Oligoclonal bands in Devic’s neuromyelitis optica and multiple sclerosis: differences in repeated cerebrospinal fluid examinations

We studied repeated cerebrospinal fluids of patients with Devic’s neuromyelitis optica (NMO) and multiple sclerosis (MS). Variations of oligoclonal bands (OBs) had opposite trends in the two groups. In MS, O Bs were detected in 399 of 411 patients (97%) and never disappeared. In NMO, O Bs were detected in three of 11 patients (27%) and always disappeared. The hypothesis that NMO and MS follow distinct patho genetic pathways is supported by our findings, which can be useful for the differentiatio n of NMO from MS.

Single High-Dose Steroid Treatment in Episodic Cluster Headache

Corticosteroids appear to be the most rapid-acting of the prophylactic drugs used in the treatment of cluster headache (CH). These agents are frequently employed as a short-term regimen to induce clinical remission. In this study, we assessed in an open fashion the effect of high dose methylprednisolone (MPD) in a group of 13 patients with episodic CH (3 females and 10 males). On the 8th day of the active period, MPD was administered intravenously at the dose of 30 mg/kg body weight, as a 3-h infusion in saline. The attack frequency was followed for 7 days. The mean daily attack frequency before MPD administration was statistically different from that reported after treatment (respectively: 1.38 ± 0.42 and 0.83 ± 0.78; P = 0.05 Student's t-test). The mean interval between MPD administration and the occurrence of the first subsequent attack was 3.8 ± 2.2 days (range: 2-7 days). Only 3 (23%) of 13 patients experienced a complete headache remission. No significant side-effects were noted after MPD administration. These data further demonstrate that in most patients with episodic CH, high-dose systemic steroid administration may invariably interrupt attack recurrence for a few days, but is ineffective in maintaining complete clinical remission. This study also suggests that MPD administered as a solitary dose does not provide any advantage above prednisone in CH treatment.

Bayesian mapping of multiple sclerosis prevalence in the province of Pavia, northern Italy

The geographical analysis of a disease risk is particularly difficult when the disease is non-frequent and the area units are small. The practical use of the Bayesian modelling, instead of the classical frequentist one, is applied to study the geographical variation of multiple sclerosis (MS) across the province of Pavia, Northern Italy. 464 MS-affected individuals resident in the province of Pavia were identified on December 31st 2000. The overall prevalence was 94 per 100,000 inhabitants. This estimate indicates an increasing MS prevalence in the province, in accordance with the vast majority of the Italian areas where prevalence studies have been repeated. We mapped the geographical variation of MS prevalence across the 190 communes of the province both with a classical approach and a Bayesian approach. The frequentist approach produced an extremely dishomogeneous map, while the Bayesian map was much smoother and more interpretable. Our study underlines the usefulness of Bayesian methods to obtain reliable maps of disease prevalence and to identify possible clusters of disease where to carry out further epidemiological investigations.

Proximal nerve conduction by high-voltage electrical stimulation in S1 radiculopathies and acquired demyelinating neuropathies

OBJECTIVE

To evaluate the reliability and sensitivity of the high-voltage electrical stimulation for studying proximal conduction of peripheral motor axons in normal subjects, S(1) radiculopathies and acquired demyelinating neuropathies.

METHODS

Twelve patients with compressive S(1) radiculopathy, 22 patients with acquired demyelinating neuropathy and 29 healthy volunteers were examined. The conduction of peripheral motor axons between lumbosacral roots and the sciatic nerve at the gluteal fold was investigated by high-voltage electrical stimulation delivered percutaneously.

RESULTS

The main electrophysiological finding in S(1) radiculopathy was an abnormal side to side difference in the amplitude of the compound motor action potential by proximal stimulation. Overall, the frequency of abnormalities detected by using high-voltage electrical stimulation was similar to that found with conventional EMG studies, and the two methods showed electrophysiological alterations in the same patients. In all patients with acquired demyelinating neuropathy, the proximal motor nerve conduction velocity from lumbosacral roots to the sciatic nerve at the gluteal fold was reduced; proximal stimulation of the motor axons revealed electrophysiological abnormalities more often than when using other electrophysiological techniques (F wave and H reflex).

