Neuromuscular Disorders in Geriatric Patients

Introduction• Neuromuscular disorders affect the nerves that control

your voluntary muscles. Voluntary muscles are the ones you can control, like in your arms and legs. Your nerve cells, also called neurons, send the messages that control these muscles. When the neurons become unhealthy or die, communication between your nervous system and muscles breaks down. As a result, your muscles weaken and waste away. The weakness can lead to twitching, cramps, aches and pains, and joint and movement problems. Sometimes it also affects heart function and your ability to breathe.

• There is too many causes for Neuromuscular Disorders for geriatric patients like

• Parkinson disease, • cervical spondylotic radiculomyelopathy,• lumbar spondylosis,• amyotrophic lateral sclerosis,• Guillain-Barré syndrome, • acquired demyelinating polyneuropathies, • myasthenia gravis,• inclusion body myositis, • polymyositis, • Huntington's disease• and polymyalgia rheumatica.

• In this presentation we will focus on• Parkinson disease• Cervical Spondylotic Radiculomyelopathy• Inclusion Body Myositis• Polymyalgia Rheumatica

1-Inclusion Body Myositis

it is an inflammatory disease, characterized by slowly progressive weakness and wasting of both distal and proximal muscles,produces progressive limb weakness over years; the median time from onset to diagnosis is 6 years. It is the most common acquired myopathy in those over the age of 50 years, affecting more males than females.

characteristics

• Phenotype is weakness and atrophy of wrist and finger flexors, quadriceps, and foreleg muscles

• instability of gait (especially when descending stairs)• reduced grip strength• Dysphagia is present in 40% and facial weakness in

one-third.• myocardial involvement is not observed, nor is there

increased risk of malignancy.

treatment• Unfortunately, there is no effective drug therapy• Supportive treatment with physical and occupational therapy,

assistive walking devices/wheelchairs, cricopharyngeal myotomy43 for severe dysphagia, and patient support groups help improve quality of life for these patients. Patients with later-onset (60-79 yr) disease progress more rapidly, requiring a walker in 6 years as compared to those with earlier-onset (40-59 yr) disease, who take 10 years to require a walker.

• There has been a recent report of a novel agent for IBM treatment, Bimagrumab, which is still under study.

2-Cervical Spondylotic Radiculomyelopathy

• Wear and tear of the cervical spine leads to deterioration of intervertebral disks with subsequent overgrowth of surrounding bone, ligaments, and supporting elements.

• This excessive tissue growth leads to compression of the spinal cord and/or cervical nerve roots resulting in myelopathy or radiculopathy, which rarely occur together.

• Radiologic manifestations of cervical spondylosis increase with age, occurring in 10% of persons in the third decade, 50% of those in the fifth decade, and more than 90% of individuals in the seventh decade.2 Despite the presence of prominent radiologic abnormalities, the vast majority of older persons do not have clinical manifestations of the radiculopathy or myelopathy, making it challenging at times to distinguish patients with symptomatic cervical spondylosis from those whose symptoms are due to another process.

Symptoms • Localized neck pain and stiffness are characteristic, although shoulder and upper

arm aching or stabbing pain also frequently occur.• By contrast, lancinating radicular pain is less common.• Slowly progressive gait impairment is the hallmark of the myelopathy but urinary

symptoms are unusual.• Nonspecific numbness and paresthesias of the upper and/or lower extremities are

often encountered, but sensory loss is uncommon or nonspecific (eg, diminished vibration perception at ankles). A narrow-based stiff gait, increased tone, and reflexes with Babinski signs indicate the presence of corticospinal tract dysfunction.

• The common sites for spondylotic overgrowth that damage the spinal cord are at the C5-6 and C6-7 intervertebral spaces, so motor signs and symptoms may be present in the hands (ie, clumsiness, weakness). If the spondylotic overgrowth has a major lateral component, root compromise may occur, producing weakness and muscle atrophy localized to a nerve root distribution. Narrowing may occur at one or more levels.

