diabetic neuropathy Flashcards
what is polyneuropathy?
primary degeneration in the nerve parenchyma which is often triggered by toxins metabolic or vascular causes; whereas polyneuritis refers to inflammation of the connective tissues in the peripheral nerves due to toxins, allergens, and infective conditions.
CLASSIFICATION
Polyneuropathy are broadly classified in two major categories, based upon whether they primarily involve the axon or myelin sheath, as demyelination, axonopathy and wallerian degeneration.
Demyelination means there is abnormality in the myelin covering that causes a decrease in nerve conduction. These can be localized or generalized. The recovery is rapid and complete.
Axonopathy or axonal degeneration means damage to the axon due to metabolic, toxic, infective or traumatic causes. Nerve conduction studies show a decrease in amplitude of the resulting motor unit action potential.
In wallerian degeneration there is demyelination along with axonal disorganization causing chromatolysis of soma. Recovery is slow and incomplete
ASSESSMENT of poly neuropathy?
Observation
The attitude of limbs, wasting of the muscles, deformity and tropic changes involving the skin, should be observed. In case the patient is on a ventilatory assistance, as in cases of acute cases of Guillaian
Barré syndrome, the setting of the ventilator, vital parameter
displayed on the pulse oximeter, etc. should be recorded.
Examination
Cranial Nerve Testing
The cranial nerve are bound to be affected in some types of poly- neuropathy and thus determines the severity and prognosis of the disease.
Sensory Examination
May be grossly affected in cases of some predominant sensory neuropathy like diabetic neuropathy, but usually patient may give complain of abnormal sensation like tingling numbness, paresthesia, walking on cotton, etc.
ROM Testing: Both active a passive ROM should be tested, tightness or contracture should be identified.
Manual Muscle Testing (MMT)
Manual muscle testing is the most important examination procedure to be carried. The muscle should be graded from 1 to 5. Individual muscle testing is a must as it gives an idea about the extent and distribution of weakness thus giving an indication about the various nerves involved.
Reflexes
Deep tendon and superficial reflexes should be checked. The response of these reflexes do not directly correspond to the degree of muscle weakness. Superficial reflexes may or may not be involved based on the nerve affected.
Endurance test should be performed for certain common activity to find the degree of fatiguability of the muscle.
Test for autonomous dysfunction: The integrity of autonomous fibers in the nerve can be tested by Ninhydrin test and Galvanic skin resistance test (For details refer Chapter 1).
Functional assessment: The patient should be assessed for all the activities of daily living to find the level of independency of the patient. It is noted that based on the distribution of the weakness the patient may have difficulty in carrying various functions like in cases of GBS, where the weakness is more marked in proximal parts of the body, the patient may exhibit difficulty or inability in performing all the weight bearing activities.
Investigation of poly neuropathy?
Electrophysiological studies like electromyography, nerve conduction velocity studies, F latency, H reflexes give adequate clues that help in the diagnostic procedure of the case. Routine blood test, biochemical test to find protein concentration in the cerebrospinal fluid are some of the common investigation done.
Although there are various types of polyneuropathy, but the most commonest ones treated by physiotherapist are GBS, diabetic neuropathy and alcoholic neuropathy hence only these three types of neuropathies are discussed in this chapter.
what is DIABETIC NEUROPATHY?
About 15 percent of the patient with diabetes develop neuropathy complication. Although not all will produce signs and symptoms. There are different types of diabetic neuropathy which are as follows.
Diabetic Mononeuropathy
Only one or two nerves are involved. Most common cranial nerves involved are third cranial nerves which causes weakness of the extraocular muscles giving rise to diabetic ophthalmoplegia. The other cranial nerves that can be frequently involved is sixth cranial nerve. The peripheral nerves are not usually involved. Very rarely there is involvement of either sciatic or femoral nerve. The exact mechanism of neurogenic involvement is not known. However, it may be due to involvement of the vascular supply to the nerves causing infarction.
Multiple Mononeuropathy
This can be further divided into two types:
• Rapidly evolving painful asymmetrical predominantly sensory
neuropathy.
• Rapidly evolving painless asymmetrical predominantly motor
neuropathy.
The first variety is very common in older age group with mild to moderate neuropathy. The patients mainly has pain at the back which may be radiating to the hip and even down to the thigh. The pain is deep and aching in character and usually aggravates at night. Deep tendon jerks may be involved at the knee mainly due to involvement of the sensory pathway of the reflex arc. Motor symptoms are very rare and are usually confined to hip and thigh musculature.
Unlike the above the second variety is predominantly motor neuropathy causing gross weakness and wasting of the proximal muscles at the hip, the thigh, and even involving the scapula and the shoulder. Sensory symptoms are very rare and if present may manifest as mild pain in the involved area. Reflexes may be reduced because of the weakness of the muscles.
