Vertigo and Dizziness

Vertigo

Definition:

Vertigo and dizziness are two distinct symptoms that can co-occur in a single patient, and distinguishing between them in clinical practice often presents a challenge. Vertigo is a sensation of spinning that can significantly impact a person's balance and perception. There are several types of vertigo, each with distinct causes and characteristics. Swaying and carousel sensation are two distinct perceptional symtoms leading to accurate diagnosis.

It may also be accompanied by symptoms like hearing loss in one ear, ringing in the ears, trouble focusing, and balance impairment. Otherwise can environmental objects spinn around affected individuals. 

History:

Vertigo, a condition recognized and documented in various cultures and medical traditions, has seen a significant evolution in its understanding over the course of history. Ancient Greek physicians, such as Hippocrates, described symptoms resembling vertigo, attributing them to imbalances in bodily humor. The Roman physician Galen further explored these symptoms, associating them with disturbances in the brain and sensory organs. This historical journey of understanding vertigo enlightens us about the progress made and the appreciation we should have for the knowledge we have today.

In the Middle Ages, medical texts often linked vertigo to mystical or supernatural causes, reflecting a lack of understanding of its physiological basis.

However, the Renaissance saw advancements in anatomy and neurology, gradually shifting the perspective toward a more scientific understanding of vertigo. This shift reassures us of the confidence we can have in the current scientific knowledge of vertigo. 

By the 19th century, with the development of modern medical science, researchers began to identify specific inner ear and neurological mechanisms underlying vertigo. The 20th century marked significant progress, with the advent of advanced imaging techniques and a deeper understanding of vestibular disorders.

Today, vertigo is recognized as a multifactorial condition with well-defined physiological and pathological causes, supported by extensive research and clinical practice. In this journey of understanding, each of us in the medical community plays a crucial role, contributing to the collective knowledge and treatment of vertigo.

Classification:

Peripheral Vertigo

Peripheral vertigo is the most common type and arises from problems in the inner ear or the vestibular nerve, which connects the inner ear to the brain.

1- Benign Paroxysmal Positional Vertigo (BPPV)

Etiology: The condition arises due to the displacement of otoconia, small calcium carbonate crystals, from their usual location in the utricle to the semicircular canals of the inner ear. This displacement disrupts the normal fluid dynamics within the canals, leading to the sensation of vertigo. The incidence of this disorder is more prevalent during the menopausal period.

Symptoms: Brief episodes of intense dizziness triggered by specific head movements. This condition is over diagnosed in general population.

Treatment: Often treated with maneuvers like the Epley maneuver to reposition the crystals. Recurrent attack occurs.

2- Meniere’s Disease

The condition is caused by an abnormal amount of fluid in the inner ear, leading to symptoms such as severe vertigo, hearing loss, tinnitus (ringing in the ear), and a sensation of fullness in the ear. Treatment typically involves dietary changes, such as a low-salt diet, medications to reduce fluid retention, and in some cases, surgery.

3- Vestibular Neuritis

Inflammation of the vestibular nerve is often caused by a viral infection, such as chickenpox, influenza, or coronavirus, and in some cases, by bacterial infections like meningococcus, pneumococcus, or Haemophilus, associated with meningoencephalitis. The symptoms include sudden, severe vertigo accompanied by nausea and vomiting, but without hearing loss. Treatment involves medications to alleviate symptoms and physical therapy to improve balance.

4- Labyrinthitis

Infection or inflammation of the inner ear labyrinth.

Symptoms: Vertigo, hearing loss, and tinnitus.

Treatment: Similar to vestibular neuritis, focusing on symptom management and recovery.

5- Perilymph fistula

A perilymphatic fistula (PLF) is defined as an abnormal communication between the perilymph-filled inner ear and the middle ear cavity, mastoid, or intracranial cavity. Typically, a PLF develops when the integrity of the oval or round window is compromised. The etiology of a PLF can be trauma-induced or idiopathic.