Treatment

• Treatment is usually conservative in nature. Patient education on lifestyle modifications and nonsteroidal anti-inflammatory drugs (NSAIDs) and physical therapy have been shown to manage such conditions

• current surgical techniques are geared toward correcting the mechanism of cord injury with the use of posterior or anterior decompression depending on site(s) of spondylotic damage.

Polymyalgia Rheumatica• Polymyalgia rheumatica (PMR) is a relatively common

chronic inflammatory condition that affects elderly individuals.

• It is characterized by proximal myalgia of the hip and shoulder girdles with accompanying morning stiffness that lasts for more than 1 hour. Approximately 15% of patients with PMR develop giant cell arteritis (GCA), and 40-50% of patients with GCA have associated PMR. Despite the similarities of age at onset and some of the clinical manifestations, the relationship between GCA and PMR is not yet clearly established.

Treatment• Prednisone is the drug of choice for PMR and treatment duration is

frequently greater than one year. If the patient does not experience dramatic improvement after three days of 10–20 mg oral prednisone per day, the diagnosis should be reconsidered.Sometimes relief of symptoms occurs in only several hours.

• Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen are ineffective in the initial treatment of PMR, but they may be used in conjunction with the maintenance dose of corticosteroid.

• Along with medical treatment, patients are encouraged to exercise and eat healthily. Exercise will help strengthen the weak muscles, and help to prevent weight gain. A healthy diet will help to keep a strong immune system, and also help build strong muscles and bones.Patients are encouraged to eat a diet of fruits, vegetables, whole grains, and low-fat meat and dairy products, avoiding foods with high levels of refined sugars and salt.

Parkinson's Disease• Parkinson disease is recognized as one of the most common

neurologic disorders, affecting approximately 1% of individuals older than 60 years.

• Parkinson's disease (PD) is a chronic and progressive movement disorder, meaning that symptoms continue and worsen over time.

• Parkinson’s involves the malfunction and death of vital nerve cells in the brain, called neurons. Parkinson's primarily affects neurons in an area of the brain called the substantia nigra. Some of these dying neurons produce dopamine, a chemical that sends messages to the part of the brain that controls movement and coordination. As PD progresses, the amount of dopamine produced in the brain decreases, leaving a person unable to control movement normally.

Signs and symptoms • Tremor : Although tremor is the most common initial symptom in Parkinson disease, occurring in approximately 70% of patients, it does not have to be present to make the diagnosis.• Bradykinesia : Bradykinesia refers to slowness of movement.• Rigidity : Some patients may describe stiffness in the limbs, but this may reflect bradykinesia more than rigidity

• postural instability or impaired balance and coordination

Treatment• Carbidopa/Levodopa -The most potent medication for Parkinson’s is levodopa. It is now

combined with carbidopa to prevent this side effect.• Dopamine agonists are drugs that stimulate the parts of the human brain influenced by

dopamine. In effect, the brain is tricked into thinking it is receiving the dopamine it needs. In general, dopamine agonists are not as potent as carbidopa/levodopa, and therefore are less likely to cause dyskinesias. Dopamine agonists can be taken alone or in combination with medications containing levodopa.

• Anticholinergics Anticholinergics can be helpful for tremor and may ease dystonia associated with wearing-off or peak-dose effect. They have little effect on other symptoms of Parkinson’s.

• MAO-B inhibitors — selegiline block an enzyme in the brain that breaks down levodopa. These drugs have a modest effect in suppressing the symptoms of Parkinson’s.

• COMT inhibitors entacapone (Comtan®) represent the newest class of Parkinson's medications. These agents have no direct effect on PD symptoms, but instead are used to prolong the effect of levodopa by blocking its metabolism. COMT inhibitors are used primarily to help with the problem of wearing-off, in which the effect of levodopa becomes short-lived.

• Other medications such as amantadine (Symmetrel) is a mild agent that is used in early Parkinson’s disease to help tremor. In recent years, amantadine has also been found useful in reducing dyskinesias that occur with dopamine medication.