Sensory System Examination
Detailed examination of sensory system is a time consuming and difficult assessment and is rarely tested in the exam. In case, you need to perform the sensory exam (e.g. child with sensory symptoms, spinal cord lesion or peripheral nerve disorder) unexpectedly, the following section will help you to cover the basics. The sensory exam includes testing for spinothalamic tract (pain, light touch and temperature), posterior column (position sense or proprioception and vibration) and cortical senses (stereognosia, graphesthesia, and extinction). Nerve fibres carrying the pain and temperature impulses enter the spinal cord and crossover to the opposite spinothalamic tract after a few higher segments and ascends to the brainstem.
Children should be sufficiently undressed but draped to preserve modesty. Initial evaluation of the sensory system is done with the child lying on the back and eyes closed.
• General Principles
o Always test the sensation in a dermatomal distribution, proximal to distal, comparing the right with the corresponding area on the left. Move from area of reduced sensation to normal or increased sensation. Map out the distribution of sensory loss and decide on the pattern of loss, which can conform to a region (due to spinal cord or upper brainstem lesion), dermatome (due to spinal cord or nerve root lesion), peripheral nerve or peripheral neuropathy pattern with involvement of multiple nerves (glove and stocking distribution).
o Often, in case of spinal lesions, a level of increased sensitivity can occur above the sensory level, which usually indicates the highest affected spinal segment.
o Because the vertebral column is longer than the spinal cord in older children, spinal cord se...
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... the meninges leads to increased resistance to passive flexion of the neck and the extended leg. This can be identified clinically by eliciting neck stiffness and Kernig's sign.
• Neck stiffness: With the child lying flat on the back in cot, slip a hand under the occiput and gently flex the neck passively. In the presence of meningeal irritation, there is resistance to flexion of the neck due to spasm of the extensor muscles of the neck. Normally, the chin can be brought up to the chest wall.
• Kernig's sign: Ask the child to lie down flat on the couch with both legs extended. Flex the hip and the knee to 90º on one side and then attempt to straighten the knee while keeping the hip flexed. Kernig's test is positive when painful spasm of the hamstrings limits the extension of the knee and at times the child will flex the head to avoid stretching of the meninges.
Let’s say that there is a mechanical sense. If someone touched your hand, your somatosensory system will detect various stimuli by your skin’s sensory receptors. The sensory information is then conveyed to the central nervous system by afferent neurons. The neuron’s dendrites will pass that information to the cell body, and on to its axon. From there it is passed onto the spinal cord or the brainstem. The neuron's ascending axons will cross to the opposite side either in the spinal cord or in the brainstem. The axons then terminates in the thalamus, and on into the Brodmann Area of the parietal lobe of the brain to process.
Lee H., the effect of infant massage on weight gain, physiological and behavioral responses in premature infants, J Korean Acad nursing, 2005; 35(8), 1451-1460.
warm) in the left upper and lower extremities; decreased strength and movement of the right upper and lower extremities and of the left abdominal muscles; lack of triceps and biceps reflexes in the right upper extremity; atypical response of patellar, Achilles (hyper) reflexes in the right lower extremity; abnormal cremasteric reflex in the right groin; fracture in cervical vertebrae #7; and significant swelling in the C7-T12 region of the spinal canal (Signs and symptoms, n.d.). The objective complaint of a severe headache could also be consistent with a spinal cord injury (Headache, nausea, and vomiting,
These patterns occur only with intense stimulation. Because strong and mild stimuli of the same sense modality produce different patterns of neural activity, being hit hard feels painful, but being caressed does not. It suggested that all cutaneous qualities are produced by spatial and temporal patterns of nerve impulses rather than by separate, modality specific transmission routes. Gate control theory of pain states that stimulation by non-noxious input is able to nullify pain.
