Diversity of Xanthomonas campestris Isolates from Symptomatic Crucifers in New York State

To assess the diversity of Xanthomonas campestris spp. infecting crucifers in New York, 154 isolates were collected over 10 years across the state. The goal was to determine if isolates of the pathogen were overwintering in New York and serving as primary inoculum in subsequent years, or if novel isolates were entering the state each year. Pure cultures of isolates were characterized using multilocus sequence analysis (MLSA), a greenhouse pathogenicity assay, repetitive element-polymerase chain reaction (Rep-PCR) using the BOX-A1R primer, and enzyme-linked immunosorbent assay. The MLSA scheme proved to be more efficient than Rep-PCR for a large sample population and for comparison with global isolates. X. campestris isolated from crucifers in New York comprised of X. campestris pv. campestris and X. campestris pv. raphani, with X. campestris pv. raphani being predominately isolated from transplants. Evidence for unique haplotypes persisting on the same farm for several years due to improper seedbed rotations was documented in addition to novel haplotypes being spread throughout states through infected transplants and seed. Rep-PCR confirmed the high diversity of X. campestris and was used to generate 15 unique fingerprint patterns from isolates collected in the first 5 years. A worldwide comparison of isolates suggests that the X. campestris pv. campestris population appears to be very homogenous with dominant haplotypes persisting for extended periods and being globally disseminated.

Differential effect of Huntington's and Parkinson's diseases in programming motor sequences of varied lengths

BACKGROUND

Parkinson's disease (PD) and Huntington's disease (HD) patients have difficulties executing sequential movements. Attention control and short-term memory probably play an important role in programming sequential movements. To investigate the contribution of these cognitive factors to programming and executing visuomotor sequences in HD and PD patients a computerized version of the Corsi Block Tapping-Test was employed.

METHODS

the performance of 11 patients with early stage PD, 11 HD patients with borderline to mild caudate atrophy and 20 healthy subjects was compared. The task was a reaction time task where targets were illuminated in groups of sequences increasing from 2 items to 5 items. Subjects reproduced the sequence (pressing the illuminated target) in the same order of appearance. Reaction Times and movement times were recorded.

RESULTS

PD patients had increasing difficulties in programming and executing series greater than three components. HD patients did not differ significantly from the controls, although they showed a tendency to lose accuracy in the longer series. Both patient groups did not differ in their attention span.

CONCLUSIONS

In PD although the spatial information may be well stored, they have difficulty accessing it when their attention is overloaded, leading to poor encoding and slow information processing. This process interferes with programming and execution of movement sequences. HD patients in the early stages of the illness seem to have more attention resources than PD patients, so that they start to show more problems in executing visuomotor sequences with longer movement sequences than PD patients.

The benzamide tiapride: treatment of extrapyramidal motor and other clinical syndromes

The benzamide derivative tiapride (Tiapridex, Synthelabo) has a highly selective antagonistic effect on striatal adenylate cyclase-independent dopamine-2 receptors. Its in vitro binding affinity is especially high for dopamine receptors which have been sensitized by pre-incubation with dopamine. The involvement of altered dopamine receptor sensitivity in several extrapyramidal dys- and hyperkinesia has been hypothesized. By its high affinity for these receptors, without any affinity for other neurotransmitter receptors of the brain, tiapride is especially well suited for the treatment of movement disorders related to functional dopamine hyperactivity. Even at higher doses, tiapride does not exceed a D2-receptor occupancy of 80%, which is in accordance with the finding that tiapride rarely causes acute extrapyramidal syndromes and has, up to now, never implicated in inducing tardive dyskinesias. On the contrary, clinical studies demonstrate its excellent efficacy in neuroleptic-induced tardive dyskinesia, L-Dopa-induced dyskinesias, psychomotor agitation in geriatric patients and choreatic movement disorders. Since tiapride is not available in the USA as yet, most of the studies concerning tiapride have been carried out in Europe. In a recent study, based on objective measurements, tiapride effectively controlled choreatic movements in patients suffering from Huntington's disease (HD). Tiapride is well tolerated in daily doses between 300 and 1200 mg. Adverse events are generally rare and mild.

Velocity modulation and rhythmic synchronization of gait in Huntington's disease

This study analyzed the ability of patients with Huntington's disease (HD) to modulate gait velocity without external sensory cues and in response to an auditory rhythmic cue within a frequency entrainment design. Uncued gait patterns of 27 patients were first assessed during normal, slower, and faster self-paced walking. During rhythmic trials, metronome and musical beat patterns were delivered at rates 10% slower and 10-20% faster than baseline cadence to cue gait patterns. After the rhythmic trials, patients were retested at normal gait speed without rhythm. Gait velocities in the patients with HD were below normal reference values in all ranges. Patients were able to significantly (p <0.05) modulate their gait velocity during self-paced and rhythmic metronome cueing but not during music. The ability to modulate gait velocity was retained regardless of the severity of the disease. Gait velocity declined with an increase in disability and chorea score. The disability score differentiated better between gait velocity of moderately and severe patients than chorea score. Slowness of gait was significantly correlated only with disability score and not with chorea. Patients had more difficulty producing adequate step rates than stride lengths during normal and fast walking speeds. After the rhythmic trials, unpaced gait velocity remained significantly (p <0.05) higher than baseline. This carry-over effect was not seen after the uncued trials. Synchronization ability was deficient in all patients, deteriorated with severity of disease, and was already compromised in patients with soft disease signs. Rhythmic tracking of music declined more with severity of disease than metronome tracking. In summary, patients were able to modulate velocity with and without external cues. Velocity adaptations to the external rhythm in music and metronome were achieved without exact synchronization between step cadence and rhythmic stimulus.

