Shimpei Tsuboki1,Tatemi Todaka1,Shu Hasegawa1,Yasuyuki Kaku2,Yuki Ohmori2,Akitake Mukasa2
- Department of Neurosurgery, Japanese Red Cross Hospital Kumamoto, Kumamoto City, Japan
- Department of Neurosurgery, Kumamoto University Hospital, Kumamoto City, Japan.
Shimpei Tsuboki, Department of Neurosurgery, Japanese Red Cross Hospital Kumamoto, Kumamoto City, Japan.
Copyright: © 2023 Surgical Neurology International This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-Share Alike 4.0 License, which allows others to non-commercially remix, transform, and distribute the work to build upon it as long as the author is credited and new creations are licensed under identical terms.
To quote this article:Shimpei Tsuboki1, Tatemi Todaka1, Shu Hasegawa1, Yasuyuki Kaku2, Yuki Ohmori2, Akitake Mukasa2. Olfactory hallucinations induced by unruptured posterior communicating artery aneurysm enhanced by excision: a case report with review of the literature. April 28, 2023; 14:152
To quote this URL:Shimpei Tsuboki1, Tatemi Todaka1, Shu Hasegawa1, Yasuyuki Kaku2, Yuki Ohmori2, Akitake Mukasa2. Olfactory hallucinations induced by unruptured posterior communicating artery aneurysm enhanced by excision: a case report with review of the literature. April 28, 2023; 14:152. Available from:
Background:Unruptured cerebral aneurysms leading to epilepsy are rare, and olfactory hallucinations caused by such an aneurysm are extremely rare. Various treatments have been proposed, including wrapping, clipping with or without cortical resection, and coil embolization, but there is no consensus on the best approach.
case description:We present the case of a 69-year-old woman who had olfactory hallucinations caused by an aneurysm of the posterior communicating artery and was treated with clipping without cortical resection with a positive result.
Diploma:To our knowledge, there has been only one report of a posterior communicating artery aneurysm with olfactory hallucinations in which clipping and cortical resection were performed. This is the first report of a posterior communicating artery aneurysm with olfactory hallucinations effectively treated with clipping alone. There have been several similar reports of middle cerebral artery aneurysms, most of which are believed to be caused by compression of the entorhinal cortex. Although a definitive treatment protocol for this condition remains elusive, we suggest that elimination of pulsatile compressive stress applied to the cerebral cortex by surgical clipping or coil embolization is critical to achieving effective seizure treatment.
Keywords:Clipping, epilepsy, IC-PC aneurysm, olfactory hallucination, aneurysm without rapture
Olfactory hallucinations are a symptom of medial temporal lobe epilepsy and occur mainly in temporal lobe brain tumors and hippocampal sclerosis, but are very rare when caused by an unruptured cerebral aneurysm. They are thought to be connected to the entorhinal cortex, amygdala, rostral insula, and even the olfactory bulb.
history and painting
A 69-year-old female patient with no significant medical history presented to a local clinic complaining of persistent olfactory disturbance characterized by a burnt dust-like odor that had existed for a month prior to her visit. A magnetic resonance imaging (MRI) scan showed the presence of an aneurysm at the bifurcation of the right internal carotid artery (ICA) and the posterior connecting artery. The patient was then referred to our clinic for further treatment. An MRI scan showed a significant communicating aneurysm at the bifurcation of the right posterior artery, and the aneurysm was within the amygdala showing high intensity on a fluid-attenuated inversion recovery image in the cerebral parenchyma surrounding the aneurysm [
(a) Preoperative fluid-attenuated inversion-recovery image on magnetic resonance imaging showed a large aneurysm located in the right posterior connecting artery and showed high intensity in the brain parenchyma surrounding the aneurysm (arrow). (b) Fluid-attenuated inversion recovery magnetic resonance image taken 1 year after surgery showed resolution of aneurysm-induced pressure drainage in the medial temporal lobe, and the high intensity surrounding the aneurysm also disappeared.
