Biagio Azzarelli

Hypoxic-ischemic encephalopathy in areas of primary myelination: a neuroimaging and PET study

The stage of regional structural and biochemical development of the central nervous system appears as a critical factor determining the distribution of hypoxic-ischemic lesions during the perinatal period. We describe the brain lesions in 12 patients who suffered hypoxia-ischemia during the perinatal period. The gestational age ranged from 35 to 42 weeks and the age at death from 2 to 16 weeks. There is one patient alive at age 18 years and a second patient at age 1 year. The cerebral cortical damage is mainly restricted to areas of primary myelination and adjacent subcortical white matter. In addition, there is thalamic, basal ganglia, brainstem, and spinal cord damage. It is postulated that selective damage occurs in those areas which at the moment of the hypoxic-ischemic insult had achieved higher rates of oxygen-glucose utilization. This hypothesis is supported by studies utilizing positron emission tomography which indicates that glucose utilization in the normal human neonatal brain follows a phylogenetic order. Regions that achieved higher levels of glucose consumption are those that suffered the brunt of the damage in our term neonates.

Dopamine in paragangliomas of the glomus jugulare

Glomus jugulare tumors have the ability to synthesize, store, and secrete biogenic amines. Although the majority of these tumors remain endocrinologically silent, on rare occasions they present either as a pheochromocytoma or with a carcinoid syndrome. We report a 20‐year‐old male with two intracranial tumors: an intrasellar neoplasm and a glomus jugulare tumor. Catecholamine catabolites in the urine were not increased, and blood pressure was always normal. The pituitary tumor was an adenoma, immunostaining positive for prolactin. The second patient, a 29‐year‐old hypertensive male, with a glomus jugulare tumor, had increased vanillylmandelic‐acid excretion. In both cases, the paraganglioma tumor cells contained numerous dense‐core vesicles (125 to 380 nm in diameter) in electron microscopy, and showed intense fluorescence by the sucrose‐potassium phosphate‐glyoxylic acid method. Using high‐performance liquid chromatography and microspectrofluorometry we were able to establish the presence of large amounts of dopamine in the cytoplasm of the tumor cells.

Primary intravascular lymphomatosis associated with Mycobacterium marinum.

Intravascular lymphomatosis (IVL) is a rare condition in which neoplastic cells preferentially infiltrate blood vessels of the central nervous system. Nonspecific symptoms associated with IVL include dementia, seizures, and multifocal cerebrovascular events. IVL was discovered at autopsy of a patient whose neurological deficits were predated by a particularly aggressive form of Mycobacterium marinum soft–tissue infection. It is speculated that IVL may have had an occult effect on the patients cellmediated immunity that predisposed him to this normally innocuous mycobacteria.

Adult White Matter Disease

Many diverse disease processes may result in white matter abnormalities. This chapter discusses the demyelinating diseases, as well as toxic, vascular, and miscellaneous causes of white matter abnormalities. The sensitivity of MRI far surpasses CT in the detection of white matter diseases (Table 19.1).1 CT is hampered by the lack of significant attenuation difference between normal and abnormal white matter and beam hardening artifact most notable in the temporal lobes and posterior fossa2,3 Proton density- and T2-weighted images are excellent for detecting white matter abnormalities. Newer pulse sequences such as cerebrospinal fluid (CSF) nulled inversion recovery (known as Fluid Attenuated Inversion Recovery [FLAIR]) show increased sensitivity for detection of white matter pathology at the expense of a slightly increased imaging time (Fig. 19.1C,D).4,4a,4b,4c

Tribute to Manuscript Reviewers

The number of manuscripts processed during the past 18 months has increased substantially and the content of many of those papers has become quite sophisticated. Each manuscript is reviewed by at least four referees. Hence, the identified journal reviewers on the masthead have been busy. In order to assist them as well as to ensure that papers are assessed by individuals knowledgeable in a similar field, to say nothing about the desire for a speedy turn-around time, the following individuals have been asked to bring their expertise to paper selection. The journal is most grateful to them for this volunteer activity.