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Biomedical subjects

John L D Atkinson

Publications and source records attributed to John L D Atkinson.

At least 19 recordsLinked to original sources
PubMed2006

Surgical anatomy of dural defects in spontaneous spinal cerebrospinal fluid leaks.

OBJECTIVE: Spontaneous intracranial hypotension is typically caused by a spontaneous spinal cerebrospinal fluid (CSF) leak. The configuration of the related dural defects can be complex. We describe our experience with the surgical anatomy of these defects. METHODS: Thirteen consecutive patients with spontaneous spinal CSF leaks who underwent surgical exploration at Mayo Clinic between 1994 and 2003 were studied. All patients' records, imaging studies, detailed intraoperative findings, and outcomes were reviewed. RESULTS: There were four men and nine women with an average age of 40 years (range, 12-62 yr). Preoperative imaging studies revealed a single site of CSF leak in eight patients, two sites in three patients, and multiple sites in two patients. Intraoperatively, the exact site of leakage could not be found in four patients. Among the other nine patients, primary closure of a meningeal diverticulum was achieved in one patient. Significant regional attenuation of the dura prevented primary repair of the leak site in eight patients. Muscle, fibrin glue, and Gelfoam (Upjohn Co., Kalamazoo, MI) soaked in patient's own blood were commonly used to pack the epidural space in an attempt to seal the site of the leak. Ligation of two nonappendicular nerve roots allowed closure of the leak in one of these patients. Postoperatively, resolution of symptoms occurred in eight patients, significant improvement was noted in three patients, and only transient resolution in two. The mean duration of follow-up was 20.5 months. CONCLUSION: Surgery for closure of spontaneous spinal CSF leaks may not be straightforward. Even when extradural CSF leakage is discovered preoperatively by imaging studies, it may not always be possible to identify the exact site of the leakage intraoperatively. Furthermore, the anatomy of the dural defects may be complex and not amenable to primary closure. In such cases, the use of adjuvant techniques during surgical exploration may be effective.

Adolescent↗
PubMed2005

Patterns of cerebral infarction in aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: The aim of this study was to analyze the distribution patterns of delayed cerebral ischemia after subarachnoid hemorrhage (SAH) and the factors that determine their occurrence. METHODS: We analyzed clinical and radiological data of 143 consecutive patients with aneurysmal SAH. Computed tomography scan revision was blinded to clinical information. Superficial infarctions were defined as territorial lesions with cortical involvement. Perioperative infarctions were excluded. RESULTS: Fifty-six patients (39%) had cerebral infarctions. They were unilateral in 34 patients (61%) and involved a single territory in 29 (52%). Location was cortical in 34 patients (61%), deep in 10 (18%), and combined cortical and deep in 12 (21%). Single infarctions were cortical in 23 of 28 cases (79%). Deep territory ischemia was more common with multiple lesions (16/28, 57% versus 6/29 with single lesions, 21%; P<0.01). Single infarctions occurred frequently in the territory of the ruptured aneurysm (22/28 patients; 79%), whereas multiple infarctions were often distant to the site of rupture (21/28 cases, 75%). History of diabetes (P=0.05), early hydrocephalus (P=0.05), and requirement of external ventricular drainage (P=0.02) were associated with the occurrence of multiple infarctions on univariate analysis. On multivariable analysis, this association only remained significant for the requirement of external ventricular drainage. CONCLUSIONS: The 2 most common patterns of delayed cerebral ischemia after aneurysmal SAH are single cortical infarction, typically near the ruptured aneurysm, and multiple widespread lesions including subcortical locations and often unrelated to the site of aneurysm rupture. These 2 patterns may represent different pathophysiological mechanisms or different degrees of severity of the same vascular process.

Adult↗
PubMed2005

A comparison of peripheral skin blood flow and temperature during endoscopic thoracic sympathotomy.