In this lab we apply the technique known as a two point discrimination test. This test will allow us to determine which regions of the skin are best able to discriminate between two simultaneous sensory impulses. According to (Haggard et al. 2007), tactile discrimination depends on the size of the receptive fields located on the somatosensory neurons. However receptive fields for other types of sensations are located elsewhere. For vision we find that the receptive fields are located inside the visual cortex, and for hearing we find receptive fields in the auditory cortex. The ability for the body to discriminate two points depends on how well that area of the body is innervated with neurons; and thus conferring to the size of the receptive fields (Haggard et al. 2007). It is important to note that the size of the receptive field generally decreases in correlation to higher innervations. As was seen in the retinal receptive fields, the peripheries of tissue had contained larger receptive fields (Hartline, 1940). In our test we hypothesized that the finger region will be able to discriminate better than the forearm. This means that they will be much more innervated with neurons than the forearm, and likewise contain smaller receptive fields. This also means that convergence is closer to a 1:1 ratio, and is less the case the farther from the fingers we go. We also think that the amount of convergence is varied with each individual. We will test to see if two people will have different interpretations of these results.
Peripheral and central mechanisms involving nerve lesions and their input are substantial when perceiving phantom pain. Due to the impairment of peripheral nerves in the process of amputation, regenerative sprouting of damaged axons occurs and the activity rate of inflamed C-fibres and demyelinated A-fibres spontaneously increases (Flor, 2002). As a consequence of this nerve injury, a neuroma, which is a mass of pruned and tangled axons, may form in the residual limb producing abnormal (ectopic) activity (Katz, 1992). Flor, Nikolajsen and Jenson (2006) proposed that ectopic discharge from a neuroma in the stump illustrates abnormal afferent input to the spinal cord, which is a possible mechanism for unpro...
In each zone, impulses and reflexes travel until they reach nerve endings in the feet and the hands. These zones are believed to be meridians along which energy flows. Placing pressure on the nerve endings in the hands and the feet will affect the organs found in that particular zone (http://www.reflexology.org/aor/refinfo/healart.htm). As well as longitudinal zones throughout the body, there are also cross-reflex points. These cross-reflex points are corresponding points on the opposite side of the body which can be useful in administering reflexology treatment when pressure is not able to be placed on the reflex point....
Scoliosis is a progressive disease. In its early stages a mild rotation and rib deformity is detected. As it progresses more vertebrae rotate, causing the ribs to crowd together on one side of the chest and to spread apart on the opposite side. The disease is usually first identified in persons 10 to 17 years old. Most cases occur in girls and become apparent during the rapid growth phase of puberty. Conditions also include shoulder unleveling, waistline discrepancies, acute headaches, shortness of breath, rib hump, chronic fatigue, and mood swings.
Musculoskeletal system: He doesn’t have any stiffness and swelling at any joints. He can walk normally and never had history of falls.
If the spine is normal then the issue is part of the child growing or a different issue that is causing enough pain to warent a trip to the doctors. If the angle is off however then it will be diagnosed as Scoliosis, Lordosis or Kyphosis respectively.
The central nervous system (CNS) consists of the brain and the spinal cord. The brain and the spinal cord serves as the collection section of the nerve impulses. With damage to the peripheral nervous system the central nervous wouldn’t be able to interpret the stimuli’s because they wouldn’t be able to receive them. This system is considered to be ...
The five senses of sight, hearing, touch, taste and smell are all sensations throughout the human body. Sensation is the involvement of sensory receptors as well as the central nervous system in order to allow us to experience outside stimuli. The system that allows us to experience sensation is the sensory system.
Central nervous system: MedlinePlus Medical Encyclopedia. (n.d.). U.S National Library of Medicine. Retrieved May 22, 2014, from http://www.nlm.nih.gov/medlineplus/ency/article/002311.htm
The methods used to determine whether the samples are different are Paired Comparison test, Duo-Trio test and Triangle test. Paired Comparison method is the method used to determine whether the two samples differ in a specified dimension such as sweetness or crispness. The two samples are presented to the panelist simultaneously and the panelist is asked to identify the sample that is higher in the specified sensory attribute.