[The clinical spectrum of progressive multifocal leukoencephalopathy: differences and similarities in patients with and without human immunodeficiency virus]

AIM

To analyse the clinical findings, complementary examinations and prognosis of patients with progressive multifocal leukoencephalopathy (PML) treated in our institution, comparing populations with and without associated human immunodeficiency virus (HIV).

PATIENTS AND METHODS

A retrospective study of the medical records of patients with probable or definite PML was carried out. Clinical variables, complementary studies (cerebrospinal fluid, magnetic resonance imaging of the brain) and prognostic variables were analysed. Non-parametric statistical tests were used to compare HIV-positive and HIV non-positive populations.

RESULTS

Fourteen patients with definite and one probable diagnosis of PML were included. Nine patients had PML associated with HIV; five had other immunosuppressive conditions (two, chronic lymphatic leukaemia; one, multiple sclerosis; one, neuromyelitis optica; and one, neurosarcoidosis); and one, no obvious immunosuppressive condition. The population with HIV presented heterogeneous dirty-appearing white matter lesions more frequently (77.7% versus 16.67%; p = 0.0247) in the cerebral MRI. No other significant differences were identified in the remaining variables analysed.

CONCLUSION

HIV/AIDS is the pathology most frequently associated with PML. With the use of immunomodulator drugs its appearance is reported in a variety of other diseases. Heterogeneous dirty-appearing white matter lesions were significantly more common in HIV patients.

Long-Term Infusional Systems: Complications in Cancer Patients

Long-term central vein catheters have found clinical application in different fields of medicine and particularly in oncology. In fact, the continuous infusion of some drugs has become the standard treatment in a wide variety of cancers, but central vein catheters are not without risks. The authors report their experience with central vein catheters. From January 1, 1998, to December 31, 1999, 98 central vein catheters were placed in neoplastic patients. Seventy-seven (78.6%) Groshong and 16 (16.3%) Port-a-cath catheters were used. The central vein catheters were placed under local anesthesia. Before placement of the central vein catheters, the patients were checked by chest X-ray and neck ultrasonography. The procedure was performed under fluoroscopic control. The central vein catheters were flushed periodically with normal saline solution and sodium heparin. Sterile transparent adhesive dressings were used to occlude the operative site. The median follow-up of patients was 9 catheter months (range, 1-24 months). There were a few early and late clinically evident complications. The early complications were dislodgement in 5 cases (5.1%). The late complications were: fibrin sleeve in 1 case (1.1%), thrombosis in 2 cases (2.1%) and skin infection in 4 cases (4.1%). The low prevalence of major complications related to implants and management of these supports an increased use in oncology.

Gastric cancer: The role of diffusion weighted imaging in the preoperative staging

PURPOSE

Evaluate the role of diffusion-weighted-imaging (DWI) in the diagnosis and staging of gastric carcinoma.

MATERIALS AND METHODS

A total of 31 patients with gastric adenocarcinoma, which underwent preoperative staging with 3Tesla Magnetic Resonance Imaging (MRI), were enrolled. Two radiologists evaluated the tumor staging in DWI. Results were compared to postsurgical pathologic findings.

RESULTS

The T factor accuracy of conventional MRI and DWI was 73% and 80% respectively; while the N staging accuracy of conventional MRI and DWI was 80% and 93%, respectively.

CONCLUSION

DWI and apparent diffusion coefficient (ADC) values showed to be useful in preoperative staging of gastric cancer.

Autosomal dominant cerebellar ataxias: a systematic review of clinical features

BACKGROUND AND PURPOSE

To assess, through systematic review, distinctive or common clinical signs of autosomal dominant cerebellar ataxias (ADCAs), also referred to as spinocerebellar ataxias (SCAs) in genetic nomenclature.

METHODS

This was a structured search of electronic databases up to September 2012 conducted by two independent reviewers. Publications containing proportions or descriptions of ADCA clinical features written in several languages were selected. Gray literature was included and a back-search was conducted of retrieved publication reference lists. Initial selection was based on title and abstract screening, followed by full-text reading of potentially relevant publications. Clinical findings and demographic data from genetically confirmed patients were extracted. Data were analyzed using the chi-squared test and controlled for alpha-error inflation by applying the Holms step-down procedure.

RESULTS

In all, 1062 publications reviewing 12 141 patients (52% male) from 30 SCAs were analyzed. Mean age at onset was 35 ± 11 years. Onset symptoms in 3945 patients revealed gait ataxia as the most frequent sign (68%), whereas overall non-ataxia symptom frequency was 50%. Some ADCAs often presented non-ataxia symptoms at onset, such as SCA7 (visual impairment), SCA14 (myoclonus) and SCA17 (parkinsonism). Therefore a categorization into two groups was established: pure ataxia and mainly non-ataxia forms. During overall disease course, dysarthria (90%) and saccadic eye movement alterations (69%) were the most prevalent non-ataxia findings. Some ADCAs were clinically restricted to cerebellar dysfunction, whilst others presented additional features.

