Overview of Amyotrophic Lateral Sclerosis
Amyotrophic Lateral Sclerosis versus Multifocal Motor Neuropathy: Utility of MR Neurography
MR neurography facilitates accurate differential diagnosis of amyotrophic lateral sclerosis and multifocal motor neuropathy by detection of fascicular enlargements specific for MMN, whereas nerves in ALS appear normal or with only moderately hyperintense but without enlarged fascicles. BackgroundDifferential diagnosis between amyotrophic lateral sclerosis and multifocal motor neuropathy relies on clinical examination and electrophysiological criteria. Peripheral nerve imaging might assist this differential diagnosis. PurposeTo assess diagnostic accuracy of MR neurography in the differential diagnosis of ALS and MMN.Materials and MethodsThis prospective study was conducted between December 2015 and April 2017. Study participants with ALS or MMN underwent MR neurography of the lumbosacral plexus, midthigh, proximal calf, and midupper arm of the clinically more affected side using high-resolution T2-weighted sequences.
Matched healthy study participants who underwent MR neurography served as a control group. Two blinded readers independently rated fascicular lesions and muscle denervation signs on a five-point scale and made an image-only diagnosis, which was compared with the clinical diagnosis to assess diagnostic accuracy. ResultsTwenty-two participants with ALS, eight participants with MMN, and 15 healthy participants were enrolled in this study. Nerves of participants with ALS either appeared normal or showed T2-weighted hyperintensities without fascicular enlargement. In contrast, nerves in MMN were characterized by fascicular swellings.
Muscle denervation signs were more prominent in ALS than in MMN. Inter-rater reliability for blinded diagnosis was of 0.82. The corresponding specificity was 37 of 37.ConclusionMR neurography is an accurate method for assisting in the differential diagnosis of amyotrophic lateral sclerosis and multifocal motor neuropathy.
ALS causes damage to motor neurons in the brain, brainstem, and spinal cord. Nerve cell destruction via apoptosis or other forms of cell death during the progression of ALS results in loss of muscle innervation, which is accompanied by muscle atrophy and degeneration. As a result, individuals with ALS become progressively weaker or paralyzed as nerve cells nourishing and sustaining the affected muscles are lost and muscles atrophy. Lateral is the area of the spinal cord damaged by ALS. 3. Sclerosis comes from the Greek word ‘sklerosis’ derived from ‘skleroun’ meaning harden, and refers to the stiffness and tightness of the limbs caused by continuous muscle contractions characteristic of ALS.
The initial symptoms of ALS are related to atrophy or muscle weakness. ALS is extremely rare, and the diagnostic odyssey can be rather arduous because other masquerading conditions or explanations often must be ruled out before ALS is formally diagnosed. The etiology or cause of nerve cell destruction in ALS remains to be fully elucidated. SOD1 has been implicated in both ALS and apoptosis and more than 100 mutations in SOD1 have been described. From a mechanistic standpoint, it has been suggested that activation of caspase enzymes may lead to destruction of motor neurons in ALS. 1.
ALS is also called Lou Gehrig’s disease after the famous baseball player Lou Gehrig who played first baseman for the New York Yankees and died of the disease in 1941. Lou Gehrig’s death shone a spotlight on ALS. The Muscular Dystrophy Association was founded in the 1950’s and began providing funding for ALS research. Today advocacy groups are helping to spur research through fund raising activities such as the acclaimed ALS Ice Bucket Challenge.
Amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis, also known as Lou Gehrig disease or Charcot disease, is the most common form of motor neuron disease 1,4 resulting in progressive weakness and eventual death due to respiratory insufficiency. Both upper and lower motor neurons are affected, with decreased motor strength and wasting of the muscles of the face, limbs, and diaphragm. There is a progressive loss of motor strength, with preservation of intellectual and sensory function. El Escorial criteria for the diagnosis of amyotrophic lateral sclerosis 7:.it requires the presence ofsigns of lower motor neuron degeneration by clinical, electrophysiological or neuropathologic examination. Signs of upper motor neuron degeneration by clinical examination.
Progressive spread of signs within a region or to other regions. Together with the absence ofelectrophysiological evidence of other disease processes that might explain the signs of LMN and/or UMN degenerations. Neuroimaging evidence of other disease processes that might explain the observed clinical and electrophysiological signs. ALS is a relentlessly progressive neurological disorder characterized by the death of upper motor neurons and anterior horn cells with secondary Wallerian degeneration 2. Eventually, the entire tract from motor strip to the spinal cord is affected by increased T2 signal and volume loss 3.
MR spectroscopy 2decreased NAA. decreased glutamate. ALS typically progresses to death in 2-6 years, usually from respiratory complications 5..
Amyotrophic Lateral Sclerosis
It can be very scary to learn that you have ALS. Talking with your doctor, getting counseling, or joining a support group may help you deal with your feelings. Each year in the United States and most of the world, only 1 to 2 people out of 100,000 get ALS. Men get ALS slightly more often than women do. ALS can occur at any age, but it most often starts in middle-aged and older adults.
ALS doesn’t cause numbness, tingling, or loss of feeling. Respiratory problems and problems with swallowing and getting enough food are the most common serious complication of ALS. As the muscles in the throat and chest weaken, swallowing, coughing, and breathing problems tend to get worse. To find out if you have ALS, your doctor will do a physical exam and will ask you about your symptoms and past health. Just because you have muscle weakness, fatigue, stiffness, and twitching doesn’t mean that you have ALS.
Those symptoms can also be caused by other conditions. If your doctor thinks that you have ALS, he or she will refer you to a neurologist. Another medicine, edaravone, might also help slow down the progression of ALS in some people. How much treatment you want for the problems caused by ALS is a personal choice that only you and your loved ones can make. As ALS symptoms get worse, you may have to choose which treatments you want for issues like breathing and eating problems.
As you make these choices, keep in mind that what’s right for one person with ALS may not feel right for another.