A Simple Guide to Acoustic neuroma

A Simple Guide to Acoustic neuroma
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What are Acoustic neuroma ?
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Acoustic neuroma is a neurofibroma of the eight nerve.


Who are at risk of Acoustic neuroma?
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1.Both sexes are equally affected.

2.Acoustic neuroma occurs more in the 50- 60 age group.

3.It forms 5-10% of the intracranial tumors in adults.


What are the different types of Acoustic neuroma?
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1.Neurofibroma I -
a. Unilateral acoustic neuroma usually
Bilateral acoustic neuromas are not common.

b. occurs in adult life,

c. the tumor involve the 8th nerve,

d. can involve any other cranial nerve or the spinal root.

e.Incidence is usually 90-95%

2.Neurofibroma II -
a. bilateral acoustic neuromas are common

b. occurs before the age of 21.

c. affects the entire nerve

d. autosomal dominant inheritance.

e. Incidence is about 5 to 10%.


What are the Causes of Acoustic neuroma?
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Acoustic neuroma in the adult begins in the Schwann's cells of the vestibular portion of the 8th nerve inside the internal auditory canal.

The tumor grows slowly and can extend into the posterior fossa to occupy the space between the cerebellum and the pons.

Because of its location, it can also compress the 5th, 7th, and less often, the 9th and 10th cranial nerves.

If it grows larger, it may also compress the pons and lateral medulla of the brain, causing blockage of the cerebrospinal fluid and increased intracranial pressure.


What are the symptoms and signs of Acoustic neuroma?
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Symptoms:
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1.unilateral hearing loss

2.tinnitus with unilateral high-pitched ringing sound

3.loss of sense of balance

4.vertigo

5.nausea and vomiting

6.altered gait

7.pressure in the ear

8.rarely headache and altered consciousness.

Signs:
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1.unilateral facial weakness.

2.sensory impairment of the nerve

3.impairment of glandular secretions

4.loss of taste

5.loss of sensation in one side of the face and mouth

6.rarely altered gag or swallowing reflexes.


How are diagnosis of Acoustic neuroma made?
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1.Contrast-enhanced CT will detect almost all acoustic neuromas that are greater than 2.0 cm in diameter

2.MRI with gadolinium enhancement may show even smaller tumors

3.Audiology and vestibular tests are done to check for Nerve versus conduction hearing loss.


What is the Treatment of Acoustic neuroma?
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Treatment of acoustic neuroma is usually by surgery and radiotherapy.

Conservative treatment
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In some cases because the neuroma grow so slowly, the tumor is monitored by annual MRI to see its growth.

This method is common among patients over 70 years old.

In rare cases, acoustical neuroma have been known to disappear spontaneously.

Acoustic neuroma may result in gradual hearing loss and tinnitus.


Surgery
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Surgical removal of acoustic neuroma usually involve microsurgery to remove the tumor.

The superior and inferior vestibular nerves are removed at surgery.

This effectively restores balance in the patient.

Radiation treatment
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Radiotherapy using gamma knife radiosurgery or fractionated stereotactic radiotherapy does not remove the tumor but is able to slow or stop its growth.


What is the Prognosis of Acoustic neuroma?
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Prognosis is good in all early diagnosis and small tumors.

Large tumors may give rise to residual neurolgical damage even afer removal.

A Simple Guide to Dizziness

A Simple Guide to Dizziness
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What is Dizziness?
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Dizziness has been used to describe different sensations.
Some may liken it to giddiness, light-headedness, unsteadiness or simply feeling faint.

The symptom of "dizziness" needs to be separated from vertigo, which is a feeling that the room is moving or spinning, or that the person is moving when they are not (or even a floating sensation).

Balance difficulty is also a separate topic where a person feels they are about to fall, has difficulty staying balanced, or may actually fall.

What are the Causes of Dizziness?

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There are many causes of dizziness:
1.insufficient blood flow to the brain

2.Lack of sleep

3.Low blood sugar

4.Low or very high blood pressure

5.Anaemia

6.Fever

7.Stress & Anxiety

6.Cochlea imbalance(Motion Sickness)

7.Cold or Influenza

8.heart disease9. Medicines

10.Brain condition such as Parkinson,brain tumours

Most dizzy spells are minor and go away after a while.

However, dizziness can also point to more serious disorders. These include:

1.Vertigo

There is a spinning sensation or feeling that your surrounding is moving around you.

It is often accompanied by nausea and vomiting.

Nystagmus, a jerky movement in the eye, is a common sign.
Vertigo often indicates an inner ear problem.

