Case 2: The 10-month-old right-hander

A 10-month-old boy presented with a right hand preference. He was born (of nonconsanguineous parents) at term following an unremarkable pregnancy and delivery with normal Apgar scores and a birth weight of 4250 g. His family history was noncontributory.

Parents first noted left-sided fisting and an inability to use the left hand at approximately four months of age. He would not grasp objects in this hand even when presented directly. He had a weak left leg. The parents did note some improvement over time. He had rolled over front to back at six months of age and had sat unassisted by seven months of age. He was unable to sit up from a lying position and did not stand. Language and social development was age-appropriate. No seizures, loss of consciousness or any abnormal movements had been observed.

Physical examination revealed a well-nourished infant in no distress. His head circumference was 46.5 cm (50% to 75%). His general examination including the skin revealed no abnormalities. The neurological examination revealed an alert infant who babbled. He had symmetrical and reactive pupils. His cranial nerves were preserved. The left thumb appeared to be smaller than the right thumb. The rest of his muscular mass and tone seemed normal. The left arm and especially the left hand were kept preferentially in a flexed position; tone was not significantly increased on the left side. There was left-handed fisting. The hand could be opened passively. He sat unassisted. There was an obvious weakness of the left side with a greater weakness in the upper extremity. When placed in a standing position, he placed more weight on his right leg. When placed ventrally, he kept his left arm next to his body and did not attempt to crawl. He was hyper-reflexive on the left side with a slight predominance in the arm and a positive Babinski sign.

An imaging study revealed the diagnosis.

CASE 2 DIAGNOSIS: PRESUMED PERINATAL INFARCTION

A computed tomography scan revealed a hypodensity in the right basal ganglia near the genu of the internal capsule measuring 20 mm × 6 mm (Figure 1).

Figure 1.

Computed tomography of the brain showing a hypodensity in the right basal ganglia

The infant had a normal detailed thromboembolic workup which included prothrombin, partial thromboplastin time, protein S, protein C, antithrombin III and antiphospholipid antibody levels, as well as factor V Leiden and methylenetetrahydrofolate reductase mutation testing. Parental prothrombotic screening was normal.

He received regular rehabilitation. During a follow-up visit at two years of age, he had minimal left-sided leg weakness and was able to walk well. He had significant left-sided arm weakness, but was able to use the left hand to assist.

Perinatal ischemic stroke is a focal cerebral infarction due to the occlusion of cerebral arteries or veins and venous sinuses between 28 weeks gestational age and 28 days of age. It is common with an incidence of one in 2500 to 4000 live births (1). Some children present with symptoms, usually seizures, in the newborn period. Many others, however, present with pathological hand preference, hemiparesis or seizures later in infancy. If they had a normal perinatal neurological history and imaging confirms focal cerebral infarction (stroke), it is termed presumed perinatal infarction (PPERI) (2).

Stroke has been associated with many factors in newborns and infants. However, strong epidemiological evidence to support direct causation is lacking for most newborns and infants and many are idiopathic (2). Potential risks include cardiac anomalies, blood disorders, infections, maternal factors, trauma, drugs and perinatal asphyxia. Cardiac disorders are the most frequent cause of ischemic stroke in children (25% of cases or more in the Canadian Pediatric Ischemic Stroke Registry) (3). Blood disorders may include prothrombotic states such as factor V Leiden mutation, prothrombin 20210A mutation, protein C or protein S deficiency, antithrombin III deficiency or increased lipoprotein (a). Acute systemic illness, particularly meningitis or sepsis, are common risks. Maternal factors may include coagulation disorders, twin to twin transfusion, in utero cocaine exposure, infection (chorioamnionitis) and placental disorders. The relationship between factors such as birth asphyxia or mode of delivery are unresolved.

Diagnosis of stroke is made by neuroimaging (ultrasound, computed tomography or magnetic resonance imaging, the latter of which is the test of choice) (4). The left hemisphere is more often involved; usually the middle cerebral artery distribution (4). Etiological investigations consist of in-depth questions about family history, maternal, pregnancy and birth history, and ‘thrombophilia’ screening. Echocardiography should be performed in all arterial cases (2). Metabolic, urine toxicology screening and lumbar puncture may be necessary.

Acute management of neonatal stroke has not been widely studied. Infections and seizures need to be treated to prevent secondary brain injury. Some recent evidence supports the use of anticoagulation (low molecular weight heparin) for three months in neonatal stroke due to sinovenous thrombosis (without large infarction or hemorrhage) or arterial ischemic strokes with obvious cardioembolic origin (4). Chronic treatment includes disability-directed, multimodal rehabilitation including physical, occupational and speech therapies. Secondary stroke prevention with acetylsalicylic acid is not usually required in perinatal strokes because recurrence is extremely rare (less than 1%) (2). Education and psychosocial support of the child and family are essential, including the alleviation of unjustified guilt suffered by many parents.

Most survivors of perinatal stroke suffer neurological morbidity (2). The outcome of perinatal stroke includes death, cerebral palsy, cognitive and behavioural disability, and epilepsy. Advanced neuroimaging now allows early prediction of some outcomes, improving counselling and treatment (2). Cognitive and behavioural outcome are more difficult to predict and tend to emerge over years, requiring regular developmental assessments and neuropsychological testing.

Golomb et al (5) studied 22 children with PPERI. The median age at diagnosis was six months (two months to eight years of age). The majority presented with abnormal hand use in the first six months of age. Hand preference earlier than normal (18 to 24 months of age) should raise concern of congenital hemiparesis with causes including stroke, as well as brain malformations, perinatal brain injuries and brachial plexus lesions. Many PPERI patients have histories of either gestational, obstetrical or prothrombotic risk factors. All patients had persistent hemiparesis; more than one-half of patients had signs of speech, learning or behavioural problems.

CLINICAL PEARLS

• Hand preference before 18 months of age is pathological and warrants a complete neurological examination and neuroimaging. Perinatal stroke is common (approximately one in 4000 live births) and the number one cause of hemiplegic cerebral palsy (2).

• Cardiac and prothrombotic evaluations should be performed in all children with perinatal stroke. Identification and rehabilitation of the many potential neurological morbidities will have the greatest impact on the quality of life for the child and the family.