Parkinson's disease: an inquiry into the etiology and treatment.

Parkinson's disease affects over one million people in the United States. Although there have been remarkable advances in uncovering the pathogenesis of this disabling disorder, the etiology is speculative. Medical treatment and operative procedures provide symptomatic relief only. Compression of the cerebral peduncle of the midbrain by the posterior cerebral artery in a patient with Parkinson's Disease (Parkinson's Disease) was noted on magnetic resonance imaging (MRI) scan and at operation in a patient with trigeminal neuralgia. Following the vascular decompression of the trigeminal nerve, the midbrain was decompressed by mobilizing and repositioning the posterior cerebral artery The patient's Parkinson's signs disappeared over a 48-hour period. They returned 18 months later with contralateral peduncle compression. A blinded evaluation of MRI scans of Parkinson's patients and controls was performed. MRI scans in 20 Parkinson's patients and 20 age and sex matched controls were evaluated in blinded fashion looking for the presence and degree of arterial compression of the cerebral peduncle. The MRI study showed that 73.7 percent of Parkinson's Disease patients had visible arterial compression of the cerebral peduncle. This was seen in only 10 percent of control patients (two patients, one of whom subsequently developed Parkinson's Disease); thus 5 percent. Vascular compression of the cerebral peduncle by the posterior cerebral artery may be associated with Parkinson's Disease in some patients. Microva-scular decompression of that artery away from the peduncle may be considered for treatment of Parkinson's Disease in some patients.

Microvascular decompression for elderly patients with trigeminal neuralgia: a prospective study and systematic review with meta-analysis.

OBJECT: Because the incidence of trigeminal neuralgia (TN) increases with age, neurosurgeons frequently encounter elderly patients with this disorder. Although microvascular decompression (MVD) is the only etiological therapy for TN with the highest initial efficacy and durability of all treatments, it is nonetheless associated with special risks (cerebellar hematoma, cranial nerve injury, stroke, and death) not seen with the commonly performed ablative procedures. Thus, the safety of MVD in the elderly remains a concern. This prospective study and systematic review with meta-analysis was conducted to determine whether MVD is a safe and effective treatment in elderly patients with TN. METHODS: In this prospectively conducted analysis, 36 elderly patients (mean age 73.0 ± 5.9 years) and 53 nonelderly patients (mean age 52.9 ± 8.8 years) underwent MVD over the study period. Outcome and complication data were recorded. The authors also conducted a systematic review of the English literature published before December 2009 and providing outcomes and complications of MVD in patients with TN above the age of 60 years. Pooled complication rates of stroke, death, cerebellar hematoma, and permanent cranial nerve deficits were analyzed. RESULTS: Thirty-one elderly patients (86.1%) reported an excellent outcome after MVD (mean follow-up 20.0 ± 7.0 months). Twenty-five elderly patients with Type 1 TN were compared with 26 nonelderly patients with Type 1 TN, and no significant difference in outcomes was found (p = 0.046). Three elderly patients with Type 2a TN were compared with 12 nonelderly patients with Type 2a TN, and no significant difference in outcomes was noted (p = 1.0). Eight elderly patients with Type 2b TN were compared with 15 nonelderly patients with Type 2b TN, and no significant difference in outcomes was noted (p = 0.086). The median length of stay between cohorts was compared, and no significant difference was noted (2 days for each cohort, p = 0.33). There were no CSF leaks, no cerebellar hematomas, no strokes, and no deaths. Eight studies (1334 patients) met the inclusion criteria for the meta-analysis. For none of the complications was the incidence significantly more frequent in elderly patients than in the nonelderly. CONCLUSIONS: Although patient selection remains important, the authors' experience and the results of this systematic review with meta-analysis suggest that the majority of elderly patients with TN can safely undergo MVD.

Type 2 diabetes mellitus: A central nervous system etiology.

BACKGROUND: Insulin resistance (hyperinsulinemia) is said to be the signal event and causal in the development of type 2 diabetes mellitus. Pulsatile arterial compression of the right anterolateral medulla oblongata is associated with autonomic dysfunction, including "driving" the pancreas, which increases insulin resistance causing type 2 diabetes mellitus. In this prospective study, we hypothesize that decompressing the right cranial nerve X and medulla will result in better glycemic control in patients with type 2 diabetes mellitus. METHODS: Ten patients underwent retromastoid craniectomy with microvascular decompression for type 2 diabetes mellitus. Patients were followed for 12 months postoperatively by blood glucose monitoring and studies of glycemic control, pancreatic function and insulin metabolism. No changes in diet, weight or activity level were permitted during the course of the project. RESULTS: Seven of the 10 patients who received microvascular decompression for type 2 diabetes mellitus showed significant improvement in their glucose control. This was noted by measurement of diabetes markers and decrease of diabetes medication dosages. One patient was completely off diabetes medication, while attaining euglucemia. The other 3 patients did not improve in their glucose control. The body mass index of these 3 patients was higher (mean, 34.4) than those with better outcomes (mean, 27.9). CONCLUSION: Arterial compression of the right anterolateral medulla appears to be a factor in the etiology of type 2 diabetes mellitus. Microvascular decompression may be an effective treatment for non-obese type 2 diabetes mellitus patients.

