[Age dependence of Doppler parameters in the basal cerebral arteries evaluated by transcranial color-coded duplex sonography. Reference data from 290 volunteers]

AIM

In this study the Doppler parameters of the basal intracranial arteries and the insonation in axial and coronary plane by temporal approach were established in healthy volunteers of all age groups with transcranial color-coded duplex sonography (TCDS).

METHODS

290 healthy probands (age 0 to 91 years) were investigated through the temporal and transnuchal ultrasound window. The angle corrected flow velocities and the resistance indices of the basal brain arteries were measured.

RESULTS

The flow velocities rapidly increase in children (from 3 years up to puberty) and gradually decrease with increased age. Vice versa, the resistance indices decrease in children and increase in older people. The flow velocities show significant differences by axial and coronary insonation in certain arteries of the circle of Willis.

CONCLUSION

The Doppler parameters of the basal intracranial arteries evaluated with TCDS depend from age. The flow velocities and resistance indices are similar in children and older people. The coronary transtemporal approach is considered a useful completion of the axial investigation.

[Correlation of clinical and magnetic resonance imaging findings in patients with brainstem infarction]

The aim of this study was the comparison of clinical and neurological findings in 30 patients presenting with ischemic brainstem lesions. These were localized in the midbrain in 4 cases, in the medulla in 12 cases and in the pons in 11 cases, while the remaining three patients demonstrated combined lesions. Symptoms were lesions of the pyramidal tract in 77% of cases, vertigo in 57% of cases, speech disturbances in 40% of cases and gait ataxia in 37% of cases. Cranial nerve lesions were evident in 87% of patients, while 33% of patients demonstrated a Horner syndrome. Brainstem lesions were diagnosed in 22 (73%) of patients on magnetic resonance imaging, while all 30 patients had clinical signs suggestive of brainstem lesions. We conclude that neuroradiological studies can provide helpful information regarding patients with brainstem lesions, but by no means replace exact neurological examination.

Expression pattern of the peripheral myelin protein 22kDa (PMP22) in neural and non-neural tissue types of adult wildtype and Trembler mice--a comparative study

The Trembler mouse was the first animal model for Charcot-Marie-Tooth disease type 1 (CMT1), one of the most frequent inherited peripheral neuropathies in man. In Trembler mouse a Gly150Asp amino acid exchange in the peripheral myelin protein 22kDa (PMP22) gene was identified as causative reason for this hypertrophic neuropathy. For most of the CMT patients suffering from the subtype 1A a duplication of the PMP22 gene is found (gene dosage effect); but several PMP22 point mutations, such as that determining the TremblerJ mouse, have also been described. Since PMP22 is expressed in neural, as well as in non-neural tissues, the expression pattern of PMP22 in different tissues seems to be of highest interest for a better understanding of the hypothesized dual function of this protein. We studied different wildtype (wt) and Trembler (Tr) mouse tissues for PMP22 expression by means of radioactive in situ hybridization (RISH) and immunohistochemistry. A PMP22 expression was found in some of the non-neural and in all neural tissue types studied. Our in situ study clearly demonstrated, that PMP22 mRNA expression in non-neural tissues is not due to peripheral innervation. In non-neural tissues no difference in the expression pattern or intensity between wt and Tr mice was detectable, whereas PMP22 expression in the peripheral nervous system (PNS) of the Tr mouse was extremely reduced. Immunohistochemical analysis of sciatic nerve sections revealed the same maldistribution of PMP22 in Tr mice as in sural nerve biopsies of CMT1 patients.

