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BALANCE DISORDER

Definition:
A balance disorder is a disturbance that causes an individual to feel unsteady, for example when standing or walking. It may be accompanied by feelings of giddiness or wooziness, or having a sensation of movement, spinning, or floating. Balance is the result of several body systems working together: the visual system (eyes), vestibular system (ears) and proprioception (the body’s sense of where it is in space). Degeneration or loss of function in any of these systems can lead to balance deficits
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Balance disorders can be caused by certain health conditions, medications, or a problem in the inner ear or the brain.

Our sense of balance is primarily controlled by a maze-like structure in our inner ear called the labyrinth, which is made of bone and soft tissue. At one end of the labyrinth is an intricate system of loops and pouches called the semicircular canals and the otolithic organs, which help us maintain our balance. At the other end is a snail-shaped organ called the cochlea, which enables us to hear. The medical term for all of the parts of the inner ear involved with balance is the vestibular system.

Symptoms:
When balance is impaired, an individual has difficulty maintaining upright orientation. For example, an individual may not be able to walk without staggering, or may not even be able to stand. They may have falls or near-falls. The symptoms may be recurring or relatively constant. When symptoms exist, they may include:

*Dizziness or vertigo (a spinning sensation)
*Falling or feeling as if you are going to fall
*Lightheadedness, faintness, or a floating sensation
*Blurred vision
*Confusion or disorientation

Some individuals may also experience nausea and vomiting, diarrhea, faintness, changes in heart rate and blood pressure, fear, anxiety, or panic. Some reactions to the symptoms are fatigue, depression, and decreased concentration. The symptoms may appear and disappear over short time periods or may last for a longer period.

Cognitive dysfunction (disorientation) may occur with vestibular disorders. Cognitive deficits are not just spatial in nature, but also include non-spatial functions such as object recognition memory. Vestibular dysfunction has been shown to adversely affect processes of attention and increased demands of attention can worsen the postural sway associated with vestibular disorders. Recent MRI studies also show that humans with bilateral vestibular damage undergo atrophy of the hippocampus which correlates with their degree of impairment on spatial memory tasks

Causes:
Problems with balance can occur when there is a disruption in any of the vestibular, visual, or proprioceptive systems. Abnormalities in balance function may indicate a wide range of pathologies from causes like inner ear disorders, low blood pressure, brain tumors, and brain injury including stroke.

Many different terms are often used for dizziness, including lightheaded, floating, woozy, giddy, confused, helpless, or fuzzy. Vertigo, Disequilibrium and pre-syncope are the terms in use by most physicians and have more precise definitions.

*Vertigo: Vertigo is the sensation of spinning or having the room spin about you. Most people find vertigo very disturbing and report associated nausea and vomiting.

*Disequilibrium: Disequilibrium is the sensation of being off balance, and is most often characterized by frequent falls in a specific direction. This condition is not often associated with nausea or vomiting.

*Pre-syncope (links to syncope, which is different): Pre-syncope is a feeling of lightheadedness or simply feeling faint. Syncope, by contrast, is actually fainting. A circulatory system deficiency, such as low blood pressure, can contribute to a feeling of dizziness when one suddenly stands up.

Problems in the skeletal or visual systems, such as arthritis or eye muscle imbalance, may also cause balance problems.

Related to the ear:
Causes of dizziness related to the ear are often characterized by vertigo (spinning) and nausea. Nystagmus (flickering of the eye, related to the Vestibulo-ocular reflex [VOR]) is often seen in patients with an acute peripheral cause of dizziness.

*Benign Paroxysmal Positional Vertigo (BPPV) – The most common cause of vertigo. It is typically described as a brief, intense sensation of spinning that occurs when there are changes in the position of the head with respect to gravity. An individual may experience BPPV when rolling over to the left or right, upon getting out of bed in the morning, or when looking up for an object on a high shelf.  The cause of BPPV is the presence of normal but misplaced calcium crystals called otoconia, which are normally found in the utricle and saccule (the otolith organs) and are used to sense movement. If they fall from the utricle and become loose in the semicircular canals, they can distort the sense of movement and cause a mismatch between actual head movement and the information sent to the brain by the inner ear, causing a spinning sensation.

