TYPES OF NEONATAL CONVULSIONS

TYPES OF NEONATAL CONVULSIONS
Ballweg (1991) suggested that the type of movements a baby has could classify the convulsions as either subtle, tonic, focal, clonic or myoclonic.
Subtle convulsions:- include movements such as blinking or fluttering of the eyelids, staring, clonic movements of the chin, horizontal or downward movement of eyes, sucking, drooling and sticking the tongue out, cycling movements of the tongue and apnea. Both term and pre­term infants can experience subtle convulsions.
Tonic convulsions:-, there will be extension or flexion of limbs, altered patterns of breathing and maintenance of eye deviations. Tonic convulsions are more common in pre­term babies.
Multi-focal clonic convulsions:- are seen in term babies and the movements include random jerking movements of extremities. Term babies also experience focal clonic convulsions, which are localized, repetitive, clonic jerking movements. An extremity, a limb or a localized muscle group can be affected.
Myoclonic convulsions :- are the least common but affect both term and pre-term babies. The movements are single or multiple flexion jerks of the feet, legs, hands or arms, which should not be confused with similar movements a sleeping baby can demonstrate.
During a convulsion, the baby may have tachycardia, hypertension, raised cerebral blood flow and raised intracranial pressure.
Causes of Convulsion in the Newborn
Central nervous system causes
Intracranial haemorrhage, Intracerebral haemorrhage, Hypoxic-ischemic encephalopathy , Kernicterus
Metabolic
Hypo- and hyperglycemia ,Hypo- and hypercalcaemia, Hypo- and hypernatraemia, Hypomagnesaemia, Inborn errors of metabolism.
Infective
High fever, Meningitis, TORCH infection,Tetanus
Iatrogenic
Respiratory stimulants, Analeptic drugs, Drug toxicity, e.g. theophylline
Others
Cerebral malformations, Drug withdrawal
Investigations
Full blood count, Blood, urine and CSF cultures, Serum IgM and IgG specific TORCH titers.
Biochemical estimation of glucose, calcium, magnesium, bilirubin and electrolytes.
Blood gas levels to detect acidosis and hypoxemia.
Ultrasonography and CT scan of the head to detect intraventricular and/or subara­chnoid haemorrhage, or congenital malformations.
MANAGEMENT
Control of Convulsions
Immediate treatment of a convulsion includes getting the assistance of a pediatrician/ neonatologist while ensuring that the baby has a clear airway and adequate ventilation either spontaneously or mechanically. It also includes turning the infant to the semi-prone position with the head neither hyperflexed nor hyperextended. Gentle oral and nasal suctioning to remove any milk or mucus if required. If the baby is breathing but cyanosed, facial oxygen is to be given at a flow rate of 2-3 liters per minute. If apnea occurs and cyanosis persists, resuscitation may be required. The baby should be handled minimum. If the baby is nursed in an incubator without covering blankets yet dressed and well supported, observation and maintenance of neutral thermal environment can be achieved.
Intravenous administration of phenobar­bitone 10 mg/kg body weight slowly over a period of 3-5 minutes is effective. A mainte­nance dose of 5 mg/kg bodyweight per day is administered intramuscularly for a period of four weeks or longer. In resistant cases I.V. phenytoin (Dilantin), 15 mg/kg at the rate of 0.5 mg/kg/minute, followed by maintenance dose of 5 mg/kg/day is administered.
Treatment of the Underlying Pathology
Hypoglycemia: Glucose infusion, 2 ml/kg of 10 percent glucose is given over a period of 2 to 3 minutes. Glucose infusion is continued at a rate of 6 to 8 mg/kg/minute. Blood glucose must be maintained at 40-60 mg/dl.
Hypomagnesaemia: Magnesium sulphate 0.2 mEq/kg is given LV. every six hours until magnesium level is normal.
Infection: Appropriate antibiotic therapy following septic work up.
Hypocalcaemia: Intravenous administration of 2 ml/kg of 10 percent calcium gluconate over 5 minutes. This is to be followed by oral calcium chloride 250 mg with each feed for few days.
Raised intracranial tension:- 10 ml of 20 percent mannitol to be given intravenously, over 30 to 60 minutes.
Observation and Recording
It is important that observations of a convulsion are documented, noting the type of movement, the areas affected, the length, any color change, any change in heart rate, respiratory rate or blood pressure and any immediate sequel.
The outcome for babies who have convul­sions depend;,; on the cause of the convulsion, the type of convulsion and the BEG tracing. Babies who have congenital malformations of the brain, hypoxic-ischemic encephalopathy or bacterial meningitis tend to have a higher mortality or a poor neurological outcome. Babies who have a late hypocalcaemia, hyponatraemia or primary subarachnoid haemorrhage are more likely to survive neurologically intact.
Babies, who experience subtle, generalized tonic and myoclonic convulsions, tend to have a poorer neurological outcome than babies experiencing the other types of convulsions do. Abnormal EEG tracings generally indicate a poor prognosis (Ballweg, 1991; Blackburn, 1993).
Managing Parents
When their baby suffers trauma during birth, or haemorrhage or convulsions, parents are likely to be extremely shocked. Although the extent of parental contact with the baby will depend on the nature of the birth injury, all parents are entitled to be given honest and clear information about their baby's condition as soon as possible after detection. It is recommended that parents receive this type of bad news when they are together and from someone who is known to them (Richards and Reed, 1991). The neonatologist giving the information will need to give time for parents to clarify their questions. Follow up explanations by nursing personnel and encouragement for parental interactions is essential. Continuing supportive care will also be required for them to deal with the stressful situation.
BIBLIOGRAPHY
1. Ballweg DD, "Neonatal Seizures: an overview", Neonatal Network, 10(1): 15-21, 1991.
2. Blackburn ST, Assessment and management of neurological dysfunction, In: Kpnner C, et al. Comprehensive Neonatal Nursing, WB Saunders, Philadelphia, 1993