Motor learning by imagery is differentially affected in Parkinson's and Huntington's diseases

Studies of motor imagery and motor learning have thus far been concerned only with its effects on healthy subjects. Therefore, in order to investigate the possible involvement of the basal ganglia, the effectiveness of motor imagery in the acquisition of motor constants in a graphomotor trajectorial learning task was examined in 11 non-demented mildly affected Huntington's disease (HD) patients and 12 non-demented Parkinson's disease (PD) patients. The patients received, after baseline, 10 min of motor imagery training, followed by a motor practice phase. Additionally, a test battery for visual imagery abilities was administered in order to investigate possible relations between visual and motor imagery. The results showed that imagery training alone enabled the HD patients to achieve a significant approach to movement isochrony, whereas the PD patients showed no marked improvements, either with motor imagery or with motor practice. Furthermore, the PD patients had more difficulties than the HD patients in solving the visual imagery tasks. Subsequent correlational analysis revealed significant relationships between the degree of caudate atrophy in the HD patients and their performance in the visual imagery tasks. However, there were no substantial correlations between the performance on the visual imagery tasks and the improvement of motor performance through motor imagery, which indicates that visual and motor imagery are independent processes. It is suggested that the dopaminergic input to the basal ganglia plays an important role in the translation of motor representations into motor performance, whereas the caudate nucleus atrophy of the HD patients does not seem to affect motor imagery, but only the visual imagery process. Furthermore, the deficits found in PD patients might also be related to their limited attentional resources and difficulties in employing predictive motor strategies.

Neurophysiological abnormalities in the Westphal variant of Huntington's disease

The Westphal variant of Huntington's disease (HD) is a distinct clinical entity of HD characterized by a rigid-hypokinetic syndrome and is often associated with a juvenile onset of disease. Definite genetic differences between the subtypes of HD have not been delineated so far. Here we present the results of a battery of neurophysiological tests including somatosensory-evoked potentials, blink reflexes, long-latency reflexes, and measurement of saccadic velocities in a Westphal HD patient. Although quantitative assessment of his motor performance showed a severe hypokinetic syndrome resembling Parkinson's disease, the results of somatosensory-evoked potentials and blink reflexes were indistinguishable from results obtained in hyperkinetic HD patients. Long-latency reflexes, however, which are typically absent in hyper-kinetic HD patients, were retained in this patient. It is concluded that neurophysiology in HD patients is not a mere reflection of the patient's symptomatology but can give insight into the underlying pathophysiological process.

Huntington's disease: N-methyl-D-aspartate receptor coagonist glycine is increased in platelets

Experiments in vertebrates and striatal tissue cultures have provided evidence for a neuroexcitotoxic cause for the neurodegeneration in Huntington's disease (HD), via N-methyl-D-aspartate (NMDA) receptors. Glycine in vitro increases the response of NMDA receptors to its agonists via the NMDA receptor-associated glycine receptor, and the same effect has been observed in vivo. Significantly increased levels of glycine have previously been found in the cerebrospinal fluid of patients with HD. In this present study glycine was measured in platelets and plasma of patients with HD and in controls by high-pressure liquid chromatography. Mean glycine concentration was significantly increased (P < or = 0.01) in platelets in HD compared to controls, though plasma glycine was normal. A possible role for glycine in the pathogenesis of HD, based on the excitotoxicity hypothesis of HD, is discussed.

Decreased plasma alanine and isoleucine in Huntington's disease

Amino acid concentrations in plasma of patients with Huntington's disease (HD) were determined in 16 patients and 21 age- and sex-matched healthy controls. Alanine and isoleucine were significantly decreased in HD plasma whereas arginine, histidine, leucine, lysine, ornithine, proline, serine, threonine, tyrosine, and valine showed no significant changes. Our findings confirm the decreases of alanine and isoleucine that were described in plasma and cerebrospinal fluid by other investigators. A possible defect in cellular uptake or metabolism of neutral amino acids seems to be a consistent feature of HD.

Associative learning in degenerative neostriatal disorders: contrasts in explicit and implicit remembering between Parkinson's and Huntington's diseases

The performances of 12 patients with Parkinson's disease (PD), 16 with Huntington's disease (HD), and young and old healthy controls were assessed on a number of tests of verbal and nonverbal declarative memory, on a test of nonmotor conditional associative learning (words and colors), and on a number of reaction time (RT) tasks. The RT tasks consisted of cued simple and choice reactions. The relationship between the precue and the imperative stimulus in the S1-S2 paradigm was nonarbitrary in the first series and arbitrary in the second series. The series with arbitrary S1-S2 associations was repeated across two successive blocks of trials. The rationale of the study was to investigate the function of the basal ganglia "complex loop," and it was postulated that HD patients would show greater deficits because of greater involvement of the caudate nucleus. The patients with HD had the slowest RTs. Across the two blocks with arbitrary S1-S2 associations, the patients with HD but not PD nevertheless showed evidence of learning in their precued RTs. In contrast, the patients with PD were better able to remember the associations in free recall than were the HD patients. It is concluded that patients with PD have relatively greater deficits in procedural learning, whereas those with HD have relatively more impairments in declarative memory, and the greater level of cognitive impairment in HD overall is interpreted as being due to more serious damage to the caudate loop.

Huntington's disease: the neuroexcitotoxin aspartate is increased in platelets and decreased in plasma

The neural degeneration observed in the striata of patients with Huntington's disease (HD) can be reproduced by excitatory NMDA receptor agonists such as aspartate and glutamate in striatal cell cultures and in striata of vertebrates injected with these substances. Therefore, we decided to investigate the role of aspartate and glutamate in HD. Aspartate, glutamate, glutamine, and phenylalanine were measured in platelets and plasma of HD patients and age- and sex-matched healthy controls (C), using HPLC methods. In HD platelets the mean aspartate concentration was significantly (p < 0.01) increased (8.9 +/- 3.8 (SD) nmol/mg protein, n = 28) compared to C (4.6 +/- 1.4 (SD) nmol/mg protein, n = 24), whereas plasma aspartate was significantly (p < 0.01) decreased in HD (0.092 +/- 0.023 (SD) mg/dl, n = 16) versus C (0.179 +/- 0.109 (SD) mg/dl, n = 21). The increase in platelet aspartate should be a direct or indirect consequence of the dominant gene defect in HD. It might therefore be present in neurons as well, especially since platelets share many characteristics with neurons. Hence, chronically increased release of aspartate with consecutive overstimulation of postsynaptic neurons via NMDA receptors might be responsible for the damage observed in striatal target cells of corticostriatal glutamatergic and aspartatergic projection fibers in HD.

