[Cramps and fasciculations: is it amyotrophic lateral sclerosis?] / Crampes et fasciculations : est-ce une sclérose latérale amyotrophique ?

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease of the adult age. It is an aggressive condition with a mean disease duration of only 3 to 5 years, characterized by progressive weakness and atrophy of limb, bulbar, and respiratory muscles. In general, death is caused by chronic hypoventilation due to respiratory insufficiency. No causal treatment is known today, but the two therapeutic agents authorized in Switzerland for the treatment of ALS can slow disease progression significantly. Other important therapeutic strategies include invasive/non-invasive ventilation, pain therapy, as well as physio-, ergo- and speech therapy on a regular basis.

La sclérose latérale amyotrophique (SLA) est la maladie du motoneurone la plus fréquente de l'adulte. C'est une maladie sévère (la survie moyenne est d'environ 3 à 5 ans), caractérisée par une dégénérescence des premier et deuxième motoneurones. Elle se manifeste par un déficit moteur amyotrophiant progressif des membres, de la langue, des muscles bulbaires et respiratoires. En général, le décès est causé par une hypoventilation chronique. Il n'existe actuellement aucun traitement curatif. Les deux médicaments autorisés en Suisse peuvent ralentir significativement la progression de la maladie et plusieurs nouvelles molécules sont à l'essai. Les traitements non médicamenteux/symptomatiques constituent le deuxième pilier de la prise en charge : ventilation non invasive, traitement des symptômes bulbaires, stabilisation du poids, physio et ergothérapie.

Fasciculaciones y calambres: bases fisiológicas y enfrentamiento clínico de un fenómeno complejo / Fasciculations and cramps: physiological bases and clinical approach of a complex phenomenon

Fasciculations and cramps originate in the motor unit, a functional unit that includes the lower motor neuron and their innervated muscle fibres. Both are common complaints in outpatient practice. These symptoms can be secondary to neurological or medical pathology, presenting a broad differential diagnosis and a complex approach. Recent neurophysiological studies have increased the knowledge of their origin mainly in amyotrophic lateral sclerosis. The symptomatic management of fasciculations and cramps depends on their etiology and includes pharmacological and non-pharmacological treatments. This article aims to present an updated review of the most relevant aspects of physiopathology, clinical approach, and differential diagnosis of both phenomena.

[Fasciculations and cramps: physiological bases and clinical approach of a complex phenomenon]. / Fasciculaciones y calambres: bases fisiológicas y enfrentamiento clínico de un fenómeno complejo.

Fasciculations and cramps originate in the motor unit, a functional unit that includes the lower motor neuron and their innervated muscle fibres. Both are common complaints in outpatient practice. These symptoms can be secondary to neurological or medical pathology, presenting a broad differential diagnosis and a complex approach. Recent neurophysiological studies have increased the knowledge of their origin mainly in amyotrophic lateral sclerosis. The symptomatic management of fasciculations and cramps depends on their etiology and includes pharmacological and non-pharmacological treatments. This article aims to present an updated review of the most relevant aspects of physiopathology, clinical approach, and differential diagnosis of both phenomena.

[The cramp-fasciculation-syndrome (CFS)]. / Das Myalgie-Faszikulations-Krampus-Syndrom (MFKS).

The present review focuses on the cramp-fasciculation syndrome, a benign disorder which is regarded as a hyperexcitability syndrome of the peripheral nervous system. The article presents clinical features, pathophysiology, differential diagnosis, therapy and a case report to illustrate the cramp-fasciculation-syndrome.

Surface electromyogram and muscle ultrasonography for detection of muscle fasciculations in pediatric peripheral neuropathy.

