Persistent Postural-Perceptual Dizziness (PPPD or 3PD)

What is PPPD?

PPPD (also called 3PD, or triple-P-D) is a chronic balance disorder that causes persistent feelings of dizziness, unsteadiness, but no spinning vertigo. Unlike spinning vertigo, the dizziness in PPPD is more of a subjective sensation of imbalance or motion. PPPD typically develops following a triggering event that disrupts the balance system, and it represents a maladaptation (improper adaptation) of the brain's ability to analyze spatial information and maintain balance. In short, the brain does not compensate well after the initial triggering event, and abnormal communications are established between the ears, the eyes and the rest of the balance system. Despite its chronic nature, PPPD is not caused by damage to the inner ear. It's a relatively new diagnosis that brings together features of previously described conditions such as chronic subjective dizziness and phobic postural vertigo

What are the Symptoms of PPPD?

The primary symptoms of PPPD must be present for at least 3 months according to the disorder's definition.

Core Symptoms 

• Persistent sensations of dizziness or unsteadiness
• A feeling of swaying or rocking, even when stationary.
• Non-spinning vertigo that occurs most days and lasts for hours.
• Feelings of detachment from one's body or environment (sensation of being "outside" your body). This is a less common symptom.
• Persistent feeling of "brain fog"

Exacerbating Factors

Symptoms are typically worsened by:

• Upright posture: Standing or walking often intensifies the sensation of imbalance.

• Motion: Both active movement (e.g., walking) and passive movement (e.g., riding in a car or public transport) can trigger symptoms.

• Complex visual environments: Crowded places like malls or busy streets, scrolling on screens, or patterned surfaces can provoke dizziness. Large open spaces also will increase symptoms: groceries, large warehouse.

• Stressful situations:  Anxiety or heightened emotional states can amplify symptoms.

• Increased severity of symptoms as the day progresses

Triggering Event for PPPD

PPPD is always precipitated by a triggering event that disrupts the balance and the integration of the different senses involved in balance by the brain. It is sometimes hard to recall, but with the right line of questioning patients will eventually point to a specific event:

• Vestibular disorders (e.g., vestibular neuritis, benign paroxysmal positional vertigo). This would be considered a "true" inner ear condition. The initial event causes a severe vertigo spell, often with nausea and vomiting. The initial episode will then resolve, but the PPPD slowly kicks in causing the chronic dizziness.

• Vestibular migraine. Just like for a vestibular disorder, the initial migraine can be severe, but it's the way the brain will compensate after this episode that will dictate whether PPPD will develop.

• Medical conditions causing dizziness (e.g., low blood pressure episodes, fainting spell)

• Psychological distress or trauma. A panic attack for instance cause eventually lead to PPPD.

• Neurological illnesses or injuries. A concussion (traumatic brain injury) is one of the most common causes in this category.

These events activate the brain's "fight-or-flight" response (stress response), leading to increased awareness of balance and body position. In PPPD, this heightened state persists even after the initial issue resolves.

Why Does PPPD Develop After A Triggering Event? (Pathophysiology)

PPPD is considered a functional neurological disorder (meaning there is no "organic" disorder, where a structural or anatomical problem can be found). 

The pathophysiology of PPPD involves a maladaptive response (an unhealthy response) of how the brain processes and integrates the information it obtains from the different sensory organs involved in maintaining balance:

• The ears (vestibular system),
• The eyes (visual system)
• The neck and various receptors in the body (proprioceptive system)

Following a triggering event, the brain believes the ears are no longer working properly and will re-wire the balance system in an unhealthy way. This maladaptive rewiring prevents the brain from effectively adjusting its perception of space and motion.

In short, we can summarize the disorder as such:

1. Improper processing of the senses (maladaptive sensory processing):
   The brain inhibits (reduces) vestibular information and instead excessively depends on visual and proprioceptive signals, resulting in sensory conflicts (mismatches) that distort the perception of space and motion.
   
   
2. Increased visual dependence:

   PPPD patients will depend heavily on their vision to maintain spatial orientation, which can intensify symptoms in environments with complex visual stimuli.

3. Chronic hypervigilence: Persistent activation of the "fight-or-flight response" (stress response) leading to increased awareness of balance and body disturbances.

Associated Conditions

Several conditions are commonly seen in patients who also suffer from PPPD. These comorbidities can worsen symptom severity and complicate treatment.

• Anxiety disorders and depression.
• Vestibular migraines.
• Functional neurological disorders.
• Traumatic brain injuries 
• Chronic cervical spine disorders 
• Chronic pain syndromes.
  
  

How To Perform A Clinical Evaluation for PPPD

History

The ENT doctor will ask you a detailed history that focuses on:

• • Symptom onset and duration
  • Type of dizziness: swaying, rocking, spinning, light headedness, falls, etc.
  • Precipitating event (e.g., vestibular disorders, migraine, head trauma, stress)
  • Triggers factors and locations: malls, groceries, driving, screens, etc.
  • Alleviating factors : sleep, rest, etc. 
  • Associated symptoms: hearing loss, ear fullness, tinnitus, ear infections, etc.
  • Neurological symptoms: blurry vision, reduced senstation, etc.
  • Cognitive symptoms (memory issues, brain fog
  • Impact on daily life and mental health: current employment status, ability to perform daily activities, etc.
  • Past medical history: migraines, diabetes, etc.
  • List of current and past medications (any ototoxicity?)

Physical Exam

The physical exam includes:

• • Otologic exam (eardrum examination with otoscope) and hearing screening with the tuning fork exam (Rinne and Weber tests)
  • Vestibular exam, specifically the head impulse testing, the head shake test and the Dix-Hallpike test. 
  • Neurological assessment to rule out other causes of dizziness. 
  • Gait and balance evaluation.