CONCLUSIONS

Autosomal dominant cerebellar ataxias encompass a broad spectrum of clinical features with high prevalence of non-ataxia symptoms. Certain features distinguish different genetic subtypes. A new algorithm for ADCA classification at disease onset is proposed.

Particulate and gaseous emissions during fluidized bed combustion of semi-dried sewage sludge: effect of bed ash accumulation on NOx formation

Combustion of two semi-dried sewage sludges in a 110 mm has been characterized in terms of particulate and gaseous emissions. Sludges differed in that they had been conditioned - at the flocculation stage of wastewater treatment - either with Ca-based inorganics or with polyelectrolytes. Combustion was efficient for both sewage sludges under all the operating conditions tested. Significant differences have instead been observed between the two types of sewage sludges as regards particulate and macro-pollutant gaseous emissions (SO2, NOx). NOx formation is significantly influenced by ash accumulation inside the bed only when sewage sludge conditioned with Ca-based inorganics is fired. The time-resolved profiles of NOx concentration and the mass flow rate of the elutriated fines have been worked out to evaluate the fuel nitrogen yield to NOx as a function of ash accumulated inside the bed divided by the air mass feed rate. Experimental results have been compared with data present in literature.

3 Tesla magnetic resonance spectroscopy: cerebral gliomas vs. metastatic brain tumors. Our experience and review of the literature

The aim of the present study is to report about the value of magnetic resonance spectroscopy (MRS) in differentiating brain metastases, primary high-grade gliomas (HGG) and low-grade gliomas (LGG). MRI (magnetic resonance imaging) and MRS were performed in 60 patients with histologically verified brain tumors: 32 patients with HGG (28 glioblastomas multiforme [GBM] and 4 anaplastic astrocytomas), 14 patients with LGG (9 astrocytomas and 5 oligodendrogliomas) and 14 patients with metastatic brain tumors. The Cho/Cr (choline-containing compounds/creatine-phosphocreatine complex), Cho/NAA (N-acetyl aspartate) and NAA/Cr ratios were assessed from spectral maps in the tumoral core and peritumoral edema. The differences in the metabolite ratios between LGG, HGG and metastases were analyzed statistically. Lipids/lactate contents were also analyzed. Significant differences were noted in the tumoral and peritumoral Cho/Cr, Cho/NAA and NAA/Cr ratios between LGG, HGG and metastases. Lipids and lactate content revealed to be useful for discriminating gliomas and metastases. The results of this study demonstrate that MRS can differentiate LGG, HGG and metastases, therefore diagnosis could be allowed even in those patients who cannot undergo biopsy.

The clinical impact of a cardiologic follow-up in breast cancer survivors: an observational study

Anthracycline-containing chemotherapy (A-CHT) can induce late cardiotoxicity adding a considerable burden to cardiovascular risk. Irradiation of left breast cancer has also been associated to an increased risk of cardiovascular disease. The aim of this observational study is to prove the usefulness of an accurate cardiovascular evaluation in left breast cancer survivors treated with radiotherapy (RT) and A-CHT. Patients with left breast cancer, on follow-up after treatment with A-CHT plus RT in an adjuvant setting, were eligible for this observational study. Patients underwent cardiovascular assessment with myocardial perfusion imaging. Thirty patients were enrolled in the study: mean age at diagnosis 55.8 years; stage: I/III; Er and/or pgR status: positive in 24/30 pts; 3 patients in pre-menopausal status. Twenty-two patients (73.3 percent) had normal perfusion imaging, 1 patient (3.3 percent) had a fixed myocardial perfusion defect, 7 patients (23.3 percent) had reversible myocardial perfusion defects; 1 patient (3 percent) with normal perfusion scan showed depressed rest and stress LVEF. Only 1 patient had a large defect and underwent coronary angiography and percutaneous coronary intervention. Five patients with small defect showed normal coronary arteries at Multislice Computed Tomography. Cardiovascular followup may reveal signs of A-CHT or RT-induced cardiotoxicity. A stress test combined with MPI- and GATED-derived data of ventricular systolic performance after stress can give information on the coronary reserve and the contractile reserve and allow early appropriate treatment.

Decision-making in Parkinson's disease patients with and without pathological gambling

BACKGROUND AND PURPOSE

Pathological gambling (PG) in Parkinson's disease (PD) is a frequent impulse control disorder associated mainly with dopamine replacement therapy. As impairments in decision-making were described independently in PG and PD, the objective of this study was to assess decision-making processes in PD patients with and without PG.