SPECT with HMPAO compared to PET with FDG in Huntington disease

OBJECTIVE

It is the aim of this study to compare the performance of 99mTc-d,l-hexamethylpropyleneamine oxime (HMPAO) SPECT with that of [18F]fluorodeoxyglucose (FDG) PET in detecting striatal dysfunction as it occurs in Huntington disease (HD).

MATERIALS AND METHODS

For the determination of regional cerebral glucose consumption, the PET camera PC-4096 was used; the cerebral uptake of HMPAO was measured using the three-head SPECT camera TRIAD. Eight patients with manifest HD, seven subjects at risk for HD, and nine normal individuals were included in the study. In both modalities data evaluation was performed using caudate-to-whole-slice (C/S) ratios. The patients' data were compared to 95% confidence intervals determined in the nine controls.

RESULTS

The PET and SPECT C/S values correlated significantly (n = 24; r = 0.87; p < 0.0001). The C/S values were significantly reduced in PET in all eight and in SPECT in seven of the eight HD patients studied. Five of the seven at-risk subjects had normal C/S values in PET and SPECT, one showed reduced C/S values in both diagnostic methods, and the remaining at-risk individual showed a reduced C/S value in PET only. Thus, concordant results between PET and SPECT were obtained in seven of eight patients and six of seven at-risk subjects studied, corresponding to an 87% accuracy of SPECT in the detection of striatal dysfunction as compared to the "gold standard" PET.

CONCLUSION

With use of a multidetector camera, HMPAO-SPECT comes near the performance of FDG-PET in the diagnosis of striatal dysfunction as it occurs in HD.

Striatal glucose consumption in chorea-free subjects at risk of Huntington's disease

Controversial data have been reported with regard to the diagnostic value of the positron emission tomographic (PET) measurement of striatal glucose consumption (rCMRGlc) in chorea-free subjects at risk of Huntington's disease (HD). For further clarification of this issue we measured striatal and cerebellar rCMRGlc in 27 chorea-free subjects at risk of HD, 20 patients with manifest HD and 20 control subjects, using PET and 18F-fluorodeoxyglucose. In 6 of the at-risk subjects cerebellar ratios of striatal rCMRGlc were decreased below the corresponding 99% confidence limit determined in the controls. This indicates that the PET measurement of rCMRGlc may, indeed, be valuable in establishing the diagnosis of incipient HD in presymptomatic at-risk subjects.

Pre- and postcentral somatosensory evoked potentials in Huntington's disease: effects of stimulus repetition rate

We recorded frontal, central and parietal somatosensory evoked potentials (SEPs) to median nerve stimulation in 20 patients with Huntington's disease (HD) and in a group of normal controls. Two stimulus repetition rates, 1 Hz and 5 Hz, were employed. In HD patients the early cortical potentials (latency range 20-30 ms) at all 3 recording locations were replaced by a widespread, broadly configured N20-25 deflection, while later potentials at 40-80 ms did not significantly differ from those of normals. In contrast to the early P22, P27 and N30 potentials in normals, the N20-25 potential in the patients was not significantly modified by changing the stimulus repetition rate. At 40-80 ms the stimulus rate effects were similar in the patients and normals. The results show that early pre- and postcentral SEPs are both pathological in HD, while later frontal and parietal components can be totally preserved. The early N20-25 in HD is possibly a subcortical potential, seen due to unmasking in the absence of early cortical deflections.

Comparison of somatosensory evoked potentials with striatal glucose consumption measured by positron emission tomography in the early diagnosis of Huntington's disease

Both somatosensory evoked potentials (SEP) and striatal glucose consumption (rCMRGlc) measured by positron emission tomography (PET) have been reported to be abnormal early in the course of Huntington's disease (HD). To compare their diagnostic value, SEP and rCMRGlc were measured in a group of 18 first degree off-spring of HD families: 6 had manifest HD with chorea and the remaining 12 individuals were chorea-free subjects at risk for HD. In five patients with manifest disease, both SEP and striatal rCMRGlc were significantly abnormal, defined in SEP as having either a bilaterally absent frontal N30 amplitude or a reduction of the parietal N20/P25 amplitude below 1 microV on at least one side; in PET as exhibiting a reduction of the cerebellar ratio (CR) of both caudate and lentiform rCMRGlc below the 99% confidence limits of these variables determined in 20 normal volunteers. The remaining patient with manifest HD had questionably abnormal SEP and significantly reduced indices of striatal rCMRGlc. The five persons at risk for HD who had normal SEP also had normal striatal rCMRGlc; those three at-risk patients with abnormal SEP also had a reduction of the CR of both caudate and lentiform rCMRGlc. Of the remaining four individuals at risk for HD who had questionably abnormal SEP, three had CR values of striatal rCMRGlc in the normal range and one a reduction of the CR of lentiform rCMRGlc. In at-risk patients, the SEP diagnosis correlated significantly with caudate (r = -0.8; p < 0.002) and lentiform (r = -0.76; p < 0.005) rCMRGlc. These data indicate a parallel deterioration of SEP and striatal rCMRGlc early in the course of HD even before the development of chorea.

