むちうち損傷　頚椎捻挫

Whiplash injury Cervical sprain

むちうちは医学的には、頚椎捻挫と呼ばれます。むちうちは、交通事故や激しいスポーツなどで、急激な衝撃を伴って、頚部が激しく前後に振られた際（過伸展、過屈曲）疼痛、頭痛、可動域制限、しびれ、耳鳴りなどの症状を呈することがあります。頚椎捻挫による損傷はレントゲンやMRIなどの画像検査では認めずらいです。むちうちの症状は、首周りの筋肉や、首から胸、背中にかけた筋肉の炎症により痛みや熱感を伴います。頚部は身体の神経を束ねる出入口であり、多くの自律神経が通るため、捻挫による炎症がひどい場合、自律神経が圧迫され、頭痛、めまい、しびれなどの症状を起こします。頚椎捻挫にはいくつか、種類があります。①頚椎捻挫型：80パーセントを占める程度のむちうち損傷です。二次的に前斜角筋症候群を発症すると前腕や手の第７，第８領域に感覚異常を認めることがあります。②バレリュー症候群・頸部交感神経症候群：頚椎捻挫による患部の炎症によって神経や頸動脈が圧迫され、めまいや、耳鳴り、嘔吐感覚を引き起こします。③神経根型：頭痛や手足の痺れなどが現れます。椎間孔といわれる脊椎の合間から伸びる神経根が圧迫され引き起こされる症状です。スパークリングテスト、ジャクソンテストなどが陽性になります。④脊髄型：むちうちによって背骨が歪み、脊髄神経を圧迫している状態です。身体全体と脳の神経信号のやりとりを阻害するため、排尿障害、尿の出づらさや、頻尿など身体の生理現象にも影響をあたえます。⑤混合型：神経根症状と頸部交感神経症候群との混合。むちうちは、受傷後から時間を置いてから発症する場合が多くあります。事故直後は症状が出なくても、後日になって、数日から数か月後に症状が表面化してくることもあるので注意が必要です。

Whiplash is medically called cervical sprain. Whiplash can present with symptoms such as pain, headache, limited range of motion, numbness, and tinnitus when the neck is violently jerked back and forth (hyperextension and hyperflexion) with a sudden impact, such as in a car accident or severe sports. Cervical sprain injuries are not easily recognized on imaging tests such as X-rays or MRIs. Whiplash symptoms include pain and burning due to inflammation of the muscles around the neck and from the neck to the chest and back. The neck is the entry and exit point for the body's bundle of nerves, and many autonomic nerves pass through it. If the inflammation from a sprain is severe, the autonomic nerves may be compressed, causing symptoms such as headache, dizziness, and numbness. There are several types of cervical sprains. (1) Cervical sprain type: This is the degree of whiplash injury that accounts for 80% of all sprains. Secondary anterior scalene muscle syndrome may cause sensory abnormalities in the seventh and eighth regions of the forearm and hand. 2) Valleloux syndrome and cervical sympathetic nerve syndrome: Inflammation of the affected area due to cervical sprain causes compression of nerves and carotid arteries, resulting in dizziness, tinnitus, and vomiting sensation. (iii) Nerve root type: Headache and numbness in the limbs appear. This symptom is caused by compression of the nerve roots extending from the intervertebral foramen, which is the space between the vertebrae. Sparkling test, Jackson test, etc. are positive. (4) Spinal cord type: The spine is distorted by whiplash and the spinal nerves are compressed. The nerve signals between the entire body and the brain are inhibited, and this can affect the physiological phenomena of the body such as dysuria, difficulty in passing urine, and frequent urination. (5) Mixed type: a mixture of nerve root symptoms and cervical sympathetic nerve syndrome. Whiplash often develops after a long time after the injury. It is important to note that symptoms may not appear immediately after the accident, but may surface at a later date, from a few days to a few months later.