The assessment of sympathetic denervation to the upper extremities during surgery for hyperhidrosis is essential in predicting postoperative outcome, particularly for endoscopic thoracic chain sympathotomy, a recently described, minimally destructive technique that minimizes postoperative compensatory hyperhidrosis. To test the hypothesis that skin blood flow (SkBF; laser Doppler flowmetry) provides a faster and more reliable indication of denervation than temperature (temp), we prospectively compared palmar SkBF and fingertip temp in 10 patients undergoing endoscopic thoracic chain sympathotomy for essential hyperhidrosis. From baseline to peak values, palmar SkBF (mean +/- SEM) increased 273.3 +/- 24.7 arbitrary units and 252.4 +/- 30.1 arbitrary units, whereas temp increased 0.9 degrees C +/- 0.3 degrees C and 1.5 degrees C +/- 0.6 degrees C on the right and left, respectively. Upon effective sympathotomy of the right thoracic chain, the time to peak SkBF was 43 +/- 13 s, whereas the time to peak temp was 277 +/- 53 s (P <0.001). On the left, the time to peak SkBF was 81 +/- 14 s, and time to peak temp was 305 +/- 34 s (P <0.001). All patients considered the sympathotomy successful. We conclude that laser Doppler SkBF is superior to temp in temporal resolution for assessment of denervation during sympathotomy and that it provides a superior qualitative and quantitative adjunct to monitoring denervation.

Adolescent↗
PubMed2005

Survival of cardiac arrest after aneurysmal subarachnoid hemorrhage.

OBJECTIVE: Survival of cardiac arrest (CA) after aneurysmal subarachnoid hemorrhage (SAH) is poorly characterized. We analyzed the clinical course and outcome of patients who survived resuscitation for CA after aneurysmal SAH. METHODS: Medical records of all patients with acute SAH treated at Mayo Clinic between 1990 and 1997 were reviewed. Three hundred five consecutive patients with angiographically proven aneurysmal SAH presenting within 7 days of ictus were analyzed. CA was defined as a pulseless state, documented by medical personnel, for which resuscitation was performed. Outcome was measured with the Glasgow Outcome Scale score at longest follow-up (mean, 16 mo). RESULTS: Data from 11 patients (3.6%) who had 14 episodes of CA were analyzed. Six patients had CA before reaching the hospital and were successfully resuscitated. Nine of 14 CA episodes occurred at hemorrhage or rehemorrhage. No patient with in-hospital CA failed to be resuscitated. Overall mortality in patients who had CA (46%) was higher than that of patients without CA (15%; P = 0.019). Outcome for all patients who had CA (mean Glasgow Outcome Scale score, 2.5) was worse than for patients without CA (mean Glasgow Outcome Scale score, 3.9; P = 0.005). However, half of the survivors of CA after SAH were living independently with limited deficit at longest follow-up. CONCLUSION: Most cases of CA occur at the time of initial or recurrent SAH. Resuscitation for in-hospital CA is likely to be successful. Although CA after aneurysmal SAH is associated with significantly higher mortality, the outcome of survivors of CA is not worse than that for other patients after aneurysmal SAH.

Adult↗
PubMed2005

Deep Sylvian fissure chordoid meningioma: case report.

OBJECTIVE AND IMPORTANCE: A case of chordoid meningioma originating in the right sylvian fissure is reported. Chordoid meningiomas are uncommon tumors. This is the first reported case of a chordoid meningioma without dural attachment arising in the sylvian fissure. CLINICAL PRESENTATION: The patient presented with a generalized seizure. A heterogeneously enhancing right frontotemporal mass was identified on magnetic resonance imaging of the brain. INTERVENTION: The patient underwent a failed stereotactic biopsy attempt elsewhere. The tumor was ultimately resected using standard microsurgical techniques. CONCLUSION: Meningiomas originate from arachnoid cap cells and can arise at locations remote from the pachymeninges. Although rare, meningiomas should be included on the differential diagnosis of sylvian fissure lesions.

Adult↗
PubMed2005

The Mayo brothers and Harvey Cushing: a review of their 39-year friendship through their personal letters.

