Cardiac microembolism: prevalence and clinical outcome.

High intensity transient signals (HITS) have been identified ultrasonically in patients with extracranial vascular or cardiac disease and are suggestive of microembolic material. We studied the prevalence of these signals in 60 patients with increased risk for cardioembolic stroke and in a control group of 20 subjects. Patient groups (n = 20) were characterized by either non-rheumatic atrial fibrillation (AFIB) (I) or a history of prosthetic valve surgery with AFIB (II) or without AFIB (III). Embolic signals were not seen in the control group. In group I, 3 patients (15%) demonstrated HITS, in groups II and III 10 patients (50%). Microembolic signals in patients with prosthetic heart valves (II, III) had a higher signal intensity, indicating different embolic material. There was no correlation of microembolic signals with the anticoagulant treatment or the position of the prosthetic valve. HITS were found in 1/9 (11%) of the patients with a bioprosthetic valve as compared to 19/31 (61%) with a mechanical valve. After 6-12 months, 1 of 12 HITS positive patients had experienced a stroke and 2 had died. None of the 28 patients without HITS had suffered a stroke, 2 had died. Microembolic signals are frequent events in patients with mechanical prosthetic valves. In these patients they do not appear to be a major prognostic factor for an impending cardioembolic stroke.

Prevalence of latent and manifest suprascapular neuropathy in high-performance volleyball players.

The aim of the present study was to evaluate the prevalence of latent and manifest suprascapular neuropathy in high-level male volleyball players. Thirty subjects were examined clinically and electrophysiologically. Suprascapular neuropathy, most probably at the level of the suprascapular notch, was demonstrated in 12 subjects, being latent in eight. Taking into account our clinical findings in a further 36 international-level players, a remarkably high overall prevalence of suprascapular nerve lesion of 33% (22 of 66 subjects) was found. All cases involved the side of the body with the player's smashing arm. These findings suggest that careful monitoring of suprascapular nerve function may be useful in high-performance volleyball players, as early diagnosis is essential to prevent more severe damage.

Latency and duration of the muscle silent period following transcranial magnetic stimulation in multiple sclerosis, cerebral ischemia, and other upper motoneuron lesions.

In muscles with sustained voluntary contraction, EMG activity is transiently inhibited after transcranial magnetic stimulation. We recorded this postexcitatory silent period (SP) at 1.5 times individual stimulus threshold level from the first dorsal interosseus muscle in 65 neurologic patients aged 11 to 80 years. When compared with 20 healthy volunteers and a subgroup of patients with peripheral neurologic conditions not affecting the tested pathways, the SP was significantly longer on the paretic side in cerebral ischemia (p < 0.001) and chronic inflammatory CNS diseases, such as multiple sclerosis or neurosarcoidosis (p < 0.01). There was a similar tendency in pyramidal tract lesions due to CNS tumors and spinal cord trauma. In lesser degrees of paresis, SP duration is more sensitive than central motor conduction time (CMCT), but its specificity awaits further evaluation. SP is dependent on the integration of motor excitatory and inhibitory pathways and, possibly, sensorimotor reflex systems. In contrast to SP duration, which proved to be an independent variable giving supplementary information over the usual CMCT measurement, SP onset latency correlates well with CMCT and peripheral nerve conduction slowing, as in polyradiculoneuritis.

[Differential diagnosis of shoulder pain: chronic neuropathy of the suprascapular nerve]. / Zur Differentialdiagnose des Schulterschmerzes: Die chronische Neuropathie des N. suprascapularis.

Suprascapular neuropathy may present with chronic shoulder pain and weakness of abduction and external rotation of the arm. Therefore, it should always be included in the differential diagnosis of shoulder pain. Usually, the nerve is compressed at the suprascapular notch or the spinoglenoid notch. Here, the nerve is relatively fixed. In the etiology, repeated and forceful movements around the shoulder joint, especially in athletes such as volleyball players, are considered to be frequent causes of suprascapular nerve damage, whereas ligament hypertrophy and ganglia are uncommon. If conservative therapy fails, surgical decompression of the nerve is required for relief of pain and resolution of weakness.

Duration, configuration and amplitude of the motor response evoked by magnetic brain stimulation in patients with multiple sclerosis.

Analysis of motor evoked potentials (MEP) after magnetic brain stimulation is often restricted to measurement of latency and amplitude. In the present study, which was conducted in healthy controls and in patients with multiple sclerosis (MS), the additional value of MEP duration and configuration was evaluated. Recordings were made from distal muscles of the upper and lower extremity. In the MS group, mean MEP duration was found to be prolonged, while amplitudes were reduced. MEP of abnormally prolonged duration, as compared to normative data derived from the control group, were found even in presence of normal central motor conduction times. These findings are compatible with increased temporal dispersion of the impulses arriving at the spinal motoneurone pool. Thus, analysis of MEP duration may provide additional information about impulse propagation along the descending motor tracts, indicating disturbed conduction properties even in the presence of normal central motor conduction time. In contrast, MEP configuration was of no value for differentiating between the two groups.