METHODS

Seven PD patients with PG and 13 age, sex, education and disease severity matched PD patients without gambling behavior were enrolled in the study. All patients were assessed with a comprehensive neuropsychiatric and cognitive evaluation, including tasks used to assess decision-making abilities under ambiguous or risky situations, like the Iowa Gambling Task (IGT), the Game of Dice Task and the Investment Task.

RESULTS

Compared to PD patients without gambling behavior, those with PG obtained poorer scores in the IGT and in a rating scale of social behavior, but not in other decision-making and cognitive tasks.

CONCLUSIONS

Low performance in decision-making under ambiguity and abnormal social behavior distinguished PD patients with PG from those without this disorder. Dopamine replacement therapy may induce dysfunction of the ventromedial prefrontal cortex and amygdala-ventral striatum system, thus increasing the risk for developing PG.

Epidemiological and ethical aspects of multiplex autoantibody testing

Arrays are one of the technologies able to detect autoantibodies by measuring simultaneously many thousands of markers from a unique biological sample. The main purpose of a diagnostic test is making an early and accurate diagnosis. From a statistical point of view, multiple testing increases the probability of false positive and false negative results. Some correction methods are available to account for this problem for instance family-wise error rate or false discovery rate. From an ethical point of view, the decision to accept or decline a test not requested has to be made autonomously. Some people may seek clarification about tests and implications of their choices. A scarcity of proven measures to reduce mortality has to be considered too. Reasons may also include avoidance of psychological harm or anxiety. Moreover, protection of confidentiality and privacy has to be respected. In conclusion, the fact that testing is optional and that surveillance advice can be offered on the basis of risk alone without a test should be discussed in the consultation. The implication of a positive test result should be discussed to make a decision about the degree to which early treatment of the condition is better than late (or no) treatment.

[Multifocal motor neuropathy. Immediate response to intravenous immunoglobulin]

Multifocal motor neuropathy, a rare insidious immune-mediated disorder, features muscular weakness and atrophy, as well as areflexia, due to nerve conduction block and is often associated with the presence of anti-GM1 antibody. We report a patient with a nine-year history of progressive upper limb weakness, misdiagnosed as amyotrophic lateral sclerosis, who responded within hours to intravenous immunoglobulin treatment with full recovery of muscle strength. This case highlights the need to search for conduction block in patients with lower motor neuron involvement.

Focal stiff-person syndrome

Stiff-person syndrome (SPS) is a disorder of motor function characterized by rigidity of axial musculature and fluctuating painful spasms, which are often induced by startle or emotional stimuli. Neurophysiological studies have demonstrated the presence of continuous motor unit activity in muscle at rest, with abnormally enhanced extereoceptive reflexes. Although criteria for the diagnosis of SPS were proposed, several variants of this syndrome have been described before. In this communication, we report the case of a patient with a focal form of SPS. A 39-year-old woman developed progressive instability in her gait, spasms and stiffness restricted to both legs. The electromyographic examination showed continuous motor unit activity of the affected muscles at rest. Moreover, high anti-GAD antibodies titers were found in CSF and serum. Clinical symptoms, electrophysiological and immunological profiles suggest a focal form of SPS. Clinical and immunological findings indicate that SPS is a heterogeneous disease, suggesting the need to redefine its diagnostic criteria. Definition of the range of clinical expression and immunological profiles could be important for the clinical management of these patients.

Mismatch between electrophysiologically defined and ventriculography based theoretical targets for posteroventral pallidotomy in Parkinson's disease

OBJECTIVES

Over the past few years many reports have shown that posteroventral pallidotomy is an effective method for treating advanced cases of Parkinson's disease. The main differences with earlier descriptions were the use of standardised evaluation with new high resolution MRI studies and of single cell microrecording which can electrophysiologically define the sensorimotor portion of the internal globus pallidus (GPi). The present study was performed on a consecutive series of 40 patients with Parkinson's disease who underwent posteroventral pallidotomy to determine localisation discrepancies between the ventriculography based theoretical and the electrophysiologically defined target for posteroventral pallidotomy.

METHODS

The tentative location of the posteroventral GPi portion was defined according to the proportional Talairach system. Single cell recording was performed in all patients. The definitive target was chosen according to the feasibility of recording single cells with GPi cell features, including the presence of motor drive and correct identification of the internal capsule and of the optic tract by activity recording and microstimulation.

