[Latency values of 248 H reflexes in 124 normal subjects]

INTRODUCTION

The Hoffmann reflex or H reflex is an electrical counterpart of the myotatic reflex. In normal adults is elicited with stimulating the tibial and the median nerves. It is useful as an adjunct study of neuroexamination and assesses the corresponding arc reflexes in their integrity.

SUBJECTS AND METHODS

248 H reflexes were studied stimulating the tibial nerve in 124 healthy subjects.

RESULTS

The latency values were: minimum 23.6 ms; maximum 29.8 ms; mean value 27.6 ± 1.41 ms.

CONCLUSION

This work explains the technique to obtain the H reflex and discusses the need for normalized values for each neurophysiology lab.

[Treatment of neuropathic pain in neurology units. The PREVADOL study]

INTRODUCTION

Neuropathic pain (NPP) is defined as a pain started or caused by an injury to or dysfunction of the nervous system. Its treatment is different to that of nociceptive pain since it does not respond to conventional analgesics or non-steroidal antiinflammatory drugs.

AIM

To describe the treatment being received by patients with NPP in the daily clinical practice of the specialist in neurology.

PATIENTS AND METHODS

An observational, epidemiological, cross-sectional study was conducted in 36 neurology units (24 extra-hospital and 12 belonging to hospitals). We collected the clinical data and the treatment administered to the first 20 patients with NPP to visit the neurology units over a period of 20 consecutive working days.

RESULTS

Data were collected for a total of 451 patients with NPP. The pharmacological groups most frequently used in patients with NPP attended in neurology units are antiepileptics (71%) and antidepressants (15%). Of these patients, 60% were being treated with a single drug (an antiepileptic agent in 84.5% of cases; antidepressants in 10.3%). Two pharmacological treatments were being received by 23.7%, and 2.3% of patients were given treatment involving three or more pharmacological agents. A total of 30% received non-pharmacological treatments, especially physiotherapy (50.4%).

CONCLUSIONS

Most patients with NPP attended in neurology units follow first-order pharmacological treatments (antiepileptics or antidepressants). Over half the patients are controlled with monotherapy, usually with an antiepileptic agent. Non-pharmacological treatments (especially physiotherapy) are used in a third of the patients.

[Epidemiological study of prevalence, incidence and neuropathic pain characterization in neurology units. PREVADOL study]

INTRODUCTION

Neuropathic pain is defined as a pain initiated or caused by a lesion or dysfunction in the nervous system. The objectives of the study were to estimate the prevalence and incidence of neuropathic pain in hospital neurology units and primary care centres, to characterize the clinical profile of the patient with neuropathic pain and to know the most frequent treatments in the pharmacological management of this type of pain.

METHODS

Observational, cross-sectional epidemiological survey carried out in 36 Neurology Units of the national territory (24 primary care centres and 12 hospitals). During 20 consecutive days neurologists collected the diagnoses of all the attended patients by any reason, up to 30 patients/day. In parallel the 20 first consecutive patients with neuropathic pain were chosen for their characterization in depth by means of a specific questionnaire.

RESULTS

A total of 12,688 patients were attended and a total of 13,555 diagnoses were collected through 713 consultation days. The most frequent diagnosis was migraine/cephalea, with a prevalence of 23.40% (95% CI: 22.66%-24.14%). Neuropathic pain represented the eighth more frequent diagnosis, with a prevalence in neurology units of 3.88% (95% CI: 3.54%- 4.22%). The prevalence of neuropathic pain was 2.92% in primary care centres and 6.09% in hospital units (p < 0.01). The daily incidence of new neuropathic pain cases was 1.24% (95% CI: 1.05%-1.53%); 1.14% in primary care neurology centres and 1.45% in hospital units.

CONCLUSIONS

The data obtained indicate that neuropathic pain is the eighth more frequent diagnosis in the neurology units. Medical assistance request by neuropathic pain is higher in the hospital units.