Motor responses evoked by magnetic brain stimulation in Huntington's disease

In 34 patients with manifest Huntington's disease (HD), and in 21 first-degree offspring without clinical signs or symptoms, the sizes, central motor latencies (CMLs) and variation in latencies of EMG responses (MEPs) following transcranial magnetic brain stimulation were studied in muscles of the upper and lower extremities. In subgroups of patients and their offspring median and tibial nerve somatosensory evoked potentials (SEPs) and electrically elicited long-loop reflexes (LLRs) in hand muscles were also investigated. Increased MEP thresholds were observed in 10% of the HD offspring, while CML, latency variability and MEP amplitudes always lay within normal range. In contrast, SEPs were abnormal in 33%. In HD patients MEPs were found to be abnormal in up to 72% of patients when all available response parameters were taken into consideration. MEP abnormalities correlated with the duration of motor symptoms and the severity of choreic motor activity. When both MEPs and SEPs were evaluated, abnormalities could be detected in 91% of all HD patients. We suggest that abnormal MEPs might reflect an altered excitability of the cortico-spinal system as a consequence of basal ganglia dysfunction, rather than a structural damage of the investigated descending pathways. To localize the pathological mechanism responsible for altered LLRs, a "loop analysis" was performed by recording LLRs, MEPs and SEPs in the same patients. Alterations of LLRs correlated best with abnormal SEPs and might therefore be explained by reduced somatosensory input to the motor cortex.

Exclusion of atrial thrombus by transesophageal echocardiography

To determine whether transesophageal echocardiography (TEE) is useful in ruling out the presence of atrial thrombus, we performed TEE in 20 patients immediately before valve replacement or valve repair and within 3 days of an autopsy in one patient. Mitral stenosis was the predominant lesion in three patients, mitral regurgitation was seen in 11 patients, five patients had mitral prosthesis malfunction, one patient had a tricuspid prosthesis malfunction, and one patient had aortic stenosis. Eight patients were in atrial fibrillation. Four patients demonstrated spontaneous contrast in the associated atria. Nine patients were receiving oral anticoagulation. Mean left atrial diameter was 5.3 +/- 1.3 mm. TEE revealed no evidence for atrial thrombus in 18 of the 21 patients; this finding was confirmed by careful inspection of the atria including the appendages. TEE demonstrated a left atrial thrombus in two patients and a right atrial thrombus in another (confirmed at the time of surgery or at autopsy). In all cases transthoracic echocardiography was negative. Our data suggest that TEE is useful in ruling out atrial thrombus, and therefore may be a useful test preceding interventions associated with an increased risk of embolism from the atria such as cardioversion, mitral valvuloplasty, or valve replacement.

Transesophageal echocardiography in patients with mechanical circulatory assistance

Transesophageal echocardiography was used to assess myocardial function and to detect complications after mechanical circulatory support for 8 patients with cardiogenic shock. In 3 of 8 patients, serial transesophageal echocardiography documented improvement of systolic ventricular function, and it was possible to wean these 3 patients from the ventricular assist device. In all patients, transesophageal echocardiography added clinically important information including the extent of left and right ventricular dysfunction (6 patients), presence of atrial or ventricular thrombus (5 patients), presence of pericardial effusion or clot (2 patients), and verification of the position of the intravascular device (1 patient). Thus, transesophageal echocardiography may provide clinically useful information regarding both the underlying cardiac disease and potential complications from the mechanical circulatory assistance.

Value of transesophageal echocardiography as an adjunct to transthoracic echocardiography in evaluation of native and prosthetic valve endocarditis

To determine if transesophageal echocardiography provides better visualization of valvular vegetations than transthoracic echocardiography, we used both methods to evaluate 24 consecutive patients (mean age, 54 years; 15 female patients and nine male patients) referred for symptoms suggestive of infectious endocarditis. Ten of the 24 patients had one or more valvular prostheses. Echocardiograms were classified as positive or negative based on visualization of valvular vegetations or abscesses. Of ten patients with a final diagnosis of infectious endocarditis on extended follow-up, transthoracic echocardiography was positive in five patients. Transesophageal echocardiography not only yielded abnormal findings in all ten of these patients, but also revealed additional information in four of the five patients with abnormal transthoracic echocardiographic examinations. Among the 14 patients who, on subsequent follow-up, were found not to have infectious endocarditis, transthoracic echocardiography was normal in 13 and falsely abnormal in one. Transesophageal echocardiography revealed no evidence of infectious endocarditis in any of these patients. The ten patients who were determined to have infectious endocarditis all had positive blood cultures and no alternative cause for their clinical presentation; in seven patients in this group who underwent operative or postmortem evaluation, infectious endocarditis was confirmed. All patients without infectious endocarditis were demonstrated to have other causes for their clinical presentation. We conclude that transesophageal echocardiography is a highly valuable test in the work-up of patients with suspected infectious endocarditis, especially those patients with inconclusive or normal transthoracic echocardiograms. In addition, transesophageal echocardiography may be of benefit to patients with previously documented infectious endocarditis and a complicated clinical course in whom additional cardiac lesions are suspected but not demonstrated by transthoracic echocardiography.

Transesophageal color Doppler echocardiography of the normal St. Jude Medical mitral valve prosthesis

Transesophageal color flow Doppler findings are reported in 36 patients with a St. Jude Medical mechanical mitral valve prosthesis who had no auscultatory evidence for prosthetic valve dysfunction. Multiple jets consistent with mitral regurgitation originating from the central and lateral portion of the prosthesis were found in all patients. Maximum jet length ranged from 11 to 51 mm (mean 21 +/- 9 mm). Maximum jet area ranged from 0.2 to 4.1 cm3 (mean 1.2 +/- 0.9 cm2). The color M-mode Doppler interrogation showed two distinct components of the regurgitant jet: brief early systolic flow consistent with valve closure followed by holosystolic regurgitant flow consistent with transvalvular leakage. Four patients (11%) had a maximum regurgitant jet length exceeding 30 mm and absence of early systolic closure regurgitant flow by M-mode color imaging, suggesting clinically silent paravalvular leakage. Two pin-sized paravalvular suture line defects were confirmed in one patient at cardiac transplantation. We conclude that transesophageal echocardiography is a highly sensitive method for detection of mitral regurgitation in the St. Jude Medical mitral prosthesis. Clinically silent paravalvular leakage should be suspected if the maximum jet length exceeds 30 mm and color M-mode interrogation fails to demonstrate an early systolic closure regurgitant flow component.