RESULTS

In all 40 patients the electrophysiologically defined sensorimotor portion of the GPi was lesioned, with significantly improved cardinal Parkinson's disease symptoms as well as levodopa induced dyskinesias, without damage to the internal capsule or optic tract. Significant differences between the localisation of the ventriculography based theoretical versus electrophysiological target were found in depth (p<0.0008) and posteriority (p<0.04). No significant differences were found in laterality between both approaches. Difference ranges were 8 mm for laterality, 6.5 mm for depth, and 10 mm for posteriority.

CONCLUSIONS

Electrophysiologically defined lesion of GPi for posteroventral pallidotomy, shown to be effective for treating Parkinson's disease, is located at a significantly different site from the ventriculography based theoretical target.

[Functional anatomy of the basal ganglia]

INTRODUCTION

The cerebral cortex of mammals is massively interconnected with the basal ganglia. The manner in which the basal ganglia process information has been accepted since it was described in the 1980s. It is not a definitive model and many aspects of it still need clarification.

DEVELOPMENT

The corpus striatum (ST) forms the entrance to the basal ganglia circuit (BG) and receives numerous afferent fibres from the cerebral cortex. Similarly, the internal segment of the globus pallidus (GPi) and the substantia nigra pars reticulata (SNpr) form the main nuclei for exit from the circuit and have an inhibitory effect on the pre-motor neurones of the ventral lamina of the thalamus. Between the entrance nucleus and the exit structures are two parallel systems of projection known as the direct and indirect pathways. The direct pathway projects monosynaptically only on the Gpi/SNpr complex. The indirect pathway projects polysynaptically on to the GR/SNpr complex after passing through the external segment of the globus pallidus (Gpe) and subthalamic nucleus. Imbalance in the activity of these two circuits will lead to alterations in discharge from the Gpi/SNpr complex which will cause bradykinesia or hyperkinesia. The bradykinesia or akinesia would be caused by increased gabaergic inhibition of the thalamic premotor neurones as a result of excessive discharge of the Gpi/SNpr complex.

CONCLUSION

Current exploration of the electrophysiology of the basal ganglia and careful analysis of the clinical findings in lesions circumscribed to certain parts of the thalamus, subthalamus and internal globus pallidus in patients with Parkinson's disease, have led to the appearance of paradoxical effects, according to the current basal ganglia model.

Periodic limb movements in syringomyelia and syringobulbia

Twenty-six patients with syringomyelia were studied with polysomnography to determine the frequency of periodic limb movements (PLM) and its relationship to the presence of a Chiari anomaly, the severity of corticospinal tract involvement, and localization of the syrinx. Sixteen patients showed PLM in stages I and II of non-REM sleep and three PLM also while awake. There were no statistically significant differences in overall disability, corticospinal signs, presence of an associated Chiari anomaly, and disease duration between patients with and without PLM, although there was a trend for patients with PLM to have more severe disease. There was preservation of the lumbosacral enlargement of the spinal cord by the syrinx in all patients with PLM. The latency delay between lower and upper limb muscles was suggestive of conduction along propriospinal pathways. Syringomyelia may lead to an abnormal state of spinal hyperexcitability favoring the appearance of PLM. Detailed magnetic resonance image studies of patients with different localizations of the syrinx cavities may help to determine which tracts are involved in the production of PLM.

A combined pattern of movement disorders resulting from posterolateral thalamic lesions of a vascular nature: a syndrome with clinico-radiologic correlation

We report a series of seven patients in whom a combined pattern of complex movement disorders restricted to one upper extremity emerged as a result of posterolateral thalamic lesions of vascular origin. This disorder was mainly characterized by choreiform and dystonic movements associated with variable, rhythmic, alternating movements of low frequency (myorhythmia). All cases showed, on computed tomography scan and/or magnetic resonance imaging, focal lesions involving the posterolateral quadrant of the thalamus. Review of similar cases reported with identical clinico-radiologic features allows us to conclude that it is possible to establish an accurate anatomoclinical correlation based on the clinical phenomenology, even before imaging studies are performed, in these cases. The opposite is not entirely possible, however, because lesions in the same quadrant of the thalamus are often associated with different patterns of abnormal movements or present without abnormal movements.

Effect of memantine (NMDA antagonist) on Parkinson's disease: a double-blind crossover randomized study

Our aim was to evaluate the effect of Memantine (1-amino 3,5-dimethyl-adamantane hydrochloride) on cardinal symptoms of Parkinson's disease and on the latency, duration, and magnitude of the response to a single dose of L-Dopa and on drug-induced dyskinesias. Twelve Hoehn-Yahr III-IV patients with idiopathic Parkinson's disease with motor fluctuations and drug-induced dyskinesias were randomized to the NMDA antagonist memantine or placebo in a cross-over design. A single-dose L-Dopa challenge was performed after each medication arm. A significant drug effect on the Unified Parkinson's Disease Rating Scale motor score was observed in "off" and "on" states (F(1,11) = 13.5; p < 0.003). No significant effect on drug-induced dyskinesias was seen. The results suggest that memantine may improve parkinsonian symptoms independently of dopaminergic drugs and, in contrast to recent findings with amantadine, it has no effect on drug-induced dyskinesias.