*Labyrinthitis – An inner ear infection or inflammation causing both dizziness (vertigo) and hearing loss.

*Vestibular neuronitis – an infection of the vestibular nerve, generally viral, causing vertigo

*Cochlear Neuronitis – an infection of the Cochlear nerve, generally viral, causing sudden deafness but no vertigo.

 

*Trauma – Injury to the skull may cause either a fracture or a concussion to the organ of balance. In either case an acute head injury will often result in dizziness and a sudden loss of vestibular function.

*Surgical trauma to the lateral semicircular canal (LSC) is a rare complication which does not always result in cochlear damage. Vestibular symptoms are pronounced. Dizziness and instability usually persist for several months and sometimes for a year or more.

   *Ménière’s disease – an inner ear fluid balance disorder that causes lasting episodes of vertigo, fluctuating hearing loss, tinnitus (a ringing or roaring in the ears), and the sensation of fullness in the ear. The cause of Ménière’s disease is unknown.

    *Perilymph fistula a leakage of inner ear fluid from the inner ear. It can occur after head injury, surgery, physical exertion or without a known cause.

    *Superior canal dehiscence syndrome – a balance and hearing disorder caused by a gap in the temporal bone, leading to the dysfunction of the superior canal.

  *Bilateral vestibulopathy – a condition involving loss of inner ear balance function in both ears. This may be caused by certain antibiotics, anti-cancer, and other drugs or by chemicals such as solvents, heavy metals, etc., which are ototoxic; or by diseases such as syphilis or autoimmune disease; or other causes. In addition, the function of the semicircular canal can be temporarily affected by a number of medications or combinations of medications.

 

Related to the brain and central nervous system:
Brain related causes are less commonly associated with isolated vertigo and nystagmus but can still produce signs and symptoms, which mimic peripheral causes. Disequilibrium is often a prominent feature.

*Degenerative: age related decline in balance function
*Infectious: meningitis, encephalitis, epidural abscess, syphilis
*Circulatory: cerebral or cerebellar ischemia or hypoperfusion, stroke, lateral medullary syndrome (Wallenberg’s syndrome)
*Autoimmune: Cogan syndrome
*Structural: Arnold-Chiari malformation, hydrocephalus
*Systemic: multiple sclerosis, Parkinson’s disease
*Vitamin deficiency: Vitamin B12 deficiency
*CNS or posterior neoplasms, benign or malignant
*Neurological: Vertiginous epilepsy
*Other – There are a host of other causes of dizziness not related to the ear.

*Mal de debarquement is rare disorder of imbalance caused by being on board a ship. Patients suffering from this condition experience disequilibrium          even when they get off the ship. Typically treatments for seasickness are ineffective for this syndrome.

*Motion sickness – a conflict between the input from the various systems involved in balance causes an unpleasant sensation. For this reason, looking          out of the window of a moving car is much more pleasant than looking inside the vehicle.

*Migraine-associated vertigo
*Toxins, drugs, medications

Pathophysiology:
The semicircular canals, found within the vestibular apparatus, let us know when we are in a rotary (circular) motion. The semicircular canals are fluid-filled. Motion of the fluid tells us if we are moving. The vestibule is the region of the inner ear where the semicircular canals converge, close to the cochlea (the hearing organ). The vestibular system works with the visual system to keep objects in focus when the head is moving. This is called the vestibulo-ocular reflex (VOR).
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Movement of fluid in the semicircular canals signals the brain about the direction and speed of rotation of the head – for example, whether we are nodding our head up and down or looking from right to left. Each semicircular canal has a bulbed end, or enlarged portion, that contains hair cells. Rotation of the head causes a flow of fluid, which in turn causes displacement of the top portion of the hair cells that are embedded in the jelly-like cupula. Two other organs that are part of the vestibular system are the utricle and saccule. These are called the otolithic organs and are responsible for detecting linear acceleration, or movement in a straight line. The hair cells of the otolithic organs are blanketed with a jelly-like layer studded with tiny calcium stones called otoconia. When the head is tilted or the body position is changed with respect to gravity, the displacement of the stones causes the hair cells to bend.