Frequency of success and complications of coronary angioplasty of a stenosis at the ostium of a branch vessel

The authors of this study hypothesized that percutaneous transluminal coronary angioplasty of a stenosis at the ostium of a branch vessel, whether isolated or associated with a bifurcation stenosis, was associated with reduced procedural success and increased in-hospital complications. One hundred six patients with 119 ostial branch stenoses were compared with 1,168 patients who underwent angioplasty of nonostial branch stenoses. An ostial branch stenosis was defined as a stenosis in the proximal 3 mm of a major branch vessel (diagonal [n = 58], posterior descending [n = 21], obtuse marginal [n = 34] and intermediate [n = 6]). The ostial branch stenosis was isolated in 61% of the patients and associated with a bifurcation stenosis in 39%. Despite a balloon to artery ratio of 1.05:1, angiographic success was 74% of ostial branch stenoses versus 91% of nonostial stenoses (p less than 0.01). Furthermore, angioplasty of ostial branch stenoses resulted in a complication rate of 13 versus 5% for angioplasty of nonostial branch stenoses (p less than 0.01). Therefore, angioplasty of ostial branch stenoses results in decreased procedural success and significant residual stenosis despite adequate balloon sizing, suggesting arterial elastic recoil and a significant increase in complications.

[Significance of trans-esophageal echocardiography as an adjunct to transthoracic echocardiography]

We describe our experience with the first 103 patients undergoing transesophageal echocardiography at our institution. The procedure was well accepted by most patients and associated with no major complications. The clinical indications for this procedure have included endocarditis, prosthetic cardiac valve dysfunction, detection of intracardiac source of embolism, atrial septal defect and thoracic aortic dissection. Transesophageal echocardiography proved to be useful in all of these diagnostic categories, especially if standard transthoracic echocardiography did not provide a complete assessment.

Cortical and subcortical glucose consumption measured by PET in patients with Huntington's disease

In 23 patients with moderate to severe Huntington's disease (HD) and 21 normal volunteers, the regional cerebral metabolic rate of glucose consumption (rCMRGlc) was measured in the cerebellum, thalamus, striatum, and cortex using positron emission tomography and the 18F-deoxyglucose method. In contrast to previous reports, rCMRGlc was reduced not only in the striatum, but also in the cerebral cortex of patients with HD as compared with normal subjects. No significant difference between HD patients and normal subjects was found for thalamic and cerebellar rCMRGlc. To investigate the relationship between the clinical status and rCMRGlc, correlation coefficients for the clinical data were calculated for absolute values of rCMRGlc and for cerebellar ratios (CR) of rCMRGlc. The duration of chorea correlated significantly only with the absolute values of frontoparietal and temporo-occipital rCMRGlc and with the CRs of most cortical regions evaluated. The severity of chorea correlated significantly only with lentiform nucleus rCMRGlc. The severity of dementia correlated significantly only with the frontoparietal and temporo-occipital rCMRGlc, the CRs of most cortical regions, and the CR for the caudate nucleus. The degree of disability correlated significantly with the CRs of all regions evaluated except the occipital and the superior frontal cortex. It appears from this study that there is a reduction not only for the striatum but also for cortical rCMRGlc in patients with manifest HD, and that the cortical reduction of rCMRGlc contributes to the severity of clinical symptoms in these patients. This challenges the concept that dementia in HD is of purely subcortical origin.

Normal striatal glucose consumption in two patients with benign hereditary chorea as measured by positron emission tomography

Positron emission tomography (PET) with [18F]-2-fluoro-2-deoxy-D-glucose (FDG) was used to investigate the regional cerebral metabolic rate of glucose consumption (rCMRGlc) in two patients with benign hereditary chorea (BHC) and 21 normal subjects. Relative and absolute values of cerebellar, striatal, thalamic, and cortical rCMRGlc were within normal limits for both patients with BHC, indicating that the choreic movement disorder encountered in these two patients was not caused by a decrease of energy metabolism in the striatum such as that found regularly in most patients with other forms of chorea (e.g. Huntington's and Wilson's disease).

Assessment of the hemodynamic response to acetyl-strophanthidin by Doppler echocardiography in normal subjects and in those with coronary artery disease or idiopathic dilated cardiomyopathy

The effect of acetyl-strophanthidin, a rapidly acting digitalis-like drug, was measured on peak flow velocity, stroke distance (an index of stroke volume) and minute distance (an index of cardiac output), determined by Doppler echocardiography in 21 subjects with a wide range of left ventricular ejection fractions (12 to 89%, average 47%). For the total study group, peak flow velocity increased from 99 +/- 10 to 110 +/- 13 cm/s (p less than 0.01), and stroke distance increased from 15.1 +/- 3.2 to 16.8 +/- 3.1 cm (p less than 0.01). Minute distance remained unchanged: 1,093 +/- 168 cm before and 1,129 +/- 187 cm after acetyl-strophanthidin (difference not significant). Improvement in Doppler parameters of forward blood flow was significantly (p less than 0.001) greater in subjects with left ventricular ejection fractions less than 60% (+17% for peak flow velocity, +22% for stroke distance and +15% for minute distance) than those with left ventricular ejection fractions greater than or equal to 60% (+4% for peak flow velocity, +2% for stroke distance and -8% for minute distance). These data suggest that Doppler echocardiography is a useful method to assess the efficacy of acute digitalis administration in improving forward blood flow.