GPi firing rate modification during beginning-of-dose motor deterioration following acute administration of apomorphine

We present a patient with clinically evident beginning-of-dose motor deterioration who had undergone posteroventral pallidotomy. This patient underwent an intrasurgical apomorphine test followed by single cell recording of the internal globus pallidus (GPi) to determine changes in GPi firing rate during the occurrence of such phenomenon. A significant increase in GPi firing rate coincident with worsening of patient disabilities prior to improvement was found. This finding suggests that beginning-of-dose motor deterioration may be mediated by enhanced thalamic inhibition.

Comparison of 1-year follow-up evaluations of patients with indication for pallidotomy who did not undergo surgery versus patients with Parkinson's disease who did undergo pallidotomy: a case control study

Many reports published during the past 5 years have shown evidence of the beneficial effect of posteroventral pallidotomy (PVP) in large groups of patients for up to 3 years, but none of them have compared patients who underwent surgery with a control group.

OBJECTIVE

To compare the evolution of Parkinson's disease symptoms at 1-year follow-up between patients who underwent surgery and those who did not.

MATERIAL AND METHODS

Ten patients with idiopathic Parkinson's disease refractory to treatment who were included in the Core Assessment for Intracerebral Transplantation program for PVP did not undergo surgery because financial support was lacking. These patients were followed up for 1 year as if they had been operated on and were finally compared with 10 patients having similar characteristics in whom PVP had been performed during the same period of time.

RESULTS

There were no significant differences at basal evaluation in the motor section scores of the Unified Parkinson's Disease Rating Scale between those patients who underwent surgery and those who did not, but a significant reduction in Unified Parkinson's Disease Rating Scale motor score in the group who underwent surgery at 1-year evaluation was found (P < 0.006). Dyskinesias, which was nonsignificantly different at basal evaluation, showed, at the 1-year follow-up, a significant reduction in the group who underwent surgery (P < 0.04). Scores from the subsets of the Unified Parkinson's Disease Rating Scale addressing rigidity, tremor, and bradykinesia also proved significantly different at the 1-year follow-up. The slope of the line generated by the two evaluations for each group showed a negative value in the group who underwent surgery (value of -0.21) and a positive value in the group who did not (value of 0.148).

CONCLUSION

At the 1-year follow-up, microelectrode-guided PVP produced significant changes in patient motor status and disease progression versus a comparable group of patients who did not undergo surgery during the same period of time.

Apomorphine induces changes in GPi spontaneous outflow in patients with Parkinson's disease

OBJECTIVE

To determine the effect of a single dose of apomorphine on internal globus pallidus (GPi) neuronal discharge in patients with Parkinson's disease (PD).

PATIENTS AND METHODS

Nine PD patients who underwent microelectrode-guided posteroventral pallidotomy (PVP) were studied. After identification of a single GPi unit discharge with sufficient spike S/N ratio to allow reliable thresholding, basal recording was followed by a single 3-mg subcutaneous injection. One-minute samples were recorded 10', 30', and 60' after apomorphine.

RESULTS

In four patients, recording was lost after 5-10 minutes. In two, changes were observed at peak-of-dose but recording was then lost, whereas three completed recording and returned to baseline, all five showing significant reduction in GPi firing rate (mean +/- standard deviation for basal and post-apomorphine were 143+/-55.6 and 52+/-19.2, respectively; p <0.002).

CONCLUSION

In patients with PD, apomorphine induces changes in GPi spontaneous discharge and modifies firing rates resembling recordings in normal primates. These findings show that clinical improvement as well as induction of dyskinesias following DA administration could be mediated by reduction of GPi outflow.