Mayo Clinic founders, William J. Mayo and Charles H. Mayo, and Harvey W. Cushing were among the most significant pioneers of modem American surgery. A review of their personal correspondence reveals a special relationship among these three individuals, particularly between William Mayo and Cushing. Their interactions within the Society of Clinical Surgery initiated their close personal and professional association, which would endure for 39 years. William Mayo strongly supported Cushing's efforts to develop the specialty of neurological surgery, and Cushing sought Mayo's advice in making important career-related decisions. Their supportive friendship and professional alliance remains an example for future generations of neurological surgeons.

Correspondence as Topic↗
PubMed2005

Emerging medical and surgical management strategies in the evaluation and treatment of intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) accounts for approximately 10% of all strokes and causes high morbidity and mortality. Rupture of the small perforating vessels of the cerebral arteries is caused by chronic hypertension, which induces pathologic changes in the small vessels and accounts for most cases of ICH; however, amyloid angiopathy and other secondary causes are being seen more frequently with the increasing age of the population. Recent computed tomographic studies have revealed that ICH is a dynamic process with up to one third of initial hemorrhages expanding within the first several hours of ictus. Secondary injury is believed to result from the development of cerebral edema and the release of specific neurotoxins associated with the breakdown products of hemoglobin. Treatment is primarily supportive. Surgical evacuation is the treatment of choice for patients with neurologic deterioration from infratentorial hematomas. Randomized trials comparing surgical evacuation to medical management have shown no benefit of surgical removal of supratentorial hemorrhages. New strategies focusing on early hemostasis, improved critical care management, and less invasive surgical techniques for clot evacuation are promising to decrease secondary neurologic injury. We review the pathophysiology of ICH, its medical management, and new treatment strategies for improving patient outcome.

Alcohol Drinking↗
PubMed2005

Hyperhidrosis: evolving therapies for a well-established phenomenon.

The socially embarrassing disorder of excessive sweating, or hyperhidrosis, and its treatment options are gaining widespread attention. In order of frequency, palmar-plantar, palmar-axillary, Isolated axillary, and cranlofacial hyperhidrosis are distinct disorders of sudomotor regulation. A common link among these disorders is an excessive, nonthermoregulatory sweat response often to emotional stimuli in body regions influenced by the anterior cingulate cortex as opposed to the thermoregulatory sweat response regulated by the preoptic-anterior hypothalamus. Diagnosis of these mechanistically ambiguous disorders is primarily from patient history and physical examination, whereas results of laboratory studies performed with indicator powder reveal the distribution and severity of resting hyperhidrosis and document the integrity of thermoregulatory sweating. Treatment options lie on a continuum based on the severity of hyperhidrosis and the risks and benefits of therapy. In general, therapy begins with antiperspirants or anticholinergics. Iontophoresis is available for palmar-plantar and axillary hyperhidrosis. Botulinum toxin type A or local excision/curettage is effective for isolated axillary hyperhidrosis not responsive to topical application of aluminum chloride. Endoscopic thoracic sympathectomy may be used for severe cases of palmar-plantar and palmar-axillary hyperhidrosis. No sole therapy of choice has emerged for craniofacial sweating. The long-term sequelae of hyperhidrosis and its treatment also are discussed.

Botulinum Toxins, Type A↗
PubMed2005

Preangiographic evaluation of spinal dural arteriovenous fistulas with elliptic centric contrast-enhanced MR Angiography and effect on radiation dose and volume of iodinated contrast material.

