Question:

Is loss of taste and smell included in the symptoms of Autoimmune Encephalitis?

Answer:

Following a brain injury many people report that their senses of taste and/or smell have been affected. This may be as a consequence of injury to the nasal passages, damage to the nerves in the nose and mouth, or to areas of the brain itself. Loss or changes to smell and taste after brain injury from autoimmune encephalitis does occur but is not yet a symptom found to be common enough that it is listen within the symptoms seen in AE. Research needs to further investigate this.

 If the effects are due to damage to the brain itself, recovery is rare. If recovery does occur, it is usually within a few months of the injury and recovery after more than two years is rare. Sadly, there are no treatments available for loss of taste and smell.

How are taste and smell affected by brain injury?

The two senses can both be affected in a number of different ways and some definitions of the terms for the different conditions are provided below:

Disorders of smell

Anosmia                             Total loss of sense of smell

Hyposmia                           Partial loss of sense of smell

Hyperosmia                       Enhanced sensitivity to odours

Phantosmia/Parosmia     ‘False’ smells – Perceiving smells that aren’t there

Dysosmia                           Distortion in odour perception

Disorders of taste

 Dysgeusia                         Distortion or decrease in the sense of taste

Ageusia                               Total loss of sense of taste

Dysgensia                          Persistent abnormal taste

Parageusia                         Perceiving a bad taste in the mouth

Psychological Effects

Taste and smell are linked to emotional memories. An odor or taste, such as flowers or a favorite food, can bring happy or sad memories flooding back. Losing this capacity, along with the loss of enjoyment of food, can be a major factor in the onset of depression. It is important for carers, family members and healthcare professionals to be aware of the need for understanding and support to help people to come to terms with such effects

Health, Safety and Hygiene issues

Taste and smell provide a vital warning system against many health and safety issues. The following suggestions can help to compensate for losing these abilities:

• Fire/smoke – Fit a smoke alarm, have electrical appliances regularly serviced, remove plugs when not in use and use an alarm to remind you of food cooking in the oven.
• Gas leaks – Have gas appliances regularly serviced and fit a gas detector. You might want to consider fitting an electric cooker and fire.
• Out-of-date food – Always eat or throw out food by its ‘use by’ date. If in doubt, throw it out! Clear out the fridge and cupboards regularly.
• Identifying products – Try to keep products such as drinks, bleach, cleaning products and solvents in their original containers. Make sure they are clearly labelled.
• Home hygiene – Ask friends/family/carers to help empty rubbish bins and keep toilets and kitchen appliances clean to avoid health risks.
• Personal hygiene – Be aware of the need to wash yourself, your clothes and bed linen regularly. Use an antiperspirant deodorant and perhaps a shoe deodorizer too. Ask a close friend or family member to advise on any problems in this area.
• Mouth care – It is important to keep your mouth clean and to brush teeth regularly, including brushing your tongue as well. Using mouthwash and dental floss helps. It is important to pay regular visits to the dentist.
• Toxic fumes – Take precautions and follow manufacturers advice when using products such as paint, cleaning products and solvents. Wear a protective mask, ensure rooms are well ventilated and don’t smoke.

Changes to taste and smell can affect appetite and eating in several ways

Any of these problems may affect your choice of food and lead to an inadequate diet. It is very important to maintain a healthy, balanced diet. The smell of food stimulates the appetite, so loss of smell can lead to reduced:

• appetite and lack of interest in food.
• Loss of smell can also lead to a reduction in saliva production, therefore dry foods, such as biscuits and crackers, may be more difficult to eat.
• The choice of foods may be limited to those which provide flavor, which can lead to a diet that doesn’t provide a balanced variety of nutrients.
• Loss of enjoyment of food can lead to avoiding eating altogether.
• Altered taste may make certain foods, such as meat, taste unpleasant and lead to those foods being avoided.

References: Headway – the Brain Injury Association