A preoperative cerebral angiogram confirmed the presence of a 14 mm aneurysm in the right posterior communicating artery.
operation and result
In general anesthesia, the ICA is exposed at neck level. A frontotemporal craniotomy was then performed and the aneurysm was visualized using the Transylvanian approach. Since the aneurysm was large, after temporary occlusion of the cervical segment of the ICA, the aneurysm was cut at the neck without examining the entire aneurysm [
Intraoperative findings of the surgical section (a) We achieved access to the aneurysm (asterisk) using the Transylvanian approach. The aneurysm was near the temporal lobe (black arrows). Black and white arrows indicate the proximal and distal neck of the aneurysm, respectively. (b) After temporary occlusion of the cervical segment of the internal carotid artery (ICA), clipping of the aneurysm neck with a flat clip was performed. The posterior communicating artery (white arrowheads) was confirmed and preserved between the optic nerve and the ICA.
Previous reports have described olfactory hallucinations as rare, with a reported prevalence of 0.9–16% in certain populations of epilepsy patients, and have been shown to be associated with the entorhinal cortex, amygdala, rostral insula, and even the olfactory bulb in relation to .
Reported cases of olfactory hallucinations caused by unruptured cerebral aneurysm.
In this study, we present a case of unruptured posterior communicating artery aneurysm accompanied by olfactory hallucinations and effectively treated with surgical clipping. Although a definitive treatment protocol for this condition remains elusive, we believe that removal of pulsatile compressive stress applied to the cerebral cortex by surgical clipping or coil embolization is critical to achieving effective seizure management.
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conflict of interest
There is no conflict of interest.
The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the journal or its management. The information contained in this article should not be construed as medical advice; Patients should consult their physician for advice on their specific medical needs.
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What does an aneurysm smell like? ›
In the present case, the patient complained of an unusual smell of something like burning rubber. However, the nature of the unusual smell perceived was completely different from the smell reported in the cases of middle cerebral artery aneurysms, such as the sweet pleasant smell of flowers, sweet fruits, or roses.What are the symptoms of a posterior communicating artery aneurysm rupture? ›
While most unruptured PCOM aneurysms are asymptomatic, when symptoms do occur, clinical manifestations typically include severe headache (HA), visual acuity loss, and cranial nerve deficit.What is aneurysm of posterior communicating artery? ›
Posterior communicating artery aneurysms (PCAs) are the common site of aneurysms, accounting for about 45.9% of all aneurysms, and have a high rupture rate. Oculomotor nerve palsy (ONP) is a common clinical manifestation of PCAs because of the adjacent anatomical relationship.Where is a PCOM aneurysm located? ›
Posterior communicating artery aneurysm, may occur at either end of the posterior communicating artery; that is at the junction with the posterior cerebral artery, or more commonly at the junction with the carotid (typically points laterally, posteriorly, and inferiorly).Do people with aneurysms have hallucinations? ›
Auditory hallucinations have been shown to arise from many different intra-cranial lesions, but seizures manifesting as musical hallucinations triggered by unruptured intracranial aneurysms are rare.Can brain aneurysms cause hallucinations? ›
For middle cerebral artery aneurysms, loss of balance, insomnia, motor and sensory impairment, and visual hallucinations were common symptoms.What is the most common symptom present when a patient is experiencing a posterior cerebral artery stroke? ›
Posterior Cerebral Artery Strokes
PCA strokes will primarily cause a visual field loss or homonymous hemianopia to the opposite side. This large occipital or PCA stroke causes people to be “blind” on one side of the visual field. This is the most common symptom of a large occipital lesion or PCA stroke.
Treatment options of PCOM aneurysm include surgical clipping and endovascular techniques; surgical treatment is preferable in large aneurysm especially when it is causing mass effect on the oculomotor nerve, aneurysms with unfavorable fundus, and those associated with fetal PCOM artery origin [3, 4].What is the risk of rupture of an unruptured aneurysm? ›
Rupture risk increased with aneurysm diameter, with aneurysms larger than 25 mm carrying a 6% annual risk of rupture.What part of the brain does the posterior communicating artery supply? ›
Posterior Communicating Artery. Second branch of supraclinoid internal carotid. Supplies thalamus, hypothalamus, optic chiasm, and mamillary bodies.