CONCLUSIONS

High-voltage electrical stimulation of peripheral motor axons shows high sensitivity in detecting proximal neuropathies; it can also define the site and relevance of proximal lesions in the peripheral nervous system better than other conventional techniques.

Quantitative measures of spasticity in post-stroke patients

OBJECTIVE

Quantitative evaluation of muscle tone in post-stroke patients; correlation of biomechanical indices with conventional clinical scales and neurophysiological measures; characterization of passive and neural components of muscle tone.

METHODS

Mechanical stretches of the wrist flexor muscles of 53 post-stroke patients were imposed by means of a torque motor at constant speed. Patients were clinically studied using the Ashworth scale for spasticity and the Medical Research Council score for residual muscle strength. The neurophysiological measures were Hoffmann reflex latency, Hmax/Mmax ratio, stretch reflex threshold speed (SRTS), stretch reflex (SR) latency and area, passive (ISI) and total (TSI) stiffness indices.

RESULTS

Hmax/Mmax ratio, SR area, ISI and TSI values were significantly higher in patients, while SRTS was significantly lower. TSI, SRTS and SR area were highly correlated to the Ashworth score.

CONCLUSIONS

This EMG-biomechanical technique allows an objective evaluation of changes in muscle tone in post-stroke patients, providing easily measurable, quantitative indices of muscle stiffness. The linear distribution of these measures is particularly indicated for monitoring changes induced by treatment. The apparatus seems suitable to characterize neural stiffness, while difficulties were found in isolating the passive components, because of the occurrence of tonic EMG activity in most spastic patients.

Hereditary motor and sensory neuropathy type II (HMSN-II) and neurogenic muscle hypertrophy: a case report and literature review

We present two siblings affected by hereditary motor and sensory type II neuropathy (HMSN-II) with neuromyotonia, and associated with muscle hypertrophy of the thighs and calves in one. We review the literature about the association between HMSN-II, neuromyotonia and muscle hypertrophy. Muscle enlargement in HMSN-II is rare and may be sporadic or under genetic control. In our patient, muscle hypertrophy was sporadic and probably due to neuromyotonia. The relationship between muscle hypertrophy and neuromyotonia can be deduced by the fact that both conditions were reduced after diphenylhydantoin treatment (200 mg/day).

The effects of flumazenil on focal, electroinduced after-discharge in rabbits

1. The anticonvulsive efficacy of flumazenil 10 mg/kg i.v., a BDZ antagonist, was studied in two models of experimental epilepsy electrically induced. 2. The EEG after-discharge, which was induced by the electrical stimulation of selected brain regions [(notably the dorsal hippocampus (Hip) and the amygdala (CAm)] was evaluated in rabbits pre- and post-drug administration. 3. In the animals submitted to electrical stimulation of the amygdala, flumazenil exerted a protective action, thereby inducing an increase in the after-discharge threshold and/or a decrease in after-discharge duration. 4. In the animals submitted to electrical stimulation of the hippocampus, flumazenil did not induced changes statistically significant. 5. Finally, the paper discusses the two possible mechanisms of action of flumazenil (a "per se" partial BDZ activity and/or a BDZ agonistic activity, which displaces the inverse agonist-like ligand) and the differencies in GABA distribution in the hippocampus and the amygdala.

Role of dopamine D-1 and D-2 antagonists in a model of focal epilepsy induced by electrical stimulation of hippocampus and amygdala in the rabbit

1. The differential role played by blockade of D-1 or D-2 dopamine receptors in mechanisms underlying seizures was studied in a model of EEG after-discharge induced by electrical stimulation of selective brain regions (dorsal hippocampus and amygdala) in the rabbit. 2. The D-2 antagonist haloperidol (1 mg/Kg) increased significantly after-discharge duration after stimulation of either hippocampus or amygdala and lowered after-discharge threshold in few animals. 3. The D-1 antagonist SCH 23390 (0.3 mg/Kg) caused no changes following stimulation of amygdala and reduced after-discharge duration when hippocampus was stimulated. 4. Haloperidol exerted a proconvulsant action in this experimental model, having a clearer influence on D-2 receptors. SCH 23390 had no effect on amygdala whereas it exerted protection on the hippocampus. 5. The present data suggest that D-1 and D-2 receptors have different roles in generating and spreading the epileptic activity.