6- Superior semicircular canal dehiscence syndrome (SSCDS)

Superior semicircular canal dehiscence syndrome (SSCDS) is a rare condition caused by an abnormal thinning or absence of bone over the superior semicircular canal, a part of the inner ear. This defect can lead to a range of auditory and balance-related symptoms.

Symptoms: Vertigo or dizziness, often triggered by loud noises or changes in pressure (e.g., coughing, sneezing). Autophony, a condition where internal sounds like your own voice, heartbeat, or footsteps are perceived as unusually loud. Hearing loss, typically conductive. Tinnitus, or ringing in the ears. Pressure-induced dizziness (Tullio phenomenon), where vertigo is triggered by sound or pressure changes.

Diagnosis: SSCDS is usually diagnosed through a combination of clinical evaluation, imaging studies (like high-resolution CT scans), and vestibular testing.

Treatment: Treatment options vary depending on symptom severity and may include surgical repair of the dehiscence for those with significant symptoms.

7- Drug-induced peripheral vertigo

Drug-induced peripheral vertigo refers to a type of dizziness or spinning sensation caused by certain medications that affect the inner ear or the vestibular nerve, which plays a crucial role in maintaining balance. Several drugs can cause drug-induced peripheral vertigo. Common ones include:

• Aminoglycoside antibiotics (e.g., gentamicin, streptomycin): These can damage the inner ear. 
• Loop diuretics (e.g., furosemide, bumetanide): This type of diuretics can cause fluid imbalances affecting the inner ear. 
• Salicylates (e.g., aspirin) : High doses can lead to ringing in the ears and vertigo. 
• Anticonvulsants (e.g., phenytoin, carbamazepine): AEDs can affect the central nervous system, leading to dizziness and vertigo.
• Benzodiazepines (e.g., diazepam, lorazepam): These can cause dizziness as a side effect. 
• Certain chemotherapeutic agents (e.g., cisplatin): Chemotherapy can be ototoxic, damaging the inner ear.

8- Trauma

Skull trauma can lead to peripheral vertigo through several mechanisms, primarily involving damage to the structures of the inner ear and the vestibular system.

• Labyrinthine Injury: The inner ear contains the labyrinth, which includes the semicircular canals and the otolith organs (utricle and saccule). Trauma to the skull can damage these structures, leading to disrupted sensory input. This damage impairs the vestibular system's ability to detect head movements and maintain balance, resulting in vertigo.
• Fractures of the Temporal Bone: Skull trauma may cause fractures in the temporal bone, which houses the inner ear. These fractures can directly damage the vestibular apparatus or disrupt the cochlea, causing vertigo due to impaired function of the inner ear.
• Vestibular Nerve Injury: The vestibulocochlear nerve (cranial nerve VIII) transmits balance and hearing information from the inner ear to the brain. Skull trauma can cause concussive injury to this nerve, leading to peripheral vertigo. Damage to this nerve affects its ability to send accurate balance signals to the brain.
• Canalithiasis: Trauma can dislodge otoliths (tiny calcium carbonate crystals) from their normal location in the otolith organs. These dislodged crystals can enter the semicircular canals, where they interfere with normal fluid movement and cause BPPV. This type of vertigo is characterized by brief episodes of dizziness triggered by changes in head position.
• Trauma-Induced fluid dynamics changes: Trauma can alter the fluid dynamics within the inner ear, leading to endolymphatic hydrops, where there is an abnormal accumulation of endolymph fluid. This condition can affect balance and lead to vertigo.
• Secondary Effects: Skull trauma can cause localized inflammation or bleeding within the inner ear or surrounding tissues. This can result in swelling or disruption of normal vestibular function, contributing to the sensation of vertigo.