PMP22 Thr118Met is not a clinically relevant CMT1 marker

It is controversial if peripheral myelin protein 22 gene (PMP22) Thr118Met represents a functionally irrelevant polymorphism or, since hemizygosity for this variant has been found in two patients with Charcot-Marie-Tooth disease type 1 (CMT1 patients), it can act as a recessive CMT1 mutation. To shed further light on this variant and its diagnostic value we searched for carriers in 1018 individuals from the German general population, in 104 probands with hereditary neuropathy with liability to pressure palsies (HNPP) who were carriers of the 1.5-Mb deletion frequently associated with this disorder, in 187 patients with the 1.5-Mb duplication, and in 22 patients with a CMT1 phenotype who did not have any detectable anomaly in the PMP22 gene. Using allele-specific PCR we identified 14 [allele frequency (AF)=0.007] in the German general population, one (AF=0.01) in the HNPP group and six (AF=0.016) and two (AF=0.05) carriers of the PMP22 Thr118Met mutation in the CMT1 groups with and without gene defect. Carriers from all groups showed nerve conduction velocities which did not differ from typical values for these groups. We conclude that the hemizygous occurrence of the 118Met allele does not usually cause CMT1. Because of previous reports on its association with disease, and because its allele product shows abnormalities in in vitro expression systems, it seems possible that this mutation, together with yet unidentified factors, predisposes to CMT1. Alternatively, previously reported disease associations occurred by chance, and the 118Met allele causes biochemical abnormalities irrelevant for CMT1 formation. In either case this mutation is not a clinically relevant disease marker.

Neuropeptide content of peripheral nerve in relation to nerve function in neuropathy

OBJECTIVE

In this study an APAAP (alcalic-phophatase-anti-alcalic-phosphatase) technique was used to distinguish afferent (calcitonin-gene-related-peptide (CGRP) or substance-P-(SP) positive) and autonomic (tyrosin-hydroxylase (TH), neuropeptide Y (NPY) or vasoactive-intestinal-polypeptide- (VIP) positive) nerve fibers in sural nerve biopsy material from patients with moderate sensory neuropathy. A panneuronal marker against protein-gene-product 9.5 (PGP 9.5) was used for detection of the total amount of nerve fibers. Second aim was to analyze possible correlations between the impairment in tests for the function of unmyelinated fibers (i.e. thermal threshold testings, sensitivity to painful mechanical stimulation, axon reflex-mediated flare reaction and sudomotor activity) and nerve pathology.

RESULTS

A high correlation between CGRP and SP (p < 0.00003) and between TH and NPY, respectively, (p < 0.004) was found, but not between afferent and autonomic markers or between specific markers and PGP 9.5. While no correlations between sensory neuropeptides (CGRP and SP) and specific testings of afferent fiber function or between neuropeptide content and clinical data could be demonstrated, there was a significant correlation between the TH content of the sural nerve and the sweat output, stimulated by acetylcholine iontophoresis at the level of the foot (p = 0.019) and upper leg (p = 0.011).

CONCLUSION

This study demonstrates the possibility of visualizing subgroups of unmyelinated nerve fibers in sural nerve biopsies selectively with this technique. The density of TH-positive sympathetic nerve fibers, but not the density of afferent c-fibers, is correlated with corresponding results in specific tests of c-fiber function.

[Secondary normal pressure hydrocephalus. A complication of chronic neuroborreliosis]

We report about a 57-year-old patient suffering from the typical symptoms of normal-pressure hydrocephalus (NPH) including gait disturbance, urinary incontinence, and mental deterioration. CSF analysis established the diagnosis of chronic active Lyme neuroborreliosis with lymphocytic pleocytosis and intrathecal Borrelia burgdorferi antibody production. After several weeks of i.v. antibiotic treatment we observed normalization of CSF parameters as well as a clear improvement of clinical symptoms so that surgical shunting was no longer indicated. Interference with subarachnoid CSF flow may be a possible cause of the observed symptomatic NPH in a patient with chronic Lyme neuroborreliosis.