Unilateral radiofrequency lesion versus electrostimulation of posteroventral pallidum: a prospective randomized comparison

Microelectrode-guided posteroventral pallidotomy (PVP) has shown to be an effective method in the treatment of a group of patients with advanced Parkinson's disease. A nonlesioning approach by means of deep brain electrodes connected to a programmable neuropacemaker has also been used to inhibit the internal segment of globus pallidus (posteroventral stimulation [PVS]) reporting comparable clinical efficacy to the one obtained with the ablative method. Nevertheless, no controlled studies have been performed to compare the efficacy of both procedures. A prospective series of 13 patients with a clinical indication for globus pallidus surgery was randomized either to a pallidotomy or stimulator implantation, and comparisons on motor and neuropsychologic measurements were made on a 3-month follow-up basis. Primary measurements of efficacy showed a comparable effect on Unified Parkinson's Disease Rating Scale and activities of daily living score after both procedures. Secondary measurements of efficacy showed that although both techniques improve hand tapping score and dyskinesia score, the bilateral improvement in the former was greater after PVS whereas the latter improved more significantly after PVP. No significant changes in neuropsychologic parameters were observed after either PVP or PVS. Side effects and surgery complications occurred in six of 13 patients (three after PVP and three after PVS): they were mild, transient, and unrelated to optic tract injury. In conclusion, the short-time effect and safety of both procedures is comparable.

Confirmation of the antidyskinetic effect of posteroventral pallidotomy by means of an intraoperative apomorphine test

We present a series of six consecutive Parkinson's disease patients undergoing posteroventral pallidotomy (PVP), who received an apomorphine injection after thermolesioning the posteroventral region of the internal globus pallidus (GPi) to evaluate the effect of the lesion on drug-induced dykinesias and therefore to proceed with further lesions or to conclude the surgery. Five of six patients failed to present dykinesias or did so to a significantly lesser degree (F [2,10] 42.6; p < 0.0001) so that surgery was concluded. One patient continued having contralateral dyskinesia despite an improvement in rigidity and bradykinesia, therefore, a new track was performed followed by a new lesion. No differences were found between intrasurgical and 1-month postoperative apomorphine test values. This report indicates that the use of an apomorphine test after thermolesioning may provide a reliable tool to check lesion efficacy on dyskinesia. The development of techniques that provide additional clinical information to the electrophysiological recording could help improve the outcome of patients undergoing pallidotomy.

Involuntary movements during thermolesion predict a better outcome after microelectrode guided posteroventral pallidotomy

Eight of the first 15 patients with advanced Parkinson's disease who underwent microelectrode guided posteroventral pallidotomy developed transient abnormal involuntary movements during thermolesion, four of whom also did so during high frequency macrostimulation. Abnormal involuntary movements found before thermolesion were choreic, ballistic, or choreoathetoid in nature, usually persisted less than 60 minutes, and were contralateral to the site of thermolesion in six and bilateral in two of them. The appearance of abnormal involuntary movements during macrostimulation or thermolesion of the internal globus pallidus correlated with better surgical outcome as measured by UPDRS motor items and CAPIT timed test, so that they seem to be of prognostic value.

Comparison of subcutaneous apomorphine versus dispersible madopar latency and effect duration in Parkinson's disease patients: a double-blind single-dose study

Twelve parkinsonian patients with severely fluctuating symptoms were given a single dose of apomorphine or Dispersible Madopar on 2 consecutive days, to confirm the latter drug's usefulness in "off" period rescue. According to our results, apomorphine proved faster in reverting "off" periods and should still be regarded as the drug of choice for this treatment modality.

[Colorectal obstruction caused by cancer]

The authors report their experience, matured in 10 years, in the management of cancer of the rectum and large bowel complicated by obstruction; 425 patients out of 493 total cases of colorectal cancer presented an intestinal obstruction and underwent emergency surgery. In 386 cases it was possible to perform resection (91%). The surgical treatment of the patients with right colon obstruction usually consisted of a right hemicolectomy. The surgical treatment of left colon obstruction is still controversial; in the experience of the authors it was accomplished by Hartmann operation mainly until 1985; in recent years the authors have introduced a procedure of intraoperative anterograde irrigation of the colon and they have performed resection-anastomosis in a single stage successfully but only in selected patients. In 4 out of twelve cases of cancer of the splenic flexure a subtotal colectomy was performed with one stage ileo-sigmoid anastomosis crowned with success. The authors examine the operative and postoperative mortality of the patients with colorectal cancer and point out that 5 years survival is worse in patients with colorectal obstruction compared to elective operations (24% versus 41%).

Role of intracortical mechanisms in the late part of the silent period to transcranial stimulation of the human motor cortex

Transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES) of the human motor cortex produce a silent period (SP) following motor evoked potentials (MEPs). The early part of the SP can be explained by decreased alpha motor neuron excitability, whereas the late part is presumably due to suprasegmental mechanisms. In order to determine the level of the suprasegmental contribution of the generation of SPs, we recorded excitatory and inhibitory responses to TMS, TES and percutaneous electrical brainstem stimulation (PBS) in the voluntarily activated first dorsal interosseous muscle of the hand. Stimulus intensities were set so that PBS and TES induced MEPs with areas equal to or larger than those of MEPs obtained with TMS. This procedure revealed that SPs were 49% and 83% shorter with TES and PBS, respectively, than with TMS. As TMS is more effective than TES or PBS in activating cortical interneurons, these findings support the idea that a significant component of the SP arises from intracortical mechanisms.