What does it mean to clip an aneurysm? ›
Brain aneurysm clipping is a type of microsurgery in which a metal surgical clip is used to close off an aneurysm in the brain. The surgeon makes a small opening in your skull to reach your brain. They use an operating microscope and very small instruments to perform detailed surgical procedures.Should an unruptured aneurysm be treated? ›
For an unruptured brain aneurysm, your doctor will decide whether it's better to treat the aneurysm now or monitor you carefully (called watchful waiting). Certain aneurysms are more likely to bleed, or rupture. A rupture is a critical and potentially life-threatening situation.What is the most common site for an aneurysm of the brain arteries? ›
Cerebral aneurysms can occur anywhere in the brain, but most form in the major arteries along the base of the skull.What happens if the posterior communicating artery is damaged? ›
This blockage keeps blood from reaching its destination in the brain, resulting in a loss of function in the affected region. Strokes can happen when a blood clot gets lodged in an artery, becomes blocked from disease, or if a blood vessel bleeds.What is the most common location for arterial aneurysms? ›
The most common location of an aneurysm is the aorta, which carries oxygenated blood from the heart to the body. The thoracic aorta is the short segment of the aorta in the chest cavity.What is the life expectancy after aneurysm clipping? ›
The short-term mortality rate is between 8.7% (one week after treatment, during the hospitalisation period), and 18.4% (after three months). One year after the vascular event, this figure reaches 22.9% and, five years later, 29%. Only 7% of the patients who survived after five years presented disabling sequelae.What kind of brain damage causes hallucinations? ›
It usually occurs as a result of damage to the frontal lobe, the temporal lobe, or the basal ganglia. Seizures can also lead to psychosis. When hallucinations are caused by psychosis, they will usually accompany other symptoms, such as: Delusions.Can a brain aneurysm cause phantom smells? ›
Survivors often report changes in their ability to taste and/or smell. If the aneurysm ruptured, smell and taste deficits can be caused by blood that irritates the nerves that control these senses.Are hallucinations a symptom of brain damage? ›
The typical symptoms shown are restlessness, confusion, disorientation, hallucinations, agitation, and delusions. Delirium occurs by the effect of injury on brain tissue chemicals. However, there are other mechanisms that can cause posttraumatic delirium in TBI patients.
Depression and anxiety are very common among survivors, whether you suffered a ruptured aneurysm or were treated for an unruptured aneurysm. These may be caused by the aneurysm itself and also by the many life changes that may occur as a result of the aneurysm.
Can an aneurysm cause psychosis? ›
Patients with brain lesions offer the unique opportunity to investigate mechanisms of psychosis. To our knowledge, this is the first reported case of pericallosal cerebral artery aneurysm associated with acute-onset psychosis with symptoms characteristic of schizophrenia.What are the symptoms of posterior cerebral artery damage? ›
- Acute vision loss.
- New onset posterior cranium headache.
- Limb weakness.
- Memory loss.
Patients with a PCA stroke may present with only a headache and mild visual changes such as vision loss, diplopia, inability to see half of the view, or difficulty reading perceiving colors, or recognizing familiar faces. Mild symptoms in the setting of a PCA stroke may delay a patient from getting medical treatment.What does the posterior cerebral artery affect? ›
The Posterior Cerebral Artery (PCA) supplies the occipital lobe, the inferior part of the temporal lobe, and various deep structures including the thalamus and the posterior limb of the internal capsule. Primary and secondary visual areas. Functions in the sensation and interpretation of visual input.Which cranial nerve is affected by posterior communicating artery aneurysm? ›
Oculomotor nerve palsy (ONP) is a rare neurological deficit associated with numerous underlying pathologies. Of these, aneurysm of the posterior communicating artery (PCOM) has been described due to the intimate association with the third cranial nerve in the basal cistern.When do you think peripheral artery aneurysm needs to be repaired? ›
PAA's are usually treated once they are larger than 2cm in diameter, but are sometimes treated when they are smaller than this. Treatment is required earlier for a PAA than an AAA or TAA, because all arteries are smaller than the aorta.What is the survival rate of arterial aneurysm? ›
Nonetheless, 85% of patients with ruptured AAA (rAAA) die and 66% of these deaths occur before reaching the hospital or without undergoing an operation . The mortality rate of the patients who undergo repair procedures is still 37%–74% .What should you avoid with an unruptured aneurysm? ›
- Don't smoke cigarettes. ...
