A 32-year-old woman describes five episodes of intractable vomiting over the last year. The episodes last several hours and are associated with a sensation that the room is spinning or tilting. At these times, it is difficult for her to walk because she loses her balance. She cannot relate the timing of the episodes to any particular inciting event. Physical examination reveals stability in the Romberg position and during tandem walk. Proprioception is intact. Dysfunction of which of the following structures best explains this patient's symptoms?
This patient is experiencing vertigo due to vestibular dysfunction. Vertigo is a sensation of motion when no motion is present or an exaggerated sense of motion for a given bodily movement. It must be distinguished from other sensations that are often described by patients using similar terminology, such as imbalance, light-headedness, and syncope. Vertigo resulting from vestibular dysfunction tends to be of sudden onset, interfere with walking, and cause nausea and vomiting. Typical causes of vestibulopathy include Meniere's disease, perilymphatic fistulas, benign positional vertigo, labyrinthitis, and acoustic neuromas.
(Choice A) Disease of the posterior column of the spinal cord can occur in syphilis (i.e., tabes dorsalis) and vitamin B12 deficiency. Typical symptoms include ataxia, decreased proprioception and vibratory sense, and hyporeflexia. This patient's normal neurologic exam makes posterior column disease unlikely.
(Choice B) Vagal nerve damage can present as hoarseness, dysphagia, abnormal gastrointestinal motility, or tachycardia. Vagal nerve dysfunction will not cause vertigo.
(Choice C) Optic tract dysfunction will result in visual problems. Vision deficits do not typically cause vertigo, but may cause people to feel unsteady on their feet.
(Choice E) Cerebellar dysfunction presents as ataxia, imbalance, incoordination, and nystagmus. Patients with cerebellar dysfunction will be unable to perform tandem walking due to their imbalance.
(Choice F) The frontal cortex controls executive functions and response inhibition. Damage to the frontal cortex results in "frontal release" symptoms, such as personality change, inability to organize or plan, and disinhibition.
Educational Objective:
Vertigo is a sensation of excessive motion compared to physical reality. It is most commonly due to dysfunction within the vestibular system.