[Encephalomyelopathy associated with monoclonal gammapathy]. / Encéphalomyélopathie associée à une gammapathie monoclonale.

We describe the case of a patient with a particular form of presumably immune-mediated encephalomyelitis associated with a monoclonal cold agglutin gammapathy. Systematic autopsy showed predominantly demyelinating lesions of the brain and spinal cord. The lesions were assumed to be the immune-mediated consequences of the underlying hematologic condition. Similarity with certain paraneoplastic syndromes is underlined.

Occupational asthma in symptomatic workers exposed to natural rubber latex: evaluation of diagnostic procedures.

BACKGROUND: Natural rubber latex (NRL) has been increasingly identified as a cause of occupational asthma (OA). OBJECTIVE: We sought to examine the accuracy of the clinical history, immunologic tests, and assessment of nonspecific bronchial hyperresponsiveness in diagnosing OA caused by latex compared with that of the specific inhalation challenge (SIC). METHODS: Forty-five consecutive patients referred for investigation of possible OA caused by latex underwent a diagnostic protocol, including an open medical questionnaire, skin prick testing against latex, measurement of bronchial responsiveness to histamine, and inhalation challenge with latex gloves. Recorded clinical history was judged retrospectively by 4 physicians who were blinded for the results of other objective tests. RESULTS: The clinical history, skin prick testing against NRL, and assessment of nonspecific bronchial hyperresponsiveness showed a high sensitivity (87%, 100%, and 90%, respectively) but a low specificity (14%, 21%, and 7%, respectively) when compared with the results of the SIC. Logistic regression analysis showed that combining the results of skin prick tests against latex with the clinical history enhanced the negative predictive value from 50% to 71%, whereas the positive predictive value remained virtually unchanged (75% vs 76%). CONCLUSION: The clinical history and immunologic tests were the most useful procedures in diagnosing NRL-induced asthma, although combining the 2 procedures remained less accurate than SIC. Further examination of the predictive values of available tests is warranted to recommend diagnostic strategies that are specific to the various agents causing OA.

Effects of vigabatrin on motor potentials evoked with magnetic stimulation.

We studied the effect of an acute loading dose of vigabatrin on threshold of motor responses and duration of silent period elicited with cortical magnetic stimulation in normal subjects. In contrast to phenytoin, vigabatrin does not increase the motor threshold of first dorsal interosseus muscle. We also show that, although vigabatrin increases GABA concentrations in the central nervous system, duration of silent period studied at various stimulus intensities is not modified after vigabatrin administration.

Magnetic transcranial stimulation in acute stroke: early excitation threshold and functional prognosis.

Magnetic transcranial stimulation was used in 90 subjects (60 acute ischaemic sylvian strokes and 30 healthy controls) in order to evaluate the clinical value of the excitation threshold (ET) in the estimation of functional prognosis. ET mean values recorded 7, 30 and 90 days after stroke (at D7, D30 and D90) in two distal muscles of the upper limbs of the patients were compared with results obtained in 30 healthy control subjects. The data from the patients who ultimately achieved a satisfactory functional recovery at D90 were compared with those from patients who had not recovered in that time. Our results suggest that ET evolution differs according to functional outcome: (1) ET mean values were increased in the stroke patients at D7, but ET was constantly lower at D30 and D90 in patients who recovered than in those who did not. (2) ET temporal evolution showed a gradual decrease of the mean values from D7 to D90 in both stroke groups. This ET decrease was more marked in the patients who recovered from D30 to D90, but with only minor change after D30. (3) The localisation of the lesion had no significant effect on ET mean values at D7, D30 or D90. We conclude that the predictive value of ET estimation might be utilised at D30 in patients with ischaemic sylvian strokes.

Magnetic transcranial stimulation in non-haemorrhagic sylvian strokes: interest of facilitation for early functional prognosis.

Magnetic transcranial stimulation was applied to 40 patients in the early stage of a non-haemorrhagic sylvian stroke. Results were evaluated with regards to the clinical outcomes at days 7, 30 and 90. The presence or absence of an early response had a critical prognostic significance. Response latency and amplitude parameters and the excitation threshold were of little value. Facilitation in patients unresponsive at rest was another determinant parameter since 9 out of 10 such cases ultimately recovered.

Abnormal motor evoked responses to transcranial magnetic stimulation in focal dystonia.

We evaluated motor responses evoked after magnetic cortical stimulation in dystonia, emphasizing the relationship between resting and facilitation state. We studied 15 normal controls (mean age, 37.9 years; range, 23 to 63) and 13 dystonic patients (mean age, 43.4 years; range, 20 to 56). Surface electrodes were placed over the right first dorsal interosseous muscle to measure motor evoked potentials and inhibitory silent periods obtained with magnetic stimulation. The amplitude ratio of motor evoked potentials measured during facilitation and at rest with low-intensity magnetic stimulation was significantly higher in dystonic patients (15.09) when compared with normal subjects (5.43; p = 0.04). The ratio of duration of silent periods evoked with 120% motor threshold (MT) and MT + 25% magnetic stimulus intensity was significantly higher in dystonic patients (78.4%) when compared with normal subjects (69.7%; p = 0.04). We conclude that with low-intensity magnetic stimulation the relationship between amplitudes of motor potentials evoked at rest and during facilitation, as well as the responses of pathways that mediate silent periods, are disturbed in focal dystonia.

Effects of diphenylhydantoin on motor potentials evoked with magnetic stimulation.

We studied the effect of an acute loading dose of diphenylhydantoin (DPH) on motor responses elicited with cortical magnetic stimulation in normal subjects. DPH increased significantly the motor threshold activation of ADM, APB, FDI and biceps. The motor threshold increase was of greater magnitude for the proximal muscle. Spinal soleus alpha-motoneuron pool excitability assessed by H-reflex was increased significantly suggesting that the motor threshold increase is related to a supraspinal effect of the drug. Our study demonstrates that the motor threshold increase observed after DPH administration occurs not only in epileptic patients but also in normal subjects.

[Cancer of the upper respiratory tract in woodworkers]. / Le cancer des voies respiratoires supérieures chez les travailleurs du bois.

The authors analyzed 49 cases of professional sinus cancers among woodworkers they confirm the large frequency of ethmoid adenocarcinoma. It appears that the age of the first symptoms is lower among woodworkers than among the general population. There is a correlation between the survival and the age on the date of the diagnose, the latency and the work conditions.