BACKGROUND AND PURPOSE: The detection and localization of spinal dural arteriovenous fistulas (AVFs) remain diagnostic challenges. This study tested the hypothesis that elliptic centric contrast-enhanced MR angiography (MRA) can be used to detect spinal dural AVFs, predict the level of fistulas, and reduce the radiation dose and volume of iodinated contrast material associated with conventional angiography. METHODS: We examined 31 patients who presented with suspected spinal dural AVF between December 2000 and March 2004. All patients underwent MRA and conventional angiography. The effect of MRA on subsequent conventional angiography was assessed by analyzing total fluoroscopy time and volume of iodinated contrast material used. RESULTS: At angiography, spinal dural AVFs were diagnosed in 22 of 31 patients, and MRA depicted an AVF in 20 of the 22 patients. MRA findings correctly predicted a negative angiogram in seven of nine cases. Of the 20 true-positive MRA results, the level of the fistula was included in the imaging volume in 14. In 13 of these 14 cases, MRA results correctly predicted the side and the level of the fistula to within one vertebral level. Fluoroscopy time and the volume of contrast agent was reduced by more than 50% in the 13 patients with a spinal dural AVF in whom MRA prospectively indicated the correct level. CONCLUSION: Contrast-enhanced MRA can be used to detect spinal dural AVFs, predict the level of fistulas, and substantially reduce the radiation dose and volume of contrast agent associated with catheter spinal angiography.

Aged↗
PubMed2004

Predictors of cerebral infarction in aneurysmal subarachnoid hemorrhage.

BACKGROUND: Clinical and radiologic predictors of cerebral infarction occurrence and location after aneurysmal subarachnoid hemorrhage have been seldom studied. METHODS: We evaluated all patients admitted to our hospital with aneurysmal subarachnoid hemorrhage between 1998 and 2000. Cerebral infarction was defined as a new hypodensity located in a vascular distribution on computed tomography (CT) scan. RESULTS: Fifty-seven of 143 patients (40%) developed a cerebral infarction. On univariate analysis, occurrence of cerebral infarction was associated with a worse World Federation of Neurological Surgeons grade (P=0.01), use of ventriculostomy catheter (P=0.01), preoperative vasospasm (P=0.03), surgical clipping (P=0.02), symptomatic vasospasm (P<0.01), and vasospasm on transcranial Doppler ultrasonography (TCD) or repeat angiogram (P<0.01). On multivariable analysis, only presence of symptoms ascribed to vasospasm (P<0.01) and evidence of vasospasm on TCD or angiogram predicted cerebral infarction (P<0.01). TCD and angiogram agreed on the diagnosis of vasospasm in 73% of cases (95% CI, 63% to 81%), but the diagnostic accuracy of this combination of tests was suboptimal for the prediction of cerebral infarction occurrence (sensitivity, 0.72; specificity, 0.68; positive predictive value, 0.67; negative predictive value, 0.72). Location of the cerebral infarction on delayed CT was predicted by neurological symptoms in 74%, by aneurysm location in 77%, and by angiographic vasospasm in 67%. CONCLUSIONS: Evidence of vasospasm on TCD and angiogram is predictive of cerebral infarction on CT scan but sensitivity and specificity are suboptimal. Cerebral infarction location cannot be predicted in one quarter to one third of patients by any of the studied clinical or radiological variables.

Adult↗
PubMed2004

Hemodynamic responses to epinephrine-containing local anesthetic injection and to emergence from general anesthesia in transsphenoidal hypophysectomy patients.

Patients undergoing transsphenoidal pituitary surgery may experience hypertensive episodes during the intranasal injection of vasoconstrictor-supplemented local anesthetics or emergence from general anesthesia. The present research characterized the blood pressure responses during transsphenoidal surgery and tested the hypothesis that the underlying pituitary disease influences the incidence and magnitude of the blood pressure responses. The records of 100 patients were retrospectively reviewed. All had direct blood pressure measurements recorded using a computer-based anesthesia recording system. Mean age was 49 +/- 17 years (+/- SD) and 52% were male. Blood pressure increased by 60 +/- 37 mm Hg systolic and 23 +/- 22 mm Hg diastolic with intranasal injection and 42 +/- 24 mm Hg systolic and 23 +/- 16 mm Hg diastolic during emergence from general anesthesia. Systolic blood pressure increased by greater than 50% in 58% of patients following intranasal injection and in 33% of patients upon emergence from anesthesia. Blood pressure responses did not differ with respect to endocrinopathy type (Cushing's disease, acromegaly, or other pathology), gender, age, surgeon, history of prior transsphenoidal surgery, history of either hypertension or diabetes, or preoperative use of either beta-adrenergic or calcium channel-blocking drugs. There was poor correlation between the epinephrine dose injected (range 30-220 microg) and systolic blood pressure response (r = 0.24; r2 = 0.06; P = 0.031). Blood pressure increases were not associated with cardiac arrhythmias, persistent myocardial ischemia, or myocardial infarction. The authors conclude that in transsphenoidal hypophysectomy patients, large blood pressure increases are common with intranasal injection and upon awakening from general anesthesia. However, the authors were not able to find a variable that might enable the prediction of which patients are most likely to experience the most intense blood pressure elevations.