Microvascular decompression after failed Gamma Knife surgery for trigeminal neuralgia: a safe and effective rescue therapy?

OBJECT: Stereotactic radiosurgical rhizolysis using Gamma Knife surgery (GKS) is an increasingly popular treatment for medically refractory trigeminal neuralgia. Because of the increasing use of GKS for trigeminal neuralgia, clinicians are faced with the problem of choosing a subsequent treatment plan if GKS fails. This study was conducted to identify whether microvascular decompression (MVD) is a safe and effective treatment for patients who experience trigeminal neuralgia symptoms after GKS. METHODS: From their records, the authors identified 29 consecutive patients who, over a 2-year period, underwent MVD following failed GKS. During MVD, data regarding thickened arachnoid, adhesions between vessels and the trigeminal nerve, and trigeminal nerve atrophy/discoloration were noted. Outcome and complication data were also recorded. RESULTS: The MVD procedure was completed in 28 patients (97%). Trigeminal nerve atrophy was noted in 14 patients (48%). A thickened arachnoid was noted in 1 patient (3%). Adhesions between vessels and the trigeminal nerve were noted in 6 patients (21%) and prevented MVD in 1 patient. At last follow-up, 15 patients (54%) reported an excellent outcome after MVD, 1 (4%) reported a good outcome, 2 (7%) reported a fair outcome, and 10 patients (36%) reported a poor outcome. After MVD, new or worsened facial numbness occurred in 6 patients (21%). Additionally, 3 patients (11%) developed new or worsened troubling dysesthesias. CONCLUSIONS: Thickened arachnoid, adhesions between vessels and the trigeminal nerve, and trigeminal nerve atrophy/discoloration due to GKS did not prevent completion of MVD. An MVD is an appropriate and safe "rescue" therapy following GKS, although the risks of numbness and troubling dysesthesias appear to be higher than with MVD alone.

Microvascular decompression in patients with isolated maxillary division trigeminal neuralgia, with particular attention to venous pathology.

OBJECT: The authors have the clinical impression that patients with isolated V2, or maxillary division, trigeminal neuralgia (TN) are most often women of a younger age with atypical pain features and a predominance of venous compression as the pathology. The aim of this study was to evaluate a specific subgroup of patients with V2 TN. METHODS: Among 120 patients who underwent microvascular decompression (MVD) for TN in 2007, data were available for 114; 6 patients were lost to follow-up. Patients were stratified according to typical (Burchiel Type 1), mixed (Burchiel Type 2a), or atypical (Burchiel Type 2b) TN. A pain-free status without medication was used to determine the efficacy of MVD. All patients were contacted in June 2008 and again in January 2009 at 12-24 months after surgery (median 18.4 months) and asked to rate their response to MVD as excellent (complete pain relief without medication), fair (complete pain relief with medication or some relief with or without medication), or poor (continued pain despite medication; that is, no change from their preoperative baseline pain status. RESULTS: Of 114 patients, 14 (12%) had isolated V2 TN. Among these 14 were 2 typical (14%), 1 mixed (7%), and 11 atypical cases (79%) of TN. Among the remaining 100 cases were 37 typical (37%), 14 mixed (14%), and 49 atypical cases (49%) of TN. In the isolated V2 TN group, all patients were women as compared with 72% of women in the larger group of 100 patients (p = 0.05, chi-square test). The average age in the isolated V2 TN group was 51.2 years (median 48.1 years) versus 54.2 years (median 54.0 years) in the remainder of the group (p = NS, unpaired Student t-test). In the isolated V2 TN group, there was a predominance of atypical pain cases (79%) versus 49% in the remainder of the group, and this finding trended toward statistical significance (p = 0.07, chi-square test). Venous contact or compression (partly or wholly) was noted in 93% of the patients with isolated V2 versus 69% of the remainder of the group (p = 0.13, chi-square test). The likelihood of excellent outcomes in the patients with V2 TN (71%) was compared with that in typical pain cases (79%) among patients in the rest of the group (that is, the bestoutcome group), and no difference was found between the 2 groups (p = 0.8, chi-square test). CONCLUSIONS: The authors confirmed that patients with isolated V2 TN were more likely to be female, tended toward an atypical pain classification with venous pathology at surgery, and fared just as well as those presenting with typical pain.

Developments in neurosurgery: "the 4 factors".

