Am 24. Dezember 2003 ist Fritz Buchthal, Prof. emeritus der Universität Kopenhagen/Dänemark an seinem Ruhesitz in Santa Barbara/Kalifornien verstorben.

The carpal tunnel syndrome (CTS) is the most common nerve entrapment syndrome and is well treatable. Electrophysiological tests allow an early and reliable recognition of a CTS, provide information on the severity of the nerve lesion, are useful for follow-up investigations after surgical treatment and play an important role in the differentiation from other neurogenic diseases. Among various tests which have been proposed for the electrophysiological assessment of a CTS, the following ones have been found to be useful and reliable: a comparison of the distal motor latencies of the median and ulnar nerve, a median-ulnar and median-radial comparison with respect to the sensory nerve latencies and sensory nerve conduction velocities, and the assessment of differences of sensory latencies between the wrist-palm and the palm-digit segments of the median nerve. In the present article. We demonstrate normal values for the above mentioned electrophysiological tests which were determined by studying the hands of 124 healthy volunteers. We also give clinical and electrophysiological examples for unusual forms of a CTS and present a literature review of the electrodiagnostics of the carpal tunnel syndrome.

Introduction: What can be obtained from electromyographic examination in patients with lumbar spinal stenosis? Methods: 120 patients received a physical and electrophysiological examination before surgical operation. The lumbar spinal stenosis was confirmed radiologically. Results: 81% of the patients had typical neurogenic claudication symptoms. 45% had paresis in one or more segments. The lumbar stenosis involved more than one segment in 44% of the patients. Mainly the spinal level L4/5 was affected (76%). EMG changes were found in 77% of the patients, usually bilateral. In 70% of the patients more than one segment was involved. The most abnormal EMG changes (more than 60%) were found in the L5- and S1-segment. Depending on the myotome, involved the EMG was three to eight times more sensitive than neurological examination alone. The EMG changes consisted of spontaneous activity, chronic neurogenic changes or both. Mainly we found a combination of spontaneous activity in S1 and chronic changes in L5. Conclusions: The EMG provides exact information of the segments involved. It is helpful in determining the type (acute and/or chronic) and severity of nerve root lesions. It is not possible to determine the level of spinal stenosis by EMG. Follow-up EMG-examinations yield information on the progression of the disease and help determine the time for surgery.

The carpal tunnel syndrome, caused by compression of the median nerve at the wrist, is the most common cause of altered sensation and pain in the hands. It is common during pregnancy and tends to resolve spontaneously after delivery. About 15% of affected women have symptoms severe enough to require neurologic examination and electrophysiologic testing. Injecting methylprednisolone just proximal to the carpal tunnel often provides temporary relief, but surgical release of the transverse carpal ligament is the only effective long-term treatment. We recommend primary surgical decompression if the first electrophysiologic test shows an absent median sensory nerve action potential or if symptoms due not resolve within 4 weeks after delivery.

The carpal tunnel syndrome, caused by compression of the median nerve at the wrist, is the most common cause of altered sensation and pain in the hands. It is common during pregnancy and tends to resolve spontaneously after delivery. About 15% of affected women have symptoms severe enough to require neurologic examination and electrophysiologic testing. Injecting methylprednisolone just proximal to the carpal tunnel often provides temporary relief, but surgical release of the transverse carpal ligament is the only effective long-term treatment. We recommend primary surgical decompression if the first electrophysiologic test shows an absent median sensory nerve action potential or if symptoms due not resolve within 4 weeks after delivery.

