No abstract

There are differences in the shape and depth of the ipsilateral and the contralateral field defects not previously reported. These findings demonstrate that certain fibers from the ipsilateral eye travel more anteriorly and laterally in Meyer's loop, and support the hypothesis that visual field defects due to anterior retrogeniculate lesions are relatively incongruous because of anatomic differences in the afferent pathways. Automated perimetry is a sensitive method of evaluating and quantifying visual field defects.

CRH, a hypothalamic peptide that is the most potent ACTH secretagogue known, also appears to be produced in the cerebral cortex and spinal cord. Depressed patients have blunted responses to exogenous CRH and normal to high concentrations of CRH immunoreactivity in single morning samples of lumbar cerebrospinal fluid (CSF). Although these data suggest that depression may be associated with hypersecretion of CRH, it has also been postulated that central nervous system insufficiency of CRH might have a pathophysiological role in certain depressive syndromes. We continuously sampled lumbar CSF via indwelling subarachnoid catheters from 1100-1700 h and measured CRH at 10-min intervals in depressed patients and normal subjects. A standardized mixed liquid meal was administered at 1300 h. CSF CRH was strikingly reduced in depressed patients compared to normal subjects [4.2 +/- 1.1 pmol/L vs. 13 +/- 2.1 pmol/L (mean +/- SEM), respectively, P less than 0.01 by Wilcoxon test]. CSF CRH concentrations rose progressively during the experiment in both groups, suggesting a diurnal rhythm and, possibly, response to a test meal. CRH had a very brief half-life in CSF (less than 10 min), suggesting that the spinal cord is the origin of CRH in lumbar CSF. The rapid transients in CSF CRH concentration demonstrate that single samples provide very limited information. There were no intraindividual correlations between CSF CRH concentrations and those of either plasma ACTH or cortisol, both of which rose in response to eating. The present data show that impaired central nervous system secretion of CRH can exist during states of severe depression.

Data are limited on seizure recurrence after antiepileptic drug (AED) discontinuation in operated seizure-free patients. We reviewed seizure outcome in patients who came off AEDs after being seizure-free for 2 years following temporal lobe surgery in our center. Thirty-nine (68%) of 57 patients who discontinued AED therapy remained seizure-free. They had a younger age at surgery than the group with seizure recurrence (p=0.01). Earlier surgery may be a favorable predictor for seizure freedom after AED discontinuation.

Thoracic disc herniation is relatively rare and frequently poses a challenge in clinical diagnosis. These protrusions have been categorized into two major anatomical types and three main clinical syndromes. A number of characteristic radiographic features have been reported. Recently, magnetic resonance imaging (MRI) has gained popularity as a neurodiagnostic imaging tool. A series of nine cases of thoracic intervertebral disc herniation is reported. The clinical aspects of the cases are discussed, and the potential value of spine MRI for thoracic disc herniation diagnosis is emphasized.