This article traces some of the developments in the practice of neurosurgery which have come about dependent upon certain technological advances.

Utility of intraoperative electromyography in microvascular decompression for hemifacial spasm: a meta-analysis.

OBJECT: In this paper, the authors' goal was to determine the utility of monitoring the abnormal muscle response (AMR) or "lateral spread" during microvascular decompression surgery for hemifacial spasm. METHODS: The authors' experience with AMR as well as the data available in the English-language literature regarding resolution or persistence of AMR and the resolution or persistence of hemifacial spasm at follow-up was pooled and subjected to a meta-analysis. RESULTS: The pooled OR revealed by the meta-analysis was 4.2 (95% CI 2.7-6.7). The chance of a cure if the AMR was abolished during surgery was 4.2 times greater than if the lateral spread persisted. CONCLUSIONS: The AMR should be monitored routinely in the operating room, and surgical decision-making in the operating room should be augmented by the AMR.

Acute disseminated encephalomyelitis: a report of two fulminant cases and review of literature.

Although the prognosis of acute disseminated encephalitis (ADEM) has generally been reported as favorable, in a small subset of patients, fulminant cerebral edema requiring critical care and surgical management may develop. This article presents a 56-year-old woman who developed ADEM and died of central brain herniation secondary to medically intractable cerebral edema. Following this experience, we encountered a 32-year-old man who also developed central brain herniation despite best medical management. We performed an urgent decompressive hemicraniectomy and frontal lobectomy followed by intensive intracranial pressure management. Few recommendations are available to guide neurologists and neurosurgeons in the management of medically intractable cerebral edema of ADEM. In this report, we present our experience with two severe cases of ADEM, review the pertinent literature, and discuss options for improved management of fulminant cases.

Microvascular decompression for trigeminal neuralgia in elderly patients.

OBJECT: Although microvascular decompression (MVD) for patients with medically refractory trigeminal neuralgia (TN) is widely accepted as the treatment of choice, other "second-tier" treatments are frequently offered to elderly patients due to concerns regarding fitness for surgery. The authors sought to determine the safety and effectiveness of MVD for TN in patients older than 75 years of age. METHODS: The authors performed a retrospective review of medical records and conducted follow-up telephone interviews with the patients. The outcome data from 25 MVD operations for TN performed in 25 patients with a mean age of 79.4 years (range 75-88 years) were compared with those of a control group of 25 younger patients with a mean age of 42.3 years (range 17-50 years) who underwent MVDs during the same 30-month period from July 2000 to December 2003. RESULTS: Initial pain relief was achieved in 96% of the patients in both groups (p = 1.0). There were no operative deaths in either group. After an average follow-up period of 44 and 52 months, 78 and 72% of patients in the elderly and control groups, respectively, remained pain free without medication (p = 0.74). CONCLUSIONS: Microvascular decompression is an effective treatment for elderly patients with TN. The authors' experience suggests that the rate of complications and death after MVD for TN in elderly patients is no different from the rate in younger patients.

Long-term survival enhanced by cordectomy in a patient with a spinal glioblastoma multiforme and paraplegia. Case report.

Spinal glioblastomas multiforme (GBMs) are rare lesions of the central nervous system with a prognosis as poor as that of their intracranial counterpart. The authors present a case of a 50-year-old man with a GBM of the spinal cord treated with surgical removal of the mass and cordectomy after the onset of paraplegia. Six years later, the patient developed hepatitis C and received interferon therapy. Six months after the start of interferon therapy, magnetic resonance imaging revealed a right cerebellar mass pathologically consistent with a GBM. Despite aggressive treatment, the patient died 1 month later. Although intracranial dissemination of spinal GBMs has been reported, this case illustrates the longest reported interval between the occurrence of a spinal GBM and its intracranial dissemination. Thus, cordectomy should be considered as a reasonable alternative in patients with complete loss of neurological function at and below the level where they harbor a malignant spinal cord astrocytoma.

Central brain herniation secondary to fulminant acute disseminated encephalomyelitis: implications for neurosurgical management. Case report.

Acute disseminated encephalomyelitis (ADEM), also known as postinfectious encephalomyelitis, is an immunologically mediated demyelinating disorder affecting the central nervous system that typically occurs after infection or vaccination. The prognosis of ADEM is generally favorable. In a small subset of patients with ADEM, however, fulminant cerebral edema requiring neurosurgical intervention will develop. Few recommendations are available to help the neurosurgeon in dealing with such cases. In this report, the authors present the case of a patient with ADEM in whom central brain herniation developed secondary to medically intractable cerebral edema. The authors review the salient features of the disease and suggest a role for neurosurgeons in cases of fulminant ADEM.

Primary treatment of a blister-like aneurysm with an encircling clip graft: technical case report.