Charcot-Marie-Tooth disease type 1A and hereditary neuropathy with liability to pressure palsies: a SacI polymorphism in the proximal CMT1A-REP elements may lead to genetic misdiagnosis

A male patient with clinical signs and symptoms of a demyelinating neuropathy was shown to have a duplication of the 1.5-Mb region on chromosome 17p11.2 by means of two-color fluorescence in situ hybridization (FISH). This duplication is typical for the vast majority of Charcot-Marie-Tooth type 1A (CMT1A) cases. Analysis of DNA extracted from peripheral blood used to detect an EcoRI/SacI 3. 2-kb junction fragment with probe pLR7.8 confirmed the CMT1A duplication, but also revealed a 7.8-kb fragment usually observed in patients with a hereditary neuropathy with liability to pressure palsies (HNPP). Both fragments observed in one patient canot result from one unequal crossover. In EcoRI/SacI Southern hybridization experiments with probe pLR7.8 DNA of his healthy parents also revealed a 7.8-kB restriction fragment. A subsequent two-color FISH analysis, however, indicated a normal status for interphase nuclei of the parents. Hence we hypothesize that the 7.8-kb fragment observed in our patient and his parents is not the product of unequal crossover during meiosis but due to a polymorphism of the SacI site in a proximal CMT1A-REP element.

Molecular diagnosis of PMP22-associated neuropathies using fluorescence in situ hybridization (FISH) on archival peripheral nerve tissue preparations

Charcot-Marie-Tooth (CMT) syndrome type 1 and tomaculous neuropathy, also called hereditary neuropathy with liability to pressure palsies (HNPP), represent two groups of neurological disorders with different subtypes, which can be distinguished at the molecular level. It is known that a 1.5-mb region on chromosome 17p11.2-12, which includes the gene for the peripheral myelin protein 22 kDa (PMP22), is duplicated in more than 95% of patients with CMT type 1A (CMT1A; gene dosage 3) and is deleted in about 90% of subjects suffering from HNPP (gene dosage 1). This duplication/deletion can be detected reliably by interphase-two-color fluorescence in situ hybridization (FISH). We report here a technique for extraction of nuclei from paraffin-embedded and cryofixed sural nerve biopsies for precise molecular diagnosis, employing interphase-two-color FISH in clinically diagnosed CMT1 or HNPP patients. Following this technique we were able to identify six CMT1A duplications in 13 clinically diagnosed CMT1 cases and five HNPP deletions in 6 clinically diagnosed HNPP cases; 8 control persons were included in this study. This is the first report on the use of FISH in the detection of 17p11.2-12 duplication and deletion in archival biopsy material.

Detection of the CMT1A/HNPP recombination hotspot in unrelated patients of European descent

Charcot-Marie-Tooth type 1 disease (CMT1) and hereditary neuropathy with liability to pressure palsies (HNPP) are common inherited disorders of the peripheral nervous system. The majority of CMT1 patients have a 1.5Mb tandem duplication (CMT1A) in chromosome 17p11.2 while most HNPP patients have a deletion of the same 1.5 Mb region. The CMT1A duplication and HNPP deletion are the reciprocal products of an unequal crossing over event between misaligned flanking CMT1A-REP elements. We analysed 162 unrelated CMT1A duplication patients and HNPP deletion patients from 11 different countries for the presence of a recombination hotspot in the CMT1A-REP sequences. A hotspot for unequal crossing over between the misaligned flanking CMT1A-REP elements was observed through the detection of novel junction fragments in 76.9% of 130 unrelated CMT1A patients and in 71.9% of 32 unrelated HNPP patients. This recombination hotspot was also detected in eight out of 10 de novo CMT1A duplication and in two de novo HNPP deletion patients. These data indicate that the hotspot of unequal crossing over occurs in several populations independently of ethnic background and is directly involved in the pathogenesis of CMT1A and HNPP. We conclude that the detection of junction fragments from the CMT1A-REP element on Southern blot analysis is a simple and reliable DNA diagnostic tool for the identification of the CMT1A duplication and HNPP deletion in most patients.