- Control your blood pressure if you have high blood pressure.
- Eat a healthy diet and exercise. ...
- Don't use drugs such as cocaine, methamphetamine or others.
An unruptured brain aneurysm may cause zero symptoms. People can live with them for years before detection.What is the prognosis for unruptured aneurysm? ›
Without the pulsating blood flow, the aneurysm will eventually clot off and shrink. Recovery time typically is two to four days.
Does everyone have a left posterior communicating artery? ›
About 20% of adults retain PCA origin from the posterior communicating artery, and in turn, the internal carotid arteries.Which two arteries are connected by the posterior communicating artery? ›
The posterior communicating artery connects the internal carotid with the posterior cerebral arteries, thus connecting the anterior and posterior cerebral circulations.Can you live a normal life after aneurysm clipping? ›
Clipping surgery is a highly successful and safe treatment for brain aneurysms. Though everyone's situation is unique, clipping surgery can make it possible to return to normal life, with the aneurysm resolved.What is the success rate of brain aneurysm clipping? ›
Surgical clipping, the better-studied of the interventions for aneurysms, has been demonstrated to completely obliterate the aneurysm in >90% of patients,12,13 but its impact on long-term survival in patients with rupture has not been well addressed.What happens to a brain aneurysm after a clipping? ›
The neurosurgeon places a titanium clip across the neck of the aneurysm. What it does: The clip preserves normal blood vessels and stops any more blood from getting into the aneurysm. It also stops the risk of a brain bleed.What is the most difficult aneurysm to treat? ›
Although responsible for only 3%-5% of all cerebrovascular aneurysms, basilar artery aneurysms (BAAs) are among the most difficult to treat.Is unruptured brain aneurysm serious? ›
Brain aneurysms are common. But most brain aneurysms aren't serious, especially if they're small. Most brain aneurysms don't rupture. They usually don't cause symptoms or cause health problems.Is an unruptured aneurysm a disability? ›
If you are suffering from the effects of a brain aneurysm you may qualify for disability benefits. The Social Security Administration recognizes brain aneurysms as an impairment in their Blue Book and you may qualify for disability benefits if certain conditions are met.What is the gold standard for aneurysm diagnosis? ›
Digital substraction angiography (DSA) remains the gold standard imaging test to evaluate cerebral artery aneurysms.What is a posterior communicating artery aneurysm? ›
Posterior communicating artery aneurysms (PCAs) are the common site of aneurysms, accounting for about 45.9% of all aneurysms, and have a high rupture rate. Oculomotor nerve palsy (ONP) is a common clinical manifestation of PCAs because of the adjacent anatomical relationship.
What makes a brain aneurysm worse? ›
*Blood thinners (such as warfarin), some medications and prescription drugs (including diet pills that act as stimulants such as ephedrine and amphetamines), and harmful drugs like cocaine can cause aneurysms to rupture and bleed.What is the significance of posterior communicating artery? ›
Objective: Although posterior communicating artery (PCoA) is a smaller branch of the internal carotid artery, it gives the main contribution in the formation of circle of Willis (CW) by communicating with the internal carotid arterial system and the vertebro-basilar arterial system.Where is posterior communicating artery aneurysm? ›
Posterior communicating artery aneurysm, may occur at either end of the posterior communicating artery; that is at the junction with the posterior cerebral artery, or more commonly at the junction with the carotid (typically points laterally, posteriorly, and inferiorly).Are there warning signs of an aneurysm? ›
One of the most obvious signs of a ruptured aneurysm is intense head pain, typically described as the worst headache of your life. Additional symptoms of a ruptured aneurysm include: Nausea and vomiting. Double or blurred vision.Are there any warning signs before a brain aneurysm? ›
Symptoms of an unruptured brain aneurysm can include: visual disturbances, such as loss of vision or double vision. pain above or around your eye. numbness or weakness on 1 side of your face.What are three major causes of an aneurysm? ›
- a weakness in the blood vessel wall that is present from birth (congenital aneurysm)
- high blood pressure (hypertension) over many years resulting in damage and weakening of blood vessels.
