(Lou Gehrig’s disease, Lou Gehrig’s disease; Charcot’s disease)
Amyotrophic lateral sclerosis and other motor neuron diseases are characterized by a continuous, relentless, progressive degeneration of corticospinal tracts, anterior horn cells, bulbar motor nuclei or a combination thereof. The symptoms vary in severity and can muscle weakness and atrophy, fasciculations, emotional lability, and paresis include the respiratory muscles. The diagnosis includes studies of nerve conduction, electromyography and the exclusion of other diseases by MRI and laboratory tests. Treatment is supportive.
(See also summary of disorders of the peripheral nervous system.)
Amyotrophic lateral sclerosis and other motor neuron diseases are characterized by a continuous, relentless, progressive degeneration of corticospinal tracts, anterior horn cells, bulbar motor nuclei or a combination thereof. The symptoms vary in severity and can muscle weakness and atrophy, fasciculations, emotional lability, and paresis include the respiratory muscles. The diagnosis includes studies of nerve conduction, electromyography and the exclusion of other diseases by MRI and laboratory tests. Treatment is supportive. (See also summary of disorders of the peripheral nervous system.) Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease (MND). MND the CNS and the peripheral nervous system can include. Common Erwiese the etiology is unknown. The nomenclature and the symptoms vary according to the part of the motor nervous system that is affected. Myopathies have similar characteristics, but they are disorders of the muscle membrane, the contractile apparatus or organelles. MND are divided into the upper and MND MND of the lower motor neuron; some disorders (eg. as ALS) have characteristics of both. MND are more common in men, usually they appear in the fifth decade of life. MND symptoms and complaints of the upper motor neuron (eg., Primary lateral sclerosis) relate to neurons of the motor cortex, the brain stem to the (corticobulbar lanes) or to the spinal cord (lanes corticospinal) rich. Generally the symptoms are stiffness, clumsiness and awkward movements, the first usually affect the mouth, larynx, or both, and then spread to the extremities. MND of the lower motor neuron affecting the anterior horn cells, the motor cranial nerve nuclei or their efferent axons of the skeletal muscles. In bulbar paralysis only the motor cranial nerve nuclei in the brainstem (bulbar nuclei) are affected. The patients present usually present with a facial muscle weakness, dysphagia and dysarthria. If the anterior horn cells of the spinal nerves (not the cranial) affected, such as in spinal muscular atrophy, are among the symptoms usually muscle weakness and atrophy, fasciculations (visible muscle twitching) and muscle spasms, usually first in one hand, a foot or tongue. Polio, an enterovirus infection that attacks the anterior horn cells, and post-polio syndrome are also MND of the lower motor neuron. Results of physical examination help distinguish between MND of the upper and MND of the lower motor neuron (see Table: distinguishing lesions by MND of the upper and lower motor neurons) and the differentiation of a weakness due to a MND of the lower motor neurons of a weakness due to a myopathy (see Table: differentiation of the cause of muscle weakness dysfunction of the lower motor neuron vs. myopathy *). Distinguishing lesions by MND the upper or lower motor neuron lesion characteristic Upper Lower lesion reflex status active decreased or absent Absent atrophy * Available fasciculations absent present tonus Increases Decreases or missing * Can appear when not in use of limbs. Differentiation of the cause of muscle weakness: dysfunction of the lower motor neuron vs. Myopathy * feature dysfunction of the lower motor neuron myopathy * distribution pattern of weakness Distal> Proximal proximal> distal Fasciculations Can there be obtained Missing reflex state Decreases Often * Nerve function intact. > = More affected than. Amyotrophic lateral sclerosis (ALS) Most patients with ALS show randomly distributed, asymmetric symptoms consist of muscle cramps, weakness and muscle atrophy of the hands (most common) or feet. The weakness proceeds to the forearms, shoulders and lower extremities. Fasciculations, spasticity, increased releasable tendon reflexes, Babinski sign, clumsiness, stiffness of movements, weight loss, fatigue and difficulty controlling facial expression and tongue movements soon follow. Other symptoms include hoarseness, dysphagia and slurred speech; because it is difficult to swallow, it appears that the salivation increase, and patients tend to choke on liquids. Late in the disease occurs pseudobulbärer affect on with inappropriate, involuntary and uncontrollable outbursts of laughing or crying. Sensors, consciousness, cognition, voluntary eye movements, sexual function and Sphinkterfunktionen are usually not affected. The cause of death is usually the insufficiency of the respiratory muscles; 50% of patients die within 3 years after onset of the disease, 20% are still alive five years, and 10% survive 10 years. A survival time of> 30 years is rare. In progressive bulbar paralysis occurs faster the deterioration and Tod.Progressive bulbar Mainly the innervated by the cranial nerves and the corticobulbar tracks muscles are affected, leading to increasing difficulties in chewing, swallowing and speaking in a nasal voice, reduced gag reflex, fasciculations and motor weakness of the facial muscles and tongue and weak lifting of the soft palate. It consists of aspiration. A pseudobulbärer affections with emotional lability may be times when the corticobulbar train is affected. Often the disorder spreads and affects extrabulbäre segments; then it is called bulbar variant of ALS. Patients with dysphagia have a very poor prognosis; respiratory complications due to aspiration often lead within 1-3 years to Tod.Progressive muscular atrophy In many cases, especially in the beginning of the disorder in childhood, the inheritance is autosomal recessive. Other cases occur sporadically. The disease can develop at any age. It is just an involvement of the anterior horn cells before, or this is more prominent than the corticospinal share. The disease tends to be benign than other MND. Fasciculations may be the first symptom. Muscle wasting and severe weakness beginning in the hands, they may spread to the arms, shoulders and legs and finally generalize. Patients can survive ? 