Heterogeneity within the autism diagnosis obscures the genetic basis of the disorder and impedes our ability to develop effective treatments. We found that by using two readily available tests, autism can be divided into two subgroups, "essential autism" and "complex autism," with different outcomes and recurrence risks. Complex autism consists of individuals in whom there is evidence of some abnormality of early morphogenesis, manifested by either significant dysmorphology or microcephaly. The remainder have "essential autism." From 1995 to 2001, 260 individuals who met DSM-IV criteria for autistic disorder were examined. Five percent (13/260) were microcephalic and 16% (41/260) had significant physical anomalies. Individually, each trait predicted a poorer outcome. Together they define the "complex autism" subgroup, comprising 20% (46/233) of the total autism population. Individuals with complex autism have lower IQs (P=0.006), more seizures (P=0.0008), more abnormal EEGs (46% vs. 30%), more brain abnormalities by MRI (28% vs. 13%). Everyone with an identifiable syndrome was in the complex group. Essential autism defines the more heritable group with higher sib recurrence (4% vs. 0%), more relatives with autism (20% vs. 9%), and higher male to female ratio (6.5:1 vs. 3.2:1). Their outcome was better with higher IQs (P=0.02) and fewer seizures (P=0.0008). They were more apt to develop autism with a regressive onset (43% vs. 23%, P=0.02). Analysis of the features predictive of poor outcome (IQ<55, functionally non-verbal) showed that microcephaly was 100% specific but only 14% sensitive; the presence of physical anomalies was 86% specific and 34% sensitive. The two tests combined yielded 87% specificity, 47% sensitivity, and an odds ratio of 4.8:1 for poor outcome. Separating essential from complex autism should be the first diagnostic step for children with autism spectrum disorders as it allows better prognostication and counseling. Definition of more homogeneous populations should increase power of research analyses.

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The accuracy of freehand ventriculostomy catheterization at the authors' institution typically required 2 passes per successful placement, and, when successful, was 1.6 cm from the Monro foramen. More importantly, 22.4% of these catheter tips were in nonventricular spaces. Although many neurosurgeons believe that the current practice of ventriculostomy is good enough, the results of this study show that there is certainly much room for improvement.

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For infants presenting with subdural hemorrhage, retinal hemorrhage, and neurological decline the “consensus” opinion is that this constellation represents child abuse and that cerebral venous sinus thrombosis and cortical vein thrombosis is a false mimic. This article contends that this conclusion is false for a subset of infants with no evidence of spinal, external head, or body injury and is the result of a poor radiologic evidence base and misinterpreted data. Underdiagnosis of thrombosis is the result of rapid clot dissolution and radiologic under recognition. A pre-existing/chronic subdural hemorrhage predisposes to development of venous sinus thrombosis/cortical vein thrombosis, triggered by minor trauma or an acute life-threatening event such as dysphagic choking, variably leading to retinal and subdural hemorrhages and neurologic decline. These conclusions are based on analysis of the neuroradiologic imaging findings in 11 infants, all featuring undiagnosed cortical vein or venous sinus thrombosis. Subtle neuroradiologic signs of and the mechanisms of thrombosis are discussed. Subarachnoid hemorrhage from leaking thrombosed cortical veins may be confused with acute subdural hemorrhage and probably contributes to the development of retinal hemorrhage ala Terson’s syndrome. Chronic subdural hemorrhage rebleeding from minor trauma likely occurs more readily than bleeding from traumatic bridging vein rupture. Radiologists must meet the challenge of stringent evaluation of neuro imaging studies; any infant with a pre-existing subdural hemorrhage presenting with neurologic decline must be assumed to have venous sinus or cortical vein thrombosis until proven otherwise.

Spontaneous extracranial ICA dissection may present with pulsatile tinnitus as the only symptom in 4% to 50% of patients. Subsequent evolution of a contralateral dissection is even more uncommon. Generally, treatment of this phenomenon is conservative utilizing anticoagulation or aspirin; however, surgical intervention may be necessary.