OBJECTIVE: Blister-like aneurysms at nonbranching sites in the supraclinoid portion of the internal carotid artery are a rare but important cause of subarachnoid hemorrhage. We report a case of subarachnoid hemorrhage caused by a ruptured blister-type aneurysm, review the pertinent literature, and hope to remind readers of the wisdom of the use of an encircling clip as the primary treatment of these challenging lesions. CLINICAL PRESENTATION: A 41-year-old woman presented with sudden onset of headache. An admission computed tomographic (CT) scan revealed thick and diffuse subarachnoid hemorrhage involving primarily the carotid cistern and the proximal left sylvian fissure. A cerebral angiogram was initially interpreted as absent for aneurysm, but a follow-up angiogram performed 1 week later confirmed an enlarging aneurysm. INTERVENTION: A craniotomy with placement of an encircling clip graft around a blister-like aneurysm was performed. CONCLUSION: Although Sundt advocated the encircling clip graft for the blister-type aneurysm almost 40 years ago, use of an encircling clip graft in the treatment of blister-like aneurysms of the supraclinoid portion of the internal carotid artery seems to be reserved as a secondary or "rescue" measure in current practice. Neurosurgeons must familiarize themselves with this distinct entity (the blister-type aneurysm), recognize the possible risks associated with parallel clipping, and consider the use of an encircling clip graft as the primary treatment.

Dimensions of the posterior fossa in patients symptomatic for Chiari I malformation but without cerebellar tonsillar descent.

BACKGROUND: Chiari I malformation (CMI) is diagnosed by rigid radiographic criteria along with appropriate clinical symptomatology. The aim of this study was to investigate the dimensions of the posterior cranial fossa in patients without significant tonsillar descent but with symptoms comparable to CMI. METHODS: Twenty-two patients with signs and symptoms comparable to CMI but without accepted radiographic criteria of tonsillar descent > 3-5 mm were referred to our clinic for evaluation. A history and physical examination were performed on all patients. In reviewing their MRI scans, nine morphometric measurements were recorded. The measurements were compared to measurements from a cohort of twenty-five individuals with cranial neuralgias from our practice. RESULTS: For patients with Chiari-like symptomatology, the following statistically significant abnormalities were identified: reduced length of the clivus, reduced length of basisphenoid, reduced length of basiocciput, and increased angle of the tentorium. Multiple morphometric studies have demonstrated similar findings in CMI. CONCLUSION: The current classification of CMI is likely too restrictive. Preliminary morphologic data suggests that a subgroup of patients exists with tonsillar descent less than 3 mm below the foramen magnum but with congenitally hypoplastic posterior fossa causing symptomatology consistent with CMI.

Technique of microvascular decompression. Technical note.

Vascular compression of the trigeminal nerve in the cerebellopontine angle is now generally accepted as the primary source or "trigger" causing trigeminal neuralgia. A clear clinicopathological association exists in the neurovascular relationship. In general, pain in the third division of the trigeminal nerve is caused by rostral compression, pain in the second division is caused by medial or more distant compression, and pain in the first division is caused by caudal compression. This discussion of the surgical technique includes details on patient position, placement of the incision and craniectomy, microsurgical exposure of the supralateral cerebellopontine angle, visualization of the trigeminal nerve and vascular pathological features, microvascular decompression, and wound closure. Nuances of the technique are best learned in the company of a surgeon who has a longer experience with this procedure.

Type 2 diabetes mellitus, etiology and possible treatment: preliminary report.

BACKGROUND: Insulin resistance has been proposed as the initial step in the cascade toward type 2 diabetes mellitus. The mechanisms underlying the development of insulin resistance are not fully understood. We hypothesize that neurovascular interactions, in particular arterial elongation, causes compression of the right lateral medulla, triggering a state of autonomic dysfunction including hyperactivity of pancreatic endocrine function, and predisposes to insulin resistance and the development of type 2 diabetes. METHODS: The clinical and operative findings were reviewed retrospectively in 15 patients with primary diagnoses of various right-sided cranial rhizopathies, but with a common diagnosis of type 2 diabetes mellitus. After microvascular decompression was performed for the primary diagnosis, arterial compression was observed of the lateral medulla and cranial nerve X and treated with microvascular decompression. Known duration of the diabetes ranged from "new" (patient was diagnosed as a result of preoperative blood work) to 16 years (mean 7.3 years). Duration of diabetes diagnosis was unknown in 2 patients. Follow-up was from 3 to 113 months (mean 29.9 months). RESULTS: Ten of the 15 patients (66%) showed improvement in their blood glucose control; 5 of those 10 (50%) did so with no (4 patients) or less (1 patient) diabetes medication. CONCLUSIONS: We have shown that arterial compression of the right lateral medulla is consistently present in patients with diabetes mellitus and that microvascular decompression can be performed safely. Further studies are necessary and are under way.