Sang Sup Chung

Microvascular Decompression for Hemifacial Spasm: A Long-Term Follow-Up of 1,169 Consecutive Cases

We analyzed the records of 1,169 patients with hemifacial spasm (HFS) who underwent microvascular decompression (MVD) and were followed up for more than 6 months from January 1987. The mean follow-up duration was 23.8 months (6–145 months). Excellent surgical outcome was obtained in 90.5% and good in 4.5%, giving an overall success rate of 95.0%. There was statistically significant relationship between vertebral artery (VA) shift and side of symptom. Permanent facial weakness and hearing impairment were 1.4% and 2.3%, respectively. There were no anatomical differences at the root entry zone (REZ) and significant differences of surgical outcome in young HFS (34 patients). Factors such as type of offender, severity of compression on the facial nerve root, and the degree of decompression of the REZ on postoperative MRI did not correlate with surgical outcome.

Percutaneous Radiofrequency Lumbar Facet Rhizotomy in Mechanical Low Back Pain Syndrome

During the period from March 1992 to June 1996, we performed percutaneous radiofrequency (RF) facet rhizotomy in 324 patients with low back pain. Employing the lesion generator, we coagulated branches of the zygapophyseal nerve to treat low back pain. The follow-up period was 6-51 months (average: 22.5 months). There were no complications during the procedure and the follow-up period and no poor results were observed. Two-hundred and thirty-one patients (103 females and 128 males) had mechanical low back pain syndrome and showed marked improvement of pain after the procedure, including 29 cases with previous spinal surgery. We concluded that percutaneous RF facet rhizotomy is a safe and effective procedure for low back pain patients, especially for those with mechanical low back pain syndrome.

MICROVASCULAR DECOMPRESSION AND PERCUTANEOUS RHIZOTOMY IN TRIGEMINAL NEURALGIA

We analyzed 417 patients with trigeminal neuralgia who underwent microvascular decompression (MVD; n = 146) or percutaneous procedures, i.e. radiofrequency rhizotomy (RFR; n = 235) and glycerol rhizotomy (GR; n = 36) between March 1973 and December 1996. MVD and RFR showed the highest rates of initial pain relief (MVD 96.5%; RFR 92.3%; GR 82.8%). RFR and GR had 5.1 and 3.3% rates of facial dysesthesia, respectively, and MVD had the lowest rate (0.3%). Among 9 cases (8.6%) with recurrences after MVD, 8 cases underwent RFR and all of them obtained good long-term results (7.2 years on average). We concluded that MVD is the treatment of choice for tolerant younger patients and should be recommended for patients who desire no sensory deficit. We also determined that radiofrequency rhizotomy is the procedure of choice for patients in whom MVD failed.

Treatment of Intra- and Extracranial Arterial Dissections Using Stents and Embolization

PurposeTo evaluate the safety and efficacy of stent placement for extracranial and intracranial arterial dissections.MethodsEighteen patients underwent endovascular treatment of carotid and vertebral dissections using intraluminal stent placement. Five patients with arterial dissection were treated, 2 using one insertion of a single stent and 3 using placement of two stents. Patients with a dissecting aneurysm were treated as follows: 7 patients with insertion of one stent, 4 with placement of two stents, and 2 by stent-assisted Guglielmi detachable coil embolization. In the 18 patients in whom stenting was attempted, the overall success in reaching the target lesion was 94.4%. Of the 17 patients treated with stents, stent release and positioning were considered optimal in 16 (94%) and suboptimal in one (6%). In patients who underwent a successful procedure, all parent arteries were preserved. There were no instances of postprocedural ischemic attacks, new neurologic deficits, or new minor or major strokes prior to patient discharge. In follow up, all patients were assessed, using the modified Rankin scale, as functionally improved or of stable clinical status. The reduction in dissection-induced stenosis or pseudoaneurysm, the patency rate obtained at follow-up, and the lack of strokes (ischemic or hemorrhagic) suggest that stent placement offers a viable alternative to complex surgical bypass or reconstructive procedures. The long-term efficacy and durability of stent placement for arterial dissection remain to be determined in a larger series.

Microvascular decompression in trigeminal neuralgia: a correlation of three-dimensional time-of-flight magnetic resonance angiography and surgical findings.

We analyzed 104 patients with trigeminal neuralgia who underwent microvascular decompression and who were followed up for more than 12 months during the period from January 1992 to June 1998. In this recent series, we utilized three-dimensional time-of-flight magnetic resonance angiography (3D-TOF MRA) for all patients with trigeminal neuralgia. A 3D-TOF MRA was beneficial in treatment planning and in predicting surgical outcome by demonstrating cranial nerve compression as well excluding other etiologies such as tumor or vascular lesions. The patients were followed up for 1–7 years (mean 5.7 ± 1.2 years). Initial pain relief was complete in 89 patients (85.6%) and partial in 12 patients (11.5%). There were three primary failures (2.9%). The acceptable pain relief rate (complete relief: 79.8%, partial relief: 11.5%) was determined in the long-term follow-up of surgical results. Pain recurred in 6 patients (5.8%). The mean time to recurrence was 48 months (36–93 months). There were no serious or annoying complications such as anesthesia dolorosa.