A 12-year-old girl presented with talipes equinus of both legs, attenuation of upper and lower limb tendon reflexes, thermal hyperalgesia, and reduction of vibratory sensation. On clinical examination, muscle twitches of fingers of both hands, as well as the abductor halluces and the dorsal interossei muscles of the right foot were observed. Nerve conduction velocity was significantly declined in the upper and lower extremities. Needle electromyography (EMG) was not performed; however, ultrasonography revealed repetitive, semi-regular muscle twitches lasting 0.2-0.4s, concomitant with muscle discharges on surface EMG in the right foot muscles. These findings were compatible with contraction fasciculation in muscles under chronic reinnervation. Nerve and muscle biopsies were suggestive of chronic motor, sensory, and autonomic neuropathy. This is the first case of pediatric peripheral neuropathy where muscle fasciculation was noninvasively identified by simultaneous surface EMG and ultrasonography.

Patrikios syndrome in two patients with treatable flail-leg weakness.

Flail-leg syndrome or lower limb diplegia is a form of motor neuron disease characterized by a slower progression rate. The differential diagnosis with motor neuropathy is important. We present two patients with a previous diagnosis of amyotrophic lateral sclerosis (ALS)-flail-leg syndrome, in whom neurophysiological studies suggested proximal conduction block. Both patients responded to immunomodulatory therapy, which suggested an immunologically mediated, treatable flail-leg syndrome phenotype. We stress the importance of fasciculations in the diagnosis of ALS, and the study of nerve root conduction in the differential diagnosis.

Single fibre electromyography in multifocal motor neuropathy with persistent conduction blocks.

OBJECTIVE: To study the process of denervation-reinnervation in multifocal motor neuropathy with persistent conduction blocks in clinically affected and unaffected muscles. METHOD: Volitional single fibre electromyography (SFEMG) was performed in the extensor digitorum communis (EDC) of seven patients. The jitter, the fibre density, and the mean interpotential interval were determined. The results before and after treatment with intravenous immunoglobulin (IVIg) between the unaffected EDC and affected EDC examined during the same SFEMG session were also compared. In addition the values of jitter, fibre density, and mean interpotential interval were analysed for correlation with the strength score on the MRC scale, the duration of the neuropathy, the number of IVIg treatment periods, and the radial nerve conduction block values. RESULTS: Mean jitter, percentage of jitters >60 micros, and impulse blocking percentage, were higher than normal in both the affected EDCs and to a lesser degree in unaffected EDCs. Jitter decreased significantly after IVIg and correlated only with the MRC score. Fibre density and mean interpotential interval were higher than normal equally in the affected EDC and unaffected EDCs, but no correlation was found with strength, duration of the neuropathy, number of treatment periods, and conduction block values. CONCLUSION: The major finding is the presence of SFEMG abnormalities in clinically unaffected EDCs. This shows a process of denervation-reinnervation even in the absence of clinical symptoms, probably more frequent than commonly supposed in this neuropathy. The rapid clinical improvement after IVIg infusions could be due to remyelination after demyelination and to an interference of IVIg with the blocking effect of antibodies on the Na+ channels at the motor nerve endings.

Peripartum management of a patient with Isaacs' syndrome.

PURPOSE: To describe the peripartum management of a patient with Isaacs' syndrome with specific reference to the anaesthetic implications of the disease process. Associated medical problems included obesity, pregnancy induced hypertension and a difficult airway. CLINICAL FEATURES: This 30-yr-old gravida V para 0 woman presented to the anaesthesia consultation clinic at 37-wk gestation to discuss pain relief options for labour and delivery. She had a history of Isaacs' syndrome (a peripheral motor neuron disorder), congenital heart disease (ASD and VSD), treated Hashimotos thyroiditis, obesity and a family history of haemachromatosis. On the day of consultation, she was hypertensive and peripheral oedema was noted. Her urine showed trace protein. Four days later, she presented to the labour suite and her cervix was 9 cm dilated. An epidural anaesthetic was given without difficulty and she had an uneventful labour and delivery course. There were no subsequent neurological complications. CONCLUSION: Isaacs' syndrome is an extremely rare peripheral motor neuron disorder. This patient was successfully managed with epidural analgesia for labour and delivered a healthy child with no congenital anomalies.

A case of Isaacs' syndrome with associated central nervous system findings.

