神經內科

神經內科san4 ging1 loi6 fo1（英文：neurology）係指研究神經系統嘅醫學領域。

相關疾病[編輯]

因為神經細胞病變而引起嘅病包括咗：

腦退化（Alzheimer's disease，AD），俗稱「老人痴呆」，係一種神經細胞慢慢噉失去功能嘅長期病。患者會漸漸噉失去各種認知能力，初頭嘅症狀主包括短期記憶能力變差－個患者會容易唔記得嘢（但舊啲嘅記憶會相對冇咁受影響）以及喺做決策上有困難^[1]，而隨住病情加深，情況會變得更差。打後個患者喺各方面－包括語言、郁動同認嘢等－會開始變到愈嚟愈差，令到後期嗰陣佢哋會連一啲日常生活上嘅決定同計劃（例如煮飯同行街）都做唔到，需要人廿四小時照顧。研究顯示，腦退化背後係腦多個部份嘅神經細胞快速萎縮，令到神經系統多部份失去原有嘅認知功能^[2]^[3]。

柏金遜症（Parkinson's disease，PD）係一種中央神經系統退化嘅病，主要令到患者嘅運動同語言能力下降。患者會有以下嘅徵狀：肌肉生硬、身體唔受控制噉震同郁得慢等等，有少數患者連認知功能同語言都會受影響，而喺最極端啲嘅個案入面，個患者仲可能會變到完全郁唔到。柏金遜症係一種長期病，而且啲症狀一般都會隨時間惡化^[4]。呢啲徵狀嘅主因係基底核（basal ganglia；一個對身體郁動嚟講不可或缺嘅腦區）嗰度多巴胺（dopamine；神經傳遞素一種）唔夠，搞到基底核嘅神經細胞大規模噉死亡^[5]。
重症肌無力（myasthenia gravis，MG）係一種影響肌肉嘅長期病。病人嘅身體產生一啲異常嘅抗體阻礙負責控制肌肉嘅神經細胞嘅神經傳遞素嘅受容體，搞到呢啲神經細胞唔能夠有效噉傳達神經訊號嚟控制身體嘅肌肉，令到佢哋肌肉冇力；呢個病症狀包括眼同面嘅肌肉冇力，而呢點可以造成病人吞嘢有困難或者講嘢有困嘢，手腳肌肉受影響嘅病人喺行路等方面都會有障礙；情況再惡劣啲嘅病人可能連唞氣用嘅肌肉都受影響，搞到要靠機械幫佢哋唞氣^[6]。
脫髓病（demyelination）係一類中央神經系統嘅病，包括一柞涉及髓磷脂受破壞嘅病：髓磷脂係一浸包住軸突嘅脂，幫手將條軸突絕緣，對神經訊號嘅傳遞嚟講好重要；一個患有脫髓病嘅病人身體有某啲問題，搞到佢啲神經細胞嘅髓磷脂受損，進而影響佢啲神經細胞傳訊號嘅能力。症狀就視乎髓磷脂受損嘅係乜嘢神經細胞，例如如果受影響嘅係視覺方面嘅神經細胞，就可能會搞到病人視力受損甚至致盲^[7]。

神經修復[編輯]

就算到咗廿一世紀初，神經細胞相關疾病依然係一啲難醫嘅病：喺多數情況之下，神經細胞嘅生成係源自喺細路個腦嘅發育－喺呢啲過程當中，某啲特殊嘅幹細胞（stem cell）會變成神經細胞；大人嘅腦好少可會再做細胞分裂，除咗係喺腦嘅某幾個特定部份之外，大人嘅腦唔多會產生新神經細胞，所以大人腦嘅神經細胞一旦萎縮就好難補救。腦退化同柏金遜症等嘅病到咗 2020 年都仲係不治之症^[8]^[9]。

一般嚟講，如果想要修復神經細胞疾病造成嘅破壞，可以由兩大思路去諗：

神經生成（neurogenesis）係指新神經細胞由幹細胞嗰度生出嚟嘅過程。呢種喺成年嘅脊椎動物嘅腦入面好少可會自然噉發生，就算發生都只係限於腦入面嘅某啲部份，而研究顯示，喺新皮層嗰浸神經細胞喺個人出世之前經已形成咗，而且研究亦都表示咗，一粒神經細胞喺功能上冇得由第粒同類細胞取代－呢個諗法就係所謂嘅神經細胞冇得互換定律（law of no inter-changeability of neurons）^[8]。雖然係噉，廿一世紀初有科學家嘅研究發現，有人工方法可以將人體第啲部份嘅幹細胞－好似係皮膚嗰度嘅幹細胞噉－變做新嘅神經細胞。理論上，如果有辦法由一個病人嘅幹細胞嗰度產生神經細胞，再用呢啲神經取代受損嗰啲神經細胞嘅話，就有可能局部醫治神經細胞疾病^[10]。
神經重生（neuroregeneration）指受咗損嘅神經細胞再生同修復。根據現時嘅神經科學知識，呢樣嘢的確係有可能嘅：證據顯示咗，周邊神經系統嘅神經細胞啲軸突如果俾啲嘢砍斷咗，係可以再生嘅^[11]；不過「要點樣先可以令一粒神經細胞自我修復」係一個大問題，所以對於神經重生呢個諗頭，廿一世紀初嘅神經科學界都仲係有啲保留^[12]^[13]。