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The balance system works with the visual and skeletal systems (the muscles and joints and their sensors) to maintain orientation or balance. For example, visual signals are sent to the brain about the body’s position in relation to its surroundings. These signals are processed by the brain, and compared to information from the vestibular, visual and the skeletal systems.
Diagnosis:
Diagnosis of a balance disorder is complicated because there are many kinds of balance disorders and because other medical conditions — including ear infections, blood pressure changes, and some vision problems — and some medications may contribute to a balance disorder. A person experiencing dizziness should see a physiotherapist or physician for an evaluation. A physician can assess for a medical disorder, such as a stroke or infection, if indicated. A physiotherapist can assess balance or a dizziness disorder and provide specific treatment.

The primary physician may request the opinion of an otolaryngologist to help evaluate a balance problem. An otolaryngologist is a physician/surgeon who specializes in diseases and disorders of the ear, nose, throat, head, and neck, sometimes with expertise in balance disorders. He or she will usually obtain a detailed medical history and perform a physical examination to start to sort out possible causes of the balance disorder. The physician may require tests and make additional referrals to assess the cause and extent of the disruption of balance. The kinds of tests needed will vary based on the patient’s symptoms and health status. Because there are so many variables, not all patients will require every test.

Diagnostic testing:
Tests of vestibular system (balance) function include electronystagmography (ENG), Videonystagmograph (VNG), rotation tests, Computerized Dynamic Posturography (CDP), and Caloric reflex test.

Tests of auditory system (hearing) function include pure-tone audiometry, speech audiometry, acoustic-reflex, electrocochleography (ECoG), otoacoustic emissions (OAE), and auditory brainstem response test (ABR; also known as BER, BSER, or BAER).

Other diagnostic tests include magnetic resonance imaging (MRI) and computerized axial tomography (CAT, or CT).

Treatment and Prevention:
There are various options for treating balance disorders. One option includes treatment for a disease or disorder that may be contributing to the balance problem, such as ear infection, stroke, multiple sclerosis, spinal cord injury, Parkinson’s, neuromuscular conditions, acquired brain injury, cerebellar dysfunctions and/or ataxia. Individual treatment will vary and will be based upon assessment results including symptoms, medical history, general health, and the results of medical tests. Additionally, tai chi may be a cost-effective method to prevent falls in the elderly.

Many types of balance disorders will require balance training, prescribed by an occupational therapist or physiotherapist. Physiotherapists often administer standardized outcome measures as part of their assessment in order to gain useful information and data about a patient’s current status. Some standardized balance assessments or outcome measures include but are not limited to the Functional Reach Test, Clinical Test for Sensory Integration in Balance (CTSIB), Berg Balance Scale and/or Timed Up and Go The data and information collected can further help the physiotherapist develop an intervention program that is specific to the individual assessed. Intervention programs may include training activities that can be used to improve static and dynamic postural control, body alignment, weight distribution, ambulation, fall prevention and sensory function. Although treatment programs exist which seek to aid the brain in adapting to vestibular injuries, it is important to note that it is simply that – an adaptation to the injury. Although the patient’s balance is restored, the balance system injury still exists

Benign Paroxysmal Positional Vertigo (BPPV):
It is caused by misplaced crystals within the ear. Treatment, simply put, involves moving these crystals out of areas that cause vertigo and into areas where they do not. A number of exercises have been developed to shift these crystals. The following article explains with diagrams how these exercises can be performed at the office or at home with some help: The success of these exercises depends on their being performed correctly.

The two exercises explained in the above article are:

*The Brandt-Daroff Exercises, which can be done at home and have a very high success rate but are unpleasant and time consuming to perform.

*The Epley’s exercises are often performed by a doctor or other trained professionals and should not be performed at home. Various devices are available      for home BPPV treatment.

Ménière’s disease:
  *Diet:
Dietary changes such as reducing intake of sodium (salt) may help. For some people, reducing alcohol, caffeine, and/or avoiding nicotine may be               helpful. Stress has also been shown to make the symptoms associated with Ménière’s worse.