Thoracoabdominal Neuropathy
In this type of neuropathy the patient has pain along one or two segments of the thoracic spine. The pain may radiate horizontally from the back to involve the abdominal area. EMG studies have shown fibrillation potentials of the back muscles and abdominal muscles confirming the involvement of spinal nerve roots.
The above type of neuropathies generally have a good prognosis and faster recovery.
Distal Symmetric Neuropathy
Most common type seen in diabetic patient. Usually begins with mild sensory symptoms of pain or paresthesia which gradually spreads. The sensory symptoms in the form of pain or paresthesia usually worsens at night and are usually confined to the distal most part of the extremities. Usually the altered sensation are present in the foot and distal leg area and very rarely may also involve the hand and wrist. This type of involvement of both the upper and lower limb has been termed as “glove and stocking” appearance.
In the later stages the patient may have involvement of the joints causing arthropathy and may eventually cause charcot joints. Ankle jerks are usually affected due to involvement of the sensory fibers of reflex pathway.
Autonomic Neuropathy
Autonomic disturbances like pupillary and lacrimal dysfunction may be noted in diabetic patients. There may be either increase or decrease of sweating. The most common autonomic disturbance seen in diabetic patient is postural hypotension which occur due to peripheral pooling of blood. The exact cause of autonomic involvement is not properly understood. However the following three mechanism have been put forth.
• Accumulation of vacuoles and granules in sympathetic ganglia
• Demyelination of the nerve fibers
• Loss of cell in the intermediate lateral column in the spinal cord.
Note Decrease tone of the GIT bowel causes nocturnal diarrhea. The patient may have reduced tone of the bladder.
Investigation of diabetic neuropathy?
Blood sugar level, urine sugar level and EMG
Medical Management?
Insulin and aldostatin are commonly used.
Physiotherapy management of diabetic poly neuropathy?
Unlike GBS, in diabetic neuropathy the sensory symptoms are more dominating hence the management also differs accordingly.
Relief of pain or paresthesia: As the patient with diabetes have pain or paresthesia due to the ongoing process of degeneration of the sensory fibres. This can be alleviated because of IFT or TENS which is given along the course of the painful area.
Care of anesthetic hand and foot: The area involved should be carefully inspected at a regular interval of time to look out for any minor cuts or aberrations and should take immediate measures to control it otherwise ignoring this minor wound may cause major ulceration in future.
• The affected part should be kept quite clean and after every washed it should be dabbed properly with a towel as wet skins are prone to develop infections.
• In case of dry weather pliability of the skin should be maintained by use of moisturizing cream or oil because dryness will precipitate a break in the skin which may encourage all forms of infection.
• The person should be instructed to use protective wears in the form of hand gloves, shoes both in and out side the house.
• The footwear should be made of microcellular material so that any form of soreness of the foot due to pressure within
the shoe may be prevented.
• Certain house hold adaptations are essential especially of
the utensils to avoid any cut or burns to the hand and feet. Thus the utensil should be properly insulated with proper handle to avoid any casualty.
Prevention of postural hypotension: Abdominal binders and elastic stockings for lower limbs are given to prevent any peripheral pooling of blood thus preventing postural hypotension. The patient may be gradually got into an erect posture by using a tilt table. In case of muscle weakness the menagement is similar to GBS.
Diabetic Peripheral Neuropathy causes ulcer in pt?
Diabetic peripheral neuropathy is a precipitating factor in almost 90% of diabetic foot ulcers. Chronically high glucose (blood sugar) levels damage nerves, including the sensory, motor and autonomic nerves. Diabetic neuropathy also damages the immune system and impairs the body’s ability to fight infection.
Sensory nerves enable people to feel pain, temperature, and other sensations. When sensory nerves of a diabetic person are damaged (sensory neuropathy), they may no longer be able to feel heat, cold, or pain in their feet. A cut or foot sore, a burn from hot water, or exposure to extreme cold might go completely unnoticed because of numbness and lack of sensation. The sore or exposed area may then become infected and not heal properly due to the body’s impaired ability to fight infection.
Peripheral neuropathy also causes muscle weakness and loss of reflexes, especially at the ankle. This may change the way a person walks and lead to foot abnormalities and deformities such as bunions, hammertoes, and charcot foot. These play an important role in the pathway of diabetic foot ulcers since they contribute to abnormal pressures in the plantar area (heel and bottom) of the foot, predisposing it to ulceration.
Shoes that no longer fit due to abnormalities and deformed foot structure may rub against toes causing blisters and ulcers on areas of the foot that are numb due to sensory neuropathy. If not treated promptly, an ulcer may become infected and spread to the bone causing osteomyelitis, a serious complication that might require surgery.
Autonomic dysfunction causes decreased sweating resulting in cracked skin and ulceration, making the skin vulnerable to infection.
