Analysis of a Minimally Invasive Intracranial Pressure Signals During Infusion at the Subarachnoid Spinal Space of Pigs

OBJECTIVE

We developed a new minimally invasive method for intracranial pressure monitoring (ICPMI). The objective of this project is to verify the similarities between the ICPMI and the invasive method (ICPInv), for different components of the intracranial pressure signal-namely, the mean value (trend) as well as its pulsatile component.

MATERIALS AND METHODS

A 9 kg anesthetized pig was used for simultaneous ICP monitoring with both methods. ICP was increased by performing ten infusions of 6 ml 0.9% saline into the spinal subarachnoid space, using a catheter implanted in the lumbar region. For correlation analysis, the signals were decomposed into two components-trend and pulsatile signals. Pearson correlation coefficient was calculated between ICPInv and ICPMI.

RESULTS

During the infusions, the correlation between the pulsatile components of the signals was above 0.5 for most of the time. The signal trends showed a good agreement (correlation above 0.5) for most of the time during infusions.

CONCLUSIONS

The ICPMI signal trends showed a good linear agreement with the signal obtained invasively. Based on the waveform analysis of the pulsatile component of ICP, our results indicate the possibility of using the minimally invasive method for assessing the neuroclinical state of the patient.

Noninvasive intracranial pressure monitoring for HIV-associated cryptococcal meningitis

Mortality and adverse neurologic sequelae from HIV-associated cryptococcal meningitis (HIV-CM) remains high due to raised intracranial pressure (ICP) complications. Cerebrospinal fluid (CSF) high opening pressure occurs in more than 50% of HIV-CM patients. Repeated lumbar puncture with CSF drainage and external lumbar drainage might be required in the management of these patients. Usually, there is a high grade of uncertainty and the basis for clinical decisions regarding ICP hypertension tends to be from clinical findings (headache, nausea and vomiting), a low Glasgow coma scale score, and/or fundoscopic papilledema. Significant neurological decline can occur if elevated CSF pressures are inadequately managed. Various treatment strategies to address intracranial hypertension in this setting have been described, including: medical management, serial lumbar punctures, external lumbar and ventricular drain placement, and either ventricular or lumbar shunting. This study aims to evaluate the role of a non-invasive intracranial pressure (ICP-NI) monitoring in a critically ill HIV-CM patient.

Megalencephaly and perisylvian polymicrogyria with postaxial polydactyly and hydrocephalus (MPPH): report of a new case

Megalencephaly (MEG), or enlargement of the brain, can either represent a familial variant with normal cerebral structure, or a rare brain malformation associated with developmental delay and neurological problems. MEG has been split into two subtypes: anatomical and metabolic. The latter features a build-up inside the cells owing to metabolic causes. Anatomical MEG has been detected in many different conditions, including many overgrowth syndromes. In 2004 Mirzaa et al. reported five non-consanguineous patients with a new MCA/MR syndrome characterized by severe congenital MEG with polymicrogyria (PMG), postaxial polydactyly (POLY) and hydrocephalus (HYD). The authors argued that these findings identified a new and distinct malformation syndrome, which they named MPPH. We report on a new case of MPPH, the first to be described after the original series (Mirzaa et al., 2004).

Severe encephalopathy associated with reactivated human herpesvirus 6 in a six year-old immunocompetent child

When a six year-old immunocompetent child affected by encephalitis was subjected to virological studies, human herpesvirus 6 variant B2 resulted to be the cause of illness. Laboratory diagnosis based on the finding of human herpesvirus 6 genome in the cerebrospinal fluid of the patient both at the beginning of the disease and on the occasion of a relapse which occurred forty days after the patient's hospital discharge. The presence of high-avidity IgG to human herpesvirus 6 detected in the patient's serum at the time of the first hospital admission proved that he had suffered from a past infection by human herpesvirus 6. In the consequence of this, the human herpesvirus 6 DNA finding in the patient's cerebrospinal fluid was to ascribed to virus reactivation. In the light of virological and serological results, the clinical case described underlines the ability of human herpesvirus 6 to cause neurological disorders not only during primary infections but also during infections supported by rescued virus.

Multicystic encephalomalacia in term infants

The terms "multicystic encephalomalacia" and "subcortical leucomalacia" (SCL) are used to describe the presence of areas of necrosis that develop into cystic lesions inside the brain. These lesions are generally due to severe asphyxia and/or hypotension. The designation SCL can also be used to describe the extent and the seat of the lesion in the brain or to distinguish subcortical lesions from periventricular and/or combined ones. In this study we give an account of our experience with eight newborns admitted to our neonatal intensive care unit, who presented clinical-neurological alterations and encephalomalacic lesions whose presence was documented by ultrasonography.