9- Tumor

Vestibular schwannoma, also known as acoustic neuroma, is a benign tumor that develops on the vestibulocochlear nerve (cranial nerve VIII), which is responsible for hearing and balance. The tumor originates from Schwann cells, which produce the myelin sheath covering nerve fibers. As the vestibular schwannoma grows, it interacts and exerts pressure on the vestibular portion of the vestibulocochlear nerve. This pressure disrupts the normal functioning of the nerve, leading to abnormal signaling in the brain that affects balance. The disruption causes the brain to receive conflicting information about the body's position, resulting in vertigo.

Central vertigo

1- Visual vertigo

It is a type of vertigo triggered or worsened by visual stimuli. Unlike traditional vertigo, which is often associated with issues in the inner ear, visual vertigo is specifically related to how visual information is processed.

- Causes and Triggers:

• Complex Visual Environments: Environments with a lot of visual motion, such as busy streets, crowds, or scenes with repetitive patterns (e.g., stripes or grids).
• Motion Sensitivity: Activities that involve a lot of visual motion, such as watching fast-moving scenes on television or in movies.
• Postural Instability: Situations where maintaining balance is challenging can exacerbate visual vertigo.
• Sensory Mismatch: Discrepancies between visual information and information from other senses (such as the inner ear's balance information) can cause symptoms.

- Symptoms: 

Dizziness, nausea, disorientation, headaches and balance problems

- Mechanisms:

• Visual Dependence: Some individuals rely heavily on visual cues for balance and spatial orientation. When these cues are complex or conflicting, it can lead to dizziness.
• Sensory Conflict Theory: The brain integrates information from the eyes, inner ear, and proprioceptive system (sensors in muscles and joints). Inconsistencies between these inputs can cause vertigo.

- Diagnosis: 

It often involves a detailed patient history and may include balance tests, eye movement tests, and vestibular function tests to rule out other causes of vertigo.

- Treatment: 

• Vestibular Rehabilitation Therapy (VRT): Aims to desensitize the patient to visual motion and improve balance through specific exercises.
• Cognitive-behavioral therapy (CBT): May help manage anxiety and stress associated with visual vertigo.
• Medications: In some cases, medications to manage symptoms like nausea and dizziness might be prescribed.
• Environmental Modifications: Reducing exposure to visually complex environments or using strategies to minimize visual motion can help manage symptoms.

- Managing Visual Vertigo: 

• Gradual Exposure: Increasing exposure to triggering environments can help desensitize the visual system.
• Visual Techniques: Using focal points or reducing head movements can help stabilize vision.
• Physical Therapy: Exercises to improve balance and coordination can reduce reliance on visual input for balance.

2- Migrainous Vertigo (Vestibular Migraine)

Migraine headaches that affect balance can cause vertigo episodes lasting from minutes to hours, often accompanied by headache, sensitivity to light and sound, and visual disturbances. Treatment typically involves migraine medications and lifestyle changes.

3- Multiple Sclerosis (MS)

Cause: Damage to the brain and spinal cord due to an autoimmune disease.

Symptoms: Vertigo can be one of the many neurological symptoms experienced by individuals with MS.

Treatment: Disease-modifying therapies and symptomatic treatments. 

4- Stroke or Transient Ischemic Attack (TIA)

Interruption of blood flow to the brain can lead to sudden onset vertigo, often accompanied by other stroke symptoms such as weakness, slurred speech, and vision problems. Immediate emergency medical treatment is crucial to restore blood flow and prevent further damage. Two important conditions associated with this issue are Vertebrobasilar Ischemic Stroke and Vertebrobasilar Insufficiency.

5- Vertiginous epilepsy

Vertigous epilepsy also known as epileptic vertigo, is a rare form of epilepsy where vertigo or dizziness is the primary or one of the prominent symptoms during seizures. Unlike typical vertigo, which is often related to inner ear or vestibular system disorders, vertiginous epilepsy originates in the brain.

Symptoms:

Vertigo: A sensation of spinning or dizziness is a crucial feature. This can be perceived as either the person spinning or the environment around them spinning.

