Autism Spectrum Disorder Is Associated with Ventricular Enlargement in a Low Birth Weight Population.
Midland County Department of Public Health, Midland, MI
To determine the relation of neonatal cranial ultrasound abnormalities to autism spectrum disorders (ASD) in low birth weight (LBW) adult survivors, a population at increased ASD risk.
This is a secondary analysis of a prospectively-followed regional birth cohort of 1105 LBW infants systematically screened for perinatal brain injury with cranial ultrasound in the first week of life and later assessed for ASD using a two-stage process [screening at age 16 years (n = 623) followed by diagnostic assessment at age 21 years of a systematically selected subgroup of those screened (n = 189)]; 14 cases of ASD were identified. For this analysis, cranial ultrasound abnormalities were defined as ventricular enlargement (indicative of diffuse white matter injury), parenchymal lesions (indicative of focal white matter injury), and isolated germinal matrix/intraventricular hemorrhage.
Compared with no cranial ultrasound abnormalities, any type of white matter injury (ventricular enlargement and/or parenchymal lesion) tripled the risk for screening positively for ASD [3.0 (2.2, 4.1)].
However, the risk of being diagnosed with ASD depended on type of white matter injury. With ventricular enlargement, the risk of ASD diagnosis was almost seven-fold that of no cranial ultrasound abnormality [6.7 (2.3, 19.7)],
and no elevated risk was found for parenchymal lesion without ventricular enlargement [1.8 (0.2, 13.6)].
Isolated germinal matrix/intraventricular hemorrhage did not increase risk for a positive ASD screen or diagnosis.
In LBW neonates, cranial ultrasound evidence of ventricular enlargement is a strong and significant risk factor for subsequent development of rigorously-diagnosed ASD.
Further Readings of Interest
Cerebral ventricular enlargement as a generalized feature of schizophrenia: a distribution analysis on 502 subjects.
Biological Psychiatry Unit, Institute of Psychiatry, University of Milan, Milan, Italy.
Enlargement of cerebral ventricles is one of the most replicated biological features, and the one quantitatively most deviant in schizophrenia.
It occurs in the early phases of the disease and may have pathogenetic relevance. Whether this abnormality is limited to a specific subgroup of patients or is a common feature to most or all patients affected by schizophrenia, however, is still a matter of debate.
The answer to this question would improve our comprehension of the nature of this abnormality and contribute to the debate between the competing hypotheses of biological homogeneity vs heterogeneity of schizophrenia.
We performed a distribution analysis of lateral ventricular dimensions of 340 schizophrenic patients and 162 non-psychiatric controls. All subjects underwent cerebral computerized tomographic scan, and ventricular dimensions were expressed as ventricular brain ratio (VBR). After removing the effect of confounding variables (age, sex and type of scanner) on individual VBR, data were power-transformed and different distribution hypotheses were tested by means of the maximum log-likelihood ratio method.
Our findings indicate that, in the mixed sample of patients and controls, a mixture of two gaussian curves represents the distribution better than a single gaussian curve, but no evidence emerged leading to rejection of the normality hypothesis in the schizophrenic patients sample. Lateral ventricular enlargement in schizophrenia is not a marker of a discrete subgroup of schizophrenia, but occurs in most, if not all, schizophrenic patients. This supports the hypothesis of biological homogeneity of the disease, at least relative to its major brain morphological abnormality.