Neurological examination in healthy term infants aged 3-10 weeks

OBJECTIVES: The neurodevelopmental progress of newborn term infants is checked routinely at around 6 weeks of postnatal age. The maturation of neurological signs in this age range however has not been systematically studied and normative data are not available. The aim of this study was to document any changes in posture, tone, reflexes, behaviour and movements in low-risk full-term infants between 3 and 10 weeks of postnatal age. STUDY DESIGN: We performed a structured neurological examination previously standardised in full-term newborns in the first 48 h after birth. In the current study, a total of 76 examinations were performed between 3 and 10 weeks of age in low-risk full-term infants. RESULTS: The results of the examinations were divided according to postnatal age. In most items, the scores changed with time, with a definite shift in their distribution occurring around 6 weeks. At this age, a reduction in flexor tone of the limbs was observed, together with an increase in active neck tone. Visual orientation in contrast had already improved by 3 weeks when all infants were able to follow a target in a full circle compared to newborns that are often only able to follow a target in an arc. CONCLUSIONS: Our results suggest that 6 weeks post-term birth is an important milestone for changes in neurological signs, particularly those related to muscle tone and posture, probably reflecting maturation of the nervous system. These findings provide important guidelines for the interpretation of the neurological examination performed at this age.     

Can clinical signs identify newborns with neuromuscular disorders?

OBJECTIVE: To evaluate retrospectively the prevalence of neuromuscular disorders in 83 newborns referred to a tertiary care center because of hypotonia and weakness and/or contractures, with a possible diagnosis of neuromuscular disorder. We also aimed to establish whether clinical signs could help to identify infants with neuromuscular disorders. STUDY DESIGN: Sixty-six of the 83 infants who fulfilled the inclusion criteria (79.5%) had an identifiable disorder, which was a neuromuscular disorder in 39 (46.9%). RESULTS: Absent or extremely reduced antigravity movements were mainly found in infants with neuromuscular disorders (sensitivity and specificity 97.4% and 75%), whereas partial range antigravity movements were more frequent in infants with other diagnosis. Contractures were mainly found in infants with peripheral nerve or muscle involvement but also were relatively frequent in infants with genetic or metabolic syndromes (sensitivity 69.2%, specificity 61.3%). Reduced fetal movements and abnormal liquor were frequent but not present consistently in infants with neuromuscular disorders (sensitivity 46.1% and 38.4%) and were found rarely in infants with other disorders (specificity 88.6% and 75.0%). CONCLUSIONS: Severe muscle weakness and contractures are the most reliable indicators of a neuromuscular disorder and should be carefully assessed in an infant with neonatal hypotonia.     

Phenylbutyrate increases SMN gene expression in spinal muscular atrophy patients

Spinal muscular atrophy (SMA) is caused by insufficient levels of survival motor neuron (SMN) protein. Recently, we found that sodium 4-phenylbutyrate (PB), a well-tolerated FDA approved drug, enhances SMN gene expression in vitro. We provide here the first evidence that oral administration of PB (triButyrate significantly increases SMN expression in leukocytes of SMA patients. This finding provides a strong rationale to further investigate the effects of PB as also supported by preliminary clinical data.     

Dopamine-containing neurons are silenced by energy deprivation: a defensive response or beginning of cell death?

Metabolic stress associated to mitochondrial dysfunction has been put forward as an important factor causing degeneration of mesencephalic dopamine-containing neurons in Parkinson's disease (PD). Here we overview how these neurons react to acute hypoxia or hypoglycemia, that are conditions of energy deprivation causing a reduced production of ATP by mitochondria. These neurons, which show a tonic firing discharge under normal condition, undergo into membrane hyperpolarization during hypoxia or hypoglycemia that silence their spontaneous activity. We outline the cellular mechanisms causing membrane hyperpolarization and the accompanied disturbances of intracellular calcium and sodium homeostasis. A better understanding of the changes occurring during transient energy deprivation might contribute to understand the physiopathology of these neurons that derives from mitochondrial dysfunction.     

Gravid uterus exteriorization at cesarean delivery for prenatally diagnosed placenta previa-accreta

Uterine exteriorization during fetal surgery permits hysterotomy away from anterior placental implantations. We employed this technique in two cesarean deliveries for anterior placenta previa-accreta, facilitating selective uterine incisions. Exteriorization of the near-term gravid uterus may be a useful adjunct to cesarean delivery for anterior placenta previa-accreta.     

Vertebral hemi-resection for bone tumor with wide invasion of the vertebral canal: modified surgical method

The authors describe a variation in the method of vertebral hemi-resection used for the treatment of neoplasms that present a wide invasion of the vertebral canal. This is followed by a review of the literature on the subject.     

Long-term roentgenographic evaluation of proximal femur prosthesis after tumor resection

The need for a better roentgenographic evaluation of implant behavior in long-term prosthetic replacement of the proximal femur was considered. The authors present the results of a group of 13 patients belonging to a wide range of ages, with more than ten-years follow-up after tumor resection, and replacement characterized by bipolar cup and non-cemented stem. A new X-ray film acquisition and evaluation method was devised. Results confirmed the good behavior of bipolar reconstructions in patients of different ages, whose sockets were still intact. In younger patients, the prevalent bipolar movement was in the outer bearing, thus limiting polyethylene particulate debris formation. However, debris formation did not significantly affect the bone/stem relationship as only one loose stem was observed in a bone submitted to radiotherapy.