Microvascular decompression of the facial nerve for hemifacial spasm in youth

Abstract. Objects: The goal of this study was to investigate the differences between clinical findings in youth and in adulthood on microvascular decompression (MVD) of the facial nerve for the treatment of hemifacial spasm (HFS). Methods: We retrospectively evaluated 855 patients who underwent MVD from January 1985 to July 1999. In our series of 33 young HFS patients, all patients had definite offending vessels. Interestingly, pathologic tortuous vertebral artery as a possible etiology was more rarely observed in young HFS patients (1/33 patients, 3.0%) than in adult patients (61/822 patients, 7.4%) (P<0.05). We did not observe any anatomical variations of the vessels or any arachnoidal thickening around the root entry zone and cerebellopontine cistern in youths. Furthermore, young HFS patients did not necessarily have poorer surgical outcomes than adult HFS patients. Conclusions: Our results suggest that the cause and progress of HFS are the same in youth as in adulthood, even though the pathogenesis of early onset remains unclear.

Significance of chronic epilepsy in glial tumors and correlation with surgical strategies

PURPOSEnThis study was designed to compare the frequency of postoperative epilepsy in patients with acute and chronic pre-operative epilepsy and with frontal or temporal lobe glial tumors based on the hypothesis that patients with chronic epilepsy do worse.nnnMETHODSnWe compared the clinical and diagnostic characteristics of the patients (n = 73) who had seizures preoperatively with those of the patients (n = 153) who did not. Among those who have had seizures preoperatively, we compared those (n = 32, chronic seizure group) who had seizures a year or more prior to surgery with those (n = 41, acute seizure group) who had seizures less than a year prior to surgery.nnnRESULTSnAmong the various factors, the frequency of benign pathology and favorable neurological state were higher in the seizure group than in the non-seizure group (p < 0.05). Complex partial seizures and low-grade tumors were frequent in the chronic seizure group, whereas simple partial seizures and high-grade tumors were frequent in the acute seizure group. Seizure-free rate was significantly higher in the acute seizure group than in the chronic group (p < 0.05). Also, the difference of seizure control rate between surgical strategies was statistically significant (p < 0.05).nnnCONCLUSIONnThis study indicates that preoperative seizure duration and frequency have a close relationship with the frequency of postoperative epilepsy in patients with glial tumors. A longer duration may allow the formation of epileptogenic foci, leading to chronic epilepsy, and eventually have a negative effect on the prognosis of the patients. Factors including histopathological characteristics of the tumor, its location, seizure duration/frequency, and symptomatology should be taken into account when deciding on surgical strategies.

Isolated pineal region metastasis of small cell lung cancer

The pineal region is an unusual site for brain metastasis and most metastatic pineal lesions are asymptomatic. Rarely the symptoms of metastatic involvement of the pineal gland precede those of the primary tumor or other metastatic sites. An 83 year-old man presented with gait disturbance and limitation of upward gaze. Brain MRI showed homogeneous enhancement of a solitary mass in the pineal region with obstructive hydrocephalus. A stereotactic biopsy was performed, and small cell carcinoma was diagnosed. A systemic investigation for the primary lesion subsequently revealed small cell carcinoma of the lung. The patient was referred for radiotherapy and chemotherapy. Although rare, metastatic tumor should be considered in the differential diagnosis of pineal region tumors, particularly in elderly patients.

Transcolumellar approach in transsphenoidal pituitary surgery for patients with small nostril.

OBJECTIVE: Sublabial approach has been widely used as the standard technique for transsphenoidal pituitary surgery. But it has several possible drawbacks, such as; postoperative flat nose deformity, hypesthesia of upper gum, and feeding difficulty until 2 to 3 weeks after surgery. As an alternative, an endonasal approach was adopted for patients who had large nostrils, such as white or acromegalic patients. In patients with small nostrils, especially oriental people, it requires an additional tension release incision that leaves a definitely visible scar at the base of nose. STUDY DESIGN: We applied the transcolumellar approach, which modified the external rhinoplasty approach on the 136 cases of transsphenoidal pituitary surgery that were performed from 1994 to June 1999. RESULTS: In all patients, we found we could reach the anterior portion of nasal septum in 7 to 8 mm in depth from the skin surface and eliminate the disadvantages of sublabial and endonasal approach. Also, this method can markedly reduce the surgical dissection time and blood loss. CONCLUSIONS: We concluded that this technique was relatively simple and more than adequate in most transsphenoidal pituitary surgery, even in patients with small nostrils.

Crossed-withdrawal reflex in a rat model of neuropathic pain: implications in neural plasticity

Recently we developed a neuropathic rat model employing a distal sciatic nerve branch injury, in which rats show vigorous behavioral signs of neuropathic pain. This study was performed to evaluate the crossed-withdrawal reflex in which any stimuli applied to the uninjured side produces allodynic signs on the injured side in our neuropathic pain model. Rats that received neuropathic surgery developed behavioral signs of neuropathic pain. In addition, these rats developed pain responses of the injured paw to stimuli applied to the contralateral uninjured paw, therefore, demonstrating the crossed-withdrawal reflex. Moreover, electrical stimulation of the uninjured paw developed evoked potentials in the ventral root on the injured side. These results suggest that information processing from input on the uninjured side to output on the injured side, can be facilitated in rats with a nerve injury and that neuroplasticity may contribute to the crossed-withdrawal reflex.