Aura: Vertigo may act as an aura, a warning sign that precedes the onset of a seizure. Depending on the seizure type and brain regions involved, other symptoms such as visual disturbances, hearing changes, confusion, or loss of consciousness may also occur. Current research suggests that vertigo is most likely caused by epilepsies originating in the lateral temporal lobe. 

Etiology:

Although a specific cause has not been consistently identified for vertiginous epilepsy, several supported hypotheses exist regarding its onset. The most common hypothesis is traumatic head injury. Other potential causes include brain tumors or cancers, strokes, inflammatory processes, and infections. 

Diagnosis:

• Medical History: Detailed history of the episodes, including the description of vertigo, associated symptoms, and any triggers.
• Neurological Examination: To assess for signs of neurological deficits.
• Electroencephalogram (EEG): To detect abnormal electrical activity in the brain. An EEG during an episode can help identify the seizure focus. Current research suggests that vertigo is most likely caused by epilepsies originating in the lateral temporal lobe.
• Imaging: MRI or CT scans may rule out structural brain abnormalities or lesions.

Treatment:

• Antiepileptic Medications (AEDs): These are the primary treatment for controlling seizures. The choice of medication depends on the type and frequency of seizures.
• Lifestyle Modifications: Avoiding seizure triggers, ensuring adequate sleep, managing stress, and adhering to a healthy diet can help reduce the frequency of seizures.
• Surgical Intervention: In cases where seizures are not well-controlled by medication, surgery to remove the seizure focus may be considered.
• Vagus Nerve Stimulation (VNS): An implanted device can help reduce seizure frequency for some individuals who do not respond to medication.

6- Tumors

Cause: Growth of benign or malignant tumors in the brain or brainstem.

Symptoms: Gradual onset of vertigo, headaches, hearing loss, and other neurological deficits.

Treatment: Surgery, radiation, or chemotherapy, depending on the type and location of the tumor.

Diagnosis and Treatment of Vertigo:

Diagnosing vertigo involves a detailed medical history, physical examination, and sometimes specific tests like:

• Dix-Hallpike maneuver for BPPV
• Audiometry for hearing assessment
• Videonystagmography (VNG)
• Vestibular Evoked Myogenic Potential (VEMP)
• Video head impulse test (VHIT)
• Rotational chair testing
• Imaging (MRI, CT scans) for central causes

Treatment varies depending on the type and underlying cause of vertigo but can include:

• Medications: Antihistamines, benzodiazepines, antiemetics, and diuretics.
• Vestibular rehabilitation therapy (VRT): Exercises to improve balance and reduce dizziness.
• Lifestyle modifications include dietary changes, stress management, and avoiding triggers.

Understanding vertigo's specific type and cause is crucial for effective management and treatment.

Dizziness

Dizziness is a broad term to describe a range of sensations, such as feeling faint, woozy, weak, or unsteady. Unlike vertigo, which explicitly involves a spinning or moving sensation, dizziness can encompass various experiences of altered spatial perception and balance. Lightheadedness, disequilibrium, and presyncope are identified as some distinct manifestations of dizziness. Each manifestation exhibits unique clinical characteristics, which can offer valuable diagnostic information.

Lightheadedness

A sensation of imminent fainting or loss of consciousness is frequently analogous to the feeling experienced when standing up too abruptly. This phenomenon may be attributed to a variety of underlying factors, including dehydration, hypotension (low blood pressure), hypoglycemia (low blood sugar), anemia, cardiovascular conditions such as arrhythmias, and adverse effects of certain medications. Understanding these potential causes is crucial for accurate diagnosis and appropriate management.

Disequilibrium

Disequilibrium is characterized by a sensation of being off-balance or unsteady, often described as a feeling of "floating." The etiology of this condition encompasses a range of factors, including vestibular disorders such as labyrinthitis and vestibular neuritis, neurological conditions like Parkinson's disease and multiple sclerosis, joint and muscle problems, and vision issues. Understanding these underlying causes is essential for effective diagnosis and treatment.

