The Role of Computed Tomography in the Presurgical Diagnosis of Foraminal Entrapment of Lumbosacral Junction

OBJECTIVE: On the basis of preoperative computed tomography (CT) scans, we studied the change of the size of anterior primary division (APD) of the L5 spinal root in the presence of foraminal/extraforaminal entrapment of the L5 spinal root. METHODS: Two independent radiologists retrospectively reviewed the preoperative CT scans of 27 patients treated surgically and compared the sizes of the APDs on bilateral L5 spinal roots. If one side APD size was larger than the other side APD size, it was described as left or right "dominancy" and regarded this as "consensus (C)" in case that there was a consensus between the larger APD and the location of sciatica, and regarded as "non-consensus (NC)" in case that there was not a consensus. Oswestry Disability Index (ODI) scores were used for preoperative and postoperative evaluation. RESULTS: On CT scans, twenty-one (77%) of 27 patients were the consensus group (APD swelling) and 6 (22%) were a non-consensus group (APD no swelling). In 9 patients with acute foraminal disc herniations, asymmetric enlargement of the APD on L5 spinal root was detected in all cases (100%) and detected in 11 (64%) of 17 patients with stenosis. Preoperative ODI score was 75-93 (mean 83) and postoperative ODI scores were improved to 13-36 (mean 21). The mean follow-up period was 6 months (range, 3-11 months). CONCLUSION: An asymmetric enlargement of the APD on L5 spinal root on CT scans is meaningfully associated with a foraminal or extraforaminal entrapment of the L5 spinal root on the lumbosacral junction.

Downbeat Nystagmus Associated With Brainstem Compression by Vertebral Artery

Rarely, downbeat nystagmus can occur due to compression of the lower brainstem by the ectatic vertebral artery and be resolved by microvascular decompression. We present a case of a 67-year-old man with downbeat nystagmus associated with brainstem compression by ectatic vertebral artery. He presented with oscillopsia and vertigo. When he turned his head upward, his symptoms were aggravated and a gait disturbance occurred. Magnetic resonance imaging and computed tomographic angiography demonstrated compression of the medulla oblongata by the left ectatic vertebral artery and other medical causes of downbeat nystagmus were ruled out. Retromastoid craniotomy was performed and after lifting the vertebral artery off the medulla, a trough-shaped indentation in the lower brainstem was identified. The ectatic vertebral artery was repositioned and a Teflon was inserted between the brainstem and the ectatic vertebral artery. Postoperatively, downbeat nystagmus had disappeared.

Long-term Follow-up Results of Gamma Knife Radiosurgery for Benign Tumors Involving Cavernous Sinus

OBJECTIVE: We describe our long-term experiences of gamma knife radiosurgical treatment on benign tumors involving cavernous sinus, including meningiomas, trigeminal neurinomas and pituitary adenomas. METHODS: From June 1990 to January 2001, forty-two patients with benign cavernous sinus tumors were treated with gamma knife radiosurgery in our institution. Of these, twenty-seven patients(64%) had precedently undergone open surgery and others(36%) were treated only with gamma knife. Tumor type distribution was meningiomas(n=20, 48%), trigeminal neurinomas(n=8, 19%) and pituitary adenomas(n=14, 33%). Mean follow-up period was 42.4 months. Mean tumor volume and mean marginal dose were 6.8cm3(Lange 0.37-39.3cm3 and 17.6Gy(range 11-35Gy) respectively. RESULTS: Tumor control was achieved in thirty-nine patients(93%). Tumor enlarged in two patients(1 meningioma and 1 pituitary adenoma). One patient with neurofibromatosis(type 2) accompanied with trigeminal neurinoma expired due to disease progression. Hormonal relapse was occurred three years after radiosurgery for pituitary adenoma in one patient. There were functional improvement in seven patients, including relief in facial pain(2 patients) and improvements of trigeminal nerve or abducens nerve deficits(5 patients). Three tumors have shown cystic change which have been of indolent course. Complications after radiosurgical treatment were oculomotor and abducens nerve palsies in one patient. CONCLUSION: For benign tumors involving cavernous sinus, gamma knife radiosurgery with its excellent long-term tumor control rates and minimal morbidity could serve as a first treatment modality or combination with open surgery in selected patients.

Endovasular Treatment of Cerebral Aneurysm Remnants after Clipping / 대한뇌혈관외과학회지

The authors report experience using GDC (Guglielmi detachable coil) for the treatment of the cerebral aneurysmal remnant following incomplete surgical clipping. All four patients in whom surgical clipping didn't result in complete obliteration of the aneurysmal sac were anterior circulation aneurysmal remnants. In three patients, aneurysmal remnants were diagnosed by routine follow-up angiography, and one case by recurrent subarachnoid hemorrhage. In all patients, remnants of the aneurysm were completely obliterated by embolization using GDC. There was no neurological morbidity and mortality associated with the treatment. Endovascular treatment of the cerebral aneurysmal remnants may be a effective and safe option for patients in whom surgical clipping does not result in complete obliteration of the aneurysmal sac.