Role of transmitral blood flow velocity by Doppler echocardiography in the evaluation of coronary artery disease

To determine the relation between presence and severity of coronary artery disease and diastolic filling abnormalities by Doppler echocardiography, recordings of transmitral inflow velocity were made at rest in 90 patients with coronary artery disease and 28 normals. At the time of the Doppler examination, 81 patients with coronary artery disease (90%) and 10 normals (36%) were treated with antianginal medications. No difference was found in the ratio between early (E) and late (A) diastolic filling velocity (E/A ratio) when comparing patients with greater than 70% obstruction of at least one coronary artery to age-matched normals, regardless of the presence or absence of wall motion abnormalities. The E/A ratio was 1.3 +/- 0.46 in coronary patients with normal wall motion, 1.2 +/- 0.47 in coronary patients with abnormal wall motion, and 1.3 +/- 0.53 in both samples of age-matched normals. Multivariate analysis of the relation between E/A ratio and other variables showed that heart rate (F = 24.46, p less than 0.00001) and age (F = 19.51, p less than 0.00001) were significant independent determinants of the E/A ratio, while the presence or severity of coronary artery disease, the presence of hypertension, the magnitude of wall motion abnormalities, and end-diastolic dimension by echocardiography were not. These data suggest that transmitral inflow velocity recordings by Doppler have limited value for the recognition of coronary artery disease, since the E/A ratio is profoundly influenced by other factors, such as heart rate and age.

Central motor conduction to hand and leg muscles in Huntington's disease

Using electromagnetic stimulation of motor cortex and cervical or lumbar roots, central conduction times to the thenar and abductor hallucis muscles bilaterally were determined in a population of 32 patients with definite Huntington's disease (HD) and 14 subjects at risk. The HD patients showed a wide variety of different severity of choreatic movements, disease duration, and total disability. None of the stimulation parameters (latency after cortical stimulation, amplitude, threshold, or central conduction time) revealed statistically significant abnormalities compared with a normal control group as well as between patient subgroups. The data indicate that central motor conduction to upper and lower extremity muscles remains normal in Huntington's disease irrespective of the severity of the disorder.

Language functions in Huntington's disease

A comprehensive language test battery (Aachen Aphasia Test) was administered to 45 patients in the early, middle or later stages of Huntington's disease (HD) and to 20 control subjects. In spontaneous speech, many HD patients exhibited a loss of conversational initiative. Dysarthria was a common finding. Reading skills were found to be impaired mainly as a consequence of dysarthria; some HD patients displayed visual dyslexia. In addition to the characteristic disturbances of writing skills due to the choreiform movement disorder, the writing of HD patients with advanced dementia indicated constructional dysgraphia, characterized by frequent omissions, perseverations and substitutions. HD patients exhibited no evidence of word-finding difficulty or other semantic deficits in spontaneous speech. There was, however, a marked impairment in visual confrontation naming, with a significant rise in naming error rate as the disease progressed in severity. In most instances, the inappropriate names referred to an object visually similar to the target object, suggesting that visual misperception is the major cause of the naming disorder in HD. Syntactical structure of spontaneous speech was typically reduced to short, simple sentence construction. Verbal stereotypes were only rarely encountered and occurred late in the course of the disease. Tests of language comprehension reflected the general degree of dementia. It is concluded that there are no primary language changes in HD. Instead, a variety of language impairments develop secondary to other neurological and neuropsychological changes.

Relation between serum digoxin concentration and the electrocardiogram

The relation between serum digoxin concentration and the electrocardiogram was assessed by correlating computerized measurements of electrocardiographic parameters (PR, QRS, QT and QTc intervals, ST segment, and T-wave amplitude) with the serum digoxin concentration in 97 patients on digoxin maintenance therapy and in 40 nondigitalized control subjects. None of the patients had unstable ischemic heart disease, electrolyte disorders, medication known to influence the ST segment, and/or the presence of a bundle-branch block or ventricular hypertrophy. We found a trend toward lengthened PR interval and shortened QT and QTc intervals in digitalized versus nondigitalized patients. Increasing serum digoxin concentrations were associated with progressive depression of the ST segment and decreased T-wave amplitude (p less than 0.001). A normal ST segment in four leads (I, aVF, V5, V6) excluded the presence of a serum digoxin concentration greater than 1.3 ng/ml in our patients, whereas severe ST-segment depression with a J point of greater than or equal to 100 microV was a strong indicator for the presence of a serum digoxin concentration greater than 2.0 ng/ml in our selected patient population (specificity 99%, sensitivity 30%, predictive accuracy 85%). We conclude that computerized electrocardiographic analysis of the ST segment may provide clinically useful information for the management of selected patients on digitalis therapy and may therefore increase the diagnostic yield of the electrocardiogram in predicting the presence of higher serum digoxin concentrations in a small but significant percentage of patients.

