Cheng-Chia Lee

Gamma knife radiosurgery for glomus jugulare and tympanicum.

Objective: To establish the role of gamma knife radiosurgery (GKS) as a treatment strategy for glomus jugulare and tympanicum. Method: A retrospective review of 14 glomus tumors, including 11 glomus jugulare and 3 glomus tympanicum tumors, which were treated by GKS in Taipei Veterans General Hospital from 1993 to 2009, was conducted. Two of these cases had undergone prior surgery with partial tumor resection, and the other 12 cases received primary treatment with GKS after a thorough neuroimaging and cerebral angiography. The tumor volume ranged from 6.5 to 22.1 ml. The maximum dose at the tumor center ranged from 21.6 to 26.3 Gy. All 14 patients were regularly followed up by clinical and radiological evaluations. The median follow-up time was 40.3 months. Results: All 14 patients had significant tumor regression after radiosurgery. The median tumor volume reduction was 34.0% (range 3–79%). Only 1 patient had temporary tumor volume progression (24% increment 6 months post-treatment), accompanied with unilateral facial palsy (from grade III to grade IV) and hearing impairment (from grade I to grade II). The tumor volume of this patient had regressed by 12 months, but facial palsy persisted. The tumor control rate in the series was 100% (n = 14/14), and the preservation rate of cranial nerve function was 92.8% (13/14). There was no complication of lower cranial nerve damage after radiosurgery. Conclusion: GKS appeared to be a good alternative or adjuvant to microsurgical resection in patients who are not amenable to complete surgical eradication, with an excellent tumor control rate and little morbidity after long-term follow-up.

An easy adjustable method of ectatic vertebrobasilar artery transposition for microvascular decompression

BACKGROUNDnMicrovascular decompression (MVD) of trigeminal neuralgia (TN) or hemifacial spasm (HFS) caused by an elongated, tortuous or enlarged vertebral or basilar artery has a higher rate of incomplete cure.nnnOBJECTIVEnWe used an easily applied and adjustable method of vertebrobasilar artery transposition and fixation to improve the immediate surgical outcome of MVD of TN or HFS due to compression by an ectatic vertebrobasilar artery system.nnnMETHODSnVertebral or basilar artery transposition was performed using the vascular sling with a strip of unabsorbable dural tape. The vertebrobasilar artery-sling complex was then fixed to the dura over the petrous bone by aneurysm clip through the dural bridge. The direction and angle of traction on the vertebrobasilar artery was adjustable using different lengths of clip or the horizontal level of the dural bridge.nnnRESULTSnThe sling and clip fixation method has been applied in 7 cases of MVD associated with vertebral or basilar artery compression. All 3 patients with TN and one with HFS had total remission of symptoms right after the procedure; one patient was completely free of spasm within 1 week after MVD and one had achieved 80% improvement of spasm in his last clinical visit 3 months after MVD. There was no major surgical complication in these 7 patients. Surprisingly, refractory hypertension was unexpectedly cured in one patient with TN following the procedure.nnnCONCLUSIONnThe vertebrobasilar artery transposition and fixation method used in the present study provided surgeons an easy and adjustable way to perform MVD safely and effectively.

Delayed microsurgery for vestibular schwannoma after gamma knife radiosurgery.

Stereotactic radiosurgery for vestibular schwannomas (VSs) has become popular during the last decade with promising clinical results after long-term follow-up. However, on rare occasions, some cases have needed traditional microsurgery to remove the tumor several months or years after radiosurgery. We present a retrospective analysis of data acquired during a 16-year period in delayed microsurgery of seven patients with VSs who underwent gamma knife surgery (GKS). A total of 444 with VS underwent GKS between March 1993 and December 2008, and 7 (1.57%) underwent delayed microsurgery at a median of 26xa0months (range from 3xa0months to 6xa0years) after GKS. The mean size of the tumor during GKS was 10.4xa0ml (range 2.3–23.5xa0ml). These seven patients were younger, and female predominant. The indications of microsurgery included adverse radiation effect with peri-focal edema, tumor enlargement, and cyst enlargement. Although the perifocal edema could lead to more difficulty in surgery than in typically performed operations for schwannoma, subtotal resection was achieved in all patients. There was no surgery-related morbidity or mortality. The histology showed benign tumor in five patients, malignant peripheral nerve sheath tumor in one, and necrotic tissue in one. The need of microsurgery for further treatment of VS after radiosurgery is rare, but can be a challenge to neurosurgeons in terms of surgical indication, timing, and techniques. The authors concluded the incidence of delayed microsurgery was 1.57% in a series of 444 patients over a 16-year period. We concluded some experience from operative indications, timing, approach, and outcome.

