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CLINICAL PRESENTATION OF STROKE IN THE NEWBORN AND INFANT
Stroke represents a focal neurological deficit lasting more than 24 hours, with a vascular basis. Lack of accompanying clinical signs makes t... Show entire abstract.
Stroke represents an increasingly easy to recognize pediatric entity, considering the continual development of imagery techniques. The definition of stroke is: a focal neurological deficit lasting more than 24 hours, with an underlying vascular cause . Thus, it can be differentiated by the transitory ischemic attack, which lasts under 24 hours. There are conditions that can mimic stroke, with focal deficits lasting more than 24 hours but with lesions that cannot be ascribed to a particular vascular territory (e.g. MELAS – mitochondrial encephalopathy; lactic acidosis). Using simple tools such as cerebral ultrasonography  or more sophisticated magnetic resonance imagery (MRI) techniques, nowadays stroke is easily recognizable and thus its consequences can be limited, but it requires a high suspicion rate and experienced medical team. The incidence of stroke varies according to the cited source: 2-3/100.000 , the differences being accounted by inclusion of neonatal intraventricular hemorrhages or to lack of classification according to age. It is known that the highest risk of ischemic stroke is encountered in the neonatal period, a risk more than 17 times greater than in the adult population with comorbidities pertaining to the cardiovascular system (e.g. diabetes mellitus, atherosclerosis, dyslipidemia) . This is to reinforce the basic principle in Pediatrics, that children should not be considered nor treated as miniature adults and stroke causes are not common to both children and adults. The causes of stroke at newborn and infant age can be precipitated by cerebrovascular, infectious, inflammatory diseases, cardiac anomalies, clotting and metabolic disorders. Usually stroke can be discriminated as ischemic or hemorrhagic using neuroimaging, but there are few exceptions when these two entities coexist, as in cerebral venous thrombosis.
METHODS - CLINICAL PRESENTATION
There are multiple forms of clinical presentation in stroke. This polymorphism in clinical signs can postpone an early diagnosis. The acute presentations include seizures (especially in infants), focal motor deficit within 24 hours (typically hemiparesis), various degrees of altered state of consciousness, coma (especially in hemorrhagic stroke or great vessel thrombosis). Headache or cervical pain, commonly encountered symptoms in other age groups, cannot be appreciated in newborns and infants . Moreover, clinical signs which can be found later on include plagiocephaly, laterocolis, focal neurological deficit, delayed motor milestones, seizures, visual deficits with or without. strabismus. Subsequently, we proceed to a detailed description of clinical signs and symptoms. Plagiocephaly can be encountered from 2-3 months of age and if not associated with other clinical signs, it can be easily overlooked by the family and considered benign (positional plagiocephaly when the child is maintained in a single favorite position). We strongly emphasize the importance of measurement of the occipito-frontal circumference (OFC) in the General Practitioner’s Office, considering that the association of plagiocephaly with microcephaly (OFC less than 2 standard deviations to mean for age and sex) is suggestive of an underlying neurological cause.