Clinical and morphological phenotype of HMSN 1A mosaicism

Clinical, neurophysiological and morphological studies on a patient with mosaicism of the 17p11.2 duplication were performed in detail for the first time. Since duplication occurs during paternal meiosis, a somatic reversion is suggested, leading to mosaicism. The proportion of nuclei with duplication varied markedly between 49% in blood cells and 74% in tissue from the sural nerve. Clinically, mild symptoms of a motor and sensory neuropathy were present. However, neurophysiological changes and findings in the sural nerve biopsy were consistent with a typical hereditary motor and sensory neuropathy type 1 (HMSN 1). Differing clinical findings in patients with mosaicism of the 17p11.2 duplication may be explained by a varying degree and/or time of reversion.

[Immunoglobulin therapy of chronic inflammatory neuropathies]

High-dose intravenous immunoglobulins (ivIg) are an effective therapy in chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN). In both diseases, data regarding ivIg long-term treatment are sparse. Therapy with ivIg was performed in 18 patients with CIDP or MMN. Sixteen patients responded to ivIg therapy; they were treated for more than 6 months. Two of them had not previously shown any positive response to other immunosuppressive treatments. Response to ivIg therapy could be observed even after a long disease duration (maximum of 19.5 years). All 16 therapy responders now have no or only mild clinical symptoms. Treatment could eventually be completely stopped in 6 patients; they have now been in complete remission without therapy for a maximum of 63 months. Ten patients still receive regular ivIg infusions in different dosages. No severe side effects were observed in the whole group. IvIg therapy is an effective, safe and easily applicable treatment regimen even in the long-term course of CIDP and MMN.

Multifocal motor neuropathy: clinical and electrophysiological findings

Multifocal motor neuropathy (MMN) can be differentiated from motor neuron disease by electrophysiological evidence of conduction block. To increase the probability of recording conduction block, we studied the whole nerve length including proximal segments in 84 patients with pure motor syndromes, using a special stimulation technique. In 8 patients, the diagnosis of MMN was confirmed by electrophysiological evidence of conduction block or temporal dispersion. The typical clinical picture of MMN with chronic progressive, asymmetrical, marked distal weakness was observed in our patients. Electrophysiological routine tests of distal nerves were usually normal except in nerve segments with conduction block. In 4 patients, conduction block could be recorded only in proximal nerve segments or spinal roots. All patients showed rapid improvement of clinical features and parallel reduction of conduction block during or after high-dose intravenous immunoglobulin (ivIG) therapy, supporting the diagnosis of an immune-mediated neuropathy. Three of them are now in remission without any therapy, whereas 5 still receive a regular ivIG course every 2-12 weeks as long-term treatment. In all patients with pure or predominantly motor syndromes and normal findings in electrophysiological routine tests of distal nerve segments, there should be proximal conduction block studies to avoid overlooking a treatable disorder such as MMN.

Mosaicism for the Charcot-Marie-Tooth disease type 1A duplication suggests somatic reversion

A female patient with clinical signs and symptoms of a demyelinating neuropathy was shown to have a duplication of the 1.5-Mb region on chromosome 17p11.2, typical of the great majority of cases of Charcot-Marie-Tooth disease type 1A (CMT1A). However, analysis of DNA extracted from peripheral blood revealed a 2:2.4 instead of the usual 2:3 ratio between the 7.8- and 6.0-kb EcoRI fragments in the proximal and distal repetitive extragenic palindromic (REP) elements of CMT1A. Detection of a 3.2-kb EcoRI/SacI kb junction fragment with probe pLR7.8 confirmed the CMT1A duplication. The dosage of this junction fragment, compared with a 2.8-kb EcoRI/SacI fragment of the proximal REP elements of CMT1A, was 2:0.58 instead of the expected 2:1 dosage for heterozygous CMT1A duplications. We hypothesized that the lower dosages of these restriction fragments specific for the CMT1A duplication were due to mosaicism; this was confirmed by fluorescence in situ hybridization analysis with the D17S122-specific probe pVAW409R1. In peripheral blood lymphocytes the percentage of interphase nuclei with a duplication in 17p11.2 was 49%. In interphase nuclei extracted from buccal mucosa, hair-root cells or paraffin-embedded nervous tissue the duplication was detectable in 51%, 66% and 74%, respectively. This is the first report of mosaicism in a patient with a CMT1A duplication identified by three different and independent techniques.

