Adult-onset epilepsy and hippocampal pathology in a California sea lion (Zalophus californianus): A case study of suspected in utero exposure to domoic acid.

Domoic acid (DA) is a naturally occurring marine neurotoxin produced by Pseudo-nitzschia diatoms. Adult California sea lions (Zalophus californianus) can experience multiple post-exposure syndromes, including acute toxicosis and chronic epilepsy. Additionally, a delayed-onset epileptic syndrome is proposed for California sea lions (CSL) exposed in utero. This brief report explores a case of a CSL developing adult-onset epilepsy with progressive hippocampal neuropathology. Initial brain magnetic resonance imaging (MRI) and hippocampal volumetric analyses relative to brain size were normal. Approximately 7 years later, MRI studies to evaluate a newly developed epileptic syndrome demonstrated unilateral hippocampal atrophy. While other causes of unilateral hippocampal atrophy cannot be completely excluded, this case may represent in vivo evidence of adult-onset epileptiform DA toxicosis in a CSL. By estimating in utero DA exposure time period, and extrapolating from studies conducted on laboratory species, this case provides circumstantial evidence for a neurodevelopmental explanation correlating in utero exposure to adult-onset disease. Evidence of delayed disease development secondary to gestational exposure to naturally occurring DA has broad implications for marine mammal medicine and public health.

Not Just Down and Out: Oculomotor Nerve Pathologic Spectrum.

The purpose of this article is to understand the complex pathologic spectrum of oculomotor nerve palsy. We review the detailed anatomy and function of the oculomotor nerve and demonstrate how the location of a lesion can drive the differential diagnosis. Lastly, we review atypical presentations of oculomotor nerve palsy to include oculomotor synkinesis and oculomotor nerve hyperactivity. Radiologists must be aware of the typical and atypical presentations of CN III palsy to accurately localize lesions as well as avoid premature exclusion of CN III pathology.

A Case Report of Hydrocephalus in a US Military Recruit.

We present a case of chronic non-communicating hydrocephalus (NCH) in a US military recruit. Non-communicating hydrocephalus is a pathologic obstruction of cerebrospinal fluid (CSF) resulting in enlargement of the ventricles and elevated intracranial pressure. The patient is an 18-year-old male recruit who was evaluated in the Naval Medical Center emergency room for left hip pain and incidentally was found to have profound ventriculomegaly on head imaging. The diagnosis and evaluation of hydrocephalus is greatly dependent on clinical history and supported by radiographic imaging. Based on these factors, one can determine if the hydrocephalus is either acute or chronic and communicating or non-communicating.

Severe CNS angiostrongyliasis in a young marine: a case report and literature review.

Angiostrongylus cantonensis is the most common cause of eosinophilic meningitis worldwide. Infection typically occurs through ingestion of undercooked molluscs or vegetables contaminated by infective larvae. Endemic regions were previously limited to southeast Asia and the Pacific basin; however, this parasite is seeing an alarming increase in global distribution with reported cases in more than 30 countries, including several states in the USA. Although infection typically results in meningitis, a broad spectrum of CNS involvement and severity is emerging as diagnostic methods (such as real-time PCR) continue to improve diagnosis. In this Grand Round, we report a case of a 20-year-old active duty US marine serving in Okinawa, Japan, afflicted with severe CNS angiostrongyliasis marked by radiculomyelitis with quadriparesis, hyperaesthesia, and urinary retention. We present this case to highlight that no clear guidelines exist for the treatment of severe CNS angiostrongyliasis and provide our consensus recommendation that treatment algorithms include use of dual corticosteroids plus anthelmintics when radicular symptoms are present. In this Grand Round we review the clinical features, epidemiology, advances to diagnostic techniques, and available data on current treatment options for CNS angiostrongyliasis. This diagnosis should be highly considered in the differential diagnosis of a patient presenting with meningeal symptoms, paraesthesia or hyperaesthesia, and CSF eosinophilia so that treatment can be started early, which is particularly important in children, because of their increased risk of severe disease and mortality. We recommend combined therapy with albendazole and prednisolone, with consideration for increased steroid dosing in severe cases.

Reversal of flow in the pulmonary artery: high-pitch spiral as a new method for dose reduction in functional imaging.

Advancements in CT technology lave led to substantial dose reductions for anatomic imaging of the heart. Here we illustrate an example where rapid repeat imaging with a high pitch spiral technique can image physiologic function. By optimal timing, and repeat sub second scanning, we illustrate an unusual case where direction of blood flow in the right pulmonary artery is reversed.