For confirming the correct location of the radiofrequency electrode before creation of a lesion, percutaneous CT-guided trigeminal tractotomy–nucleotomy is most commonly performed with the patient prone and awake. However, for patients whose facial pain and hypersensitivity are so severe that the patients are unable to rest their face on a support (as required with prone positioning), awake CT-guided tractotomy-nucleotomy might not be feasible. The authors describe 2 such patients, for whom percutaneous intraoperative CT-guided tractotomy-nucleotomy under general anesthesia was successful. One patient was a 79-year-old man with profound left facial postherpetic neuralgia, who was unable to tolerate awake CT-guided tractotomy-nucleotomy, and the other was a 45-year-old woman with intractable hemicranial pain that developed after a right frontal lesionectomy for epilepsy. Each patient underwent a percutaneous intraoperative CT-guided tractotomy-nucleotomy under general anesthesia. No complications occurred, and each patient reported excellent pain relief for up to 6 and 3 months after surgery, respectively. Percutaneous intraoperative CT-guided tractotomy-nucleotomy performed on anesthetized patients is effective for facial postherpetic neuralgia and postoperative hemicranial neuralgia.
Eric M. Thompson, Kim J. Burchiel and Ahmed M. Raslan
Nathaniel Whitney, Ahmed M. Raslan and Brian T. Ragel
Severe traumatic brain injury (TBI) in pregnant women can result in devastating outcomes for both the mother and the fetus. Historically, there has been concern regarding the issues involved when the fetus is not yet viable outside the womb. Currently, the ability to treat severe TBI with aggressive management of intracranial pressure (ICP) has led to the possibility of sustaining maternal life until the fetus is of a viable age and can be delivered. The authors present the case of a young woman 21 weeks pregnant with a severe TBI (Glasgow Coma Scale Score 3) in whom safe medical ICP management became ineffective. A decompressive craniectomy was performed to obviate the need for aggressive medical management of elevated ICP using fetal-toxic medications, and thus providing the fetus the best chance of continued in utero development until a viable gestational age was reached.
Kim J. Burchiel, Shirley McCartney, Albert Lee and Ahmed M. Raslan
In this prospective study the authors' objective was to evaluate the accuracy of deep brain stimulation (DBS) electrode placement using image guidance for direct anatomical targeting with intraoperative CT.
Preoperative 3-T MR images were merged with intraoperative CT images for planning. Electrode targets were anatomical, based on the MR images. A skull-mounted NexFrame system was used for electrode placement, and all procedures were performed under general anesthesia. After electrode placement, intraoperative CT images were merged with trajectory planning images to calculate accuracy. Accuracy was assessed by both vector error and deviation off the planned trajectory.
Sixty patients (33 with Parkinson disease, 26 with essential tremor, and 1 with dystonia) underwent the procedure. Patient's mean age was 64 ± 9.5 years. Over an 18-month period, 119 electrodes were placed (all bilateral, except one). Electrode implant locations were the ventral intermediate nucleus (VIM), globus pallidus internus (GPI), and subthalamic nucleus (STN) in 25, 23, and 12 patients, respectively. Target accuracy measurements were as follows: mean vector error 1.59 ± 1.11 mm and mean deviation off trajectory 1.24 ± 0.87 mm. There was no statistically significant difference between the accuracy of left and right brain electrodes. There was a statistically significant (negative) correlation between the distance of the closest approach of the electrode trajectory to the ventricular wall of the lateral ventricle and vector error (r2 = −0.339, p < 0.05, n = 76), and the deviation from the planned trajectory (r2 = −0.325, p < 0.05, n = 77). Furthermore, when the distance from the electrode trajectory and the ventricular wall was < 4 mm, the correlation of the ventricular distance to the deviation from the planned trajectory was stronger (r2 = −0.419, p = 0.05, n = 19). Electrodes placed in the GPI were significantly more accurate than those placed in the VIM (p < 0.05). Only 1 of 119 electrodes required intraoperative replacement due to a vector error > 3 mm. In this series there was one infection and no intraparenchymal hemorrhages.
Placement of DBS electrodes using an intraoperative CT scanner and the NexFrame achieves an accuracy that is at least comparable to other methods.
Jorge L. Eller, Ahmed M. Raslan and Kim J. Burchiel
Based on specific, objective, and reproducible criteria, a classification scheme for trigeminal neuralgia (TN) and related facial pain syndromes is proposed. Such a classification scheme is based on information provided in the patient's history and incorporates seven diagnostic criteria, as follows. 1) and 2) Trigeminal neuralgia Types 1 and 2 (TN1 and TN2) refer to idiopathic, spontaneous facial pain that is either predominantly episodic (as in TN1) or constant (as in TN2) in nature. 3) Trigeminal neuropathic pain results from unintentional injury to the trigeminal nerve from trauma or surgery. 4) Trigeminal deafferentation pain results from intentional injury to the nerve by peripheral nerve ablation, gangliolysis, or rhizotomy in an attempt to treat either TN or other related facial pain. 5) Symptomatic TN results from multiple sclerosis. 6) Postherpetic TN follows a cutaneous herpes zoster outbreak in the trigeminal distribution. 7) The category of atypical facial pain is reserved for facial pain secondary to a somatoform pain disorder and requires psychological testing for diagnostic confirmation. The purpose of a classification scheme like this is to advocate a more rigorous, standardized natural history and outcome studies for TN and related facial pain syndromes.
