Recurrent spontaneous vertigo with interictal headshaking nystagmus
Sun-Uk Lee1, Jeong-Yoon Choi1, Hyo-Jung Kim1
1From the Department of Neurology (S.-U.L., J.-Y.C., J.-S.K.), Seoul National University College of Medicine, Seoul, South Korea; Dizziness Center (S.-U.L., J.-Y.C., J.-S.K.), Clinical Neuroscience Center, and Research Administration Team (H.-J.K.), Seoul National University Bundang Hospital, Seongnam, South Korea.
Neurology
|May 25, 2018
Summary
Recurrent spontaneous vertigo (RSV) with headshaking nystagmus (HSN) may stem from a hyperactive velocity-storage mechanism. This condition often resolves or improves over time, with no patients developing other vestibular disorders.
Area of Science:
- Neuroscience
- Ophthalmology
- Vestibular System Disorders
Background:
- Recurrent spontaneous vertigo (RSV) of unknown etiology is often accompanied by interictal headshaking nystagmus (HSN).
- Understanding the pathophysiology of RSV-HSN is crucial for diagnosis and management.
Purpose of the Study:
- To define a disorder characterized by recurrent spontaneous vertigo (RSV) and interictal headshaking nystagmus (HSN).
- To characterize HSN in patients with RSV-HSN and compare it to other vestibular disorders.
Main Methods:
- Characterized HSN in 35 patients with RSV-HSN.
- Compared HSN characteristics with patients suffering from compensated vestibular neuritis (VN), vestibular migraine (VM), and Ménière disease (MD).
- Assessed time constant (TC) of HSN and horizontal vestibulo-ocular reflex (VOR).
Main Results:
- Patients with RSV-HSN exhibited a significantly larger HSN time constant (12 seconds) compared to VN (5s), VM (5s), and MD (6s).
- Horizontal VOR time constants were also larger in RSV-HSN patients.
- Over half of the patients experienced symptom resolution or improvement within a median follow-up of 12 years.
Conclusions:
- RSV-HSN is linked to a hyperactive and asymmetric velocity-storage mechanism.
- This mechanism likely causes intermittent vertigo attacks when compensation is disrupted.
- The long-term prognosis for RSV-HSN is generally favorable, with no progression to VM, MD, or cerebellar dysfunction observed.
Related Concept Videos
02:21Spontaneity
30.1K
A spontaneous process is one that occurs naturally under certain conditions. A nonspontaneous process, on the other hand, will not take place unless it is “driven” by the continual input of energy from an external source. Processes have a natural tendency to occur in one direction under a given set of conditions. Water will naturally flow downhill (spontaneous process), but uphill flow (nonspontaneous process) requires outside intervention such as the use of a pump. Iron exposed to...
30.1K
01:30Spontaneous and Induced Mutations
2.3K
Spontaneous mutations arise infrequently during DNA replication due to errors in the process. A key factor behind these errors is tautomeric shifts in nitrogenous bases, where bases transition from keto to enol forms or amino to imino forms. This shift can alter base-pairing rules, leading to mutations. Additionally, reactive oxygen species (ROS) arising from aerobic metabolism can damage DNA, resulting in depurination (loss of a purine base) or depyrimidination (loss of a pyrimidine base).
2.3K
02:11Effects of Temperature on Free Energy
28.4K
The spontaneity of a process depends upon the temperature of the system. Phase transitions, for example, will proceed spontaneously in one direction or the other depending upon the temperature of the substance in question. Likewise, some chemical reactions can also exhibit temperature-dependent spontaneities. To illustrate this concept, the equation relating free energy change to the enthalpy and entropy changes for the process is considered:
28.4K
02:49Second Law of Thermodynamics
27.1K
In the quest to identify a property that may reliably predict the spontaneity of a process, a promising candidate has been identified: entropy. Processes that involve an increase in entropy of the system (ΔS > 0) are very often spontaneous; however, examples to the contrary are plentiful. By expanding consideration of entropy changes to include the surroundings, a significant conclusion regarding the relation between this property and spontaneity may be reached. In thermodynamic models, the...
27.1K
02:39Gibbs Free Energy
39.2K
One of the challenges of using the second law of thermodynamics to determine if a process is spontaneous is that it requires measurements of the entropy change for the system and the entropy change for the surroundings. An alternative approach involving a new thermodynamic property defined in terms of system properties only was introduced in the late nineteenth century by American mathematician Josiah Willard Gibbs. This new property is called the Gibbs free energy (G) (or simply the free...
39.2K
02:16Solution Formation
38.0K
There is no one solvent that can dissolve every type of solute. Some substances that readily dissolve in a certain solvent might be insoluble in a different solvent. A simple way to predict which substances dissolve in which solvent is the phrase "like dissolves like". This means that polar substances, such as salt and sugar, dissolve in a polar substance like water. In contrast, non-polar substances are more soluble in non-polar solvents such as carbon tetrachloride.
This selective...
This selective...
38.0K