Smell and Taste Disorders After a Head Injury

The loss of smell is a complex issue, and may be caused by a head injury or craniofacial trauma. Other causes may include damage to the nasal passages, or a fracture in the cribriform plate. Scent enters the nose via this region and travels up the ophthalmic nerve. A shearing-type injury to the head may damage the olfactory nerve, which then travels up the nose. An injury to this area may damage the primary olfactory centers located in the frontotemporal region of the brain.

Symptoms

Several problems can occur after a head injury, including a decreased sense of smell and taste. Although COVID-19 is not particularly contagious, it has been linked to loss of smell and taste in patients. Although it is rare to suffer total sensory loss, it can occur. There are three main causes of decreased sense of smell after a head injury: a direct disruption of nerve fibers that carry smell information to the brain, a decrease in smell-processing centers in the brain, and a damaged nasal lining.

A 49-year-old woman presented with a mild head injury resulting in an olfactory loss and phantom odors. This condition was noted in an otherwise healthy woman with no other symptoms. Magnetic resonance imaging revealed lesions in the right frontal lobe, with bleeding in the olfactory sulcus and bulb. While the brain may not be completely affected, the symptoms are a sign that brain damage is present.

Causes

The brain’s olfactory system is composed of several structures. These structures are located in the frontal lobe, between the insula and the orbitofrontal cortex. In addition to these structures, smaller regions play an important role in smell and taste. These areas are collectively known as olfactory regions. Head injuries can damage or completely destroy these regions, resulting in smell and taste disorders.

Various causes contribute to loss of smell. Nasal injury or damage to nerves in the nose may result in loss of taste. A head injury to the head is one of the most common causes of this problem. Although it is rare for someone to recover completely from this complication, the damage to the brain may lead to loss of smell. People use smell to stimulate their appetite, so the loss of smell may lead to decreased appetite. Additionally, decreased salivary production means that dry foods may be harder to eat.

In addition to loss of smell, a traumatic brain injury can also affect the person’s sense of taste. A traumatic brain injury can damage the olfactory nerve, which connects the mouth and the nose to the brain. The olfactory nerve is a critical area of the brain, and injuries to this area can result in loss of smell and taste. In fact, most people don’t discover they have a loss of smell until several weeks after the injury.

Treatment

A person who has suffered a TBI may notice they have difficulty smelling or tasting right after the injury. There are many possible causes for these symptoms, including a virus called COVID-19 and a traumatic brain injury. If you notice a change in your sense of smell or taste, you should visit a doctor to diagnose the cause and recommend treatment. Treatment for these symptoms will depend on the type of injury you suffered.

Traumatic brain injuries can result in a loss of smell. Treatment will depend on which part of the brain was injured. The olfactory nerve is responsible for transmitting information from the nose and mouth to the brain. Because smell and taste are so closely connected, any damage to this nerve will also result in a decrease in sense of smell. Fortunately, doctors have developed new MRI techniques that allow doctors to more accurately assess brain damage, allowing them to make more accurate diagnoses and treatment recommendations.

Recovery

Smell and taste disorders are common after a traumatic brain injury (TBI). It’s estimated that one out of five people over the age of 40 will experience some degree of loss of smell or taste. Even more people will experience altered smell or taste. Age is a common factor in impaired sense of smell, as are certain medical conditions, such as COVID-19 (smell-related encephalitis).

Olfactory function problems may result from bruising of the brain or shearing of olfactory nerve fibres that cross from the nose to the brain. A pre-existing nasal disorder may also make recovery more difficult. For a grade one TBI, olfactory function problems are rare, but occur in up to 15 percent of patients. In grades two and three of a TBI, the odds of olfactory function loss are much higher.