![]() ![]() More extensive hemorrhage was noted with more severe trauma. Intralabyrinthine hemorrhage has been most reported to occur in the basilar turn of the cochlea and the vestibule. The first pathology reported was intralabyrinthine hemorrhage. In numerous animal studies and clinical reports dating back to the late 1800s, concussions have been reported to result in direct inner ear damage. Bartholomew and colleagues ( 4) recently published a historical review of the research into LC. The pressure effects from mTBI will extend to the intralabyrinthine compartment and has historically been termed Labyrinthine Concussion (LC). Prevention of Second Impact Syndrome by delaying return of athletes to competition until after recovery from mTBI is imperative. ![]() It is almost exclusively seen in the young and is believed to be due to dysregulation of cerebral blood flow and resulting edema. This can result in elevation of intracranial pressure, subsequent herniation, and death. Second impact syndrome ( 3) is a rare and devastating phenomenon which occurs when a patient has a second head injury while still recovering from mTBI. These events and DAI in the central vestibular system with its connections in the cerebellum and brainstem doubtless could result in symptoms of dizziness secondary to concussion ( 2). Post-trauma perfusion changes, biochemical changes and inflammation can lead to additional pathology. Diffuse axonal injury (DAI) presumably results in several of the symptoms seen in post-concussion syndrome. In addition to these compressive and tensile forces are rotational forces that result in axonal shearing. Direct compressive and tensile forces occur during the “coup” and “contrecoup” impacts of the brain against the inside of the skull. The mechanism of brain trauma from concussion is likely due to both direct and indirect factors. While it seems obvious that damage to the brain can cause “dizziness”, damage to the inner ear is an under-recognized and quite common source for the symptom of dizziness. There are multiple pathologies that can potentially provoke the symptoms of dizziness of which we will explore in this paper. ![]() Exactly what is meant by dizziness, however, is probably not as important as what provokes the symptom. Patients often find it difficult to describe their dizziness, and even patients who ultimately are determined to have the same disorder will describe the symptoms very differently. Definitions range from “giddiness” to unsteadiness to rotary vertigo spells. However, the symptom “Dizziness” is ill-defined at best. Dizziness is the second most common symptom of concussion (mTBI) and predictive of a prolonged recovery from Post-Concussive Syndrome. Approximately 50% of these patients will have persistent symptoms, i.e., Post-Concussion Syndrome, at 1 month and 15% at 1 year. That is likely an undercount since many mTBI do not present for treatment. Mild traumatic brain injury or concussion (mTBI) has been reported to occur more than a million times annually in the U.S. A review of the literature and a general approach to the patient with post-concussive dizziness will be detailed as well as a review of the above-mentioned diagnostic categories. These diagnoses are not mutually exclusive and PCD patients frequently exhibit a combination of these disorders. Among the diagnoses seen as causes for PCD are (1) Central vestibular disorders, (2) Benign Paroxysmal Positional Vertigo (BPPV), (3) Labyrinthine dehiscence/perilymph fistula syndrome, (4) labyrinthine concussion, (5) secondary endolymphatic hydrops, (6) Temporal bone fracture, and (7) Malingering (particularly when litigation is pending). Unfortunately, many patients are not adequately evaluated for vestibular disorders until long after the onset of their symptoms. The importance of the identification of the peripheral component in PCD lies in our ability to remedy the peripheral vestibular component to a much greater extent than the central component. Further, our ability to test peripheral vestibular function has improved and has allowed us to identify peripheral disorders that in the past would have remained unnoticed. Symptoms that traditionally have been ascribed to central vestibular dysfunction may be due to peripheral dysfunction. The differential diagnosis of post-concussive dizziness (PCD) can be divided into non-vestibular, central vestibular and peripheral vestibular causes with growing recognition that patients frequently exhibit both central and peripheral findings on vestibular testing. Among patients who suffer a concussion (mild traumatic brain injury or mTBI), dizziness is second only to headache in symptom frequency. Dizziness is a frequent complaint after head trauma. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |