Thymic cyst: is a correct preoperative diagnosis possible? Report of a case and review of the literature

A case of a giant cervico-mediastinal cyst of thymic origin in an 8-year-old child is presented. The cyst was asymptomatic except for deformity due to its size. In spite of several diagnostic approaches like ultrasonography, computed tomography, cyst puncture with biochemical analysis of cyst content and direct contrast injection and radiography after emptying of the cyst, the ultimate diagnosis as to the origin of the cyst was not disclosed until after operation and histopathological examination of the operative specimen. On a more general basis the diagnostic possibilities and pitfalls are discussed.

CONCLUSION

a correct preoperative diagnosis of a thymus cyst is difficult and in many instances impossible even when all diagnostic measures at hand are utilized, including radiographic methods, computed tomography, magnetic resonance imaging, ultrasonography and biochemical examination of cyst aspirate and estimation of tumour markers in cyst fluid and serum.

Do nerve conduction studies predict the outcome of carpal tunnel decompression?

Patients (n = 3336) who had been tested for suspected carpal tunnel syndrome (CTS) were contacted by postal questionnaire and their opinions sought of the overall subjective outcome of any treatments using a five-point rating scale. Operative results were compared with preoperative nerve conduction, clinical and demographic variables, and a multiple logistic regression analysis used to identify significant prognostic factors. Among 1268 surgical procedures that were identified, the overall surgical success rate was 69%. Preoperative nerve conduction study findings, greater age, lower symptom scores, longer disease duration, and male gender were significant predictors of poor outcome. Nerve conduction studies had the strongest effect, with patients with middle-grade abnormalities having better results than those with either very severe or no abnormality. Surgical carpal tunnel decompression has a significant failure rate. The preoperative nerve conduction studies account for a proportion of the total variation in outcome.

The value of the history in the diagnosis of carpal tunnel syndrome

Details of the clinical history were elicited by questionnaire from 8,223 patients with suspected carpal tunnel syndrome and compared with the neurophysiological findings. Distribution of symptoms to the radial part of the hand and nocturnal exacerbation of symptoms showed the strongest individual correlations with positive nerve conduction studies. The regression model derived from the complete questionnaire achieved an overall sensitivity of 79% and specificity of 55% for the diagnosis of carpal tunnel syndrome when compared with the nerve conduction study results as a gold standard. A simple regression model for evaluating the history compares favourably with widely used clinical signs in its ability to predict the findings of nerve conduction studies.

A neurophysiological grading scale for carpal tunnel syndrome

Different ways of expressing the severity of carpal tunnel syndrome (CTS) are found in the existing literature and in clinical records. This paper documents the distribution of patients on a scale based upon the nerve conduction study findings, which are largely independent of the exact normal values used in any given laboratory and demonstrate a highly significant linear relationship between the neurophysiological grading and a numerical score derived from the clinical history. Patients with more characteristic stories of CTS generally have higher neurophysiological grades. The scale is as follows: normal (grade 0); very mild (grade 1), CTS demonstrable only with most sensitive tests; mild (grade 2), sensory nerve conduction velocity slow on finger/wrist measurement, normal terminal motor latency; moderate (grade 3), sensory potential preserved with motor slowing, distal motor latency to abductor pollicis brevis (APB) < 6.5 ms; severe (grade 4), sensory potentials absent but motor response preserved, distal motor latency to APB < 6. 5 ms; very severe (grade 5), terminal latency to APB > 6.5 ms; extremely severe (grade 6), sensory and motor potentials effectively unrecordable (surface motor potential from APB < 0.2 mV amplitude).

[Use and abuse of visual aids--presentation technique]

In today's health service, doctors cannot avoid teaching or lectures. Visual aids are an important part of any successful presentation. Adequate overheads and slides can be easily made using ordinary office equipment and simple cameras. Modern computers and laser printers are also an exciting medium for producing visual aids. Nevertheless, if the talk is to achieve its purpose, good pictures must be presented in the correct way, along with an absorbing commentary. Both these aspects of presentation technique require careful preparation, but are seldom taught to medical students or junior staff as a necessary tool for their future work as doctors.

Visual evoked potential monitoring of optic nerve function during surgery

A study was made with intra-operative flash--visual evoked potentials (VEP) monitored using a fibre-optic/contact lens photo stimulator in 57 patients undergoing intra-orbital surgical procedures with potential risk to the optic nerve. The VEPs recorded under enflurane and nitrous oxide anaesthesia did not differ significantly in latency or amplitude from the pre-operative recordings. Transient abolition of the VEP was seen under many circumstances and did not correlate with the outcome of surgery, but absence of a previously normal VEP for more than four minutes during surgical manipulation within the orbit did show a correlation with post operative impairment of vision. The technique provides early warning to the surgeon of threats to the integrity of the optic nerve.

Unexpected death of children with achondroplasia after the perinatal period

This report describes six cases of achondroplasia, four of whom died unexpectedly in early childhood. Clinical details and pathological findings are reported. Unexpected death seems to be a feature of children with achondroplasia, and appears to be related to brain-stem lesions secondary to deformities of the foramen magnum and posterior fossa.

Fatal pneumonia associated with two viruses in a child with lymphoblastic leukaemia

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