25 years old. Tips and risks Go from ALS or another motor neuron disease from patients, the characteristics of a weakness of the upper and / or lower motor neuron have (z. B. Babinski sign plus atrophy and fasciculations). Primary lateral sclerosis and progressive pseudobulbar muscle stiffness and symptoms of distal motor weakness increase gradually with involvement of the extremities in primary lateral sclerosis and the lower cranial nerves in progressive pseudobulbar. Fasciculations and muscle atrophy may follow many years later. It takes several years to these disorders lead to severe disability. Diagnostic Electro-diagnostic testing MRI of the brain and, if no cranial nerve involvement is present, the cervical spine laboratory tests to check further, treatable causes for the diagnosis speaks a progressive, generalized motor weakness without significant sensory disorders. Differential Diagnosis Other diseases that cause pure muscle weakness, should be excluded: disorders of neuromuscular transmission Various myopathies (including non-flammable and substance-induced.) Spinal muscular atrophy (mostly in children) polymyositis dermatomyositis thyroid and adrenal disorders electrolyte abnormalities (eg, hypokalemia, hypercalcemia, hypophosphatemia. ) Various infections (eg. as syphilis, Lyme disease, hepatitis C) autoimmune mediated motor neuropathies are cranial nerves affected, a treatable cause is less likely. Symptoms of upper and lower motor neuron plus weakness in the facial muscles strongly support ALS. Tips and risks are affected cranial nerves and the findings compatible with ALS, an alternative treatable cause is less likely. Testing An electro-diagnostic testing should be performed to verify the presence of a disorder of neuromuscular transmission or demyelination. Such findings are not available in MND; the nerve conduction velocities are normal usually until late stages of the disease inside. The Nadelelektromyographie (EMG) is the most informative study shows fibrillations, positive waves, fasciculations and sometimes huge potential, even in unaffected limbs. An MRI of the brain is required. There is no clinical evidence or EMG findings for a conditional by the cranial nerve motor weakness, an MRI of the cervical spine is indicated to rule out structural lesions. Laboratory tests will be done to check treatable causes. The tests include blood count, electrolytes, creatine kinase and thyroid function tests. carried electrophoresis of serum and urine protein immunofixation to check on a paraprotein that is rarely associated with MND. The discovery of an underlying paraproteinemia may indicate that the MND is paraneoplastic and the treatment of paraproteinemia can improve the MND. Antibodies against myelin-associated glycoprotein (MAG) are associated with a demyelinating motor neuropathy, which can mimic an ALS. 24-hour urine is collected to test for heavy metals in patients who were exposed to these. It can be performed a spinal tap to address the clinical suspicion of other diseases; leukocytes or protein levels are elevated, an alternative diagnosis is likely. VDRL test in serum, erythrocyte sedimentation rate and determination of certain antibody (rheumatoid factor, Borrelientiter, HIV, Hepatitis C virus, antinuclear antibodies [ANA], anti-Hu [to check for paraneoplastic anti-Hu syndrome) are displayed only when appropriate risk factors in the medical history to suggest such an investigation. Genetic Testing (z. B. superoxide dismutase gene mutation or genetic abnormalities, spinal muscular atrophy verusachen) and enzyme determinations (eg. As hexosaminidase A) should only be performed when patients are interested in genetic counseling. For disorders that are detected by these tests, there are no known specific treatments. Treatment Supportive treatment riluzole in ALS (Editor’s note: Riluzole is approved for all types of ALS and in Germany much more common than in the US (used in> 90% of ALS patients).) There are MND no specific treatment , However, a antiglutamaterges drug, riluzole can 50 mg p.o. 2 times / day, prolong the lives of patients by 2-3 months. A multidisciplinary treatment approach in a team helps patients deal with the worsening neurological disabilities. The following drugs may help reduce the symptoms: Baclofen A strong anticholinergic spasticity quinine or phenytoin for cramps (. Eg atropine drops, scopolamine patch, amitriptyline) to reduce saliva production In pseudobulbar affect, amitriptyline, fluvoxamine, or combination of dextromethorphan and quinidine in patients with progressive bulbar palsy had surgery to improve swallowing only limited success. Conclusion Consider a MND in patients who have a diffuse upper and / or lower motor weakness without sensory abnormalities. Pulling Be ALS considered in patients with signs of upper and lower motor neuron plus a weakness in the facial muscles. Run to the exclusion of other disorders by a MRI of the brain, an electro-diagnostic testing and laboratory tests. The mainstay of treatment is supportive care (for example, multidisciplinary support to cope with the disability;. Drug treatment of symptoms such as spasticity, cramps and pseudobulbärer affect). (Editor’s note: Also: Non-invasive / invasive ventilation and PEG-conditioning with dysphagia.)