Ahmed M. Raslan, James K. Liu, Sean O. McMenomey and Johnny B. Delashaw Jr.
Staged resection of large vestibular schwannomas (VSs) has been proposed as a strategy to improve facial nerve outcomes and morbidity. The authors report their experience with 2-stage resections of large VSs and analyze the indications, facial nerve outcomes, surgical results, and complications. The authors compare these results with those of a similar cohort of patients who underwent a single-stage resection.
A retrospective review of all patients (age > 18 years) who underwent surgery from 2002 to 2010 for large (≥ 3 cm) VSs at the authors' institution with a minimum of 6 months follow-up was undertaken. A first-stage retrosigmoid approach (without meatal drilling) was performed to remove the cerebellopontine angle portion of the tumor and to decompress the brainstem. A decision to stage the operation was made intraoperatively if there was cerebellar or brainstem edema, excessive tumor adherence to the facial nerve or brainstem, a poorly stimulating facial nerve, or a thinned or splayed facial nerve. A second-stage translabyrinthine approach was performed at a later date to remove the remaining tumor. The single-stage resection consisted of a retrosigmoid approach with meatal drilling. Patient charts were evaluated for tumor size, extent of resection, tumor recurrence, House-Brackmann facial nerve function grade, and complications.
Twenty-eight and 19 patients underwent 2- or single-stage resection of a large VS, respectively. The average tumor size was 3.9 cm (range 3.2–7 cm) in the 2-stage group and 3.9 cm (range 3.1–5 cm) in the single-stage group. The mean follow-up was 36 ± 19 months in the 2-stage group versus 24 ± 14 months in the single-stage group. Gross-total or near-total resection was achieved in 27 (96.4%) of 28 patients in the 2-stage group and 15 (79%) of 19 patients in the single-stage group (p < 0.01). Anatomical facial nerve preservation was achieved in all but 1 patient (94.7%), and there were no recurrences on follow-up imaging in the 2-stage group. Good facial nerve functional outcome (House-Brackmann Grades I and II) at last follow-up was achieved in 23 (82%) of 28 patients in the 2-stage group and 10 (53%) of 19 patients in the single-stage group (p < 0.01). Cerebrospinal fluid leak–related complications (intracranial hypotension, blood patch, and lumboperitoneal shunt for pseudomeningocele) were more common in the 2-stage group. There were no postoperative strokes, hemorrhages, or deaths in either group.
The authors' results suggest that staged resection of large VSs may potentially achieve better facial nerve outcomes. There does not appear to be added neurological morbidity with staged resections.
Daniel R. Cleary, Alp Ozpinar, Ahmed M. Raslan and Andrew L. Ko
Fossil records showing trephination in the Stone Age provide evidence that humans have sought to influence the mind through physical means since before the historical record. Attempts to treat psychiatric disease via neurosurgical means in the 20th century provided some intriguing initial results. However, the indiscriminate application of these treatments, lack of rigorous evaluation of the results, and the side effects of ablative, irreversible procedures resulted in a backlash against brain surgery for psychiatric disorders that continues to this day. With the advent of psychotropic medications, interest in invasive procedures for organic brain disease waned.
Diagnosis and classification of psychiatric diseases has improved, due to a better understanding of psychiatric patho-physiology and the development of disease and treatment biomarkers. Meanwhile, a significant percentage of patients remain refractory to multiple modes of treatment, and psychiatric disease remains the number one cause of disability in the world. These data, along with the safe and efficacious application of deep brain stimulation (DBS) for movement disorders, in principle a reversible process, is rekindling interest in the surgical treatment of psychiatric disorders with stimulation of deep brain sites involved in emotional and behavioral circuitry.
This review presents a brief history of psychosurgery and summarizes the development of DBS for psychiatric disease, reviewing the available evidence for the current application of DBS for disorders of the mind.
Andrew L. Ko, Alp Ozpinar, Albert Lee, Ahmed M. Raslan, Shirley McCartney and Kim J. Burchiel
Trigeminal neuralgia (TN) occurs and recurs in the absence of neurovascular compression (NVC). While microvascular decompression (MVD) is the most effective treatment for TN, it is not possible when NVC is not present. Therefore, the authors sought to evaluate the safety, efficacy, and durability of internal neurolysis (IN), or “nerve combing,” as a treatment for TN without NVC.