Widespread expression of the peripheral myelin protein-22 gene (PMP22) in neural and non-neural tissues during murine development

The gene encoding the peripheral myelin protein PMP22 is affected by various mutations in the hereditary peripheral neuropathies Charcot-Marie-Tooth disease type 1A (CMT1A), Déjérine-Sottas syndrome (DSS) and hereditary neuropathy with liability to pressure palsies (HNPP). In contrast to the recent remarkable progress in the genetics of the PMP22 gene, the biological function of PMP22 remains largely unknown. In this report, we have confirmed by using in situ hybridization techniques that high levels of PMP22 mRNA are present in maturing peripheral nerves of the 2-week-old mouse, a finding consistent with the PNS-specific defect observed in hereditary peripheral neuropathies. However, high levels of PMP22 transcripts were also found in the villi of the adult gut, and PMP22 expression was detected in various non-neural tissues during embryonic mouse development. In early embryogenesis (9.5 days postconception, dpc), PMP22 RNA expression appears restricted to the epithelial ectodermal layer. During early organogenesis (11.5 dpc), particularly high levels of expression are present in the capsule surrounding the liver and in the forming gut, while low levels of PMP22 mRNA can be found in precartilagous condensations forming the vertebrae and the ventricular layer of the myelencephalon. During midgestation development (14.5 dpc to 16.5 dpc), the number of PMP22-positive tissues increases, and high expression is detected in several mesoderm-derived tissues, in particular connective tissues of the face region, bones including the vertebrae, the lung mesenchym, and in muscles. In addition, high expression is also found in ectoderm-derived tissues, especially the epithelia of the lens and the skin. These findings strongly suggest that PMP22 serves not only a PNS-specific function but is also of broader biological significance in cell proliferation and/or differentiation.

[Value of proximal conduction block study in diagnosis of inflammatory neuropathies]

Conduction block is a common finding in inflammatory neuropathies, indicating circumscribed demyelination. Since demyelination and conduction block are often localized proximally, the whole ulnar nerve including its proximal segments was studied fractionally in 31 patients with inflammatory neuropathies. In 5 of 15 patients with Guillain-Barré syndrome, conduction block at the spinal roots was the first electrophysiological finding indicating demyelinating neuropathy. Segmental conduction blocks were also found in 8 of 9 patients with chronic inflammatory demyelinating polyneuropathies (CIDP) and 4 of 4 patients with atypical neuropathies. In 3 patients, multifocal motor neuropathy (MMN) could only be differentiated from motor neuron disease by recording proximal conduction block. Corresponding to clinical recovery, conduction block improved with immunoglobulin therapy in CIDP and MMN patients. The technique of proximal conduction block studies clearly improves the diagnosis of focal demyelination in inflammatory, treatable neuropathies. They should be performed particularly in patients with atypical neuropathies in whom electrophysiological tests of distal nerve segments show normal results.

