Posts tagged inner ear disorder
Acoustic neuromas are benign tumors that develop very slowly, on the eighth cranial nerve inside the ear, and they can have a major impact on a person. It is known that only about five individuals out of 100,000 actually have acoustic neuromas, but those who do have them may experience symptoms such as facial numbness, vertigo, a slow diminution of hearing in one or the other ear, problems with balance, and possibly tinnitus.
In extreme cases, the tumor itself can grow to a size where it actually becomes life-threatening, so its early detection is very important. The issue with early detection is that, as mentioned, the development of such a tumor is generally slow, which makes the symptoms experienced very gradual in nature.
In many cases, these symptoms are actually just attributed to normal aging and don’t attract any real attention because they’re thought to be a consequence of diminishing capability. Individuals who experience any of the symptoms referenced above should seek medical attention at the earliest opportunity. This is so that if there is an acoustic neuroma in progress, steps can be taken to have it treated before it gets critical.
How Acoustic Neuromas Develop
The cranial nerve where a neuroma begins to develop is the nerve which joins the inner ear and the brain, and it has a profound impact on both hearing and balance. This is why the symptoms of an acoustic neuroma include side effects that are both hearing-related and balance-related. It’s common for people with an acoustic neuroma to have problems with steadiness in their daily routine, even walking around the household.
Hearing can be impacted by the development of tinnitus, and possibly also a direct loss of hearing. As an acoustic neuroma grows larger and larger, it will begin to crowd the brain itself, as well as those nerves which manage facial expression and facial sensitivity. If an acoustic neuroma goes completely undetected and is allowed to continue growing, it can eventually put so much pressure on the cerebellum or brainstem, that a life-threatening situation can occur.
Causes of Acoustic Neuromas
There are two main causes of acoustic neuromas, the first of which is a sporadic form, and the second being related to a syndrome known as neurofibromatosis type II or NF2. Neurofibromatosis II is an inherited condition in which noncancerous tumors grow in the nervous system, and most of the time these noncancerous tumors are acoustic neuromas. For this inherited type of acoustic neuroma, it is fairly common for them to begin development in both of the patient’s ears, before the age of 30. This is a rare disorder that only makes up about 5% of all acoustic neuromas, meaning that the overwhelming majority of acoustic neuromas are of the sporadic form. Unfortunately, doctors and scientists do not yet understand what causes the sporadic form, although at least one risk factor has been identified as exposure to unusually high levels of radiation, primarily in the area of the neck and head.
Treatment for Acoustic Neuromas
There are three primary approaches to treatment of acoustic neuromas: radiation therapy, surgery, and observation. You can think of observation as ongoing monitoring or watchful waiting. Since acoustic neuromas are not cancerous and grow only slowly, there is usually not an immediate or urgent need for any more drastic form of treatment. What happens after the observation period will depend on how rapidly the acoustic neuroma grows, and what kind of impact it’s having on an individual.
Surgical procedures will take one of three tracks. Translabyrinthine surgery calls for an incision to be made behind the ear, so that a portion of the middle ear as well as the bone behind the ear can be removed, and this approach is generally used on tumors bigger than 3 cm. Sub-occipital surgery operates on the back of the head, and can be used for any sized tumors, and unlike translabyrinthine surgery which causes total hearing loss, sub-occipital surgery holds at least the potential for preserving your hearing. Middle fossa surgery also holds out hope for preserving a patient’s hearing, as it removes a small bone piece over the ear canal, so that tumors of a smaller size can be removed.
Radiation therapy is recognized as state-of-the-art treatment for acoustic neuromas, as it sends high radiation dosages directly at the tumor, while also limiting damage or exposure to all surrounding tissue. There are two types of radiation therapy which are generally used in the treatment of acoustic neuromas. The first of these is multi-session fractionated stereotactic radiotherapy (FRS). This delivers small doses of daily radiation over a period lasting several weeks, and is generally the more successful of the two radiation approaches. The second method for radiation therapy is known as single fraction stereotactic radiosurgery (SRS). In this approach, hundreds of small radiation beams are directed at the tumor in one comprehensive session. While this has the advantage of requiring only a single treatment session, it has historically been somewhat less effective than the FRS radiation therapy approach.
It may look like a mouthful to say, but the medical condition known as benign paroxysmal positional vertigo (BPPV) can easily be understood by breaking it down into its constituent terms. Benign means non-life threatening and paroxysmal means that it occurs only in sudden bursts. Positional means that it is triggered by specific positions or head movements and vertigo is a sensation of dizziness. Taken altogether, someone who has BPPV would experience brief periods of dizziness, which are brought on by abrupt, unanticipated head motions.
