This Quiz On Central Vestibular Disorders

Explanation
Geotropic nystagmus is not characteristic of a central disorder. Geotropic nystagmus refers to a type of horizontal nystagmus where the fast phase of the eye movement is directed towards the ground. In central disorders, the nystagmus is typically vertical or torsional in nature, such as up-beating or down-beating nystagmus. Direction-changing nystagmus can also be seen in central disorders, where the direction of the nystagmus changes with the gaze position. Therefore, geotropic nystagmus is the only option that is not characteristic of a central disorder.

Explanation
Non-suppression with visual fixation refers to a condition in which the patient is unable to suppress the nystagmus (involuntary eye movements) when fixating on a visual target. This finding suggests a central disorder because it indicates dysfunction in the central nervous system, specifically the brainstem or cerebellum, which are responsible for coordinating eye movements. In contrast, peripheral disorders typically do not affect the ability to suppress nystagmus with visual fixation. Therefore, non-suppression with visual fixation is a red flag for a central disorder.

Explanation
This question is asking for the percentage of patients with vestibular migrane who have headaches at the time of their vertigo attack. The correct answer is 10%. This means that out of all the patients with vestibular migrane, only 10% of them experience headaches during their vertigo attacks.

Explanation
Based on the symptoms presented by the child, including spells of fright, crying, staggering, palor, diaphoresis, and vomiting, the most likely vestibulopathy that can be suspected is Benign paroxysmal vertigo of childhood. This condition is characterized by recurrent episodes of vertigo, which can cause these symptoms in children. The other options, such as basilar migraine, Cogan's syndrome, and hydrocephalus, do not typically present with the same combination of symptoms as described in the question.

Explanation
The patient's symptoms of hearing loss, tinnitus, acute vertigo, ipsilateral facial pain, diplopia, dysphagia, dysarthria, and hoarseness are indicative of a posterior circulation stroke. The anterior inferior cerebellar artery (AICA) supplies the lateral pons, cerebellum, and internal auditory canal, which can result in the described symptoms when there is an infarct or ischemia in this area. Therefore, AICA is the suspected cause of the vertebrobasilar insufficiency in this patient. PICA (posterior inferior cerebellar artery) supplies the medulla and cerebellum, and its involvement would present with different symptoms.

Explanation
The patient's presentation of acute vertigo, ipsilateral facial pain, diplopia, dysphagia, dysarthria, and hoarseness, along with Horner syndrome but no tinnitus or hearing loss, suggests a posterior inferior cerebellar artery (PICA) insufficiency. The PICA supplies blood to the lateral medulla, which includes the vestibular nuclei, facial nucleus, and nucleus ambiguus. The symptoms described are consistent with a lateral medullary syndrome, also known as Wallenberg syndrome, which is caused by a PICA infarction.

Explanation
Type II Chiari malformation is the most common and presents in childhood. Type II Chiari malformation is characterized by the displacement of the cerebellar tonsils and vermis through the foramen magnum, along with a myelomeningocele. This condition is typically diagnosed during infancy or early childhood and is often associated with other congenital abnormalities, such as spina bifida. Type I Chiari malformation, on the other hand, typically presents in adolescence or adulthood and involves the displacement of only the cerebellar tonsils through the foramen magnum. Type III and Type IV Chiari malformations are rarer and have more severe neurological symptoms.

Explanation
When a patient presents with blurred vision, elevated CSF globulin, and variable vestibular symptoms, multiple sclerosis is suspected. Multiple sclerosis is a chronic autoimmune disease that affects the central nervous system, including the optic nerves. Blurred vision is a common symptom in multiple sclerosis due to inflammation and damage to the optic nerves. Elevated CSF globulin levels can be seen in multiple sclerosis, indicating increased immune activity. Variable vestibular symptoms, such as dizziness and balance problems, can also occur in multiple sclerosis due to damage to the nerves that control balance and coordination.

Explanation
Fine nystagmus is a type of involuntary eye movement that is characterized by small, rapid, and oscillatory movements of the eyes. It is believed to be caused by abnormalities or dysfunction in the vestibular nerve, which is responsible for transmitting sensory information about balance and spatial orientation from the inner ear to the brain. The vestibular nerve plays a crucial role in maintaining eye stability, and any disruption or damage to this nerve can result in the development of fine nystagmus. Therefore, the correct answer is vestibular nerve.

Explanation
Coarse nystagmus refers to an involuntary eye movement characterized by larger, more pronounced oscillations. The cerebellum is responsible for coordinating and regulating motor movements, including eye movements. Dysfunction in the cerebellum can disrupt the smooth coordination of eye movements, leading to coarse nystagmus. Therefore, it is believed that cerebellar dysfunction is related to the occurrence of coarse nystagmus.