Modulation of muscle responses evoked by transcranial magnetic stimulation during the acquisition of new fine motor skills

1. We used transcranial magnetic stimulation (TMS) to study the role of plastic changes of the human motor system in the acquisition of new fine motor skills. We mapped the cortical motor areas targeting the contralateral long finger flexor and extensor muscles in subjects learning a one-handed, five-finger exercise on the piano. In a second experiment, we studied the different effects of mental and physical practice of the same five-finger exercise on the modulation of the cortical motor areas targeting muscles involved in the task. 2. Over the course of 5 days, as subjects learned the one-handed, five-finger exercise through daily 2-h manual practice sessions, the cortical motor areas targeting the long finger flexor and extensor muscles enlarged, and their activation threshold decreased. Such changes were limited to the cortical representation of the hand used in the exercise. No changes of cortical motor outputs occurred in control subjects who underwent daily TMS mapping but did not practice on the piano at all (control group 1). 3. We studied the effect of increased hand use without specific skill learning in subjects who played the piano at will for 2 h each day using only the right hand but who were not taught the five-finger exercise (control group 2) and who did not practice any specific task. In these control subjects, the changes in cortical motor outputs were similar but significantly less prominent than in those occurring in the test subjects, who learned the new skill.(ABSTRACT TRUNCATED AT 250 WORDS)

Cervical dystonia due to spinal cord ependymoma: involvement of cervical cord segments in the pathogenesis of dystonia

We report a patient with a progressive motor disorder dominated by pyramidal signs in all four extremities and cervical dystonia in the form of torticollis, who had imaging features of cervical cord tumor on magnetic resonance imaging (MRI) scanning. Ependymoma was the final diagnosis by histology. Cervical dystonia presenting as a manifestation of an identified focal central nervous system (CNS) lesion is infrequent. We believe our patient to be the first adult example of cervical cord tumor giving rise to cervical dystonia. Adding this entity to the list of differential diagnosis of torticollis is considered, and its mechanisms are discussed.

Orbicularis oculi responses to stimulation of nerve afferents from upper and lower limbs in normal humans

A brief mechanical or electrical stimulus to peripheral nerve afferents from the upper and lower limbs elicited a small and inconsistent EMG response of the orbicularis oculi muscles. This response was facilitated when the stimuli were delivered at fixed leading time intervals, of 45-300 ms, with respect to a supraorbital nerve electrical stimulus. Also, the peripheral nerve stimulus modified the conventional blink reflex responses, inducing facilitation of R1 and inhibition of R2. These results suggest a complex processing of sensory inputs from the face and the limbs at the brainstem, where they are probably integrated in a network of interneurons influencing the excitability of facial motoneurons.

Akinesia in Parkinson's disease. II. Effects of subthreshold repetitive transcranial motor cortex stimulation

We studied the effects of repetitive transcranial stimulation of the motor cortex (rTMS) on choice reaction time (cRT), movement time (MT), and error rate (ER) in a serial reaction-time task in six medicated patients with Parkinson's disease (PD) and 10 age-matched normal controls. In normal subjects, subthreshold 5-Hz rTMS did not significantly change cRT, slightly shortened MT, but increased ER. In the patients, rTMS significantly shortened cRT and MT without affecting ER. These effects did not impair procedural learning. Performance on a grooved peg-board test was improved by rTMS in the same PD patients, especially when they were off medications, but worsened in the normal subjects. Repetitive, subthreshold motor cortex stimulation can improve performance in patients with PD and could be useful therapeutically.

Abnormal facilitation of the response to transcranial magnetic stimulation in patients with Parkinson's disease

We studied the facilitation of the motor evoked potential (MEP) elicited with transcranial magnetic stimulation by increasing the stimulus intensity and the degree of voluntary activation of the target muscle in patients with Parkinson's disease (PD) and in normal volunteers. The threshold intensity for eliciting MEPs with the muscle at rest did not differ in PD patients and normal subjects. At rest, stimuli of similar intensity, related to the individual's threshold, elicited MEPs with amplitudes consistently larger in patients than in normal subjects, although when we compared the averaged MEP amplitude across all stimulus intensities, the differences reached only borderline statistical significance. Voluntary muscle activation elicited a smaller increase in the MEP area in PD patients than in normal subjects. Increasing the degree of voluntary muscle activation at fixed stimulus intensities elicited a smaller increase of MEP amplitude, duration, and area in PD patients than in normal subjects. These results suggest that control of the excitability of the motor system is abnormal in PD patients, with enhancement of excitability at rest and weak energization during voluntary muscle activation.