Laterocolis: Preference of the newborn or infant for a lateralized position of the head prompts to neurological and ophthalmological evaluations. Clinical as well as paraclinical (magnetic resonance imagery) examination of the cervical region is necessary. It should be noted that postural laterocolis due to in utero positioning is only a diagnosis of exclusion. Seizures in the newborn period represent a characteristic form of acute clinical presentation of stroke in this age group and should be firstly taken into consideration, before proceeding to other diagnostic possibilities. Early diagnosis and effective treatment have been noted with the increasing use of aEEG (amplitude-integrated electroencephalography), which is a simplified method of continuous cerebral activity monitoring, used in the neonatal intensive care unit (NICU). It uses a single channel, with a filtrated and compressed over time recording. Recent studies have demonstrated its utility in the NICU, for diagnosis and treatment of epileptic events in preterm and term newborns and for determining the long-term neurological outcome in this age group , . Detection of seizures in the newborn depends on the degree of training of the medical staff and on the correlation with the aEEG recording. In our clinic we perform a poligrafic EEG monitoring using 8 scalp electrods and different sensors for ECG, muscle and respiratory function, with greater chances to reach a correct diagnosis, Difficulties in diagnosing neonatal seizures arise with the display of stereotyped behavior at wake – sleep – wake transitions, due to medication or gestational maturation. The events should be considered as seizures if they surpass the age context, have a repetitive character and can be correlated with EEG phenomena . The clinical aspect of neonatal seizures consists of: clonic focal (unifocal, multifocal, hemiconvulsive), tonic focal (asymmetric posture of body, limbs, sustained eye deviation), mioclonic, extensor spasms, flexor spasms or combination . The cerebral lesion can be identified further in time, in infancy or even later, when cerebral MRI is performed, at the onset of seizures. The child can present with inaugural focal or generalized status epilepticus as a clinical expression of a presumed perinatal stroke (occuring between 28 days antepartum and 28 days postpartum). Infantile spasms are a very distict form of seizures which can be encountered at a distance from the moment of injury and we are describing them sepparatly for better understanding. They usually come in clusters, upon awakening or drowsiness, with bending of the head and torso in a fetal-like position, and can be flexor or extensor spasms, involving all four limbs symmetrically or being more proeminent on one side of the body. Spasms are associated with a typical aspect of the EEG, called hypsarrhythmia, consisting of a very high amplitude, disorganized backgroud tracing and with delayed motor development, altogether comprising West syndrome. This diagnosis calls for an emergency therapeutic solution, as the duration of hypsarrhythmia correlates with the future cognitive deficit of the child  Motor def icit: Typically it involves one hemibody and it has various degrees of severity according to the time of presentation, plegia in acute presentation and paresis later on. The definition of stroke cannot be fully applied in the newborn, considering that the neurologic deficit can be subtle and can gain visibility during the later weeks of the child’s life. The motor deficit is asymmetrical, predominantly affecting the distal arm. A careful neurologic examination reveals early asymmetric hand movements (the paretic hand is clenched in a fist), as well as asymmetric posture reflexes (especially Vojta and Collis horizontal reaction – Vojta examination method) and archaic reflexes (Moro, automatic gait reflex, Galant). At this age group we cannot consider the extensor plantar reflex as a sign, knowing that it is a normal reaction up until the age of 18 months. Because the medial cerebral artery is the most frequently involved site of the ischemic lesion, in almost 85% of the cases, the motor deficit usually involves the right hemibody.
Delay in motor milestones: The moment of injury can easily be missed, with very subtle clinical signs despite a possible large cerebral lesion. Later in the course of the development, the infant does not achieve the normal motor milestones, drawing the attention of the family or caregivers by lack of head control or failure to sit.
This neuromotor delay can be overlooked in the case of overweight infants, who are thought to have a constitutional slow motor status. Thus, the diagnosis and the consequent kinesiotherapy in these cases are often delayed, further contributing to depriving the child of a normal development. Giving the high neural plasticity at this age group, the cognitive and language development delay are more correlated with the persistence of epileptic seizures and less with the cerebral lesion itself .
Visual def icit associated or not with strabismus are part of the clinical signs encountered in children with neonatal or presumed perinatal stroke . After the age of 3 months, parents can notice that their children have difficulty in following toys or trouble in seeing the spoon during meals. Compensatory laterocolis can be associated, in order to focus better. An ophthalmologic evaluation is necessary, with measurement of visual fields if possible and visual evoked potentials. Even in infants with no initial associated eye pathology, ophthalmologic evaluation and follow-up are necessary in order to monitor and treat visual deficits which can constitute further causes of neuromotor delay or poor school performance . RESULTS: Cerebral ultrasound may offer information concerning further neurological outcome, when is done more than once and when it reveals an affected internal capsule. This can have a prognostic value indicating the probability of hemiparesis later in time. Computed tomography can be used when the child is unstable, when there are contraindications to be sedated or the access to magnetic resonance is difficult. It may be useful when postsurgical monitoring is necessary (ex. drainage of intracranial hematomas, cerebral shunting, etc.), but it may miss the lesion in the first 24 hours. Magnetic resonance can identify the stroke site even when it has a pial localization or when this is affecting the posterior circulation of the brain. The method has the long exposure time disadvantage and the difficulty to perform serial examinations.
The clinical presentation of stroke in the newborn and infant can be recognized during a thorough history and clinical examination. Early diagnosis and treatment increases the likelihood of a near as normal development as possible and thus raises the quality of life of the child and family and lowers the costs of integrating a disabled person into the society