Prevalence and clinical correlates of non-Wenckebach, narrow-complex second-degree atrioventricular block detected by ambulatory ECG

Among 113 patients with transient, narrow-complex second-degree atrioventricular (AV) block detected by ambulatory ECG, there were 20 with non-Wenckebach behavior. Based on the presence or absence of PR interval shortening after single blocked complexes, patients with narrow-complex non-Wenckebach patterns could be separated into a pseudo-Mobitz II group of 16 patients (greater than or equal to 20 msec of PR shortening after the blocked complex) and a classic Mobitz II group of four patients (constant PR interval). These groups had additional distinct ECG and clinical features. Patients with the pseudo-Mobitz II pattern had a 44% prevalence of associated Wenckebach block during the same ambulatory recording, whereas Wenckebach behavior did not occur in patients with classic Mobitz II block. Pseudo-Mobitz II block occurred at significantly longer cycle lengths (876 vs 585 msec) and with significantly longer PR intervals (225 vs 165 msec) preceding the blocked complex than did classic Mobitz II block. Syncope was the presenting symptom in 38% of patients with pseudo-Mobitz II block and in all patients with classic Mobitz II block. Patients with pseudo-Mobitz II block had a 56% prevalence of associated coronary disease and a 44% prevalence of congestive heart failure; the mortality rate was 38% in this group over 4 years of follow-up, but in all instances death was due to associated disease rather than to conduction itself. In contrast, patients with classic Mobitz II block had hypertensive or valvular disease but no evidence of coronary disease or congestive failure; all are alive with pacemakers after 3 years of follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

[Left ventricular diastolic function in PTCA: a Doppler echocardiographic study]

The measurement of left ventricular inflow by Doppler echocardiography provides a continuous, non-invasive assessment of parameters of diastolic function. We studied changes in left ventricular diastolic function during percutaneous transluminal coronary angioplasty (PTCA) of the left anterior descending coronary artery (LAD). In ten patients, the diastolic flow velocity profile across the mitral valve was measured by Doppler echocardiography, before and 60 s after inflation and 60 s after deflation of the balloon. The peak velocity of early diastolic filling (VE) significantly decreased during angioplasty, from 68 +/- 12 to 56 +/- 10 cm/s (p less than 0.001), while the peak velocity of late diastolic filling caused by atrial contraction (VA) showed no change. This resulted in a significant decline in the diastolic velocity ratio (VE/VA) from 1.11 +/- 0.47 to 0.92 +/- 0.35 (p less than 0.01). The total area under the diastolic flow velocity profile representing the total filling volume fell from 14.3 +/- 4.1 to 10.9 +/- 3.6 cm (p less than 0.001). The early diastolic filling fraction decreased from 68 +/- 5% to 64 +/- 7%, in favor of the filling fraction due to atrial contraction, which increased from 32 +/- 5%, to 36 +/- 7% (p less than 0.01). 60 s after deflation of the balloon, the parameters of diastolic filling returned to baseline values. We conclude from our results that diastolic dysfunction caused by angioplasty of the LAD results in a decrease in early diastolic left ventricular filling, which is completely reversible after 60 s.

[Comparison of 3 ECG computer programs with interpretation by physicians]

Three ECG computer programs-Hewlett Packard analog program (HP), Telemed analog program (T) and Marquette 12 SL digital program (MAC)-were evaluated and their accuracy of ECG reading compared with the reading of 4 experienced interpreters on 140 ECGs of patients with various clinical abnormalities. Major disagreement with effect on patient management, and minor disagreement were defined at a joint session with a senior (consensus). The computers identified all normal ECGs correctly (sensitivity 100%). The percentage of major agreements (full agreements and minor disagreements) between consensus and computer was 79% for HP, 90% for T and 93% for MAC. The number of disagreements varied widely between readers and in relation to the different computers. Major problems for the computers were the interpretation of rhythm disturbances and the diagnosis of myocardial infarction, T-wave changes and ventricular hypertrophy: major diagnoses missed by the readers were first degree AV block, QT prolongation, and myocardial infarction. Although there was a considerable difference of accuracy between the 3 computer systems, all of them are sufficiently accurate to be useful to most clinicians. However, every ECG should be over-read by a physician, particularly if a clinical decision is based on the ECG diagnosis.

Diagnosis of juvenile-adult form of neuroaxonal dystrophy by electron microscopy of rectum and skin biopsy

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Impairment of rapid movement in Huntington's disease

Patients with Huntington's disease (HD) and relatives at risk were examined with respect to their capacity to produce rapid voluntary motor activity. For this purpose, the fastest possible self-paced single isometric forefinger extensions and the fastest alternating forefinger movements were tested. In addition to these fastest voluntary performances, the time course of spontaneous hyperkinetic finger movements and the peak frequency of finger and hand tremor were analysed as a measure of the temporal characteristics of involuntary movements. Comparison of these parameters in HD patients and individuals at risk with age and sex-matched normal controls revealed a significant slowing of all types of contractions or movements in the majority (up to 95%) of the patients and in up to 40% of the relatives at risk. Reaction times were only slightly prolonged, and the abnormalities of the movement parameters showed no correlation with detailed psychometric data. Hence it is unlikely that the disturbance in the execution of rapid motor acts is due to dementia. Tremor was also slower than normal and the hyperkinesias were still slower than the fastest voluntary contractions. It appears from this study that slowness of motor performance is not only evident in Parkinson's disease but may represent a more general dysfunction in basal ganglia disease.

Survival of patients with acute renal failure requiring dialysis after open heart surgery: early prognostic indicators

We analyzed pre- and postoperative data from 36 consecutive patients, who developed acute renal failure requiring hemodialysis after open heart surgery, to determine which factors predicted survival. Seventeen patients (47%) survived. Age, sex, preoperative renal dysfunction, severity of underlying heart disease, perioperative myocardial infarction, cardiopulmonary bypass time, and oliguria did not influence outcome (by univariate analysis). However, the number and type of postoperative complications, before the first hemodialysis and 48 hours thereafter, were found to be significant predictors of outcome. Univariate as well as multivariate analysis showed that the highest mortality rate was associated with the presence of respiratory failure, central nervous system dysfunction, hypotension, and infection (48 hours after first hemodialysis). Thirty-three (92%) of the 36 patients were correctly classified as survivors or nonsurvivors based on the presence or absence of any one of three prognostic indicators (three or more complications before the first hemodialysis and persisting 48 hours later; hypotension before the first dialysis and persisting 48 hours later; or central nervous system dysfunction 48 hours after hemodialysis was initiated). We conclude that an assessment of prognosis can be made in such patients as early as 48 hours after the first hemodialysis based on the number and type of complications.