Modulation of motor cortical outputs to the reading hand of braille readers

We used focal transcranial magnetic stimulation to map the motor cortical areas targeting the first dorsal interosseous and the abductor digiti minimi muscles bilaterally in 10 proficient braille readers and 10 blind controls who were matched for age (mean, 50.6 yr) and age at time of blindness (mean, 7.5 yr). The proficient braille readers had learned braille at age 8 to 14 years and used it daily for 5 to 10 hours. Controls had not learned braille until age 17 to 21 years and used it daily for < 1 hour. In the controls, motor representations of the right and left first dorsal interosseous and abductor digiti minimi muscles were not significantly different. However, in the proficient braille readers, the representation of the first dorsal interosseous muscle in the reading hand was significantly larger than that in the nonreading hand or in either hand of the controls. Conversely, the representation of the abductor digiti minimi muscle in the reading hand was significantly smaller than that in the nonreading hand or in either hand of the controls. These differences were not due to differences in motor thresholds. Our results suggest that the cortical representation of the reading finger in proficient braille readers is enlarged at the expense of the representation of other fingers.

Rapid modulation of human cortical motor outputs following ischaemic nerve block

The amplitudes of motor evoked potentials to transcranial magnetic stimulation from muscles immediately proximal to a temporarily anaesthetized (Bier's block) human forearm increase in minutes after the onset of anaesthesia and return to control values after the anaesthesia subsides. In order to determine the level at which the early modulation of human motor outputs takes place, we recorded maximal H reflexes, peripheral M responses, motor evoked potentials to transcranial magnetic stimulation, and motor evoked potentials to transcranial electrical stimulation and spinal electrical stimulation from a muscle immediately proximal to a limb segment made ischaemic by a pneumatic tourniquet. The amplitudes of motor evoked potentials to transcranial magnetic stimulation, but not to transcranial electrical stimulation and spinal electrical stimulation, were larger during ischaemia, implying that the site of change was in the motor cortex. The maximal H/M ratios were unaffected by ischaemia, indicating that alpha-motor neuron excitability to segmental Ia inputs remained unchanged. The map of cortical representation areas for this muscle obtained with transcranial magnetic stimulation was also enlarged. Taken together, our findings suggest that the temporary removal by ischaemic nerve block of myelinated afferent inputs reduces inhibition at the motor cortical level and that this disinhibition is responsible for the increased excitability of the corticospinal system.

Postexercise depression of motor evoked potentials: a measure of central nervous system fatigue

Fatigue of voluntary muscular effort is a complex and multifaceted phenomenon. Fatigue of peripheral nervous system components, including the contractile apparatus and the neuromuscular junction, has been well studied. Central nervous system components also fatigue, but studies have lagged for want of objective methods. Transcranial magnetic stimulation is a relatively new technique that can be used to assess central nervous system excitability from the motor cortex to the alpha-motoneuron. In six normal volunteers, including four of the investigators, the amplitudes of motor evoked potentials elicited by transcranial magnetic stimulation were transiently decreased after exercise, indicating fatigue of motor pathways in the central nervous system. The decrease in amplitude was associated with a feeling of fatigue. The mechanism of this phenomenon is apparently decreased efficiency in the generation of the motor command in the motor cortex.

Bioprostheses at twelve years

From January 1976 through December 1986, seven different types of bioprostheses have been implanted in our center. The following bioprostheses (total 1,414) were implanted in 1,098 patients: Carpentier-Edwards 567, Hancock 302, Liotta 268, Ionescu-Shiley 127, Angell-Shiley 72, Vascor 68, Implamedic 10. Follow-up ranged from 1 to 12 years, cumulative duration of follow-up was 6,747 patient-years and 8,637 valve-years, being 95.4% complete. Cumulative actuarial probability of being free from tissue valve failure (TVF) was 85.1% +/- 2.0% at 10 years, and 61.6% +/- 9.6% at 12 years. Actuarial probability of being free from TVF was 71.2% +/- 10.8% at 12 years for Carpentier-Edwards, 51% +/- 21.7% at 12 years for Hancock, 73.4% +/- 14.1% at 11 years for Angell-Shiley, 53% +/- 27.4% at 9 years for Liotta, 68% +/- 14.8% at 11 years for Ionescu-Shiley, 53.2% +/- 22.2% at 7 years for Vascor, 72.2% +/- 21.5% at 5 years for Implamedic bioprostheses. In this comparison of seven different bioprostheses, there is a large group of valves behaving in a very similar way. Only a few prostheses showed a constant and early negative trend.