This is a continuation of a series. View part three here.
The five senses are traditionally thought of as sight, hearing, touch, smell and taste. The loss of even part of one of our senses can be devastating. How much moreso when the loss is total and/or to multiple senses. Perhaps the sense of taste is the one that most people would choose, if they had to lose one. But think how life would be so much less full without the ability to truly enjoy a good meal. In this series of blogs, I examine paralysis, spinal cord injury and the sensory losses that accompany this type of injury.
Smell and Taste Losses
The sensory loss of smell and taste are connected. A client who cannot smell also often may experience inability to taste. Although loss of smell and taste can be separate injuries most individuals report a joint loss of these two related senses. This may be because of the common confusion of loss of taste with loss of flavor. This joint injury can be the result of cranial nerve and frontal lobe damage associated with injury to the olfactory bulbs beneath the frontal lobes. The loss of sensory smell can occur separately in both nostrils.
The effect of loss of the sense of smell should not be underestimated. The vast majority of brain injured patients suffering losses in the sense of smell had ongoing problems with employment, even though neuropsychological testing was relatively normal.
Loss of smell and taste are commonly reported following head and/or nasal trauma. An ear, nose and throat doctor may be to provide an assessment of the impairment. This involves taking a thorough history and carrying out a complete examination along with clinical testing of these senses. The doctor should have available a reliable and objective method of quantifying partial or total loss of these senses.
The ability to appreciate flavor involves gustatory, olfactory, tactile, and thermal sensations. When smell loss is severe or total food and drink often become bland. Clinical testing may show that the ability to detect and identify salt, sour, sweet, and bitter remains intact. True loss of taste is rare following trauma because it involves three cranial nerves often with bilateral nerve damage. Each nerve on one side will innervate taste buds on both sides of the body. In addition, taste buds are scattered widely throughout the mouth and throat so that it is almost impossible for a single neural injury to cause significant loss of taste.
Salt, sour, sweet, and bitter are traditionally tested by the application of salt, lemon juice, sugar, and quinine solutions placed onto the tongue. Each side of the tongue can be tested separately as can the front and back part of the tongue. This is necessary because of the different innervation of these areas.