The diagnostic value of eye movement recordings in patients with Huntington's disease and their offspring

Eye movements were studied with EOG in a large number of Huntington's disease (HD) patients (N = 48) and their offspring (subjects at risk, N = 97). The following oculomotor paradigms were investigated: horizontal and vertical saccades of different sizes (10-80 degrees), smooth pursuit eye movements, optokinetic and vestibular nystagmus. It was found that 75% of the HD patients had pathologically slow saccades. This number rose to 87% if other oculomotor deficits were included. Thus a small, but definite number of HD patients had normal eye movements. This included patients with disease durations of more than 14 years. A comparison with the results of clinical and evoked potential studies on these patients showed that they were clinically only mildly affected but did not form a different group of HD patients. Subjects at risk had statistically (P less than 0.01) slower horizontal saccades (average 427 deg/sec) than the controls (455 deg/sec). For 11% of the subjects at risk horizontal saccade velocity was pathological and altogether 22% had some oculomotor deficits. Subjects with pathological slow horizontal saccades also had a high incidence (64%) of pathological evoked potentials. Thus, subjects with pathological slow horizontal saccades can be considered to have a high risk of developing the clinical symptoms of HD.

Short- and long-term therapy with tocainide for malignant ventricular tachyarrhythmias

Tocainide was administered to 228 patients referred for treatment of recurrent ventricular tachyarrhythmias that were refractory to therapy with conventional antiarrhythmic drugs. After baseline studies, 1200 to 2400 mg tocainide/day was given for 4 days. Tocainide was effective in 49% of 180 patients evaluated with monitoring and exercise testing and in 35% of 48 patients undergoing electrophysiologic testing. No clinical parameter predicted the response to tocainide, although there was a correlation with the effect of lidocaine. Tocainide was selected for long-term treatment in 73 patients who were followed for an average of 26.4 months (range 1 to 92 months). The incidence of sudden death was 4.3% per year and two patients had nonfatal recurrence of arrhythmia. It is concluded that tocainide is effective and well tolerated during long-term use if therapy is evaluated carefully and is individualized.

Evoked potentials in patients with Huntington's disease and their offspring. II. Visual evoked potentials

Visual evoked potentials (VEPs) to full-field and half-field stimulation were recorded in a large sample of patients with Huntington's disease (n = 36) and subjects at risk (first-order offspring, n = 55) using a checkerboard pattern reversal stimulus. Whereas a clear diminution of the amplitudes found confirmed earlier findings in patients with Huntington's disease, further alterations of VEP wave forms consisted in the absence of asymmetric hemisphere lateralization to half-field stimulation (i) and severe distortion with amplification of the early NPN/PNP complexes (ii). Considering at least two different abnormal parameters necessary to represent a reliable indicator of the disease, 24 patients (67%) and 14 (25%) of the persons at risk exhibited pathological results. In contrast, only 2 among 36 patients (5%) but 30 (55%) among the offspring exhibited normal results. The diagnostic and predictive value of the investigation of VEPs in Huntington's disease is discussed.

Evoked potentials in patients with Huntington's disease and their offspring. I. Somatosensory evoked potentials

Spinal and cortical somatosensory evoked potentials (SEPs) were recorded in a large sample of patients with Huntington's disease (n = 37) and subjects at risk (first order offspring, n = 43). The SEPs were elicited by stimulation of the median and tibial nerves and recorded at Erb's point, the cervical level (C2) and at the corresponding scalp areas. The most striking finding in patients with Huntington's disease was a drastic diminution of the amplitude of the early cortical components, especially N20/P25 for the median nerve and N33/P40 for the tibial nerve. The latencies (Erb's point, C2, cortical) were only slightly prolonged in comparison to the normal values. Forty-three per cent of the persons at risk exhibited pathological results with a clear reduction in amplitude of the early cortical responses or with a pathological side difference between the amplitudes. Fifty-three per cent of the persons at risk exhibited a normal result. Two persons at risk (= 6%) could not be classified unambiguously. Some patients with benign and symptomatic chorea were investigated. These showed normal results with one exception. The diagnostic and predictive value of the investigation of SEPs in Huntington's disease is discussed.

Local complications associated with indwelling Swan-Ganz catheters: autopsy study of 36 cases

Thirty-six hearts of patients who died with indwelling Swan-Ganz catheters in place were prospectively examined to assess the incidence and extent of localized lesions in the right side of the heart. Bland mural thrombosis in the superior vena cava, the right atrium and the pulmonary artery was found in 22 of 36 cases (61%). Patients with catheter periods greater than 2 days had a greater incidence and extent of bland mural thrombosis (79%) than patients with short-term catheterization (41%, p less than 0.01). Anticoagulation had no influence on bland mural thrombosis. Valvular hemorrhage occurred in 31% and aseptic valvular vegetations in 8% of the hearts. No case of infective endocarditis was found. Four of 36 cases (11%) had evidence of pulmonary infarction that appeared to be unrelated to the lesions in the right side of the heart. Endocardial lesions were common complications of indwelling Swan-Ganz catheters but had no significant impact on the clinical courses of the patients.

Absence of long latency reflexes to imposed finger displacements in patients with Huntington's disease

Long latency reflexes in the electromyogram (EMG) of the first dorsal interosseus muscle were elicited by short finger displacements under isometric conditions. In all healthy subjects tested the spinal response was followed by a second involuntary component. Patients with Huntington's disease lacked the late EMG response almost completely, but exhibited a spinal component indistinguishable from that of the control group. A spinal mechanism responsible for this result is unlikely, since double stretches evoked two distinct EMG responses in these patients. Moreover, drastically reduced cortical somatosensory evoked potentials in all patients support the notion that the second EMG response seen in our motor paradigm is of supraspinal origin.