Malignant transformation of supratentorial ganglioglioma

Gangliogliomas in the central nervous system are usually enign; however, incidences of anaplastic change have been eported. Most malignant transformation is related to radiaion therapy, often occurring several years after treatment [1–3]. his study describes the malignant transformation into anaplastic umors of two well-differentiated gangliogliomas with unique cell ype. These transformations occurred over a period of only eight onths and were not related to radiation. This report examines the linical characteristics, MR images, and histopathological features f these transformed tumors.

Elevated Amylase and Lipase Levels in the Neurosurgery Intensive Care Unit

Background: Multiple factors may affect pancreatic enzyme levels even in the absence of pancreatitis. In the general intensive care unit (ICU), we examined the incidence, various clinical factors, and sequelae associated with elevated pancreatic enzymes in the neurosurgery ICU. Methods: Eighty‐nine patients who were admitted to the neurosurgery ICU with gastrointestinal symptoms and signs from January to October 2007 were classified into 2 groups according to their pancreatic enzymes as follows: normal pancreatic enzyme levels (n = 46) and elevated levels (n = 43). We analyzed the general data, including sex, age, indications for admission, types of surgery, initial Glasgow coma scale (GCS) score, neurosurgery ICU‐stay days, and mechanical ventilator‐use days. We also collected data on vital signs, serum markers, and drug prescriptions. Radiological examinations, including sonography and computed tomography (CT) scans of the abdomen were performed. Results: Nearly half of the patients who were admitted to the neurosurgical ICU with gastrointestinal symptoms and signs had elevated serum pancreatic enzymes. Elevated pancreatic enzyme levels were significantly associated with anemia (p = 0.048) and renal failure (p = 0.026), and were not associated with sex, age, indications for admission, types of surgery, initial GCS, neurosurgery ICU‐stay days, mechanical ventilator‐use days, hypotension, fever, usual ICU drugs, and other serum hepatic markers. High pancreatic enzyme levels were associated with a high mortality (p = 0.02). Abdominal CT had a high positive‐predictive rate for the diagnosis of pancreatitis (63%). Conclusion: Various neurosurgery events and diagnoses may lead to different degrees of serum pancreatic enzyme elevation. Patients with elevated pancreatic enzyme levels have a higher mortality rate than those with normal enzyme levels. We believe that abdominal CT should be indicated for patients if their amylase levels are more than 3‐fold the upper normal limit and lipase levels are more than 5‐fold.

Herpes Zoster Cervical Myelitis in a Young Adult

Varicella zoster virus infection, which causes chickenpox and herpes zoster (HZ), is not uncommon in the general population. Varicella zoster virus can be latent in cranial nerve or dorsal root ganglia, and reactivate several decades later to produce vesicles with post-herpetic neuralgia. HZ myelitis usually occurs in elderly or immunocompromised patients. We report here a case of HZ myelitis of the cervical spinal cord in a 35-year-old woman who was immunocompetent. Cervical myelitis developed 1 month after the eruption of vesicles. Pure sensation loss was limited initially from the C2 to T1 dermatomes, but later progressed to lower limb sensory loss and sphincter function impairment. The patients motor function was also mildly affected. Despite the initial rapid neurological deterioration, the symptoms dramatically improved after 5 days of parenteral acyclovir and steroid administration with rehabilitation. We therefore propose that early medical intervention is necessary for better and earlier recovery.

Telovelar approach for choroid plexus papilloma in the foramen of Luschka: A safe way using a neuromonitor

BACKGROUNDnTumors located in the 4th ventricle are always challenging to neurosurgeons, especially tumors that extend to the cerebellopontine (CP) angle by the foramen of Luschka. Recent advances in microsurgical technique, including the neuromonitor and brainstem mapping, facilitate the surgical resection of tumors located in the foramen of Luschka. Herein, we present the use of the telovelar approach to access a choroid plexus papilloma within the right foramen of Luschka.nnnCASE PRESENTATIONnA 28-year-old female presented with a history of sudden onset pulsatile headache and syncope twice without prodrome. The brain MRI revealed a 4th ventricular tumor deviated to the right foramen of Luschka and extending to the CP angle, 2.2 cm in diameter. There was no secondary hydrocephalus due to the patent foramen of Magendie and left foramen of Luschka. The patient underwent suboccipital craniotomy and C1 laminectomy with a telovelar approach. The right tonsil was elevated and teal chloride was incised from the foramen of Magendie to the telovelar junction. The tumor was centrally decompressed, and the margin was gently dissected from the brainstem and cerebellum peduncles. Functions of the facial, cochlear, glossopharyngeal, vagus, and hypoglossal nerves and nuclei were monitored. Mapping of the facial nucleus, ambiguous nucleus, and hypoglossal nucleus was also done. Total tumor removal was achieved and the histology showed choroid plexus papilloma. No functional neurological disorientation was observed after surgery.nnnCONCLUSIONnThe report demonstrated a safe and effective surgical approach to the foramen of Luschka. The approach yielded a better view of the foramen of Luschka laterally, and up to the middle cerebellar peduncle superiorly. Also, it minimized neural damage, and preserved the function of the cranial nerves and nucleus.