We report a 44-year-old female with Isaacs' syndrome, peripheral motor neuropathy, and features of central pontine myelinolysis (CPM). The patient presented with stiffness and muscle spasms accompanied by profound sweating. She also had bilateral Babinski signs. Electrodiagnostic abnormalities were characteristic of Isaacs' syndrome. Magnetic resonance imaging demonstrated features of CPM. She gained modest relief from baclofen, valproate, and diazepam. She improved dramatically following plasmapheresis and continued to recover on prednisone. She was weaned from steroids without relapse.

Muscle pain, fatigue, and fasiculations.

This article discusses muscle pain, fatigue, and fasiculations. Muscle pain and fatigue are common problems in general medicine and in neurology, while fasiculations raise concern about a potentially ominous disease. The author reviews the conditions that cause pain and similar conditions arising from nonmuscular soft tissues. The article includes a general evaluation to be used for each of these clinical problems.

[A case of Isaacs' syndrome preceding the recurrence of malignant thymoma--generating site of ectopic activity and therapy].

We described a-44-year old male patient with Isaacs' syndrome occurring 8 months before the recurrence of malignant thymoma. Electrophysiological examination suggested that spontaneous muscle activities were generated at the distal terminals of the motor nerves. Double filtration plasmapheresis alleviated the symptoms of neuromyotonia for a short term. Administration of valproic acid had more prolonged effects lasting for 2 months until his death from relapsed thymoma. Our results support that autoimmune mechanisms, especially humoral factors, are playing an important role in the pathogenesis of Isaacs' syndrome and that anti-convulsants therapy is important.

[Isaacs' syndrome with abnormal F response and effects of double filtration plasmapheresis: a case report].

We reported a case of Isaacs' syndrome with abnormal F response detected electrophysiologically. A 14-year-old female was admitted to Hirosaki University Hospital with complaints of progressive myokymia and muscle cramp. PHT and CBZ were partially effective, but discontinued for drowsiness. A neurological examination revealed prominent myokymia and muscle cramp in the legs. The myokymia were worsened by exercise, bathing and diet. An electrophysiological examination showed characteristic F-response; high amplitude, long duration and increased number of phases. The epidural nerve block brought about a disappearance of the myokymia and an improvement of the abnormal features of F response. After repeated double filtration plasmapheresis, the myokymia and abnormal features of F response were remarkably reduced. Although Isaacs' syndrome is thought to have a hyperexcitability at the site of distal peripheral nerve, we suggested that the hyperexcitability might exist at the site of proximal region, and that immunological mechanisms underlie the cause of myokymia and unusual F-response in this case.

Magnetic resonance imaging of the superior oblique muscle in superior oblique myokymia.

High resolution, magnetic resonance imaging was used to quantitatively study the morphometry of the superior oblique muscles of two patients with superior oblique myokymia, as well as 18 superior oblique muscles of 14 patients with normal superior oblique function. The cross sectional area of each superior oblique muscle was measured at 3-millimeter intervals along the entire muscle length. In both cases of myokymia, the affected superior oblique muscles were significantly smaller than normal (P < .05). These anatomical changes in the superior oblique muscle of patients with myokymia suggest that an antecedent injury to the trochlear nerve has occurred. This injury, even if clinically unapparent, may be the initial event which leads to subsequent development of superior oblique myokymia.

Motor neuron 'bistability'. A pathogenetic mechanism for cramps and myokymia.

In three patients suffering from chronic muscle cramps, spasms and myokymia, these involuntary contractions were triggered in the triceps surae, quadriceps, flexor carpi radialis or flexor digitorum by means of single or short-train stimulation of homonymous Ia afferents, elicited by electrical means or tendon taps. In some cases cramp was induced by the first afferent volleys; more often, however, continued stimulation produced stepwise recruitment of motor units (whose rhythmic firing was visible as myokymia in the muscle) until cramp developed. Cramps and myokymic discharges could usually be terminated by a single maximal stimulus to the motor axons (producing antidromic invasion and Renshaw inhibition of the motor neurons), or by short trains of volleys in inhibitory pathways from the skin. The fact that it was possible to induce myokymia and cramps by brief synaptic excitation and terminate them by antidromic invasion or synaptic inhibition, suggests that the mechanism generating these disturbances is intrinsic to alpha-motor neuron somata. Similar on-off switching of self-sustained motor discharges has been observed in the decerebrate cat and is known to depend on 'bistability' of the motor neuron membrane. We propose that a similar mechanism is responsible for discharges that produce cramp.