Your Body During a BPPV Episode
Many of the issues which affect your balance originate in the inner ear, like BPPV. It starts when some of the calcium carbonate crystals which are normally carried in the gel of the utricle, somehow navigate out of that environment and into at least one of the three semi-circular canals, which are filled with fluid, and are thus also capable of hosting the crystals.
These semi-circular canals depend on fluids to determine head motions, and when the fluids become oversaturated with calcium carbonate crystals, your ability to balance is disrupted. These particulates cause excessive movement in the fluids within your inner ear, creating what we commonly know as vertigo (dizziness).
When this fluid moves, there are nerve endings inside the ear which sense that motion and transmit messages to the brain about head movements. Inaccurate signals are sent to the brain, and as a result, the BPPV patient feels dizzy and disoriented.
People Affected by BPPV
Even though you might never have heard of BPPV, it’s not an exceptionally rare condition. In fact, more than 100 out of every 100,000 people in America are affected by BPPV, most of whom are adults. The disorder rarely impacts children, and is far more prevalent in older people, particularly seniors.
The cause of the disorder is not yet understood, with most people reporting that they simply woke up one day, and as they got out of bed, realized that the bedroom was spinning all around them. Although the beginnings of BPPV are unclear, scientists and doctors have noted a correlation between the disorder and other diseases such as diabetes, osteoporosis, and inner ear infections.
It can be difficult to diagnose BPPV, because the movement of the calcium carbonate crystals does not show up on imaging scans such as magnetic resonance imaging (MRI). However, a BPPV can abruptly position their head in a way that causes the crystals to move within the fluid of the semi-circular canals, which triggers the false signals that induce dizziness.
This dizziness causes the person’s eyes to move in a very definite and predictable pattern known as nystagmus. This occurs because there is a close relationship between the eye muscles and the inner ear, which allows for a person to remain focused on immediate surroundings during head movements.
Because the false signals sent to the brain make it think the head is moving, it also mistakenly triggers eye movement, which is supposed to help maintain equilibrium. However, in this false scenario, nystagmus acts as a telltale sign.
Treatment of BPPV
Sometimes medications are prescribed as a treatment for BPPV, and in other cases, surgical solutions are recommended. But in most cases, the most effective treatment by far is relocating the wandering calcium carbonate crystals back into the utricle chamber where they belong.
The first step in this mechanical approach calls for identification of which semi-circular canal(s) the crystals have migrated to. Once that is known, a doctor will guide the patient through a series of head maneuvers which are designed to encourage the crystals to return to their original position. Self-treatment is not recommended, and it calls for a doctor who is skilled in guiding a patient through the proper maneuvers so that no damage is done to the head or neck areas.
Effectiveness of Treatment Programs
Studies have demonstrated that the success rate for properly diagnosed and guided BPPV treatment is around 90%. Once the calcium carbonate crystals have been returned to their proper position, most patients report no more than minor residual spinning sensations, and even these diminish within a couple of months.
However, it is possible for the condition to recur, and come back in full force. This usually occurs within five years of treatment, and when it does come back, it can again be treated successfully, using the gravity method of guiding the crystals back to their proper position in the ear.
While physicians have long noted that children with balance and hearing difficulties resulting from inner ear issues also have a high rate of hyperactivity, a recent study now shows why. In a lab, it was noted that certain mice with deafness or other inner ear disorders were unusually hyperactive. Given the circumstances, researchers decided it was a good opportunity to study why this was happening. Generally, hyperactivity was thought to originate within the brain. Hyperactivity is therefore treated as being a brain disorder. It was not until recently when this new study was published that things could begin to change.
The inner ear of a human is responsible for two things: balance and hearing. Therefore, a change in the senses seemed to produce a molecular change in the brain, and this is the first documented study of its kind. It was found that the hyperactive mice had a genetic defect. The same gene found in humans is responsible for the transportation of certain minerals and nutrients to the body, and further investigation revealed that the removal of this specific gene in a healthy mouse increased its amount of activity. Further testing also revealed that two proteins when removed from the mice also increased motor activity. The two proteins are key to neural signaling and brain pathways, and explains why they aid in maintaining the level of activity. When the proteins were re-administered, a normal rate of activity resumed.
Researchers are optimistic that with more testing, hyperactivity may be controlled merely by administering the missing proteins. It is also suggested by these findings that other mental disorders may also originate from other sensory dysfunctions. Since this is a relatively new understanding more research is needed, but this has proved to be an enlightening find.