The diagnosis of blocked cerebrospinal fluid shunts: a prospective study of referral to a paediatric neurosurgical unit

A prospective study was undertaken of all children referred to the Hospital for Sick Children with a provisional diagnosis of shunt blockage over a 5-month period. Fifty-two admissions were recorded, relating to 45 children, 5 of whom had multiple admissions. Only 19 of the 52 admissions led to a final diagnosis of shunt malfunction. No source of referral, whether by the child's general practitioner or from another hospital, was found to be more accurate than direct referral by the parents to the neurosurgical ward. Headache, vomiting and irritability were not significant indicators as to whether the child's shunt was actually blocked, and nor was the duration of the symptoms. Drowsiness was a significant, but not definite, indicator of shunt blockage, while pyrexia made it more likely that the patient had an alternative diagnosis. In 35 of the admissions a computed tomographic scan was performed: a normal scan, unchanged from previous scans, did not reliably exclude the diagnosis of shunt blockage. Percutaneous manometry via the reservoir of the shunt system was performed during 26 admissions: this investigation produced no false positives nor false negatives, but was equivocal in 5 cases, all of which were found at surgery to have a definite shunt blockage. The accuracy of the diagnosis of shunt blockage made prior to referral to a neurosurgical unit is discussed, together with the implications for resource use.     

Cognitive impairment after unilateral hemispheric injury of congenital or adult origin.

OBJECTIVE: The purpose of this study was to assess and compare cognitive functioning in adults with unilateral hemispheric injury due to either congenital damage or an ischemic event in young adulthood. METHOD: Adults with cerebral palsy resulting from left hemispheric brain damage were compared with adults who had a unilateral stroke in either the left or the right hemisphere. Our primary interest was to determine the impact on hemispheric dominance as revealed by dichotic listening, a task that assesses the bias for preferential listening and processing of sounds. Performance also was determined on a language-related task (word finding) and a spatial task (dot localization). RESULTS: Scores on the Quick Neurological Screening Test indicated that all participants demonstrated significant neuromotor deficits, whereas scores on the Barthel Index indicated that the participants were functional in basic activities of daily living. On cognitive assessments, healthy control participants demonstrated a pronounced left-hemisphere dominance and right-ear advantage; participants with injury to the left hemisphere showed a strong shift toward a right-hemisphere and left-ear dominance. In particular, injury of congenital origin appeared to foster this neural reorganization and localization of language-related functions into the healthy hemisphere. This shift was associated with a deterioration of performance on both the language and the spatial tasks. CONCLUSION: The importance of appreciating subtle deficits after unilateral injury is important in therapy. The dichotic listening test may provide a simple and useful means for evaluating persistent unilateral brain dysfunction in the clinical setting.     

An Improved Method of Removing Polyurethane Foam-Covered Gel Prostheses

One of the advantages of polyurethane foam-covered prostheses has been that in the first 5 to 10 years after their use, the amount of capsular contraction was found much less than when similar ``slick' prostheses were used. Another advance was their fixation to the surrounding tissue thus giving a more natural appearance and movement with the muscles when the arms were moved in any direction. The formation of a thick capsule also acted as a protection against gel granuloma due to rupture of the prosthesis and has been thought to be a factor in the lower capsule contraction rate. The greatest disadvantage has been that its removal was extremely difficult and this has continued up until the technique described in this paper has been introduced.     

AS-5370 potently antagonizes 5-HT3 receptor-mediated responses on NG108-15 cells and on the rat vagus.

The action of a novel 5-HT3 receptor antagonist, AS-5370, has been studied on two electrophysiological models for 5-HT3 receptors: whole-cell patch-clamp recordings from mouse neuroblastoma-rat glioma (NG108-15) cells and grease-gap recordings from rat isolated vagus nerve. The 5-hydroxytryptamine (5-HT)-induced fast inward current of voltage-clamped NG108-15 cells was antagonized by 1 nM AS-5370 in an insurmountable manner. On the rat vagus, AS-5370 reduced the maximum depolarizing response to 5-HT in a concentration-dependent manner. The IC50 for AS-5370 on the rat vagus was 0.3-1.0 nM. The EC50 for 5-HT on the rat vagus was not appreciably affected by AS-5370. On the rat vagus, the (R) enantiomer of AS-5370 was about 30 times more potent than the (S) enantiomer. The antagonist action of AS-5370 on these two cell types was compared with that of (+)-tubocurarine. Unlike tubocurarine, the effect of AS-5370 on NG108-15 cells was not readily reversed during wash. On the rat vagus, tubocurarine antagonized in a competitive manner with an IC50 of 0.3-1.0 microM (pKb = 7.2). It is concluded that AS-5370 is a potent 5-HT3 receptor antagonist on both NG108-15 cells and the rat vagus, but it does not act in a competitive manner.     

Visual function in Huntington's disease patients and presymptomatic gene carriers.

Disturbances of visual cognition, visuomotor performance, and visual memory have been described frequently in Huntington's disease (HD). Early stage visual abnormalities could contribute to these deficits. We evaluated visual processing in 20 control subjects who were non-gene carriers at risk for HD, nine presymptomatic gene-positive subjects, and eight subjects with a recent diagnosis of Huntington's disease. Visual perceptual tests of contrast sensitivity and motion discrimination were used to probe early stage visual processing. Extraocular movements were evaluated in a neurologic examination, and the Digit Symbol test was used to test visual motor performance. Contrast sensitivity did not differ among the three groups. Motion discrimination was impaired in HD subjects but not in the presymptomatic gene carriers when compared to gene noncarriers. Among gene carriers, impaired motion discrimination performance was associated with poorer Digit Symbol performance and extraocular abnormalities. These findings suggest that the early stages of HD are associated with disturbances of motion perception as well as disruptions of visual motor and ocular motor performance.     

Barium-coated surgical stents and computer-assisted tomography in the preoperative assessment of dental implant patients.

At surgery, the results of preoperative radiographic evaluation are used in conjunction with surgical stents to determine the ideal site and angulation of implants. However, it would be desirable to be able to plan the optimal implant location before the actual surgical appointment. This paper presents a technique in which barium-coated stents or dentures are used in conjunction with computer-assisted tomography to locate important anatomic landmarks, such as the inferior alveolar nerve, and anomalies of the underlying bone, such as deficiencies in ridge height, preoperatively. This allows more accurate determination of optimal implant placement.     

Erythromycin-Induced Immune Hemolytic Anemia

A 3-year-old female receiving Pediazole (erythromycin ethylsuccinate and sulfisoxazole) for tonsillitis and otitis media developed severe hemolytic anemia. No serum drug-dependent antibodies could be demonstrated with an in vitro 'immune-complex' method using Pediazole, pure erythromycin ethylsuccinate or pure sulfisoxazole. However, a method using red cells coated with erythromycin base showed in vitro lysis of the erythromycin-coated red cells. This is only the second case of immune hemolytic anemia associated with erythromycin and the first where in vitro drug-dependent hemolysis was demonstrable.