Viruses, such as those causing the common cold or flu, can also attack the inner ear and its nerve connections to the brain, resulting in severe vertigo.
In a more serious case, a bacterial infection such as mastoiditis can make a person lose his hearing and sense of balance.
Poor blood flow to the inner ear can also lead to vertigo. This is often due to the hardening of the arteries (arteriosclerosis) which is commonly seen in patients with diabetes, high blood pressure or high blood cholesterol.

2.Light-headedness

A typical form of light-headedness occurs when you stand up too fast for the blood to reach your brain. This form of light-headedness is often transient and harmless. More persistent forms of light-headedness can be caused by:

Loss of body fluids, for instance, loss of water in excessive sweating.

Changes to your blood pressure caused by medicines such as anti-hyptensives, diuretics and anti-depressants.

Medical conditions such as diabetes, Parkinson's disease and Anaemia.

3.Motion sickness or sea-sickness

People prone to this condition can experience nausea and even vomiting when travelling in cars, airplanes, boats, or ships.
Motion sickness occurs when the central nervous system receives conflicting messages from four different systems of the body. They are the inner ears, the eyes, pressure receptors in our skin and sensory receptors in the muscles and joints.

It is the complex interaction of these four systems that gives us our sense of balance and equilibrium.

The inner ears, specifically the three semicircular canals in each ear, detect motion in three dimensions, that is, forward-backward, up-down, and left-right.

The central nervous system (that is, the brain and spinal cord) receives all the information from the four systems to make some sense of the body's position in relation to the environment.
Thus, if you are sitting in the back seat of a moving car, your inner ears and skin receptors will detect the motion of your travel. And if your eyes see the same motion, you will not become "car sick". But if you are reading in the car, your eyes see only the pages of your book, so your brain receives conflicting signals and you become "car sick."

How to diagnose Dizziness?
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History:
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1.duration of dizziness - to determine if acute or chronic.

2.any evidence of vertigo i.e. episodic sudden sensation of circular turning motion of your body or your surroundings - this is a sign of nervous system or ear disease.

3.sensation of lightheadedness, floating, giddiness, unsteadiness, fainting - all known as pseudovertigo and are more likely to be a sign of cardiovascular disease. 4.occasional dizziness episodes - e.g. benign positional vertigo attacks are brief, usually lasting a minute, and then subside rapidly.

5. Continous dizziness episodes may indicate Meniere's syndrome which is characterized by paroxysmal attacks lasting 30 minutes to several hours of vertigo, tinnitus, nausea and vomiting, sweating and pallor and progressive deafness.

6. effect of position (of head or body) or a change in posture on the dizziness - e.g. benign positional vertigo is a common type of vertigo that is induced by changing head position, especially tilting the head backwards, changing from lying to sitting position or turning to the affected side.

Physical examination

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1.Observe for pallor of skin or conjunctiva. Moderate or severe anemia will cause lightheadedness and dizziness, but usually not true vertigo

2.Blood pressure taken when lying down and again after rapidly arising to standing position. Very High blood pressure may cause true vertigo or lightheadedness.

Low blood pressure or postural drop in blood pressure is more likely to cause lightheadedness not true vertigo

3.Examine the ear for abnormalities. Abnormalities on ear examination with no other abnormalities found on nervous system examination may suggest ear wax, otitis media (middle ear infection), cholesteatoma or petrositis

4.Complete nervous system examination should be performed including visual acuity, inspecting for nystagmus, cranial nerve and cerebellar signs.

If abnormalities are found may suggest multiple sclerosis, advanced brain stem tumor, acoustic neuroma or basilar artery insufficiency

What is the Treatment of Dizziness?
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Treatment of dizziness depends on whether the symptom indicates a more serious condition.

Most cases of dizziness and motion sickness are mild and self-treatable disorders.

1.Medications given usually act to balance the inner ear nerves or increase blood flow to the inner ear. Iron and vitamin supplements may be given to treat anaemia.

Other than medicines, the following may relieve some of your discomfort:
2.Avoid rapid changes in position, especially standing up quickly from lying down or turning around from one side to the other.

3.Avoid extremes of head motion (especially looking up) or rapid head motion (especially turning or twisting).

4.Remove or reduce using products that impair circulation, e.g. nicotine, caffeine, and salt.

5.Avoid stress or anxiety, or substances that can trigger dizziness. These include substances that you are allergic to.

6.Avoid hazardous activities such as driving a car, operating dangerous equipment or climbing a ladder.
7.Avoiding motion sickness

Always travel in a manner such that your eyes will see the same motion that your body and inner ears feel.

When in a car, look forward into the distance.

On a ship, watch the horizon

In a plane, choose the window seat if you can, and look out of the window.
Do not read while travelling and do not sit in a seat facing backwards.

8.Treating balance disorders

The main way is to treat the underlying disease or disorder that may be causing the imbalance in the first place. These diseases include ear infection, stroke, multiple sclerosis and other diseases of the nerve.