- fatty plaques (atherosclerosis) resulting in a weakness of the blood vessel wall.
Signs of a Leaking Aneurysm
Some cerebral aneurysms may start to leak before they rupture, causing a sudden severe headache. This symptom, also called a sentinel headache, is a warning sign of a major rupture. Many patients report a sentinel headache six to 20 days before a rupture.
Symptoms of a ruptured brain aneurysm usually begin with a sudden agonising headache. It's been likened to being hit on the head, resulting in a blinding pain unlike anything experienced before. Other symptoms of a ruptured brain aneurysm also tend to come on suddenly and may include: feeling or being sick.What are pre aneurysm signs? ›
- A severe headache that comes out of nowhere (often described as the worst headache one has ever felt)
- Blurred vision.
- Feeling nauseated.
- Throwing up.
- A stiff neck.
- Sensitivity to light.
- Double vision.
Survivors often report changes in their ability to taste and/or smell. If the aneurysm ruptured, smell and taste deficits can be caused by blood that irritates the nerves that control these senses. If the aneurysm did not rupture, smell and taste deficits can occur if the aneurysm compresses the surrounding nerves.
What are the side effects of aneurysm clipping? ›
Risks of aneurysm clipping include bleeding, infection, and stroke-like symptoms. There is no easy formula that can allow physicians and their patients to reach a decision on the best course of therapy—all therapeutic decisions must be made on a case-by-case basis.What is the life expectancy of a brain aneurysm? ›
About 25% of people who experience a brain aneurysm rupture die within 24 hours. Around 50% of people die within three months of the rupture due to complications. Of those who survive, about 66% experience permanent brain damage. Some people recover with little or no disability.How does your personality change after a brain aneurysm? ›
Most survivors experience temporary loss of control over emotions. This can manifest itself in anger, frustration, and lashing out at yourself and others. You may find that you get tearful for no reason at all. Confusion about what is happening to you is also common, so do not be reluctant to talk about it.What part of head hurts with aneurysm? ›
An unruptured brain aneurysm may not have any symptoms, especially if it's small. However, a larger unruptured aneurysm may press on brain tissues and nerves. Symptoms of an unruptured brain aneurysm may include: Pain above and behind one eye.What triggers an aneurysm? ›
Causes of aneurysms
high blood pressure (hypertension) over many years resulting in damage and weakening of blood vessels. fatty plaques (atherosclerosis) resulting in a weakness of the blood vessel wall. inherited diseases that may result in weaker than normal blood vessel walls.
- Don't smoke cigarettes. ...
- Control your blood pressure if you have high blood pressure.
- Eat a healthy diet and exercise. ...
- Don't use drugs such as cocaine, methamphetamine or others.
Can people live a long time with a brain aneurysm? Absolutely. Many aneurysms cause no symptoms at all.Is an aneurysm a high risk for COVID? ›
As far as we are aware, most patients with genetically-triggered aortic disease, thoracic aortic aneurysm or dissection, or other arterial aneurysms or dissections, are not at higher risk for developing severe COVID-19 complications, unless they fall into one or more of the high risk categories below.What part of the brain causes olfactory hallucinations? ›
Focus on olfactory hallucinations
If an abnormal smell occurs for less than a few minutes, it is usually from the uncus, in the temporal lobe of the brain. Olfactory hallucinations lasting longer than a few minutes, up to several hours, are usually because of disturbances of the olfactory organ, nerves, or bulb.
Olfactory neuroblastoma, or esthesioneuroblastoma, is a tumor that grows in the nasal cavity. The nasal cavity has nerves and other tissue that are responsible for the sense of smell. This kind of tumor begins in the nasal cavity and can grow into the nearby eyes and brain.
How long do olfactory hallucinations last? ›
Phantosmia is usually temporary and should go away in a few weeks. But your symptoms may linger if a neurological issue is the cause. You should see a healthcare provider if phantom smells last for more than a few weeks.