How To Diagnose PPPD

The diagnosis of PPPD is clinical, meaning we don't need a particular test or exam to confirm the diagnosis. We rely on the set of symptoms, triggering events and physical exam. We also make sure there isn't another diagnosis that better explains the presentation of our patient. 

Even if the diagnosis is clinical, we frequently conduct a minimal set of tests to ensure there is no other vestibular or neurological disorder present. This is particularly important as symptoms may persist for many months or even years, leading to increased medical anxiety. Patients seek reassurance that they are not suffering from a serious condition, and having objective findings to support our diagnosis is often crucial.

• Audiogram: Evaluates hearing and the overall health of the inner ear. Important to rule out disorder such as Ménière's disease. Read more about audiograms here.

• Vestibular tests such as VNG and vHIT. Eliminates "peripheral" vestibular disorders such unilateral deficits, and issues with eye-ear coordination (oculomotor evaluation). Read more about these tests here.
  
  

• Neuroimaging (e.g., MRI) if structural brain abnormalities are suspected.

• Psychological assessments for anxiety or depression (I rely on the referring physician or the family physician to assist with this).

Treatment of PPPD

Effective management requires a multidisciplinary approach:

1. Vestibular physiotherapy 

Vestibular therapy aims to retrain the brain's ability to process sensory information through gradual exposure exercises (among others):

• Desensitization to motion stimuli (e.g., head movements).
• Balance training to reduce reliance on visual inputs.

2. Medications

The most effective medical therapy has been shown to be anti-depressants (not to treat depression, but at a much smaller dose they can treat PPPD). They are used to modulate (control) sensory processing and reduce anxiety. The two most used classes are:

• Tricyclic antidepressants (TCAs) such as nortriptyline (Aventyl)
• Selective serotonin reuptake inhibitors (SSRIs) such as venlafaxine (Effexor)

It is important to note that medication alone will not be enough to treat PPPD. The medications allow for the brain to "reset" the maladaptive (unhealthy) wiring, but vestibular physiotherapy is needed to assist in re-establishing a healthy wiring between the brain, the ears, the eyes and the proprioceptive system.

It's also important to understand that long-term medication use is rarely necessary. After maintaining symptom control for a minimum of 12 months, we will start gradually reducing the medication (refer to the next section for further details).

3. Cognitive behavioral therapy (CBT)

CBT helps address anxiety and avoidance behaviors associated with PPPD. Just like vestibular physiotherapy and medications, CBT is a critical component in the treatment of PPPD, and it's important to inform our patients not to underestimate its efficacy. While this is a simplified overview of CBT (it's out of my area of expertise!), I explain it to patients in the following way:

• The CBT techniques focus on reframing catastrophic thoughts about dizziness.
• Patients learn coping strategies for managing symptoms in triggering environments

4. Virtual reality (still experimental)

Virtual Reality (VR) is emerging as a promising tool for treating PPPD:

• Controlled Exposure: VR allows gradual exposure to triggering stimuli in a safe environment
• Customization: Therapists can tailor VR scenarios to individual patient needs
• Engagement: VR can make therapy more interactive, potentially improving patient adherence
• Measurable Outcomes: VR systems can track patient progress, aiding in treatment adjustments

Recent studies show promising results. While research is ongoing, VR is increasingly seen as a valuable complement to traditional PPPD treatments, offering a novel approach to vestibular rehabilitation.

5. Treating associated conditions 

As we mentioned, it is very common for patients with PPPD to also suffer from another related condition. The most common ones I encounter in my practice are vestibular migraines, concussions (traumatic brain injuries), anxiety and cervicogenic issues (neck arthritis, etc.). Treating those conditions along with PPPD is critical to ensure prompt recovery. 

I Started my PPPD treatment - What Can I Expect Now?

The prognosis for PPPD varies depending on the duration of symptoms, the severity of the condition and the presence of associated disorders that complicate treatment (depression, anxiety, other neurological disorders, etc). Thankfully, most people respond very well to treatment. Here is a breakdown of the different responses to treatment we see:

1. Positive Outcomes: Most patients experience significant improvement with treatment. Significant symptom improvement (over 50% improvement) is expected at 6 months, and control (>90% improvement) is achievable in many cases within 12 months. Of course, the longer a patient suffered from PPPD before initiating treatment, the longer we expect the recovery time. In patients who achieve control of symptoms and maintain this control for at least 12 months, we tend to gradually wean off the anti-depressant medication (slowly, over weeks). It’s not uncommon for some of these patients to maintain a low dose maintenance therapy as it often helps a co-existing anxiety or sleep disorder. 

2. Chronic Symptoms: A subset may continue to have mild but manageable symptoms long-term. They are able to resume work and normal daily activities, but will still report some dizziness that will fluctuate in intensity. These patients stay on the medication and require physiotherapy and/or psychotherapy (CBT) sporadically during the year to cope with occasional relapses in the symptoms. 

3. Complete Remission: While less common, some patients achieve complete resolution of symptoms. Treatment is no longer necessary. 

With appropriate therapy combining vestibular rehab, CBT, and medication, most individuals regain functionality and improve their quality of life. Fluctuations in symptoms are normal, even for those experiencing significant improvement. These "temporary setbacks" may arise when a patient feels fatigued, lacks adequate rest, or faces stress at work or home. It's crucial to stay positive, recognize the factors exacerbating your symptoms, and revisit foundational strategies: consult your physiotherapist for exercises or your neuropsychologist for a therapy session.