Myotonic dystrophy: correlation of clinical symptoms with the size of the CTG trinucleotide repeat

An unstable DNA sequence of a gene encoding a protein kinase has been identified as the molecular basis of myotonic dystrophy. The correlation between different symptoms of myotonic dystrophy and the size of this unstable base triplet (CTG)n repeat was investigated in 14 patients. DNA was prepared from whole blood by standard procedures. Detailed clinical, psychological, electrophysiological (quantified measurement of myotonia, electrocardiography) and other laboratory examinations (muscle biopsy in 4 patients, slit lamp examination) were performed. Triplet size correlated significantly with muscular disability and inversely with age at onset of the disease. A greater frequency of mental and gonadal dysfunction could be observed in patients with a larger repeat size. Other symptoms, however, such as cataract, myotonia, gastrointestinal dysfunction and cardiac abnormalities were not correlated with repeat size. Somatic mosaicism with different amplification rates in various tissues might be one possible explanation for the variable phenotypes. Furthermore, other factors such as different expression of the myotonic dystrophy gene might contribute to the clinical variability of the disease at a given triplet size.

[Paranoid hallucinatory psychoses as the first manifestation of HIV infection]

All parts of the central nervous system may be involved in HIV infection, resulting in a variety of neuropsychiatric syndromes some of which resemble functional psychoses. Corresponding to the HIV-associated disease these syndromes differ in course and severity. A very common form is the AIDS-dementia complex, especially late in the course of disease. Up to now, however, a specific therapy is not available. A case of severe psychosis with paranoid delusions and hallucinations in a patient with otherwise asymptomatic HIV infection is reported. From her biography it was concluded that the infection occurred 10 years earlier. During therapy with azidothymidine, symptoms disappeared within 3 months, and more than one year after admission to our hospital the patient was still able to work. According to the course of the disease in this patient, reports from the literature and pathogenetic theories, an early therapy with antiviral agents is recommended in HIV-induced subacute encephalitis.

Histologic evidence for a toxic polyneuropathy due to exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in rats

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a considerable environmental hazard in industrial societies. Its toxic effects on animals and humans are numerous, but little is known about its neurotoxicity. We studied the neurotoxic effects of TCDD in 80 male, adult Wistar rats. The substance was dissolved in corn oil and a single dose injected intraperitoneally (8.8 micrograms, 6.6 micrograms, 4.4 micrograms or 2.2 micrograms/kg). Neurophysiological examinations proved a dose-related, statistically significant slowing of sensory and motor conduction velocities. Ten months after the application of TCDD peripheral nerves showed a progressive, and proximally accentuated neuropathy. The extent of changes, however, differed remarkably between individual animals. Our data indicate that TCDD caused a toxic polyneuropathy in rats.

Electrophysiologic evidence for a toxic polyneuropathy in rats after exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

At present, experimental data on the neurotoxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin are still lacking. Therefore, electrophysiologic studies were performed in 80 adult, male Han/Wistar rats intraperitoneally injected with a single, low dose of TCDD (8.8, 6.6, 4.4 or 2.2 micrograms/kg) dissolved in corn oil. 20 control animals received corn oil only. The typical 'wasting syndrome' of high-dose TCDD-intoxication was therefore not observed. Motor and sensory nerve conduction velocities in the right sciatic nerve showed dose-dependent and statistically significant slowing in TCDD-exposed rats as compared to controls. Spontaneous activity in the flexor digitorum muscle of the right hind paw and in tail muscles could be seen in the electromyogram of TCDD-group 1 (100%), group 2 (93%), groups 3 and 4 (87% each). This was significantly less frequent in the controls (21%). These findings give electrophysiologic evidence for a toxic polyneuropathy in rats after a single, low dose of TCDD.

[Peripheral facial paralysis as the first symptom of unknown metastatic primary tumor]

The spread of metastases to the brain and the leptomeninges is usually a terminal event in patients with known malignancies. We report on two patients, in whom the diagnosis of a diffusely metastasizing carcinoma was considerably delayed by the initial symptom of a peripheral facial nerve paralysis. The clinical, neuroradiologic and cerebrospinal fluid findings are discussed. A malignant neoplasm with diffuse or focal metastasis to the leptomeninges is a rare cause of peripheral facial paralysis of unclear genesis. The necessity of a lumbar puncture plus magnetic resonance imaging of the brain to enable an early diagnosis is emphasized.