Neuropathy is a dose-limiting side effect for a number of effective chemotherapeutic agents. A better understanding of effective mechanisms will lead to novel treatment strategies that will protect neurons without decreasing therapeutic efficacy. The assessment of the efficacy and neurotoxicity of various chemotherapeutic agents is vital, for a determination of the maximum allowable dose. The introduction of chemotherapy in the 50s and 60s of the twentieth century has resulted in the development of curative therapeutic interventions for patients with several types of solid tumours and hemopoietic neoplasms. The important obstacles encountered in the use of chemotherapy have been the toxicity to the normal tissue. During the past 8 years there has come about a new level of understanding of the mechanisms through which chemotherapeutic agents work. This has opened the door to new paradigms of treatment in which molecular, genetic, and biologic therapy can be used together to increase the sensitivity of abnormal cells to treatment, and to protect the normal tissues of the body from therapy-induced side effects. The implementation of new strategies could change the way therapy is delivered over the next few years and improve the outcome especially in patients with neoplasms that are currently resistant to conventional dose therapy.

Guillain-Barré syndrome (GBS) is no longer considered a single entity. It is generally accepted as an acute immuno-mediated, predominantly motor neuropathy of the peripheral nervous system [[3], [7]]. In most cases the pathogenesis appears to reflect an inflammatory autoimmune attack on myelin-forming cells that results in demyelination [[2]]. However, axonal damage with varying degrees of Wallerian-like degeneration may also occur in 3 to 16 % of GBS patients [[7]]. These patients are generally more severely affected and tend to recover more slowly [[5]]. A separate clinical subset of axonal GBS with a peak incidence in summer - termed acute motor axonal neuropathy (AMAN) - has been reported almost exclusively in Chinese children [[4]]. Its characteristic features comprise rapidly progressing ascending paresis, axonal degeneration of predominantly intramuscular motor nerve terminals, while not involving the sensory nerves, and rapid recovery. Campylobacter jejuni infections seem to play a causative role [[1], [7]].

We examined 73 patients on artificial respirators between 2 to 168 hours after cardiopulmonary resuscitation. During that time period, bilateral Medianus SEPs were obtained according to standardized conditions. At the end of the observation period, the neurological outcome was determined and correlated with the obtained SEP results. Statistically significant correlations (p < 0.001) were found for the central conduction time and the amplitude of the N-20 as well as of the P-25 peaks. All patients with no cortical activity either suffered brain death (N=4) or died in a persistant vegetative state (N=6). Patients with pathologically reduced N-20 peaks <0,5 mu V (N=11)also died in a persistant vegetative state. This study emphasizes the value of medianus-SEP diagnostics in the area of neurological, intensive medical care and demonstrates that the proof of a cortical "flat line" during hypoxic coma is coupled with a fatal prognosis. The proof of inconspicuous cortical primary potentials by itself does not always entail a positive prognosis.

We performed a Median nerve SEP monitoring on six comatose patients with global cerebral hypoxia after cardiopulmonary resuscitation (kardiopulmonale Reanimation). The purpose of the study was to determine the exact recovery time of the scalp recorded potentials after circulation had stopped. The recordings began 90-180 minuts after kardiopulmonale Reanimation.

We performed a Median nerve SEP monitoring on six comatose patients with global cerebral hypoxia after cardiopulmonary resuscitation (kardiopulmonale Reanimation). The purpose of the study was to determine the exact recovery time of the scalp recorded potentials after circulation had stopped. The recordings began 90-180 minuts after kardiopulmonale Reanimation. One patient had an isoelectric SEP at the beginning and during the time period and died after 24 hours with the clinical signs of brain death. In five patients the N20 peak initially was well defined and showed an increase in amplitude of 11,8 % (2-25 %) within 12 and 24 hours. The P25 peak initially also was well defined, but showed an increase in amplitude of 110 % (50 -185 %), and stabilized after about 12 hours. The amplitudes of the N35 peak increased by 218% (60 -464%). The potentials of medium and late latency (P45 and N70 peak) were initially absent in all five patients, but were noticed for the first time 3,5 to 9 hours after onset of the hypoxia. The recovery time of the somatosensory evoked cortical potentials (SEP) by Median nerve stimulation after global cerebral hypoxia can therefore be determined to last about 12 hours.