睇埋[編輯]

攷[編輯]

↑ "About Alzheimer's Disease: Symptoms". National Institute on Aging.
↑ Burns A, Iliffe S (February 2009). "Alzheimer's disease". BMJ. 338: b158.
↑ Querfurth HW, LaFerla FM (January 2010). "Alzheimer's disease". The New England Journal of Medicine. 362 (4): 329–44.
↑ "Parkinson's Disease Information Page". NINDS.
↑ Davie CA (2008). "A review of Parkinson's disease". British Medical Bulletin. 86 (1): 109–27.
↑ Zhang Z, Guo J, Su G, Li J, Wu H, Xie X (17 November 2014). "Evaluation of the quality of guidelines for myasthenia gravis with the AGREE II instrument". PLOS ONE. 9 (11): e111796
↑ Chabas, D., Baranzini, S. E., Mitchell, D., Bernard, C. C., Rittling, S. R., Denhardt, D. T., ... & Heller, R. (2001). The influence of the proinflammatory cytokine, osteopontin, on autoimmune demyelinating disease. Science, 294(5547), 1731-1735.
↑ ^8.0 ^8.1 Nowakowski, R. S. (2006). "Stable neuron numbers from cradle to grave". Proceedings of the National Academy of Sciences. 103 (33): 12219–12220.
↑ Wade, Nicholas (1999-10-15). "Brain may grow new cells daily". The New York Times.
↑ Callaway, Ewen (26 May 2011). "How to make a human neuron". NatureNews. doi:10.1038/news.2011.328. By transforming cells from human skin into working nerve cells, researchers may have come up with a model for nervous-system diseases and perhaps even regenerative therapies based on cell transplants. The achievement, reported online today in Nature, is the latest in a fast-moving field called transdifferentiation, in which cells are forced to adopt new identities. In the past year, researchers have converted connective tissue cells found in skin into heart cells, blood cells, and liver cells.
↑ Yiu G, He Z (August 2006). "Glial inhibition of CNS axon regeneration". Nature Reviews. Neuroscience. 7 (8): 617–627.
↑ Llinás, Rodolfo R. (2014-01-01). "Intrinsic electrical properties of mammalian neurons and CNS function: a historical perspective". Frontiers in Cellular Neuroscience. 8: 320.
↑ Hilgetag, C. C. & Kaiser, M. 2004 Clustered organisation of cortical connectivity. Neuroinformatics, 2, 353–360.

[1] "About Alzheimer's Disease: Symptoms". National Institute on Aging.

[2] Burns A, Iliffe S (February 2009). "Alzheimer's disease". BMJ. 338: b158.

[3] Querfurth HW, LaFerla FM (January 2010). "Alzheimer's disease". The New England Journal of Medicine. 362 (4): 329–44.

[4] "Parkinson's Disease Information Page". NINDS.

[5] Davie CA (2008). "A review of Parkinson's disease". British Medical Bulletin. 86 (1): 109–27.

[6] Zhang Z, Guo J, Su G, Li J, Wu H, Xie X (17 November 2014). "Evaluation of the quality of guidelines for myasthenia gravis with the AGREE II instrument". PLOS ONE. 9 (11): e111796

[7] Chabas, D., Baranzini, S. E., Mitchell, D., Bernard, C. C., Rittling, S. R., Denhardt, D. T., ... & Heller, R. (2001). The influence of the proinflammatory cytokine, osteopontin, on autoimmune demyelinating disease. Science, 294(5547), 1731-1735.

[cradle-8] 8.0 ^8.1 Nowakowski, R. S. (2006). "Stable neuron numbers from cradle to grave". Proceedings of the National Academy of Sciences. 103 (33): 12219–12220.

[9] Wade, Nicholas (1999-10-15). "Brain may grow new cells daily". The New York Times.

[10] Callaway, Ewen (26 May 2011). "How to make a human neuron". NatureNews. doi:10.1038/news.2011.328. By transforming cells from human skin into working nerve cells, researchers may have come up with a model for nervous-system diseases and perhaps even regenerative therapies based on cell transplants. The achievement, reported online today in Nature, is the latest in a fast-moving field called transdifferentiation, in which cells are forced to adopt new identities. In the past year, researchers have converted connective tissue cells found in skin into heart cells, blood cells, and liver cells.

[11] Yiu G, He Z (August 2006). "Glial inhibition of CNS axon regeneration". Nature Reviews. Neuroscience. 7 (8): 617–627.

[12] Llinás, Rodolfo R. (2014-01-01). "Intrinsic electrical properties of mammalian neurons and CNS function: a historical perspective". Frontiers in Cellular Neuroscience. 8: 320.

[13] Hilgetag, C. C. & Kaiser, M. 2004 Clustered organisation of cortical connectivity. Neuroinformatics, 2, 353–360.

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