 *Drugs:
#Beta-histine (Serc) is available in some countries and is thought to reduce the frequency of symptoms
#Diuretics such as hydrochlorothiazide (Diazide) have also been shown to reduce the frequency of symptoms
#Aminoglycoside antibiotics (gentamicin) can be used to treat Ménière’s disease. Systemic streptomycin (given by injection) and topical gentamicin         (given directly to the inner ear) are useful for their ability to affect the hair cells of the balance system. Gentamicin also can affect the hair  cells of the cochlea, though, and cause hearing loss in about 10% of patients. In cases that do not respond to medical management, surgery may be indicated.

      *Surgery for Ménière’s disease is a last resort.
#Vestibular neuronectomy can cure Ménière’s disease but is very involved surgery and not widely available. It involves drilling into the skull and  cutting the balance nerve just as it is about to enter the brain.
#Labyrinthectomy (surgical removal of the whole balance organ) is more widely available as a treatment but causes total deafness in the affected ear.

Labyrinthitis:
Treatment includes balance retraining exercises (vestibular rehabilitation). The exercises include movements of the head and body specifically developed for the patient. This form of therapy is thought to promote habituation, adaptation of the vestibulo-ocular reflex, and/or sensory substitution. Vestibular retraining programs are administered by professionals with knowledge and understanding of the vestibular system and its relationship with other systems in the body.

Bilateral vestibular loss:
Dysequilibrium arising from bilateral loss of vestibular function – such as can occur from ototoxic drugs such as gentamicin – can also be treated with balance retraining exercises (vestibular rehabilitation) although the improvement is not likely to be full recovery

Medication:
Sedative drugs are often prescribed for vertigo and dizziness, but these usually treat the symptoms rather than the underlying cause. Lorazepam (Ativan) is often used and is a sedative which has no effect on the disease process rather helps patients cope with the sensation.

Anti-nauseants, like those prescribed for motion sickness, are also often prescribed but do not affect the prognosis of the disorder.

Specifically for Meniere’s disease a medication called Serc (Beta-histine) is available. There is some evidence to support it is effective to reduce the frequency of attacks. Also Diuretics, like Diazide (HCTZ/triamterene), are effective in many patients. Finally, ototoxic medications delivered either systemically or through the eardrum can eliminate the vertigo associated with Meniere’s in many cases, although there is about a 10% risk of further hearing loss when using ototoxic medications.

Treatment is specific for underlying disorder of balance disorder:

#anticholinergics
#antihistamines
#benzodiazepines
#calcium channel antagonists, specifically Verapamil and Nimodipine
#GABA modulators, specifically gabapentin and baclofen
#Neurotransmitter reuptake inhibitors such as SSRI’s, SNRI’s and Tricyclics

Research:
Scientists at the National Institute on Deafness and Other Communication Disorders (NIDCD) are working to understand the various balance disorders and the complex interactions between the labyrinth, other balance-sensing organs, and the brain. NIDCD scientists are studying eye movement to understand the changes that occur in aging, disease, and injury, as well as collecting data about eye movement and posture to improve diagnosis and treatment of balance disorders. They are also studying the effectiveness of certain exercises as a treatment option.

Other projects supported by the NIDCD include studies of the genes essential to normal development and function in the vestibular system. NIDCD scientists are also studying inherited syndromes of the brain that affect balance and coordination.

The NIDCD supports research to develop new tests and refine current tests of balance and vestibular function. For example, NIDCD scientists have developed computer-controlled systems to measure eye movement and body position by stimulating specific parts of the vestibular and nervous systems. Other tests to determine disability, as well as new physical rehabilitation strategies, are under investigation in clinical and research settings.

Scientists at the NIDCD hope that new data will help to develop strategies to prevent injury from falls, a common occurrence among people with balance disorders, particularly as they grow older.
Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:
http://en.wikipedia.org/wiki/Balance_disorder
http://www.medicinenet.com/vestibular_balance_disorders/article.htm#what_is_a_balance_disorder

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Why Drunk People Take Risks

New brain imaging research shows that social drinkers have decreased sensitivity in brain regions involved in detecting threats, and increased activity in brain regions involved in reward.

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After alcohol exposure, threat-detecting brain circuits can’t tell the difference between a threatening and a non-threatening social situation.