LGMD2A: genotype-phenotype correlations based on a large mutational survey on the calpain 3 gene

We present here the clinical, molecular and biochemical findings from 238 limb-girdle muscular dystrophy type 2A (LGMD2A) patients, representing approximately 50% (238 out of 484) of the suspected calpainopathy cases referred for the molecular study of the calpain 3 (CAPN3) gene. The mean age at onset of LGMD2A patients was approximately 14 years, and the first symptoms occurred between 6 and 18 years of age in 71% of patients. The mean age at which the patients became wheelchair bound was 32.2 years, with 84% requiring the use of a wheelchair between the age of 21 and 40 years. There was no correlation between the age at onset and the time at which the patient became wheelchair bound, nor between the sex of the patient and the risk of becoming wheelchair bound. Of the cases where the CAPN3 gene was not affected, approximately 20% were diagnosed as LGMD2I muscular dystrophy, while facioscapulohumeral muscular dystrophy (FSHD) was uncommon in this sample. We identified 105 different mutations in the CAPN3 gene of which 50 have not been described previously. These were distributed throughout the coding region of the gene, although some exons remained free of mutations. The most frequent mutation was 2362AG-->TCATCT (exon 22), which was present in 30.7% of the chromosomes analysed (146 chromosomes). Other recurrent mutations described were N50S, 550DeltaA, G222R, IVS6-1G-->A, A483D, IVS17+1G-->T, 2069-2070DeltaAC, R748Q and R748X, each of which was found in >5 chromosomes. The type of mutation in the CAPN3 gene does not appear to be a risk factor for becoming dependent on a wheelchair at a determined age. However, in the cases with two null mutations, there were significantly fewer patients that were able to walk than in the group of patients with at least one missense mutation. Despite the fact that the results of phenotyping and western blot might be biased due to multiple referral centres, producing a diagnosis on the basis of the classical phenotype is neither sufficiently sensitive (86.7%) nor specific (69.3%), although western blot proved to be even less sensitive (52.5%) yet more specific (87.8%). In this case LGMD2I was a relevant cause of false-positive diagnoses. Considering both the clinical phenotype and the biochemical information together, the probability of correctly diagnosing a calpainopathy is very high (90.8%). However, if one of the analyses is lacking, the probability varies from 78.3 to 73.7% depending on the information available. When both tests are negative, the probability that the sample comes from a patient with LGMD2A was 12.2%.

Case reports: chronic paroxysmal hemicrania-tic syndrome

The coexistence of chronic paroxysmal hemicrania and trigeminal neuralgia is called chronic paroxysmal hemicrania-tic syndrome. We describe the case of a man who has suffered both types of pain occurring synchronously but with different localization on the ipsilateral side. The pain attacks could be abolished with indomethacin and carbamazepine. To the best of our knowledge, this is the third case to be reported, the first in the male sex. We review this new disorder and discuss the pathophysiology.

[Estimation of the neurologic demand in a health care area of Madrid, Spain (area 11, University Hospital, 12 of October)]

OBJECTIVES

To analyse the demand for neurologic care and the neurological resources in a health district.

PATIENTS AND METHODS

Demographic, medical care aspects, neurologic care demands and neurological resources of the health district 11 of Madrid (University Hospital "12 de Octubre"), referred to 1996, were reviewed.

RESULTS

The rate of aging (17%) and the consulting rates in the National Health System (86%) versus private care were high in this health district. The neurologic care demands were 17.5-18.1 and 36 consultations respectively per 1,000 inhabitants/year. There were 2 patient-care neurologists and 3.7 neurologic beds per 100,000 inhabitants.

CONCLUSIONS

The neurologic care was considered high and with a tendency to increase. The available neurological resources were judged to be insufficient.

[Amyotrophic neuralgia: review of 37 cases]

INTRODUCTION

Amyotrophic neuralgia is characterized by pain of acute or subacute onset, accompanied by weakness and occasionally by atrophy of the brachial muscles, of unknown origin. We present our experience over the past 20 years.

PATIENTS AND METHODS

We made a retrospective review of 37 patients with the above diagnosis, following the criteria of other series of such cases published in the literature.