[Communication in the neonatal intensive therapy unit: the opinions of parents and of medical personnel compared]

Within the framework of an European international project, the issue of parents-staff communication in Neonatal Intensive Care Units was explored. 5 Italian unit participated in the project. 80 mothers and 62 fathers of singleton, not malformed, very low birthweight babies were interviewed during the fourth week of their baby's life, while the views of the health personnel (60 doctors and 106 nurses) were collected through an anonymous, self-administered questionnaire. Most of the staff feels that parents should be informed completely about their baby's conditions and prognosis, while the actual practices about transmission of information are reported differently according to professional status: more nurses than doctors feel that the information is not as complete as it should be. Uncertainty of prognosis is the most commonly quoted reason for restricting the information. Parents, on the other hand, are generally satisfied about the information received, although some of them complain about the style of communication, and especially the need to ask repeatedly in order to be informed. These results show some of the gaps existing in communication both within the staff and with parents, and suggest possible ways of improvement.

Polymerase chain reaction in the early diagnosis of HIV-1 infection in high risk subjects

We investigated the presence of the HIV-1 infection using the polymerase chain reaction (PCR) test in seronegative sexual partners of HIV-infected subjects and in children born to seropositive mothers. By using PCR assay, no HIV-1 DNA was detected in 32 female partners of HIV positive patients including three pregnant women who were also studied during pregnancy and after delivery. HIV-1 DNA was found in 12 out of 38 children born to seropositive mothers; five of them also had detectable serum HIV-1 p24 Ag levels. On the whole, our data stress the importance of using a very sensitive technique, i.e. PCR, for the early diagnosis of HIV-1 infection.

Bioelectric brain maturation in fullterm infants and in healthy and pathological preterm infants at term post-menstrual age

At the same post-menstrual age (39-41 weeks), EEG maturation assessed according to the Nolte and Haas method (Nolte, R. and Haas, H.G. (1978) Dev. Med. Child Neurol., 20, 167-182) was studied in 16 fullterm infants (FT), 17 healthy preterm infants (HP) and 18 pathological preterm infants (PP) affected by brain lesions (haemorrhage and/or leucomalacia). There were no significant differences in respect to EEG maturational codes, EEG types or bioelectrical age between the FT and HP groups. The preterm infants affected by brain lesions presented higher percentages of younger EEG codes (i.e. 36 weeks) in State 1 and a higher number of fluctuations between one maturation code and another in both State 1 and State 2, with respect to the HP group. Also, although the PP infants with young EEG codes did not present serious background EEG abnormalities, they did reveal minor EEG abnormalities, such as excessive asynchrony of the 'tracé alternant', lack of frontal sharp transients and monomorphic TA 'bouffees' with little activity at 2-6 c/s. However, no relationship between young EEG codes and onset-offset or duration of the states was found: young codes were often randomly distributed in successive State 1-State 2 epochs, regardless of groupings. Bioelectric age appropriate to the post-menstrual age precedes a normal development or only minor handicap at 24 months, while EEG immaturity of more than 2 weeks corresponds to later major handicaps. The prognostic value of EEG immaturity of between 1.1 and 2 weeks is uncertain.

The risk of convulsions: a longitudinal study of normal babies and infants with neonatal damage in the first 6 years of life

After carefully reviewing the epidemiological literature on this subject, we assessed the risk of febrile, isolated or epileptic convulsions in normal babies and infants with neonatal damage. We considered 417 term or preterm infants with birth injury and compared them with 400 healthy full-term newborns, all born between 1978 and 1980, studying each one individually until at least the age of 6 using the chi 2 test, the risk factors in relation to the convulsive outcome in all the groups were processed. We also calculated the relative risk of outcome of both febrile convulsions and epilepsy. Our results show that as far as the onset of seizure disorders in the term infant is concerned, the predisposing factors are asphyxia, neurological syndrome, and previous barbiturate intake. In contrast with this, for premature infants the risk factors are severe apnea and severe prematurity.

State of the art of magnetic resonance (MR) in neonatal hypoxic-ischemic encephalopathy

Magnetic resonance (MR) has begun to play an important role in neonatal neurology. Several MRI techniques have been applied to the diagnosis of hypoxic ischemic encephalopathy. Cerebral perfusion examined by intravoxel incoherent motion, a non-invasive tool, seems to be opening new inroads for detecting variations (neurophysiological modifications) in cerebral flows during hypoxic ischemic encephalopathy. MR spectroscopy allows identification of specific biochemical alteration of spectra patterns at various moments of hypoxic ischemic distress, including: (1) primary expression of metabolic disorders induced by the lack of blood and O2, revealed by a peak of the water-suppressed H1 spectrum, the earliest and most persistent-marker; (2) a secondary marker for the establishment of permanent lesions of anoxic-ischemic origin revealed that variations of the phosphocreatine/inorganic phosphorous index in the P31 spectrum are of diagnostic and prognostic significance in this phase. In relation to different neuropathological, structural lesions, MRI becomes particularly important in diagnosing the acute phase of cerebral edema and the different types of infarct. MRI is especially fruitful in monitoring the evolution of the lesion, providing an evaluation of myelinization, and defining the neuropathological outlook. Spectroscopic studies on human neonates have helped establish the therapeutic effects of mannitol in cerebral metabolism. MR studies on neonate animals seem to open new therapeutic prospect for CA antagonists.

