Acute Vestibular Syndrome (AVS) is a type of acute vertigo attack. It occurs with no loss in hearing and with abrupt onset, and symptoms last for at least 24 hours. This clinical syndrome is characterised by intense symptoms of vertigo, instability while walking, or imbalance, spontaneous nystagmus, nausea and intolerance to head movements. There is also an absence of auditory/neurological symptoms. The condition is a possible symptom of a central disorder such as ischaemia of the brain stem or cerebellum, although the majority of cases are of vestibular neuritis.
What are the symptoms and signs of acute vertigo?
- Vertigo: abrupt onset of the sensation that everything around the body is moving (or vice versa) and when horizontal (from right to left or from left to right depending on the damaged side). Other times there is a sense of rotation (clockwise or counter-clockwise) even vertically (from top to bottom or from bottom to top).
- Instability when walking or impossibility of standing: all vertigo is accompanied by instability of the body, both when static and walking, to varying degrees. The patient cannot stand or does so with great difficulty, turning to the side when walking, towards the sick and hypofunctioning side. The condition worsens when the eyes are closed.
- Spontaneous nystagmus: nystagmus is an involuntary and repeated ocular movement, indicative of an alteration of the vestibular (mainly peripheral) system. It occurs in different directions and senses, depending on the condition and cause. Its assessment is crucial for all types of vertigo, but more so in acute vertigo. A simple test is carried out, that can indicate with a high degree of certainty if it is peripheral or central nystagmus.
- Severe neurovegetative process (nausea and vomiting): Connections of the vestibular system with the regulating centre of the vomiting reflex make nausea and vomiting very common in vertigo.
- Intolerance to head movements: The functional difference between the right and left vestibules in acute vertigo increases when the head is moved from side to side, accentuating dizziness and nausea. This is why a patient keeps their head still so as to not increase the symptoms.
Treatment of acute vertigo
Acute peripheral vertigo or vestibular neuritis is frequently incorrectly treated, with excessive sedatives and prolonged patient rest. Continuous administration of sedatives delays the central compensation of the vestibular deficit, so its use should not exceed 2 or 3 days.
Several studies suggest the most effective treatment is Vestibular Rehabilitation Therapy (VRT), a physiotherapeutic treatment with dynamic exercises that accelerate and increase the physiological phenomenon of central balance compensation. They are aimed at the stabilisation of the gaze and the compensation of postural balance and walking.
The VRT facilitates the recovery of the corporal balance and the return to normal habits in small increments. Habitual behaviours should begin early, even within the first 24 hours of the vertigo occuring.