[Inflammatory pseudotumor of the bladder]

A case report presents a 30-year-old lady with a pseudotumor of the bladder as large as a fist. The tumor originated from an inflammation around the rest of a suture following appendectomy with a latency of 7 years.

Prognostic value of somatosensory- and motor-evoked potentials in patients with a non-traumatic coma

A total of 28 patients with non-traumatic coma were studied both with somatosensory- and motor-evoked potentials. While somatosensory-evoked potentials (SEP) have proved to be useful in predicting the outcome in patients with severe brain damage, the aim of this study was to find out whether the additional evaluation of motor-evoked potentials (MEP) could contribute to a better prediction of the outcome than SEP alone. Our results clearly indicate that in terms of prognostic value, SEP are superior to MEP. Nine patients with bilaterally preserved MEP died, while all of the patients with bilaterally preserved SEP and a central conduction time less than or equal to 6.5 ms survived, with a Glasgow outcome score of 1 to 3. Therefore, we cannot recommend the inclusion of MEP in the prognostic evaluation of patients with non-traumatic coma.

[Recurrent urinary incontinence: cystomanometry--conditio sine qua non?]

The value of cystometry in the diagnosis of recurrent urinary incontinence is to differentiate between urge and stress incontinence. This is possible through determination of detrusor hyperactivity characterized by uninhibited detrusor contractions. Cystometry is necessary since neither history nor clinical examination can differentiate between urge and stress incontinence. Both types of incontinence are in many patients found together and factors causing stress incontinence, for instance coughing, may also cause spontaneous, uninhibited detrusor contractions. The diagnosis of detrusor hypoactivity is also important although lack of detrusor contractions is not identical to lack of contractility. In only 50% of patients are detrusor contractions present following correction of the urinary incontinence and increase of urethral resistance. In the other half of the patients, lack of detrusor contractility remains. There is evidence that a so-called micturition-stop-test may allow a prognosis in cases of lack of bladder contractility. Cystometry is, therefore, a conditio sine qua non although it only gives information concerning the function of the detrusor. Concerning the evaluation of the bladder outlet, additional radiological and urodynamic examinations are necessary.

Event-related brain potentials (P300) and neuropsychological deficit in patients with focal brain lesions

Sixteen patients with chronic focal brain lesions were investigated with an acoustic P300 test and psychological tests of spatial abilities (Maze Tracing Speed Test, Form Board Test), cognitive speed (Sequential Number Connection Test), categorization (Figure Sorting Test), verbal fluency and vigilance. Neither the psychological battery nor P300 analysis discriminated frontal from retrorolandic brain lesions. Abnormalities of P300 significantly correlated with impairments in those psychological tests which had a spinal component in common. We suggest that abnormality of the P300 with focal brain damage rather indicates higher mental function impairment than direct effects of the lesion.

[Somatosensory evoked potentials in surgery of the spine]

The authors report on their experience using cortical somatosensorially evoked potentials in 23 studies on 21 patients. The method is used intraoperatively when the spinal cord is at risk, for early identification of functional damage to the cord. The potentials found are classified according type of manifestation and compared with the results obtained by other authors.

Somatosensory tibial nerve evoked potentials with parasagittal tumours: a contribution to the problem of generators

Somatosensory evoked potentials following stimulation of the median nerve at the wrist and the tibial nerve at the ankle were recorded in 5 patients with parasagittal tumours, 4 in the fronto-parietal and 1 in the frontal region. Three had intracerebral tumours and 2 parasagittal meningiomas. The extent of each lesion was determined by CT scan, showing a unilateral process involving predominantly the paracentral lobule and adjacent parts of the post- and precentral gyri ("Mantelkante') in 4 patients and a more frontal location of one meningioma affecting mainly the superior frontal gyrus. SEPs recorded from the patients with fronto-parietal tumours showed a uniform pattern with a complete absence of the wave N70 of the tibial SEP elicited by stimulating the nerve contralateral to the lesion. All other waves, including the P40-N50 complex on both sides and the median SEP, were in the normal range. In contrast, the frontal meningioma led to an only slightly altered from of the waves immediately following the initial P40-N50 complex. It is concluded that the tumour abolished the generators of the wave N70 which are apparently located in the cortical somatosensory leg area. Therefore unilateral loss of the wave N70 is indicative of parasagittal lesions. The results may give good evidence that the P40-N50 complex is generated in the thalamus or thalamo-cortical connections.

Peripheral and central conduction times in hereditary pressure-sensitive neuropathy

Seven members of a family with histologically proven hereditary pressure-sensitive neuropathy (HPSN) agreed to be examine clinically and electrophysiologically. A sural nerve biopsy specimen taken from the propositus who suffered from a partial brachial plexus palsy showed typical 'sausage-like' myelin sheath thickenings reflecting a failure of axon-adjusted myelination. Reduced motor and sensory conduction velocities involving several nerves were found in the four family members with clinical signs of HPSN. In addition, central conduction times in the auditory and somatosensory pathways were determined measuring the interwave latency I-V in brainstem auditory-evoked potentials and the interpeak latency N14-N20 in median nerve sensory-evoked potentials. Central conduction times in both afferent systems were within normal limits. The absolute delay of peak N14 and N20 in median and P40 in tibial nerve-evoked potentials was probably due to an impaired conduction in the peripheral branch of the bipolar ganglion cell. Whether the central axon branch in the dorsal columns was also involved could not be decided.

[Brainstem auditory evoked potentials applied to clinical neurology (author's transl)]

Pathological alterations of the brainstem auditory evoked potential in 5 patients suffering from different kinds of brainstem diseases (reversible tumorous infiltration of the brainstem, multiple sclerosis, mesodiencephalic syndrome, apallic syndrome, braindeath) are shown. The alterations resemble the findings of animal experiments reported by Buchwald and Huang 1975: The particular components of brainstem auditory evoked potentials (waves IV-V, III, II and I) may decrease in amplitude or even completely disappear. The components are affected in a sequential reversed order, i.e. if a particular component has disappeared or shows a significant latency increase, the subsequent components are similarly affected. These observations suggest that the particular components are generated by different structures of the afferent acoustic pathway. This underlines the usefulness of brainstem auditory evoked potential recordings in detecting brainstem disorders.