Lack of clinical-EEG effects of naloxone injection on infantile spasms

In a previous study we found depressed ACTH and normal beta-endorphin values in the cerebrospinal fluid of patients with West's syndrome, whereas normal peptide levels were present in infants with secondary Infantile spasms. This prompted us to study the effects of naloxone administration in children with West's syndrome. After informed consent was obtained from the parents, the effects of naloxone administration on clinical and EEG findings were evaluated in five infants 5-9 months old (3 males, 2 females) with cryptogenic infantile spasms and hypsarrhythmia. The infants were studied at the onset of symptomatology before therapy. An average of 5-10 groups of spasms were present per day. Naloxone (12 micrograms/kg body weight) was administered as an intravenous bolus in two cases, as a slow venous drip in another two cases, and intramuscularly in the last case. EEG and polygraphic monitoring were performed for 2 h. Naloxone did not induce any acute behavioral changes and the number of seizures remained unchanged after treatment. These data reject the possibility that endogenous opioids tonically modulate infantile spasms. Further studies are required to ascertain the involvement of POMC peptides in West's syndrome.

[Intracranial hemorrhages in the full-term newborn infant. Psychomotor development and neurologic sequelae]

Recently increased utilization of high definition T. C. scan and U. S. has led, in recent years, to diagnose and to localize the intracranial haemorrhage of the term newborns. It has been possible to study the outlook of this disease. The neuro-psychological development of the children, affected by intracranial haemorrhage at the birth, is more impaired when the haemorrhage is intraparenchimal: intracerebellar or intracerebral. Our cases show that a haemorrhage causes only discord on the neuro-psycholological development. When, on the other hand, haemorrhage is associated with anoxicbrain damage, especially bilateral, take place major sequelae.

[Follow-up of children born from gestosis mothers]

Seventy children, born from mothers affected from EPH gestosis during pregnancy, were examined. They were two-ten years old, forty females and thirty males, nineteen preterms and fifty-one born at term. Their weight, and head circumference were estimated. Thirty-two children were submitted to terman Merril test and further thirty-eight to Picq Vayer test. The findings were evaluated according to term or preterm birth and to importance of mother's gestosis (EPH1, EPH2, EPH3). The auxological outcomes were satisfactory, particularly after the five-six years of age. Two children were heavily retarded. The others had a normal I.Q., but there was evident failure in immediate memory and in vocabulary's subtest. Moreover fifty % of heavier gestosis children revealed a discordant psycomotor behaviour due to specific failures.

Coproporphyrin excretion in healthy newborn babies

The urinary and fecal coproporphyrins (CP) undergo significant changes in cholestatic diseases of both adults and infants and their determination may provide a diagnostic tool. Little is known about CP excretion in the first days of life. The authors have studied the daily urinary and fecal excretion of CP as well as the I and III isomer distribution in 10 healthy newborn babies from 1 to 10 days old. CP were determined by the solvent partition method and the isomer distribution by thin-layer chromatographic technique. Preliminary studies on urinary porphyrin pattern were performed using a personal high-performance liquid chromatographic method. CP excretion was almost 10 times higher on the 1st day than on the 10th, when expressed by adult standards. The isomer I accounted for almost 80% of the total amount on the first days, whereas at the end of the study, both the CP total amount and isomer distribution overlapped the infant and adult pattern. The authors propose a personal interpretation based on a possible transient enzymatic defect in the metabolic chain of heme synthesis.

[Study of factors affecting the renin-angiotensin-aldosterone system in the premature infant]

Renin-angiotensin-aldosterone system (RAA), Na-K dietary intake and Na-K urinary excretion in 36 premature babies have been investigated. The plasmatic renin activity (PRA) and plasmatic aldosterone level (P-aldo) resulted significantly increased in comparison with children previously studied, 20 days - 23 months old (p less than 0,01). P-aldo demonstrated, in premature babies, a negative correlation with Na-K intake and urinary excretion (p less than 0,001 and less than 0,01 respectively); in the groups nourished with maternal milk or "adapted" formulae P-aldo mean value was significantly more elevated than in the group nourished with formulae "unadapted" (p less than 0,01). A different Na dietary intake seems to be the most important factor influencing P-aldo level also in premature babies. No correlation between PRA - electrolyte excretion was found in any group. The main factor influencing PRA seems to be the age of infants as well as, probably, other hemodynamic mechanisms.