Suprascapular nerve lesion as an occupational neuropathy in a semiprofessional dancer.

A 25-year-old semi-professional dancer developed painless, isolated weakness of external rotation of the right arm. Physical examination was otherwise normal. Electromyography showed selective partial denervation of the infraspinatus muscle. Stimulation of the suprascapular nerve at Erb's point demonstrated delayed conduction to the infraspinatus muscle. Clinical and electrophysiological findings implicated a distal lesion of the suprascapular nerve. Almost complete recovery of muscle function after 4 months of suspending the training program of Latin dances supports the view that the nerve injury occurred as an occupational neuropathy. It is assumed that repetitive, forceful movements of the arm with external rotation and abduction had induced compression of the nerve at the spinoglenoid notch.

[Vigilance disorders in intensive care patients. The central anticholinergic syndrome as a differential diagnosis of a brain stem lesion]. / Störungen der Vigilanz bei Intensivpatienten. Zentralanticholinerges Syndrom als Differentialdiagnose der Hirnstammläsion.

Four days after implantation of a biventricular assist device (Berlin heart) the 39-year-old patient showed a sudden loss of vigilance and tetraplegia. Clinical skills and neurophysiological states indicated a serious lesion of the brain stem. After a test application of Physostigmine 2 days later, the neurological deficits improved dramatically. The case demonstrates that neurological deficits can also be caused by or combined with an acute anticholinergic syndrome. The application of Physostigmine allows disorders caused by brain lesions to be differentiated from transitory syndromes.

Quantitative evaluation of the silent period, evoked by transcranial magnetic stimulation during sustained muscle contraction, in normal man and in patients with stroke.

It is well known that transcranial stimulation, delivered during sustained muscle contraction, evokes a temporary suppression of motor activity (silent period). The aim of the present study was to further analyze this inhibition in 20 healthy subjects and in 10 patients with previous stroke. Transcranial magnetic stimulation was performed at the vertex, recording responses from first dorsal interosseus (FDI) muscle. Normative data were provided from the control group. The results indicate a narrow range of onset latency, a wide interindividual variation of duration but small interside differences and a sufficient intraindividual stability. As the duration showed an approximately linear increase with increasing stimulus intensities, a standardized paradigm was employed, applying individually adjusted stimulus strengths of 50% above the threshold able to evoke a silent period. There was no relationship between silent period parameters and 1) age, 2) body length, and 3) innervation force. In the patient group, silent period duration was significantly prolonged when recordings were obtained from the affected side. This finding might prove to be an interesting new parameter in the investigation of motor disturbance due to previous stroke. With regard to the physiological basis of the phenomenon, spinal and cortical influences are discussed.

Neuromyotonia: report of a case.

Neuromyotonia is a rare condition of peripheral nerve dysfunction characterized by the signs of motor nerve hyperactivity, namely, myokymia, fasciculations, and muscular stiffness. Relaxation of voluntary muscle contraction is delayed, and fluid movements are impaired to a variable degree. Signs of sensory involvement are less frequent. Usually, therapy with carbamazepine or phenytoin provides rapid improvement. In the present communication, a typical case is reported, and the most important differential diagnoses are outlined.

Results of four technical investigations in fifty clinically brain dead patients.

Fifty consecutive patients (aged 19-77 years, median 56 years) with primary cerebral diseases and the clinical signs of absent cortical and brainstem function were subjected to electroencephalography (EEG), brainstem acoustic evoked potentials (BAEP), extracranial Doppler ultrasonography (ECD) and arterial digital subtraction angiography (DSA). In the majority of cases the results of the technical tests agreed with the clinical signs and were suggestive of brain death. However, in one patient EEG revealed clear bioelectrical activity. In 6 cases, doubts existed about whether the EEG was isoelectric; in 3 of the 6 cases biological activity might have been present. In 31 of 42 patients ECD showed a typical pattern of intracranial circulatory arrest, in 9 of 42 ECD revealed a pattern suggestive of the cessation of cerebral blood flow. In four patients BAEP recordings compatible with brain death were recorded 2-3 days before intracranial circulatory arrest. In 2 patients with isoelectric EEG and absent BAEP arterial DSA demonstrated residual perfusion. The findings are discussed in view of the conceptional differences concerning brain death. It is concluded that the strict application of the concept of death of the whole brain requires angiographic demonstration of absent intracerebral blood flow.

Magnetic transcranial brain stimulation and multimodality evoked potentials in an adrenoleukodystrophy patient and members of his family.

In a patient with adrenoleukodystrophy (ALD), prolonged conduction times along the corticospinal tract and afferent sensory pathways were demonstrated using magnetic transcranial brain stimulation and multimodality evoked potentials, respectively. On investigation of two healthy family members (one an obligate carrier), slight latency increases in evoked potentials suggested impaired conduction along the respective pathways. Thus, the combined use of these methods (1) is helpful in assessing the location and extension of demyelinating lesions and (2) may raise the sensitivity in detecting subclinical involvement in patients with ALD and in carriers.