Isolated trigeminal neuralgia as the presenting symptom of cerebellopontine infarction: a case report

Abstract

Trigeminal Neuralgia (TN) characteristically presents as unilateral recurring shock-like pain in the trajectory of the trigeminal nerve and its branches. Secondary TN is rare due to an ischemic lesion of the trigeminal root entry zone in pons. Here we report a patient with a cerebellopontine infarction transecting the central trigeminal pathways, resulting in isolated trigeminal neuralgia. A 72-year-old male patient presented to our emergency department with numbness and recurrent shock-like pain attacks on the left side of his face lasting 3 to 5 seconds starting abruptly 20 days ago and increasing in frequency in the last two days. Neurologic examination revealed slight hypoesthesia to touch on the left maxillary trigeminal nerve dermatome. There was no other abnormality in the neurological examination. In the initial work-up, Diffusion-Weighted Magnetic Resonance Imaging (MRI) showed hyperintensity on the junction of the pons and left inferior cerebellar peduncle, the root-entry-zone of the left trigeminal nerve, without hypointensity in Apparent Diffusion Coefficient (ADC) sequence. Noncontrasted Computer Tomography (CT) revealed hypodensity in the same region. After the admission, an MRI showed the lesion was T1-hypointense, T2-hyperintense, minimally heterogeneously IV gadolinium-contrast enhancing, consistent with subacute infarction. Secondary TN without any other abnormal neurologic signs attributed to an ischemic lesion of the trigeminal root entry zone in pons is unusual, but not impossible, and responds well to carbamazepine treatment. Patients who present with TN should undergo a comprehensive work-up to identify probable secondary matters.

Keywords

• secondary
• Trigeminal neuralgia
• Cerebellopontine angle
• Cerebral infarction

Supporting Institution

Conflict of interest: There is no conflict of interest. Fundation: No subsidies or grants has contributed to the work.

Project Number

1

Thanks

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Serebellopontin iskeminin semptomu olarak izole trigeminal nevralji: bir olgu sunumu

Abstract

Trigeminal Nevralji (TN) karakteristik olarak trigeminal sinir ve dallarının bölgesinde tek taraflı tekrarlayan şok benzeri ağrı olarak kendini gösterir. Ponsta trigeminal kök giriş bölgesinin iskemik lezyonuna bağlı sekonder TN çok nadirdir. Burada merkezi trigeminal yolları kesen ve izole trigeminal nevralji ile sonuçlanan serebellopontin enfarktı olan bir olguyu sunuyoruz. Yetmiş iki yaşında erkek hasta, 20 gün önce aniden başlayan ve son iki gündür sıklığı artan yüzünün sol tarafında 3-5 saniye süren uyuşma ve tekrarlayan şok benzeri ağrı atakları ile acil servisimize başvurdu. Nörolojik muayenede sol maksiller trigeminal sinir dermatomunda dokunmaya karşı hafif hipoestezi saptandı. İlk incelemede, Difüzyon Ağırlıklı Manyetik Rezonans Görüntüleme (MRG), Görünür Difüzyon Katsayısı'nda (ADC) hipointensite olmadan, sol trigeminal sinirin kök giriş bölgesi olan pons ve sol inferior serebellar pedinkül bileşkesinde hiperintensite gösterdi. Kontrastsız Bilgisayarlı Tomografide (BT) aynı bölgede hipodensite saptandı. Başvurudan sonra MRG, lezyonun subakut enfarkt ile uyumlu, T1-hipointintens, T2-hiperintens, minimal heterojen IV gadolinyum-kontrast tutulumu gösterdiği belirlendi. Ponstaki trigeminal kök giriş bölgesinin iskemik lezyonuna atfedilen başka herhangi bir anormal nörolojik belirti olmaksızın sekonder TN olağann dışıdır, ancak imkansız değildir ve karbamazepin tedavisine iyi yanıt verir. TN ile başvuran hastalar, olası ikincil sorunları belirlemek için kapsamlı bir incelemeden geçmelidir.

Keywords

• trigeminal nevralji
• sekonder
• Serebellopontin açı
• Serebral enfarktüs

Project Number

1

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