RESULTS

Twenty four of the patients were men and thirteen were women. The average age was 38 (11 to 71). A relevant clinical history was recorded in 9 cases; infection (5), surgery (4), remote trauma (3) and vaccination (1). There was a painful onset of the condition in 32 patients; objective weakness of the superior brachial plexus (30), inferior (5) or both (2). Atrophy was present in 23 and hypoaesthesia in 13. Two patients had fasciculations and 9 had hyperreflexia. In all patients electromyographic studies showed a neurogenic pattern of denervation of the muscles clinically affected. The severity of the condition was divided into mild (18), moderate (16) and intense (3). Prognosis was good in 24 and sequelae remained in 11. There were 2 bilateral cases and 2 relapses but no familial cases.

CONCLUSIONS

There was a ratio of men/women of 1.8:1 and onset usually when the patient was in his forties. Mild infection, surgery, remote trauma and vaccination were the commonest clinical factors. Onset was painful in 85%. Muscular weakness was predominantly in the superior brachial plexus (85%), followed by atrophy in 62%. There was hypoaesthesia in a third of the patients. Most cases were mild (50%) and made a complete recovery (70%). Our findings are similar to those described in most series in the literature.

[Cardiac involvement in neuromuscular diseases]

Many neuromuscular disorders involve the heart, occasionally with overt clinical disease. Muscular dystrophies (dystrophinopathies, limb girdle muscular dystrophy, Emery-Dreifuss muscular dystrophy, Steinert's myotonic dystrophy), congenital myopathies, inflammatory myopathies and metabolic diseases (glycogenosis, periodic paralysis, mitochondrial diseases) may produce dilated or hypertrophic cardiomyopathy and heart rhythm or conduction disturbances. Furthermore the heart is commonly involved in some hereditary and degenerative diseases (Friedreich's ataxia and Kugelberg-Welander syndrome) and acquired (Guillain-Barré syndrome) or inherited (Refsum's disease and Charcot-Marie-Tooth syndrome) polyneuropathies. A cardiologist's high clinical suspicion and a simple but systematic skeletal muscle and peripheral nerve investigation, including muscle enzymes quantification, neurophysiological study and muscle biopsy, are necessary for an accurate diagnosis. In selected patients, more sophisticated biochemical and genetic analysis will be necessary. In most cases, endomyocardial biopsy is not essential for the diagnosis.

Clinical heterogeneity in two pedigrees with the 3243 bp tRNA(Leu(UUR)) mutation of mitochondrial DNA

We studied two pedigrees with a mutation at the nucleotide 3243 of mitochondrial DNA (mtDNA). The proband from the first pedigree had clinically defined MELAS plus maternally transmitted insulin-dependent diabetes mellitus (IDDM). The propositus of the other pedigree had exercise intolerance, lactic acidosis and ragged-red fibers (RRF). In the first pedigree, both the mother and the sister's proband harbored the point mutation in their muscle. The mother had 40% of mutant mitochondrial genomes and the sister 70%. In the second pedigree, the mutation was present in both muscle and blood from the proband as well as in blood from all other members studied. Proportion of mutant mtDNA was 90% in muscle and ranged from 40% to 90% in blood.

Gangliosides and Guillain-Barré syndrome: the Spanish data

Although ganglioside administration has been suspected as being responsible for Guillain-Barré syndrome (GBS) and peripheral neuropathies in some patients, current epidemiological, experimental, and clinical data do not support such an association. In Spain, a total of 17 cases of suspected GBS and neuropathy had been reported to the National Drug Surveillance System as of April 15, 1992. No definite relationship between ganglioside administration and the illness in these cases could be established after careful review of available data.