Presyncope

Presyncope is characterized by a near-fainting experience where an individual feels as though they are on the verge of losing consciousness, although they typically do not actually faint. This condition is often accompanied by symptoms such as lightheadedness, weakness, and blurred vision.

The etiology of presyncope includes several factors, such as vasovagal syncope, which involves a reflex causing a sudden drop in heart rate and blood pressure; orthostatic hypotension, characterized by a significant decrease in blood pressure upon standing; cardiac conditions including arrhythmias and heart valve problems; and significant blood loss or severe dehydration. The vasovagal reflex, also known as vasovagal syncope or neurocardiogenic syncope, is a common cause of fainting. It occurs when the body overreacts to certain triggers, such as the sight of blood, extreme emotional distress, or prolonged standing. This overreaction involves a sudden drop in heart rate and blood pressure, leading to reduced blood flow to the brain and causing a temporary loss of consciousness.

Psychogenic dizziness

This type of dizziness is linked to psychological factors rather than physical issues. It is often associated with anxiety and panic disorders, where hyperventilation and elevated anxiety levels can lead to dizziness and a sensation of imbalance. Symptoms typically include dizziness accompanied by palpitations, sweating, and a feeling of impending doom. Treatment usually involves psychological therapies, such as cognitive-behavioral therapy (CBT), and, in some cases, medications for anxiety.

Ethiology of dizziness:

• Inner Ear Problems: The inner ear is crucial for maintaining balance. Issues like benign paroxysmal positional vertigo (BPPV), labyrinthitis, and Meniere's disease can cause dizziness.
• Circulatory Issues: Conditions that affect blood flow, such as orthostatic hypotension, heart disease, or atherosclerosis, can lead to dizziness.
• Neurological Conditions: Disorders affecting the nervous system, including stroke, multiple sclerosis, tension headache, increased intracranial pressure (ICP) and intracranial tumors, can result in dizziness.
• Medications: Many medications list dizziness as a side effect, including antihypertensives, sedatives, and certain antibiotics.
• Psychological Factors: Anxiety, panic attacks, fatigue and depression can cause dizziness. Anxiety and panic attacks are often accompanied by hyperventilation and a feeling of unsteadiness.
• Anemia: A low red blood cell count can reduce oxygen supply to the brain, leading to dizziness.
• Dehydration and Electrolyte Imbalance: These can affect blood volume and pressure, leading to dizziness.

Diagnosis:

Diagnosing the cause of dizziness involves a detailed medical history, physical examination, and possibly several diagnostic tests:

• Blood tests: Check for anemia, blood sugar levels, and electrolyte imbalances.
• Electrocardiogram (ECG): To evaluate heart function.
• Hearing and balance tests: To check for inner ear problems.
• Imaging: MRI or CT scans to detect neurological conditions. 

Treatment:

The treatment for dizziness depends on the underlying cause:

• Rehydration: Drinking fluids and managing electrolytes.
• Medications: Adjusting current medications or prescribing new ones to address specific conditions (e.g., antihistamines for vertigo, anti-anxiety medications, or cardiovascular medications).
• Lifestyle changes include dietary adjustments, stress management techniques, and avoiding triggers.
• Vestibular rehabilitation therapy (VRT) for balance disorders.
• Cognitive-behavioral therapy (CBT) for anxiety-related dizziness.
• Self-Care and Prevention
• Stay hydrated: Drink plenty of water, especially during hot weather or exercise.
• Eat regularly: Maintain stable blood sugar levels by eating small, frequent meals.
• Avoid sudden movements: Stand up slowly from sitting or lying positions.
• Exercise regularly: Engage in activities that improve balance and circulation.
• Manage stress: Practice relaxation techniques like deep breathing, meditation, or yoga.