Working with 12 healthy participants who drink socially, researchers used functional magnetic resonance imaging (fMRI) to study activity in emotion-processing brain regions during alcohol exposure. When participants received a placebo instead of alcohol, they showed greater activity in the amygdala, insula, and parahippocampal gyrus — brain regions involved in fear and avoidance — when shown a picture of a fearful facial expression.

Alcohol, meanwhile, activated striatal areas of the brain that are important components of the reward system, but did not increase brain activity in areas involved in fear.

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Sources:

* Science Daily April 30, 2008

* The Journal of Neuroscience April 30, 2008

The Vulnerable Lobes

Medical students have always been fascinated by the story of Phineas Gage, a normal, hard working 26-year-old labourer. He became famous in 1848, when an iron rod pierced his skull and brain and exited on the opposite side. He survived this extensive trauma and was physically normal. His life aroused scientific curiosity as physicians suddenly realised that, contrary to popular opinion at that time, all parts of the brain where not essential for life.

The brain controls the physical functions of the body, determines our intelligence, memory, personality and ability to respond to change. It has four paired lobes. Of these, the parietal, temporal and occipital lobes have well elucidated mapped areas for functions like sight, speech, hearing and movement. The frontal lobes (through which the rod pierced Gage), situated just behind the forehead, are responsible for subtle psychological functions like mental maturity, recognition of social norms of behaviour, emotional development and appropriate responses to society.

English: Four brain lobes frontal lobe(red) pa...

English: Four brain lobes frontal lobe(red) parietal lobe(orange) temporal lobe(green) occipital lobe(yellow) and insula(purple) is also shown. others are Brain stem(black) Cerebellum(sky blue). Polygon data are from BodyParts3D maintained by Database Center for Life Science(DBCLS). ???: ????? ???(??) ???(?????) ???(??) ???(??) ??? ?????? ? ??(??) ??(??) ????????Database Center for Life Science(DBCLS)???????BodyParts3D??? (Photo credit: Wikipedia)

The frontal area of the brain is protected to some extent by the skull bones. However, damage to the frontal lobes can occur as a result of accidents. Surgery may be performed on the frontal lobes to remove cysts or tumours, to treat intractable epilepsy, or very rarely for psychiatric disorders. The effects of injury to the frontal lobes are often subtle and difficult to pinpoint as the IQ (intelligence quotient) may remain normal. There may be weakness without actual paralysis, inability to perform sequential movement (like dressing for work), lack of flexibility and spontaneity, poor attention and difficulty in expressing thoughts lucidly despite increased talking. Sexual habits may change with promiscuity or disinterest or socially inappropriate behaviour. The entire personality of the individual may change, making him or her unpleasant, obnoxious and intolerable.

The brain fibres in the frontal lobes mature as we grow older and develop fully around the age of 25. Genetic defects or injury in the uterus, during birth or within this time frame, can result in faulty connections, inadequate development and poor release of brain chemicals like dopamine. This can cause learning disabilities, antisocial personalities and sometimes even major psychiatric illnesses like schizophrenia. Also the size of our brain, particularly of the frontal lobes, shrinks over time. This affects important human abilities such as planning, reasoning and problem solving.

Not all brains age or deteriorate at the same rate. Part of this process is genetic and the degeneration sets in at a certain chronological age triggered by an in-built biological alarm. This apparently inevitable mental decline is further influenced by environmental factors, which can be modified favourably.

The concept of retraining ageing brain circuits has been gaining popularity. There are DVDs and books available on brain exercises. The numbers game Sudoku is in almost every newspaper. Retraining the frontal lobes can also be done quite simply by memorising passages or poetry from books. Repetition of a task makes performance rapid and more efficient with less room for error, as the cascading chemical reactions in the brain then occur on accustomed pathways. Older adults who regularly participate in cognitive activity improve their memory, speed of thought and attention span. This helps them to efficiently manage their day-to-day activities and their finances. The benefits of brain training can be enhanced by regular physical activity.

Look after your brain as it is the only one you have.

* Protect it from injury by wearing seat belts and using helmets.

* Do not hit anyone on the head (this particularly includes corporal punishment).

* If anyone has had an accident or brain surgery, tolerate their idiosyncrasies, changes in personality, unreasonable anger and emotional outbursts.

Sources: The Telegraph (Kolkata, India)