Tuberculous spondylitis

Japanese: 脊椎カリエス - せきついカリエス（英語表記）Tuberculous spondylitis

What is the disease?

From the lungs Mycobacterium tuberculosis ( Results ) This is tuberculous spondylitis, which is caused by blood-borne infection. Lumbar ( Yotsui ) , Thoracic spine ( Today ) , thoracic and lumbar vertebrae, etc. Cervical spine ( Watch ) is rare.

First Vertebral body ( I want to follow ) is destroyed, then Intervertebral disc ( Kanban ) As the disease progresses, the lesions spread to the adjacent vertebral bodies. Caseous necrosis ( Thinking ) A necrotic lesion resembling rotten cheese is formed around the vertebral body. abscess ( Use ) In the lumbar spine, abscesses form within the iliopsoas muscle, but abscesses around the vertebral body and iliopsoas abscesses form due to gravity. buttocks ( Denbu ) , Groin ( Gross ) If it progresses further, the vertebral body will collapse, Kyphosis ( Kowan ) This causes deformation.

Spine ( During ) Kyphosis deformity is Spinal cord ( Spinal cord ) Caution is required as it can cause paralysis and heart and lung dysfunction. In recent years, HIV (AIDS virus) infection has also been attracting attention as a risk factor for tuberculosis infection.

What is the cause?

In most cases, tuberculosis bacteria that have formed lesions in the lungs are carried via the bloodstream, but in rare cases, the urinary tract may be the source of infection, and there may be cases where there are no obvious lung lesions. The incidence rate is on the decline, but in recent years, the number of elderly people affected has been increasing.

How symptoms manifest

Symptoms include slight fever, loss of appetite, and general fatigue, while local symptoms include lower back pain and stiffness of the spine. The lower back pain is milder than that of pyogenic spondylitis and progresses slowly. Percussion pain ( This is how it works ) (It hurts when you hit it) is also one of its characteristics.

Symptoms of an abscess include a feeling of tightness and heaviness in the abdomen, buttocks, and groin area, but in the case of an iliopsoas abscess, the hip joint is restricted in extension due to pain, and the hip joint is in a flexed position. Granulation ( Hateful ) When spinal cord paralysis occurs due to spinal deformities such as abscesses or kyphosis, symptoms include weakness and numbness in the lower limbs and difficulty walking.

Testing and diagnosis

Plain X-rays show narrowing of the intervertebral disc space and irregularities in the vertebral bodies. As the condition progresses, the vertebral bodies are destroyed. wedge ( Wedge ) In addition, the accumulated fluid accumulates on the sides of the spine in the thoracic vertebrae. Fusiform shadow ( Guardian Inspector ) In the lumbar spine, it appears as an abscess shadow in the psoas muscle. CT scans show abscesses in and around the vertebral bodies and calcification of necrotic bone.

MRI is an important test for understanding the extent of the lesion and its relationship to the nerves. In particular, contrast-enhanced MRI shows the characteristic findings of reactive granulation tissue surrounding the caseous necrotic focus in the center of the lesion.

Blood tests show an increase in the white blood cell count and a positive CRP, but these are not characteristic. sputum ( Conclusion ) You have to do some tests.

A definitive diagnosis is made by identifying tuberculosis bacteria through microscopic examination or culture of tissue or abscess obtained by biopsy (a test to take a small piece of tissue with a needle). Culture tests take 4 to 8 weeks, but recently, tests using the DNA or RNA of the bacteria have been developed, making it possible to make an early diagnosis.

Treatment methods

Conservative treatment is the rule, and chemotherapy with antituberculous drugs is the basis. If the disease progresses to the point where bone destruction is significant or spinal cord paralysis appears, surgical treatment is performed. Also, if kyphosis occurs in children, surgery may be required as it may progress to a severe deformity.

What to do if you notice an illness

Spondylitis is an infectious disease, so if you are around someone infected with tuberculosis and have the symptoms mentioned above, you should get tested immediately. Recently, it has been occurring in young people who have never been infected with tuberculosis, so caution is required.

If spinal caries is diagnosed, tuberculosis prevention methods are applied and tests are performed to see if the bacteria are being excreted.

Takahito Asatsuma

Source: Houken “Sixth Edition Family Medicine Encyclopedia” Information about the Sixth Edition Family Medicine Encyclopedia

Japanese:

どんな病気か

　肺からの結核菌(けっかくきん)が血行性に運ばれて発症する結核性脊椎炎です。脊椎の部位別には腰椎(ようつい)、胸椎(きょうつい)、胸腰椎などの順に多く、頸椎(けいつい)はまれです。

　最初に椎体(ついたい)が破壊され、次いで椎間板(ついかんばん)にも病巣が波及し、進行すると隣接した椎体にも病巣が広がります。病気が進行すると、椎体内に乾酪壊死(かんらくえし)といわれるチーズの腐ったような壊死巣が形成され、椎体周囲に膿瘍(のうよう)が形成されます。腰椎では腸腰筋の筋肉内に膿瘍が形成されますが、椎体周囲の膿瘍や腸腰筋膿瘍は重力のため臀部(でんぶ)、鼠径部(そけいぶ)などに降下して流注膿瘍となります。さらに進行すると椎体が潰れ、後弯(こうわん)変形を生じます。

　脊柱(せきちゅう)後弯変形は、脊髄(せきずい)麻痺や心・肺機能障害の原因となるため注意が必要です。また、近年はHIV（エイズウイルス）感染が結核感染の危険因子として注目されています。

原因は何か

　大部分は肺に病巣を形成した結核菌が血行性に運ばれて発症しますが、まれに泌尿器が感染源となることがあり、明らかな肺病変がない場合もあります。発生頻度は減少傾向にありますが、近年は高齢者の罹患例が増加しています。

症状の現れ方

　全身的には微熱、食欲不振、全身倦怠感などが、局所症状としては腰背部痛、脊柱の硬直などがみられます。腰背部痛は化膿性脊椎炎に比べると軽度で、緩やかに経過します。罹患部位の脊椎の叩打痛(こうだつう)（叩くと痛みが出る）も特徴のひとつです。

　膿瘍の症状としては、腹部、臀部、鼠径部の突っ張り感や重苦しさですが、腸腰筋膿瘍では疼痛のため股関節の伸展が制限され、屈曲位をとります。また、結核性の肉芽(にくげ)、膿瘍や後弯などの脊柱変形により脊髄麻痺を生じると、下肢の脱力、しびれや歩行障害が現れます。

検査と診断

　単純X線写真では椎間板腔が狭くなり、椎体の不整像がみられ、進行すると椎体が破壊され楔(くさび)状になり、後弯を生じます。また、たまったうみが胸椎では脊柱の脇に紡錘状陰影(ぼうすいじょういんえい)として、腰椎では腸腰筋膿瘍陰影としてみられます。CT検査では、椎体内や周囲の膿瘍像や壊死した骨の石灰化像がみられます。

　MRIは病巣の広がりや神経との関係を知るうえで重要な検査です。とくに造影MRIでは、病巣中央の乾酪壊死巣を取り巻く反応性肉芽が造影される所見が特徴です。

　血液検査では白血球数の増加やCRPの陽性がみられますが、特徴的ではなく、ツベルクリン反応や喀痰(かくたん)検査が必要です。

　確定診断は、生検（針で組織の一部を採取する検査）によって得られた組織や膿瘍の顕微鏡検査や培養検査で結核菌を同定することです。培養検査は4～8週間かかりますが、最近は菌のDNAやRNAを利用した検査法が行われ、早期に診断が可能になっています。