Controlled and uncontrolled thrombocytosis. Its clinical role in essential thrombocythemia

Only two of 19 patients with spontaneously evolving essential thrombocythemia remained asymptomatic in a 421 patient-month observation. The rest of the patients showed hemorrhagic diathesis (four patients), nonspecific neurological semiology (two patients), and occlusive vascular illness in cerebral, myocardic, arterial, and often multiple locations (total, 12 patients). Peripheral neuropathy was found in five of 10 patients studied. In this series the incidence of cerebral ischemia in the uncontrolled condition was 180 times higher than the epidemiologic expectancy in a population not affected by the disorder. Of 35 ischemic attacks, 22 occurred when the platelet count was more than than 1000 X 10(9)/l, 13 when the count ranged from 650 to 990 X 10(9)/l, and none occurred at counts of less than 650 X 10(9)/l. In contrast, therapeutic control of the thrombocytosis caused all complications to disappear. These findings point out the danger of the natural course of the illness and justify active therapy. At the same time they call into question some of the most commonly used criteria in the diagnosis of essential thrombocythemia.

Differential action upon sleep states of ventrolateral and central areas of pontine tegmental field

In order to study oral pontine mechanisms of the sleep- wakefulness cycle (SWC), modifications in the total amount, frequency, and duration of episodes of wakefulness (W), drowsiness (D), slow sleep (SS) and paradoxical sleep (PS) together with modifications in the hourly distribution of both sleep states were analyzed in 15 adult cats. Three animals were used as sham-operated controls. Six of them, Group I, received unilateral lesions in ventral and lateral areas of the nucleus reticularis pontis oralis (RPO) and rostral nucleus reticularis pontis caudalis (RPC). The remaining 6 cats, Group II, had unilateral lesions in the central part of the same nuclei. After ventrolateral lesions (Group I) decrease of PS and SS occurred, but only PS changes reached statistically significant values; while, on the contrary, a significant increase of SS and PS followed central lesions (Group II). Hourly distribution analysis indicated that in Group I decrease of both sleep states took place mainly at night, while in Group II increase of both SS and PS occurred during day. These results suggest a complex and non- uniform influence of the pontine tegmental area on SWC mechanisms. Effects obtained after unilateral lesions, precisely located in ventral and lateral or central parts, point to the existence of two functionally distinct, although almost overlapping, systems, at this level.

Alternance of states within the sleep wakefulness cycle. An approach to its study

Intrinsic and dynamic aspects of the sleep-wakefulness cycle (SWC) are studied. From a dynamic point of view, results indicate a tendency to maintain vigilance (alerta wakefulness-W-and drowsiness-D) or sleep (slow sleep-SS-and paradoxical sleep-PS). Transitions from vigilance to sleep are more probable than the reverse. Drowsiness plays an important role as a distributor stage in the SWC of the normal cat since the same probabilities of passing from it to W than to SS exist. Furthermore transitions from sleep (SS and PS) were more frequently observed to D than to W.

The influence of the rostropontine-ventrolateral region on the sleep-wakefulness cycle

Lesions affecting the ventrolateral area of the nucleus reticularis pontis oralis produced, in chronic implanted cats, a significant decrease of paradoxical sleep.

Multiple sclerosis: a clinico-biological study of 100 cases in Spain

A study was carried out on 100 cases with the clinical diagnosis of multiple sclerosis. Several clinical and analytical factors were considered and correlated. Special attention was paid to data obtained from cerebrospinal fluid (CSF) electrophoresis. The degree of severity of the disease does not affect the selective evaluation frequency of gamma-globulin or its average values. A greater frequency of definite gamma-globulin increase is observed in patients with a stationary development than in those a progressive development although, in both instances, the average values of gamma-globulin do not show any significant difference. There is no correlation between the CSF data and the presumed clinical site of the lesion. Those patients with a single lesion have a lower incidence of pathological data in CSF than those with multiple lesions. A higher proportion of pathological results is seen in CSF of patients with a chronic evolution from the onset than in chronic-intermittent cases. The cases studied during a relapse show a marked decrease in the frequency of definite gamma-globulin increase and paretic colloidal curves. This group of patients gives lower average values of gamma-globulin, total protein and cells, than those patients examined out of relapse. These results are in agreement with recent immunopathological observations.