A stroke is a medical emergency that occurs when the brain’s blood supply is interrupted, causing brain cells to die from a lack of oxygen and nutrients. While many people are familiar with classic signs like sudden weakness or slurred speech, strokes can sometimes present with highly unusual or subtle symptoms. Recognizing these non-standard presentations, such as changes in sensory perception, is important. This article explores the uncommon connection between a stroke and sudden alterations in the sense of smell.
The Link Between Smell Perception and Stroke
A stroke can affect the sense of smell because the brain areas dedicated to processing olfactory information are damaged. The smell pathway begins in the nose but is interpreted centrally, involving structures like the temporal lobe and the olfactory cortex. When a blockage or bleed occurs in an artery supplying blood to these regions, the disruption causes a malfunction in odor perception.
This sensory change is less frequent than typical motor or speech disturbances, but it is a documented neurological occurrence. Studies show that stroke survivors are significantly more likely to report phantom odor perception. This symptom is determined by the location of the compromised blood flow, where misfiring neurons in the damaged area are interpreted by the brain as a sudden smell.
Types of Altered Olfactory Sensations
The sudden change in smell experienced during a stroke usually falls into two categories: perceiving smells that are not present, or experiencing a distortion of real smells. Phantosmia, or “phantom smell,” is the perception of an odor when no physical source exists in the environment. This sensation can be intense and often causes distress.
The most common phantom odors reported are unpleasant, such as burning rubber, smoke, or a strong metallic or chemical smell. Another alteration is dysosmia, a distorted perception where actual odors are perceived incorrectly. For instance, a pleasant smell like coffee might suddenly smell rotten or foul. These sensory changes result directly from neurological malfunction within the olfactory processing pathways.
Recognizing Other Atypical Stroke Symptoms
Since smell changes are atypical, it is helpful to recognize other less common symptoms that might signal a stroke, especially when classic warning signs are absent. Many people mistake these subtle symptoms for minor ailments, leading to dangerous delays in seeking medical care. A sudden, severe headache, often described as the “worst headache of life” or a thunderclap headache, can indicate a hemorrhagic stroke.
Other atypical presentations include acute confusion or a sudden, isolated onset of vertigo or dizziness. In women, sudden, unexplained hiccups or acute body pain have been noted as less common symptoms that should be taken seriously. These signs reinforce the idea that a stroke can affect any part of the brain and manifest in countless ways.
Immediate Action and Emergency Response
If a person suddenly experiences any unusual symptom, including an abrupt change in the sense of smell, immediate action is necessary. A stroke is an emergency, and the priority is to call emergency services, such as 911 or the local equivalent, without delay. The speed of treatment directly correlates with the potential for recovery and minimizing long-term brain damage.
While the F.A.S.T. test (Face drooping, Arm weakness, and Speech difficulty) is the primary screening tool, do not wait for these classic signs before seeking help. If any sudden, unexplained symptom occurs, including an olfactory hallucination, it warrants an immediate medical assessment. Noting the exact time the symptom began is also necessary for emergency medical personnel to determine the appropriate course of treatment.