Losing the ability to smell, known as anosmia, or experiencing a reduced sense of smell, called hyposmia, is a frequent consequence of head injuries. This can significantly affect quality of life, impacting enjoyment of food and personal safety. Recovery is possible for many through various strategies and medical guidance. Approximately 20% of individuals experience some form of olfactory involvement after a traumatic brain injury.
How Head Injury Affects Smell
A head injury can disrupt the sense of smell through several biological mechanisms. Olfactory nerves, which transmit smell information from the nose to the brain, can be damaged where they pass through the cribriform plate, a thin bone at the skull’s base. A sudden impact can shear or sever these fibers, particularly in coup-contrecoup injuries.
Damage can also occur directly to brain regions processing smell, such as the olfactory bulb, olfactory cortex, and parts of the temporal lobe. Contusions or bleeding in these areas can lead to compression or tissue damage, hindering the brain’s ability to interpret signals. Additionally, inflammation and scarring can interfere with nerve function and regeneration.
Active Steps for Olfactory Recovery
Smell training, also known as olfactory training, is a practical strategy to encourage the return of a diminished sense of smell. This method involves repeatedly exposing oneself to specific scents to stimulate the olfactory system and promote nerve regeneration and neuroplasticity. Research suggests smell training can improve olfactory sensitivity in about 30-36% of individuals with post-traumatic anosmia.
To perform smell training, select four distinct scents, typically from floral, fruity, spicy, and resinous categories. Common choices include rose, lemon, clove, and eucalyptus essential oils. Place a few drops of each oil onto separate cotton pads or in small jars. Sniff each scent for 20-30 seconds, focusing intently, twice a day. Continue this routine for at least 12 weeks, potentially rotating new scents.
Beyond smell training, maintaining healthy lifestyle practices supports overall brain health and indirectly aids recovery. This includes adequate sleep, good nutrition, and avoiding irritants that could impact nasal passages. These habits contribute to an environment conducive to healing.
Consulting Medical Professionals
Seeking professional medical advice is important when experiencing smell loss or reduction after a head injury. Early consultation is advisable for any neurological symptoms. If smell does not return or worsens, a follow-up with a specialist is recommended.
Specialists like an Ear, Nose, and Throat (ENT) doctor (otolaryngologist) or a neurologist can assess olfactory dysfunction. They may conduct a medical history review, physical examination, and administer specific smell tests, such as the University of Pennsylvania Smell Identification Test (UPSIT). Imaging techniques like MRI scans can also evaluate brain injury and rule out other potential causes. While no universally effective long-term drug treatments exist for post-traumatic anosmia, corticosteroids might be considered in the acute phase to reduce inflammation.
Living with Reduced Sense of Smell
Living with a diminished sense of smell presents practical challenges and safety concerns. Since the ability to detect smoke, gas leaks, or spoiled food is impaired, regularly check smoke and carbon monoxide detectors and be diligent about food expiry dates.
To enhance food enjoyment, which is often significantly affected by smell loss, focus on the basic tastes (salty, sweet, sour, bitter, umami), and emphasize food’s texture, temperature, and visual appeal. Using strong-flavored spices and herbs can also add interest to meals.
Acknowledging the emotional impact of smell loss, which can include feelings of isolation, anxiety, and a reduced quality of life, is important. Seeking support from networks or professional counseling can be helpful if the condition impacts mental well-being.