Acromegaly↗
PubMed2004

Influence of aspirin on outcome following aneurysmal subarachnoid hemorrhage.

OBJECT: Previous studies have indicated an increased incidence of death in patients with subarachnoid hemorrhage (SAH) who are currently receiving anticoagulation therapy. The significance of previous aspirin use in patients with SAH is unknown. The authors analyzed the effects of prior aspirin use on clinical course and outcomes following aneurysmal SAH. METHODS: The medical records of 305 patients with angiogram-confirmed aneurysmal SAH who consecutively presented to our institution between 1990 and 1997 within 7 days of ictus were analyzed. Twenty-nine (9.5%) of these patients had a history of regular aspirin use before onset of the SAH. The Glasgow Outcome Scale (GOS) was used to measure patient outcome at the longest available follow up. Aspirin users were older on average than nonusers (59 years of age compared with 53 years; p = 0.018). The mean admission Hunt and Hess grades of patients with and without aspirin use were similar (2 compared with 2.3; p = 0.51). Two trends, which did not reach statistical significance, were observed. 1) The rebleeding rate in aspirin users was 14.3%, compared with a 4.7% rebleeding rate in nonusers (p = 0.06). 2) Permanent disability from vasospasm was less common among aspirin users (23% compared with 50%; p = 0.069). Outcomes did not differ between aspirin users and nonusers (mean GOS Score 3.83 compared with GOS Score 3.86, respectively; p = 0.82). CONCLUSIONS: Despite trends indicating increased rebleeding rates and a lower incidence of permanent disability due to delayed ischemic neurological deficits, there was no significant effect of previous aspirin use on overall outcome following aneurysmal SAH. Based on these preliminary data, the presence of an intracranial aneurysm is not a strict contraindication to aspirin use.

Adult↗
PubMed2004

Cardiopulmonary resuscitation in critically ill neurologic-neurosurgical patients.

OBJECTIVES: To establish the rate of successful cardiopulmonary resuscitation (CPR) and to study outcome predictors in patients who experienced in-hospital cardiac arrest after being admitted to the neurologic-neurosurgical intensive care unit (ICU) with a primary neurologic diagnosis. PATIENTS AND METHODS: We identified patients admitted to the neurologic-neurosurgical ICU between 1994 and 2001 who experienced in-hospital cardiac arrest and received CPR. Functional outcome was assessed using the modified Rankin scale. RESULTS: During the study period, 38 consecutive patients experienced in-hospital cardiac arrest and received CPR. The median age of the patients was 65 years (range, 16-81 years), and the mean interval from admission to CPR was 12 days (range, 3 hours to 47 days). Acute intracranial disease was present in 32 patients (84%). Twenty-one patients (55%) were in the ICU at the time of the cardiac arrest; cardiac arrests in the wards occurred at a mean interval of 9 days (range, 1-45 days) after ICU discharge. Cardiopulmonary resuscitation achieved return of spontaneous circulation in 23 patients (61%). Seven patients (18%) were discharged from the hospital, 5 of whom later achieved a modified Rankin scale score of 2 or lower. Cardiac arrest after a deteriorating clinical course resulted in uniformly fatal outcomes. Duration of CPR shorter than 5 minutes and CPR in the ICU were associated with survival and good functional recovery. CONCLUSIONS: Cardiopulmonary resuscitation is a worthwhile procedure in severely ill neurologic-neurosurgical patients, regardless of the patient's age. However, the outcome after CPR appears much worse in patients with a prior deteriorating clinical course.