This was a retrospective review of all cases of Type 1 TN involving all patients 18 years of age or older who underwent evaluation (and surgery when appropriate) at Oregon Health & Science University between July 2006 and February 2013. Chart reviews and telephone interviews were conducted to assess patient outcomes. Pain intensity was evaluated with the Barrow Neurological Institute (BNI) Pain Intensity scale, and the Brief Pain Inventory–Facial (BPI-Facial) was used to assess general and face-specific activity. Pain-free survival and durability of successful pain relief (BNI pain scores of 1 or 2) were statistically evaluated with Kaplan-Meier analysis. Prognostic factors were identified and analyzed using Cox proportional hazards regression.
A total of 177 patients with Type 1 TN were identified. A subgroup of 27 was found to have no NVC on high-resolution MRI/MR angiography or at surgery. These patients were significantly younger than patients with classic Type 1 TN. Long-term follow-up was available for 26 of 27 patients, and 23 responded to the telephone survey. The median follow-up duration was 43.4 months. Immediate postoperative results were comparable to MVD, with 85% of patients pain free and 96% of patients with successful pain relief. At 1 year and 5 years, the rate of pain-free survival was 58% and 47%, respectively. Successful pain relief at those intervals was maintained in 77% and 72% of patients. Almost all patients experienced some degree of numbness or hypesthesia (96%), but in patients with successful pain relief, this numbness did not significantly impact their quality of life. There was 1 patient with a CSF leak and 1 patient with anesthesia dolorosa. Previous treatment for TN was identified as a poor prognostic factor for successful outcome.
This is the first report of IN with meaningful outcomes data. This study demonstrated that IN is a safe, effective, and durable treatment for TN in the absence of NVC. Pain-free outcomes with IN appeared to be more durable than radiofrequency gangliolysis, and IN appears to be more effective than stereotactic radiosurgery, 2 alternatives to posterior fossa exploration in cases of TN without NVC. Given the younger age distribution of patients in this group, consideration should be given to performing IN as an initial treatment. Accrual of further outcomes data is warranted.
Aaron Chance, Jesse J. Liu, Jeffrey S. Raskin, Viktor Zherebitskiy, Sakir H. Gultekin and Ahmed M. Raslan
Complex neurocristopathy, a disorder resulting from the aberrant proliferation of tissues derived from neural crest cells, has been previously reported in 2 patients, both involving ophthalmic melanoma and other tumors. One patient had a periorbital neurofibroma, sphenoid wing meningioma, and choroid juxtapapillary meningioma. The other patient had a choroidal melanoma and an optic nerve sheath meningioma. The authors describe clinical and pathological findings in a patient who underwent resection of 2 distinct lesions: primary CNS melanoma at T-12 and an L-5 schwannoma. Clinical and histopathological findings of the case are reviewed. To the authors’ knowledge, this is the first patient to present with complex neurocristopathy involving both a spinal melanoma and schwannoma.
Andrew L. Ko, Albert Lee, Ahmed M. Raslan, Alp Ozpinar, Shirley McCartney and Kim J. Burchiel
Trigeminal neuralgia (TN) occurs and recurs in the absence of neurovascular compression (NVC). To characterize what may be distinct patient populations, the authors examined age at onset in patients with TN with and without NVC.
A retrospective review of patients undergoing posterior fossa surgery for Type I TN at Oregon Health & Science University from 2009 to 2013 was undertaken. Charts were reviewed, and imaging and operative data were collected for patients with and without NVC. Mean, median, and the empirical cumulative distribution of onset age were determined. Statistical analysis was performed using Student t-test, Wilcoxon and Kolmogorov-Smirnoff tests, and Kaplan-Meier analysis. Multivariate analysis was performed using a Cox proportional hazards model.
The charts of 219 patients with TN were reviewed. There were 156 patients who underwent posterior fossa exploration and microvascular decompression or internal neurolysis: 129 patients with NVC and 27 without NVC. Mean age at symptoms onset for patients with and without NVC was 51.1 and 42.6 years, respectively. This difference (8.4 years) was significant (t-test: p = 0.007), with sufficient power to detect an effect size of 8.2 years. Median age between groups with and without NVC was 53.25 and 41.2 years, respectively (p = 0.003). Histogram analysis revealed a bimodal age at onset in patients without NVC, and cumulative distribution of age at onset revealed an earlier presentation of symptoms (p = 0.003) in patients without NVC. Chi-square analysis revealed a trend toward female predominance in patients without NVC, which was not significant (p = 0.08). Multivariate analysis revealed that age at onset was related to NVC but not sex, symptom side or distribution, or patient response to medical treatment.
NVC is neither sufficient nor necessary for the development of TN. Patients with TN without NVC may represent a distinct population of younger, predominantly female patients. Further research into the pathophysiology underlying this debilitating disease is needed.