Since normal structural details of human greater auricular nerve (GAN) have not as yet been studied with modern techniques, light and electron microscopic findings of seven presumably normal GANs, obtained from five patients during radical neck dissection, were compared with those of normal sural nerves (SNs). In GANs there was a tendency to higher densities per mm2 and a larger number of small-diameter fibers in myelinated fibers (MFs) and unmyelinated fibers (UFs) without obvious signs of de- or regeneration. UF histograms were unimodal in both groups, with mean UF diameters being somewhat smaller in GANS than in SNs. Schwann cell complexes containing several or even numerous UFs were more frequent in GANs than in SNs. In GANs, UF often occurred focally in great numbers within large Schwann cell complexes (polyaxonal complexes), not commonly seen in normal SNs. It is concluded that these structural peculiarities in GANs reflect natural conditions in short sensory nerves irrespective of any specific function.

We present data of 2 patients suffering from chronic motor-sensory multifocal neuropathy with persistent conduction block. The first case concerns a 9-year follow-up of a female, aged 24 years at onset with persistent multiple conduction blocks and a tendency towards generalization of clinical deficits. Eight years after onset sural nerve biopsy revealed extreme interfascicular variations of de/remyelination, onion bulb formation, fiber loss, edema, and proliferation of basal lamina of endoneurial capillaries. Serum antibodies against GM1 gangliosides were not detected. The second case, a 29-year-old Yemenitic male with a 5-year history, exhibited conduction blocks in motor and sensory fibers, and a normal sural nerve biopsy. Our results are discussed with respect to those of some 30 cases individually reported in the literature.

The reflex time was determined by means of a computerized device. In controls reflex time varied from 15.8 to 22.2 ms, depending on age and body size. In spasticity reflex time was shortened in most patients, probably because impulse transmission at the spinal synapse is shortened due to an increased excitability of the anterior horn cells. In L4 root compression and in most patients with neuropathy reflex time was prolonged, even in patients with normal motor and sensory conduction velocity. Prolongation of reflex time is mainly due to a delayed excitatory postsynaptic potential (EPSP) rising phase at the spinal synapses.

Reports on biopsy findings in multifascicular nerves in lepromatous leprosy (LL) are rare and detailed morphometrical data are not available. In a case of early LL with normal electrodiagnostic findings in sural nerve, the present study revealed marked segmental de- and remyelination concomitant with the sequelae of considerable Wallerian degeneration of preferentially small myelinated fibers (MF) in spite of a normal number/nerve and density/mm2. Segmental de- and remyelination of several consecutive internodes in teased fibers suggests continuous bacterial spread via Schwann cells. In 2 more advanced LL-cases, nervous parenchyme was severely reduced, in a borderline lepromatous (BL) case obviously in part caused by cell infiltrates and granulomata. Distinct fascicle differences in MF-involvement were demonstrated by coefficients of variation of MF/mm2 and teased fiber preparations in LL, consistent with the hypothesis of initial focal spread of bacteria. Numbers and densities of endoneurial vessels were increased only in the later stages of LL. Enlargement of endoneurial area, due to different factors, was encountered except for the most severe LL-case with extensive endoneurial collagenization. Morphometric results were compared with those of other neuropathies. Intact and degenerating bacteria mostly in phagosomes of Schwann cells associated with unmyelinated axons and in macrophages were seen only in the early LL- and the BL-case. Sparse mononuclear cell infiltrates and small focal necrosis, present even in LL-cases, underline the complex pathogenesis of nerve fiber involvement.

In the human sural nerve, large myelinated fibers contained 35 Schmidt-Lanterman (SL) clefts per mm, and small myelinated fibers contained only eight SL clefts per mm. The incidence of SL clefts is linearly related to myelin thickness. The SL clefts extended over 13 micron in large and over 9 micron in small fibers, the total extent of the SL region amounting to nearly 50% of internodal length in large and to 6% in small fibers. In the SL region, the fiber diameter was 6% larger than outside this region, and the axon was 17% smaller in large and 28% smaller in small fibers. The paranodal-nodal region occupied less than 2% of internodal length in large fibers and 6.5% in small fibers; in the nodal region the axon diameter was reduced by 40-50%.