Significance of degenerating endoneurial cells in peripheral neuropathy

In 42 human sural nerve biopsies degeneration of endoneurial cells was evaluated semiquantitatively at the electronmicroscopic level. These cells were of non-Schwannian origin since they were not surrounded by a basement membrane. Most of the degenerating cells resembled endoneurial fibroblasts: their remaining cytoplasmic processes were quite extensive, not finger-like as in macrophages, and their cytoplasm did not contain conspicuous lysosomes or phagolysosomes that would identify them as degenerating macrophages. Criteria for regarding these cells as degenerating were defects of the cytoplasmic surface membrane with extracellularly situated organelles. The ratio between normal and degenerating endoneurial cells in five different groups of peripheral neuropathies was compared to a group of normal controls. No degenerating endoneurial cells were found in the latter. The largest proportion of degenerating endoneurial cells was noted in patients with panarteritis nodosa (30% of the endoneurial cells evaluated). Between 9% and 18% of the evaluated endoneurial cells were seen degenerating in hereditary motor and sensory neuropathies, in neuropathies associated with IgG or IgM gammopathy, and in chronic demyelinating inflammatory polyradiculoneuropathy. These findings suggest that degeneration of endoneurial cells is a nonspecific sign of peripheral neuropathy occurring in various types of neuropathy, although vasculitis represents the most frequent cause. Thus, degeneration of endoneurial cells can be added to the growing list of changes that possibly indicate an inflammatory disorder, even during the intervening stage when apparent inflammatory cell infiltrates are lacking.

[Vasculitic neuropathy in the Garin-Bujadoux-Bannwarth syndrome. A contribution to the understanding of the pathology and pathogenesis of the neurological complications in Lyme borreliosis]

Clinical examinations and nerve biopsies were performed on four patients with meningoradiculoneuritis and positive serology for Borrelia (Garin-Bujadoux-Bannwarth syndrome). Three patients had a painful multiplex mononeuropathy, while one presented with a picture resembling a Guillain-Barré syndrome. Nerve biopsy in two patients revealed marked perivasculitis, in part with thrombosis of the epineural vasa nervorum. In the other two patients there were small pericapillary infiltrates in the endoneurium with strikingly many plasma cells. These findings speak, on the one hand, for angiopathic-ischaemic nerve damage, but on the other for a local immune reaction to the causative microorganism, because of the plasma-rich endoneural infiltrates. The authors suggest that angiopathic-ischaemic tissue lesions and/or local immune reactions may play a role also in the pathogenesis of CNS complications of Lyme disease.

[Hereditary neuropathy with liability to pressure palsies. A contribution to the differential diagnosis of multiplex mononeuropathy]

Hereditary neuropathy with liability to pressure palsies could be diagnosed in two families. This little-known, dominantly inherited disorder is clinically characterised by recurring, spontaneously regressive palsies of peripheral nerves, mostly after minimal mechanical compression of the nerve concerned. It can be clearly differentiated from mononeuropathies of different pathogenesis even in clinically not involved nerves, by means of pathological neurographic findings and by the detection of pathognomonic myelinic thickenings in nerve biopsies. Prognosis is favourable if recurrences are avoided. This means that counselling of the patients and their families is of prophylactic significance.

Disposition of clotiazepam: influence of age, sex, oral contraceptives, cimetidine, isoniazid and ethanol

Factors influencing the disposition of clotiazepam in man were evaluated in a series of pharmacokinetic studies in healthy volunteers given a single 5 mg dose. Old age caused an increased volume of distribution of clotiazepam in women, and its clearance tended to be reduced in elderly men. Use of oral contraceptives, cimetidine, isoniazid or a single dose of ethanol had no significant effect on the kinetics of clotiazepam. Although clotiazepam is biotransformed by microsomal oxidation, its clearance appears to be relatively uninfluenced by factors known to alter the clearance of other oxidized benzodiazepines.