performed in all infants with suspected seizures. The neurological examination should include an assessment of the level of consciousness, tone, gaze, body-posture (Fig. 1), tendon, cranial nerve and newborn reflexes. The general body examination focuses on finding indications for an underlying disease/condition. The skin is inspected for bleeding and bruising (Fig. 2), eruptions (Fig. 3), birth-marks (for example in the face, indicating phacomatosis).

Initial laboratory work-up

The initial laboratory work-up focuses on finding those conditions where an immediate treatment is mandatory either to save the life of the infant, or to minimize the ongoing brain damage and thereby reduce any subsequent neurodisability in surviving children.

It is important to prioritize laboratory tests directed at the recognition of metabolic disturbances and infections that, if untreated, can lead to permanent brain damage (Table 3). Hypoglycaemia is readily identified using point-of-care

Extended laboratory tests

If initial laboratory testing is negative a more thorough investigation should take place aiming to rule out rare causes of neonatal seizures.

After consultation with specialists in inborn errors of metabolism and/or neonatal neurology, a work-up plan for rare diseases is done. In Table 4 a list of uncommon and sometimes treatable disorders is found.

Rare cases of some diseases easily missed on ordinary metabolic screening can be identified using a loading dose of the missing substrate.9

Neurophysiological diagnosis and monitoring

This is discussed in-depth in Chapter 5 of this issue (Boylan and Vanhatalo). Once the first-line biochemical tests have been acquired, and any urgent treatment organised, ideally neurophysiological monitoring should be started. With the availability of simplified aEEG monitoring that also acquires and stores the raw EEG, this is possible in many units on a 24 h per day basis. During the last decade the use of amplitude-integrated EEG (aEEG) has become standard of care in the diagnosis of

Neuroimaging

Cranial ultrasound is readily available in most modern NICUs and offers a rapid cotside tool with the possibility of identifying many intracranial pathologies.13, 14 A cranial ultrasound is routine management in the investigation of neonatal seizures. It should be carried out as soon as possible after the first occurrence of seizures and will help in early diagnosis of many underlying causes including intraventricular haemorrhage, arterial stroke, malformation and infections.

Magnetic resonance

Conclusions

Neonatal seizures present a clinical situation necessitating rapid examination, evaluation and treatment. Integrating good clinical judgement together with modern diagnostic tools, symptomatic and causative treatment can be instituted, with the aim of improving the outcome as much as possible. An accurate prognosis can be given in many cases, although some cases remain resistant to treatment and defy all attempts to diagnose the cause.

Practice points

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    Encourage staff and parents to make video

Conflict of interest statement

None declared.

Funding sources

NEMO a collaborative project funded by the European commission under the 7th framework programme.

References (17)

  • G.B. Boylan et al.

    Automated neonatal seizure detection

    Clin Neurophysiol

    (2006)
  • L.M. Leijser et al.

    Using cerebral ultrasound effectively in the newborn infant

    Early Hum Dev

    (2006)
  • P. Govaert et al.

    Diagnostic management of neonatal stroke

    Semin Fetal Neonatal Med

    (2009)
  • D. Kohelet et al.

    Risk factors for neonatal seizures in very low birthweight infants: population-based survey

    J Child Neurol

    (2004)
  • J.J. Volpe

    Neonatal seizures

  • H.C. Glass et al.

    Neonatal seizures

    Curr Treat Options Neurol

    (2009)
  • R.R. Clancy

    Summary proceedings from the neurology group on neonatal seizures

    Pediatrics

    (2006)
  • F.S. Silverstein et al.

    Improving the treatment of neonatal seizures: National Institute of Neurological Disorders and Stroke workshop report

    J Pediatr

    (2008)
There are more references available in the full text version of this article.

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