Idiopathic scoliosis: a transcranial magnetic stimulation study.

STUDY DESIGN: Various neurophysiological parameters of the motor system were investigated in 43 female patients with Idiopathic Scoliosis (IS) and 31 sex and age matched controls using transcranial magnetic stimulation (TMS). OBJECTIVE: To investigate whether asymmetries in excitatory and inhibitory brain processes, as studied by TMS, are a causative factor in IS. SUMMARY OF BACKGROUND DATA: Previous studies associated IS with pathological asymmetries of the cerebral cortex and the brain stem at the level of the corticospinal tracts. METHODS: Forty-three female patients with right IS and 31 normal female subjects entered the study. Various TMS parameters, including the study of ipsilateral pyramidal tract, were studied. Electrophysiological data were correlated with clinical data, the degrees of the scoliotic curve and the Perdriolle and Nash & Moe indexes. RESULTS: In upper limbs, detailed testing failed to reveal any statistically significant differences between the patient and the control group. In lower limbs, side-to-side differences of central motor conduction time (CMCT) and facilitated cortical-to-muscle latencies were increased in the scoliotic patients (p<0.05). This finding correlated significantly with Nash & Moe and Perdriolle indexes (Spearman's r=0.406 and 0.575, respectively, p<0.05). Following the Bonferroni adjustment, however, differences in CMCT SSDs were not statistically significant (p>0.05). CONCLUSION: The present TMS data do not support the concept of a generalized brain asymmetry in IS. In lower limbs, a trend towards increased asymmetries in side-to-side differences of CMCT and cortical latencies was detected probably representing subclinical involvement of the corticospinal tracts secondary to mechanical compression. Finally, it is concluded that non-decussation of the pyramidal tracts is not involved in the pathogenesis of IS.

A phase I clinical trial of dextromethorphan in intractable partial epilepsy.

We conducted an open-label pilot study of dextromethorphan (DM) in intractable partial epilepsy with the following objectives: a preliminary evaluation of the drug's safety and efficacy in the epileptic patient and a definition of a concentration range which can be safely achieved in future studies. Sixteen patients with drug-resistant, localization-related epilepsies entered the trial. After an 8-week baseline period, DM was added to the existing antiepileptic drugs at a dose of 40 and 50 mg every 6 h (160 and 200 mg/day). Each treatment period lasted 8 weeks. Seizure control improved after administration of DM, especially in the group of intermediate and slow metabolizers. Two patients, however, experienced increased seizure frequency and withdrew from the study. Adverse effects during DM administration were mild and transient. DM was well tolerated even in patients with high plasma levels of the drug (up to 15020 ng/dl). Our results indicate that DM is safe and effective in the treatment of comedicated patients with intractable partial epilepsies.

Myasthenia gravis: correlation of age with clinical course and anti-AChr antibody levels.

We studied the significance of age as a factor affecting prognosis and anti-AChR antibody levels in myasthenia gravis, comparing patients with symptom onset before 50 (37 patients) and at or after 50 (33 patients). More of the older patients, compared to younger ones (69.9% versus 32.4%,p<0. 05) progressed to severe disease in the first three years of treatment. Five older patients died during myasthenic crises, whereas no deaths occured in the younger group. In addition; older patients did not respond as favorably as younger ones to anticholinesterase treatment and more of them required combination therapy. AntiAChR antibody levels were significantly lower in older patients (9.2 versus 34.9 nM, p<0.005). We conclude that symptom onset at or after the age of 50 predicts unfavorable outcome in myasthenia gravis and is associated with lower anti-AChR antibody levels. This group of patients requires earlier treatment with corticosteroids, immunosuppressive drugs or both.

[Periodic discharges and diagnosis of central nervous system diseases]. / Activitiés périodiques électro-encéphalographiques dans le diagnostic des affections cérébrales.

Periodic discharges are easily identified on conventional EEG traces. Proper interpretation requires systemic analysis of their spatial, temporal and morphological characteristics. These EEG changes are always abnormal and can be observed in various CNS diseases. Periodic discharges were found in 127 patients from a total number of 3212 patients suffering from 9 different CNS diseases. This study confirms the high incidence of periodic discharges in subacute sclerosing panencephalitis (89%), in acute necrotizing encephalitis (85%) and in Creutzfeldt-Jakob disease (75%). Their prognostic value and their relationship to epilepsy is shortly discussed.

Contribution of CT scan to the diagnosis of Fahr's syndrome.

Of 7040 patients who were examined with CT scan for various reasons, 72 (1.02%) showed symmetrical intracranial calcifications. On the basis of the extent of the calcifications, the patients were divided into 3 groups of which the first (10 cases), with extensive calcifications, showed clear findings of hypoparathyroidism; the second (4 cases), with less extensive calcifications, showed borderline laboratory findings and the third (58 cases), with calcifications only in the internal part of the globus pallidus, had no relation to any disturbance of the parathyroid function. The limited percentage (4.2%) of calcifications detected by ordinary cranial X-rays was discussed as compared to those diagnosed by CT scan; this is due to the weakening of the relationship which existed in the past between hypoparathyroidism and calcifications. Patients with extensive calcifications do not seem to have a significantly higher proportion of neurological impairment (35.8%) than patients who showed limited calcifications (34.5%). On the other hand, patients with extensive calcifications showed more frequent mental disorders (50%) compared to those who showed limited calcifications (34.5%). The proportion of mental disorders is still higher in patients with dilatation of the subarachnoid spaces (56.7%) compared to those who do not show dilatation (23.8%). Finally, of the 72 patients with calcifications, 15 (20.8%) showed extrapyramidal syndrome, possibly due to calcium salt deposits in the metasynaptic dopamine receptors while 13 (18%) were taking anticonvulsant drugs which, apart from influencing the metabolism of calcium, also influence the activity of alkaline phosphatase and are involved in the creation of calcifications.