著者
城倉 健
出版者
一般社団法人 日本めまい平衡医学会
雑誌
Equilibrium Research (ISSN:03855716)
巻号頁・発行日
vol.82, no.4, pp.269-276, 2023-08-31 (Released:2023-10-03)
参考文献数
16

Vestibulo-ocular reflex (VOR), one of brainstem reflexes that maintains balance, is controlled by the cerebellum. This cerebellar control system of VOR is further coordinated by the cerebrum (e.g., visual suppression of VOR). Therefore, in central lesions, dysregulated, abnormally increased VOR gain may be the underlying pathology of chronic dizziness, unlike in peripheral vestibulopathy, which always involves decreased VOR gain. The characteristics of VOR dysregulation are quite different between brainstem-cerebellar lesions and cerebral lesions. Abnormally increased VOR gain is the major mechanism underlying the chronic dizziness in patients with brainstem-cerebellar lesions, whereas decreased visual suppression rate of VOR is the major mechanism underlying the chronic dizziness in patients with cerebral lesions. Of course, there could be coexisting peripheral vestibulopathy (decreased VOR gain), so that it is necessary to consider all pathologies causing increased VOR gain, decreased visual suppression rate of VOR, and decreased VOR gain to identify the precise mechanism of dizziness, especially in eldery people.
著者
城倉 健
出版者
日本神経治療学会
雑誌
神経治療学 (ISSN:09168443)
巻号頁・発行日
vol.38, no.4, pp.441-445, 2021 (Released:2022-04-28)
参考文献数
8

Peripheral vestibular disorders can be diagnosed by characteristic nystagmus, whereas central vestibular disorders can be diagnosed by neurologic signs/symptoms other than vertigo/dizziness. Thus, in the differential diagnosis of vertigo/dizziness, both nystagmus and neurological symptoms should be examined. When a diagnosis of benign paroxysmal positional vertigo is made, the canalith repositioning maneuver should be attempted by all practitioners. Vertigo/dizziness usually dose not persist for a long period of time due to vestibular compensation. However, some of dizziness may persist because of collapsed vestibular compensation mechanism or central sensitization. In the treatment of dizziness, it is useful to know the mechanism of chronicity.

1 0 0 0 OA めまい

著者
城倉 健
出版者
日本神経学会
雑誌
臨床神経学 (ISSN:0009918X)
巻号頁・発行日
vol.61, no.5, pp.279-287, 2021 (Released:2021-05-19)
参考文献数
19
被引用文献数
2

めまいの病態は,眼球偏倚(および結果として生じる眼振)に反映されることが多い.末梢性めまいである良性発発作性頭位めまい症は,耳石が迷入した半規管刺激による眼球偏倚がそのまま出現する.良性発作性頭位めまい症以外の末梢性めまいでは,一側の半規管障害をすべて総和した眼球偏倚となる.一方,中枢性めまいでは,中枢前庭経路(半規管経路+耳石器経路)が小脳により抑制制御を受けているため,前庭経路の直接障害による眼球偏倚に加え,小脳からの脱抑制による眼球偏倚も出現する.小脳による中枢前庭経路の抑制制御は,めまいの回復に重要な役割を担う前庭代償にも深く関わっている.めまいを治療する際には,こうしためまいの病態を理解し,病態に応じて特異的に介入する必要がある.
著者
城倉 健
出版者
日本神経治療学会
雑誌
神経治療学 (ISSN:09168443)
巻号頁・発行日
vol.33, no.3, pp.349-351, 2016 (Released:2016-11-10)
参考文献数
2
被引用文献数
1

Vertigo/dizziness of the central origin is usually associated with other neurological signs or symptoms such as motor palsy, sensory deficit, dysarthria, ocular motor palsy, limb ataxia, and truncal ataxia. On the other hand, vertigo/dizziness of the peripheral origin is characterized by positional torsional nystagmus (posterior canal benign paroxysmal positional vertigo), direction–changing horizontal nystagmus (lateral canal benign paroxysmal positional vertigo), or unidirectional horizontal nystagmus (other acute peripheral vestibulopathies). Direction–changing horizontal nystagmus and unidirectional horizontal nystagmus can also be seen in the central vertigo/dizziness ; these nystagmus are caused by a disruption and/or cerebellar disinhibition of the vestibular nucleus.Most peripheral vertigo/dizziness can be diagnosed by characteristic nystagmus, whereas neuroimaging study is necessary to confirm the diagnosis of central vertigo/dizziness. In the acute phase of vertigo/dizziness, antihistamine may be used to reduce symptom. For benign paroxysmal positional vertigo, the most common cause of vertigo/dizziness, canalith–repositioning maneuver is effective.