Hippocampal volume in adolescent-onset alcohol use disorders

OBJECTIVE: Alcohol use disorders (defined as DSM-IV alcohol dependence or abuse) are prevalent and serious problems among adolescents. As adolescence is marked by progressive hippocampal development, this brain region may be particularly susceptible to the adverse effects of adolescent alcohol use disorders. This study compared the hippocampal volumes of adolescents and young adults with adolescent-onset alcohol use disorders to those of healthy matched comparison subjects. METHOD: Magnetic resonance imaging was used to measure the hippocampal volumes and volumes of comparison brain regions in 12 subjects with alcohol use disorders and 24 comparison subjects matched on age, sex, and handedness. RESULTS: Both left and right hippocampal volumes were significantly smaller in subjects with alcohol use disorders than in comparison subjects. Total hippocampal volume correlated positively with the age at onset and negatively with the duration of the alcohol use disorder. Intracranial, cerebral, and cortical gray and white matter volumes and measures of the mid-sagittal area of the corpus callosum did not differ between groups. CONCLUSIONS: In the mature brain, chronic alcohol use disorders are associated with graded global brain dysmorphology. Although the etiology, neuropsychological consequences, and permanence of these hippocampal findings need to be further examined, these findings suggest that, during adolescence, the hippocampus may be particularly susceptible to the adverse effects of alcohol.     

N-Acetylaspartate concentration in the anterior cingulate of maltreated children and adolescents with PTSD

OBJECTIVE: Anterior cingulate dysfunction has been implicated in the pathophysiology of posttraumatic stress disorder (PTSD). The authors hypothesized that integrity of the anterior cingulate may be affected in childhood PTSD.METHOD: Single voxel proton magnetic resonance spectroscopy (proton MRS) was used to measure the relative concentration of N-acetylaspartate and creatine, a marker of neural integrity, in the anterior cingulate of 11 children and adolescents who met DSM-IV criteria for PTSD secondary to maltreatment and 11 healthy matched comparison subjects.RESULTS: The ratio of N-acetylaspartate to creatine was significantly lower in the maltreated subjects with PTSD than in the comparison subjects. CONCLUSIONS: The lower N-acetylaspartate/creatine ratio in subjects with PTSD suggests that anterior cingulate neuronal metabolism may be altered in childhood PTSD.     

Comparison of regional cerebral blood flow and glucose metabolism in the normal brain: effect of aging

The regional cerebral blood flow (rCBF) and metabolic rate for glucose (rCMRGlc) are associated with functional activity of the neural cells. The present work reports a comparison study between rCBF and rCMRGlc in a normal population as a function of age. 10 young (25.9+/-5.6 years) and 10 old (65.4+/-6.1 years) volunteers were similarly studied at rest. In each subject, rCBF and rCMRGlc were measured in sequence, during the same session. Both rCBF and rCMRGlc values were found to decrease from young (mean rCBF=43.7 ml/100 g per min; mean rCMRGlc=40.6 micromol/100 g per min) to old age (mean rCBF=37.3 ml/100 g per min; mean rCMRGlc=35.2 micromol/100 g per min), resulting in a drop over 40 years of 14.8% (0.37%/year) and 13.3% (0.34%/year), respectively. On a regional basis, the frontal and the visual cortices were observed to have, respectively, the highest and the lowest reduction in rCBF, while, for rCMRGlc, these extremes were observed in striatum and cerebellum. Despite these differences, the ratio of rCBF to rCMRGlc was found to have a similar behavior in all brain regions for young and old subjects as shown by a correlation coefficient of 88%. This comparative study indicates a decline in rCBF and rCMRGlc values and a coupling between CBF and CMRGlc as a function of age.     

Adenovirus myelitis and Epstein-Barr myelitis: two unusual viral causes with similar presentations

We report two cases of viral myelitis, one associated with adenovirus and the other with Epstein-Barr virus. The clinical presentation and course were similar, with viral illness, paraplegia with a D4 sensory level, and fever. Spinal magnetic resonance imaging showed a T2 cervico-dorsal high intensity signal. Cerebrospinal fluid examination showed pleocytosis without oligoclonal bands. Both patients recovered after treatment with high-dose methylprednisolone.These two cases suggest a similar clinical and paraclinical pattern in viral transverse myelitis. Moreover, treatment with corticosteroids seems to be useful in viral myelitis.     

Spinal cord magnetic resonance imaging in multiple sclerosis: importance of determining degree of atrophy as a marker of disease course

Spinal cord magnetic resonance imaging (MRI) is of particular interest in the management of multiple sclerosis (MS) especially in primary progressive forms. Most of the demyelinating lesions are located in the cervical or dorsal cord. Spinal cord area reduction has been recently correlated with the progression of disability (Losseff et al., 1996, Lycklama a Nijeholt et al., 1998). The aim of this study was to confirm this first result, to assess the reproducibility of this method and to correlate demyelinating lesions with spinal cord area reduction. Fifty two patients were included and compared with 15 controls (normal subjects). T2 Sagittal and axial plane images were performed to localized hypersignal lesions. Spinal cord area was obtained by a volume acquired inversion prepared fast spoiled gradient echo acquisition (MP-Rage) sequence. We compared the mean area value with clinical parameters (age, course of the disease, expanded disability status scale ?EDSS) and with the number and location of demyelinating lesions. Demyelinating lesions were found in 82p.100 of MS patients and in none of controls. Mean spinal cord area was closely similar to Losseff et al. (1996) results and was reduced compared with controls (p<0.001). Spinal cord reduction was correlated with disability, studied by the EDSS. Furthermore, no correlation was found between demyelinating lesions and spinal cord area reduction. This study confirms the interest of spinal cord area mesurement in MS. Spinal cord atrophy is a reliable marker for axonal loss. This method should be of particular interest for the follow-up of axonal loss in thepeutic trials especially in primary progressive MS.     

Solitary tract nuclei in acute heart failure

BACKGROUND AND PURPOSE: Symmetrical necrosis of the brain stem nuclei has been described as a consequence of severe transitory cerebral hypoxia mainly in neonates or young adults who experienced an episode of acute ischemia due to transitory acute heart failure. We report selective bilateral lesions of the solitary tract nuclei in 5 adults with short survival intervals after acute heart failure. METHODS: In 5 patients who died due to cardiovascular pathology, histological examination was performed on multiple samples of cerebral hemispheres, on transverse sections of the midbrain and pons, and on transverse serial sections of the medulla stained with hematoxylin-eosin, Klüver-Barrera, and Luxol fast blue. The 3-dimensional reconstruction of the extension and topography of the medullary lesions was obtained with computed image analysis. RESULTS: In 4 subjects who died soon after an episode of acute heart failure (range of survival 10 hours to 2 days), the dorsal portion of the solitary tract nuclei showed an eosinophilic roundish aspect bilaterally. In their context, the neurons showed changes characteristic of ischemic coagulation necrosis. In a fifth patient, a 32-year-old man who died 15 days after an episode of cardiac arrest, 2 circumscribed symmetrical infarcts with macrophagic and astrocytic reactions were found at the same level. The topography of the lesions and the inflammatory reaction and gliosis of patient 5 suggest that the findings in the other 4 patients correspond to initial features of selective lesions of the solitary tract nuclei after acute heart failure: the short interval of survival prevented the evolution of the reactive process. The nucleus is localized at the watershed zone between the terminal branches of the medullary collateral vessels of the vertebral arteries, thus representing the last meadow in the case of sudden fall of the systemic blood flow due to acute heart failure. The absence of lesions of other medullary and pontine nuclei accounts for a selective vulnerability of the neurons of the solitary tract nuclei, and the selective dendritic lesions suggest an excitotoxic component to ischemic cell death. CONCLUSIONS: The commonly accepted resistance of the medullary centers to ischemic hypoxia in adults apparently could be due to the rapidity of death, which prevents the evolution of lesions that can be diagnosed. In addition, minor lesions in the medullary tegmentum after acute heart failure could play a role in the prevention of the resumption of autonomous cardiac and respiratory functions despite life-saving procedures.