Adolescent↗
PubMed2004

Pathogenesis, natural history, and treatment of unruptured intracranial aneurysms.

Unruptured intracranial aneurysms (UIAs) are a major public health issue. These lesions have become increasingly recognized in recent years with the advent of advanced cerebral imaging techniques. Epidemiological evidence from multiple sources suggests that most intracranial aneurysms do not rupture. Therefore, it is desirable to identify which UIAs are at greatest risk of rupture when considering which to repair. It is important to compare size-, site-, and group-specific natural history rates with size-, site-, and age-specific morbidity and mortality associated with UIA repair because increased natural history risk often is associated with increased risk of aneurysm repair. Patient age is crucial in decision making because of its major effect on operative morbidity and mortality; however, it does not substantially affect natural history. The effect of age is most notable in patients about 50 years of age and older for open surgery and about 70 years of age and older for endovascular procedures. In general, rupture risk is lowest for patients in asymptomatic group 1 (no history of subarachnoid hemorrhage) with UIAs less than 7 mm in diameter in the anterior circulation. Surgical morbidity and mortality are most favorable for asymptomatic patients younger than 50 years who have UIAs less than 24 mm in diameter in the anterior circulation and no history of ischemic cerebrovascular disease. Endovascular morbidity and mortality may be less age dependent, and this could favor endovascular procedures, particularly in patients aged 50 to 70 years. An important issue is determining immediate vs long-term risk regarding treatment effectiveness and durability. This issue emphasizes the importance of long-term follow-up in patients after surgical and endovascular procedures.

Adult↗
PubMed2003

Utility of intraoperative ultrasound for tumors of the cauda equina.

STUDY DESIGN: A retrospective chart review of patients with tumors of the cauda equina was performed. OBJECTIVES: To assess the role of intraoperative ultrasound for detecting tumor migration and modifying the approach to cauda equina tumors. SUMMARY OF BACKGROUND DATA: Rostral migration of cauda equina tumors relative to preoperative imaging is well described. The utility of intraoperative ultrasound to identify tumor migration and to modify the surgical approach was analyzed. METHODS: The medical records of nine consecutive patients undergoing biopsy or resection of a cauda equina tumor diagnosed by magnetic resonance imaging at the authors' institution from January 1994 through December 2000 were reviewed. Four patients with tumors of the cauda equina underwent transdural sonography of the intraspinal compartment after initial laminectomy and before durotomy. RESULTS: In three patients, the findings on intraoperative ultrasound showed rostral migration of the lesion with respect to the preoperative magnetic resonance imaging, necessitating additional laminectomy and modifying the site of durotomy. One tumor had migrated rostrally one full bony vertebral segment, whereas two tumors each had migrated one half of a bony vertebral segment. Pathology examination in the three patients whose lesions had migrated rostrally demonstrated a schwannoma in every case. In one patient, intraoperative ultrasound showed no lesion migration with respect to the preoperative magnetic resonance imaging, and no modifications to the surgical approach were needed. Pathology examination of this patient demonstrated an ependymoma. CONCLUSIONS: Intraoperative ultrasound was useful in documenting rostral migration of cauda equina tumors, and facilitated appropriate laminectomy and durotomy. The technique may be particularly valuable for schwannomas of the cauda equina, which seem to have a greater potential for rostral migration.

Adenocarcinoma↗
PubMed2003

MRI depiction of chronic intradural (subdural) hematoma in evolution.

The usual chronic subdural hematoma encountered in the elderly is actually thought to be a chronic intradural hematoma, which has been described clinically and anatomically. However, the evolution of how this chronic hematoma occurs remains enigmatic. We report the first magnetic resonance (MR) depiction of an apparent chronic intradural hematoma in evolution over several months in a 61-year-old man after a minimal head injury. The time delay from injury, subsequent focal pachymeningeal T1-gadolinium enhancement, and apparent splitting of the pachymeninges by proven chronic hematoma should serve as a stimulus for further MR investigations of this interesting process.

Accidental Falls↗