Fahim Ahmed, Butt Mohammad, McGivern Damian V
Department of Cardiovascular and Respiratory Studies, Castle Hill Hospital, Cottingham, UK.
J Med Case Rep. 2010 Dec 17;4:408. doi: 10.1186/1752-1947-4-408.
The differential diagnosis of altered mental status and behavioral change is very extensive. Paraneoplastic limbic encephalitis is a rare cause of cognitive impairment, which should be considered in the differential diagnosis.
A 64-year-old British Caucasian woman presented to our hospital with a 12-week history of confusion and short-term memory loss. She was hyponatremic with a serum sodium level of 128mmol/L. Moreover, there was evidence of left hilar prominence on the chest radiograph. A thoracic computed tomography scan showed left hilar opacity with confluent lymphadenopathy. A percutaneous biopsy confirmed a diagnosis of small cell lung cancer. There was no radiological evidence of brain metastasis on the computed tomography scan. In view of continued cognitive impairment, which was felt to be disproportionate to hyponatremia, a magnetic resonance imaging scan of the brain was undertaken. It showed hyperintense signals from both hippocampi, highly suggestive of limbic encephalitis presenting as a paraneoplastic manifestation of small cell lung cancer. She had a significant radiological and clinical response following chemotherapy and radiotherapy.
This case highlights the importance of considering paraneoplastic syndromes in patients with neurological symptoms in the context of lung malignancy. If initial investigations fail to reveal the cause of cognitive impairment in a patient with malignancy, magnetic resonance imaging may be invaluable in the diagnosis of limbic encephalitis. The clinical presentation, diagnostic techniques and management of paraneoplastic limbic encephalitis are discussed in this case report.
精神状态改变和行为变化的鉴别诊断范围非常广泛。副肿瘤性边缘叶脑炎是认知障碍的一种罕见病因，在鉴别诊断中应予以考虑。
一名64岁的英国白种女性因12周的意识模糊和短期记忆丧失前来我院就诊。她低钠血症，血清钠水平为128mmol/L。此外，胸部X线片显示左肺门突出。胸部计算机断层扫描显示左肺门模糊，伴有融合性淋巴结病。经皮活检确诊为小细胞肺癌。计算机断层扫描未发现脑转移的影像学证据。鉴于持续存在的认知障碍，且认为与低钠血症不成比例，遂对脑部进行了磁共振成像扫描。扫描显示双侧海马呈高信号，高度提示边缘叶脑炎，为小细胞肺癌的副肿瘤表现。化疗和放疗后，她在影像学和临床上均有显著改善。
该病例强调了在肺癌患者出现神经症状时考虑副肿瘤综合征的重要性。如果初始检查未能揭示恶性肿瘤患者认知障碍的病因，磁共振成像在边缘叶脑炎的诊断中可能具有重要价值。本病例报告讨论了副肿瘤性边缘叶脑炎的临床表现、诊断技术和治疗方法。