The natural history and results of treatment of superior oblique myokymia.

OBJECTIVE: To investigate the clinical presentations and long-term course of patients with superior oblique myokymia (SOM). METHODS: The medical records of all 16 patients with the diagnosis of SOM seen in the Neuro-Ophthalmology Unit of The Wilmer Ophthalmological Institute, The Johns Hopkins Hospital, Baltimore, Md, between 1976 and 1993 were reviewed. Follow-up information was obtained for 14 (88%) of the 16 patients. RESULTS: Of the 16 patients with SOM, nine (56%) were male and seven (44%) were female. The age of onset of symptoms ranged from 22 to 50 years (mean age, 34 years). All patients were otherwise healthy with no history of neurologic illness. Seven (44%) of the 16 patients complained of paroxysms of uniocular "shimmering," "fluttering," or oscillopsia lasting seconds, three (19%) complained of vertical and torsional diplopia, and six (38%) had both types of symptoms. Five (31%) of the 16 patients underwent neuroimaging studies within 1 year of onset of symptoms. All imaging study results were normal. Follow-up information was obtained for 14 patients (88%). The time from onset of symptoms to our most recent contact was 3 to 29 years. Of the seven patients who received no treatment, five (71%) continue to have symptoms to date. Three patients received medical treatment only; one of the three has experienced lasting benefit with carbamazepine. Four patients underwent superior oblique tenectomy combined with inferior oblique myectomy after not responding to medical treatment. All four patients experienced resolution of all ocular symptoms after surgery. CONCLUSIONS: Because SOM is a much more chronic disease than formerly realized and because of the poor long-term effects and potential side effects of the medications used, medical treatment of SOM is not the optimum way to manage the disease. Extraocular muscle surgery is the treatment of choice when symptoms of SOM are intolerable to the patient.

Hypothermia, hyperhidrosis, myokymia and increased urinary excretion of catecholamines associated with a thymoma.

OBJECTIVE: To report a rare syndrome associated with a thymoma and its first successful treatment with gammaglobulin. CLINICAL FEATURES: A 49-year-old white male presented with marked hypothermia, hyperhidrosis, myokymia and increased urinary excretion of catecholamines four weeks after complete excision of a malignant thymoma. He became increasingly drowsy, obtunded and required ventilatory support. INTERVENTION AND OUTCOME: A catecholamine secreting tumour was excluded and he was treated with intravenous gammaglobulin for five days, with dramatic improvement in his condition. Six months later he remains in remission. CONCLUSION: The response to treatment in this patient suggests an immunological pathogenesis for this rare group of symptoms associated with a thymoma.

AAEM minimonograph #37: facial and limb myokymia.

Myokymia is a clinical phenomenon associated with characteristic electromyographic activity referred to as myokymic discharges. These are spontaneously generated bursts of individual motor unit potentials with each burst recurring rhythmically or semirhythmically, usually several times per second. It involves facial muscles more commonly than those of the extremities, and is most often seen in association with Guillain-Barré syndrome, multiple sclerosis, radiation plexopathy, pontine tumors, and timber rattlesnake envenomation. An alteration in the biochemical microenvironment of axon membranes at one of the various sites along the motor axon is the likely basis for the altered membrane excitability that underlies the myokymic discharges in most cases. The similarity of these discharges to those seen with hypocalcemic tetany, and the ability to manipulate myokymic discharges by altering serum-ionized Ca++, suggests that decrease in the ionized Ca++ in the microenvironment of the axon may play an important role.