Gamma Knife Radiosurgery for the Management of Intracranial Dural Arteriovenous Fistulas

BACKGROUNDnThis report presents our 15-year experience with Gamma Knife radiosurgery (GKS) for the treatment of 321 patients with dural arteriovenous fistulas (DAVFs) in different locations.nnnMETHODSnThe most common locations of DAVFs were the cavernous sinus (206 cases) and transverse-sigmoid sinus (72 cases), which together accounted for 86.6 % of cases. In all, 54 patients had undergone embolization or surgery prior to radiosurgery, and the other patients underwent GKS as the primary treatment. During GKS, radiation was confined to the involved sinus wall, which was considered the true nidus of the DAVF. Target volume ranged from 0.8 to 52 cm(3). Marginal and maximum doses to the nidus ranged from 14 to 25 Gy and from 25 to 36 Gy, respectively.nnnRESULTSnThe mean follow-up time was 28 months (range 2-149 months). In 264 of 321 patients (82 %) available for follow-up study, 173 (66 %) showed complete obliteration of DAVFs with symptomatic resolution, 87 (33 %) had partial obliteration, 2 (0.8 %) had stationary status, 1 (0.4 %) had progression, and 1 (0.4 %) died from a new hemorrhagic episode. Complications were found in only two (0.8 %) patients, one with venous hemorrhage and one with focal brain edema after GKS.nnnCONCLUSIONSnGKS is a safe, effective treatment for DAVFs. It provides a minimally invasive therapeutic option for patients who harbor less-aggressive DAVFs but who suffer from intolerable clinical symptoms. For some aggressive DAVFs with extensive venous hypertension or hemorrhage, multimodal treatment with combined embolization or surgery is necessary.

Quantifying the Cerebral Hemodynamics of Dural Arteriovenous Fistula in Transverse Sigmoid Sinus Complicated by Sinus Stenosis: A Retrospective Cohort Study

BACKGROUND AND PURPOSE: Sinus stenosis occasionally occurs in dural arteriovenous fistulas. Sinus stenosis impedes venous outflow and aggravates intracranial hypertension by reversing cortical venous drainage. This study aimed to analyze the likelihood of sinus stenosis and its impact on cerebral hemodynamics of various types of dural arteriovenous fistulas. MATERIALS AND METHODS: Forty-three cases of dural arteriovenous fistula in the transverse-sigmoid sinus were reviewed and divided into 3 groups: Cognard type I, type IIa, and types with cortical venous drainage. Sinus stenosis and the double peak sign (occurrence of 2 peaks in the time-density curve of the ipsilateral drainage of the internal jugular vein) in dural arteriovenous fistula were evaluated. “TTP” was defined as the time at which a selected angiographic point reached maximum concentration. TTP of the vein of Labbé, TTP of the ipsilateral normal transverse sinus, trans-fistula time, and trans-stenotic time were compared across the 3 groups. RESULTS: Thirty-six percent of type I, 100% of type IIa, and 84% of types with cortical venous drainage had sinus stenosis. All sinus stenosis cases demonstrated loss of the double peak sign that occurs in dural arteriovenous fistula. Trans-fistula time (2.09 seconds) and trans-stenotic time (0.67 seconds) in types with cortical venous drainage were the most prolonged, followed by those in type IIa and type I. TTP of the vein of Labbé was significantly shorter in types with cortical venous drainage. Six patients with types with cortical venous drainage underwent venoplasty and stent placement, and 4 were downgraded to type IIa. CONCLUSIONS: Sinus stenosis indicated dysfunction of venous drainage and is more often encountered in dural arteriovenous fistula with more aggressive types. Venoplasty ameliorates cortical venous drainage in dural arteriovenous fistulas and serves as a bridge treatment to stereotactic radiosurgery in most cases.

Gamma knife radiosurgery for lymphoplasmacyte-rich meningioma

Lymphoplasmacyte-rich meningioma with the features of lasmocytoma was first described in 1971 [1]. In 1993, ymphoplasmacyte-rich meningioma was proposed as a variant f meningioma in the World Health Organization classification 2]. Since lymphoplasmacyte-rich meningioma has neoplastic and nflammatory features simultaneously, its biological behavior and rognosis are not so clearly understood. We report a case of ymphoplasmacyte-rich meningioma in a 60-year-old female who nderwent a subtotal surgical resection. However, the residual umor progressed on the suprasellar region one year after opertion, and we arranged Gamma-Knife radiosurgery (GKS) for er. Seven months after GKS, significant tumor shrinkage was oted without any adverse radiation effects (ARE). There is a diference in response to radiation between benign meningiomas nd lymphoplasmacyte-rich meningiomas. This interesting clinical ourse may help us understand more about this rare meningioma.