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Biomedical subjects

J L Atkinson

Publications and source records attributed to J L Atkinson.

At least 19 recordsLinked to original sources
PubMed2001

Isolated medulla oblongata function after severe traumatic brain injury.

The objective was to report the first pathologically confirmed case of partly functionally preserved medulla oblongata in a patient with catastrophic traumatic brain injury.A patient is described with epidural haematoma with normal breathing and blood pressure and a retained coughing reflex brought on only by catheter suctioning of the carina. Multiple contusions in the thalami and pons were found but the medulla oblongata was spared at necropsy. In conclusion, medulla oblongata function may persist despite rostrocaudal deterioration. This comatose state ("medulla man") closely mimics brain death.

Brain↗
PubMed2001

Corpus callosal signal changes in patients with obstructive hydrocephalus after ventriculoperitoneal shunting.

BACKGROUND AND PURPOSE: Few reports have documented signal abnormalities within the corpus callosum on MR studies obtained after ventricular decompression in patients with hydrocephalus. Our purpose was to establish the frequency of this finding in shunted patients and attempt to elucidate its cause and clinical significance. METHODS: All patients with hydrocephalus shunted between 1989 and 1999 with postoperative MR studies available for review were included in the study group. Imaging analysis consisted of documenting hypointense signal on T1-weighted sagittal images and hyperintense signal on double-echo T2-weighted axial images within the corpus callosum. RESULTS: Characteristic signal abnormalities in the corpus callosum were noted in nine of 161 patients with shunted hydrocephalus studied with MR imaging. All nine patients were asymptomatic in regard to these MR findings. Comparison with preoperative scans and surgical records revealed that all patients with signal changes on postshunt scans had chronic obstructive hydrocephalus at presentation. Preshunt MR images were notable for marked elevation of the corpus callosum, which subsequently descended after ventricular decompression, suggesting that the cause of the signal changes was related to compression of the corpus callosum against the rigid falx. CONCLUSION: Signal abnormalities within the corpus callosum after ventricular shunting for obstructive hydrocephalus are not uncommon and are probably produced by compression of the corpus callosum against the falx before ventricular decompression. This distinctive appearance should not be mistaken for significant disease. Recognition of this pattern of signal abnormality will help avoid unnecessary intervention.

Adult↗
PubMed2000

Absent headache despite CSF volume depletion (intracranial hypotension).

CSF volume depletions, whether from leak or shunt overdrainage, typically cause low CSF opening pressures, orthostatic headaches, and diffuse pachymeningeal gadolinium enhancement on MRI. The authors report three patients-two with overdraining CSF shunts and one with proven CSF leak-with the typical pachymeningeal enhancement but without headaches. In CSF leaks and CSF shunt overdrainage, like MRI abnormalities and CSF alterations, the clinical features also show considerable variability. The independent variable remains the CSF volume depletion.

Aged↗
PubMed2000

False pituitary tumor in CSF leaks.

The authors describe five patients with typical clinical and MRI features of CSF leak and large enhancing pituitaries. The source of CSF leak was identified and surgically repaired in three patients. This was followed by disappearance of clinical symptoms and resolution of MRI abnormalities, including the pituitary enlargement. Enhancing enlargement of pituitary is another head MRI abnormality in CSF leaks, likely reflecting a secondary pituitary hyperemia.

Adenoma↗
PubMed2000

Exaggerated hemodynamic responses to nasal injection and awakening from anesthesia in a Cushingoid patient having transsphenoidal hypophysectomy.

A 51-year-old female patient, with an adrenocorticotrophic hormone-secreting pituitary tumor, was scheduled for transphenoidal hypophysectomy. She had a history of recent onset diabetes mellitus and a 2-year history of arterial hypertension. Despite ongoing medical therapy, preoperative blood pressure was 150-160/90-120 mm Hg. During general anesthesia, in response to perinasal infiltration with 10 ml of a solution containing lidocaine 200 mg and epinephrine 100 microg, blood pressure increased from 144/80 mm Hg to 317/175 over 3 minutes, as assessed by direct blood pressure monitoring. At the completion of the anesthetic, as the patient awakened and coughed and moved, blood pressure again increased dramatically, this time from 154/87 mm Hg to 285/170 over 3 minutes. Five months postoperatively, the patient's serum cortisol concentrations had normalized and her cuff blood pressure was 126/82, despite a reduction in her antihypertensive medications. The dramatic intraoperative blood pressure changes in this patient were attributed to the effects of hypercortisolemia on the normal physiologic responses to epinephrine and patient movement.

Administration, Intranasal↗
PubMed2000

Neuroimaging in deteriorating patients with cerebellar infarcts and mass effect.

BACKGROUND AND PURPOSE: The decision to proceed with surgery in cerebellar infarct with mass effect (CIMASS) in deteriorating patients is based on clinical features. The potential role of neuroimaging in predicting deterioration has not been systematically studied. In this study we determine the role of neuroimaging in predicting deterioration in CIMASS. METHODS: -We retrospectively reviewed the clinical and neuroimaging features in 90 patients with cerebellar infarcts. We selected for detailed analysis CIMASS in 35 patients. RESULTS: Eighteen patients remained stable and 17 deteriorated. Of these 17 patients, 8 were treated conservatively and 9 had surgery. Radiological features indicative of progression were more common in deteriorating patients compared with stable patients: fourth ventricular shift (82.3% versus 50%, P:=0.075, OR=4. 67), hydrocephalus (76.5% versus 11.1%, P:=0.0001, OR=26), brain stem deformity (47% versus 5.6%, P:=0.0065, OR=15.1), and basal cistern compression (35.3% versus 0%, P:=0.0076, OR=20.91). Differences in upward displacement of the aqueduct and pontomesencephalic junction from Twining's line, tonsillar descent on sagittal MRI, and infarct volumes between stable and deteriorating patients were not statistically significant. CONCLUSIONS: Hydrocephalus, brain stem deformity, and basal cistern compression may herald deterioration in CIMASS. Admission to a neurological-neurosurgical intensive care unit and consideration of preemptive surgery are warranted in these patients. Vertical displacement of tonsils or aqueduct, demonstrated by MR imaging, did not predict deterioration.

Brain Stem Infarctions↗
PubMed2000

Recurrent intraneural ganglion cyst of the tibial nerve. Case report.

Different theories have evolved to explain the pathogenesis and the cell of origin of intraneural ganglion cysts. Reportedly only three cases of intraneural ganglion of the tibial nerve have been located within the popliteal fossa, and all of these were thought to arise within the nerve. The authors report a case of a recurrent tibial intraneural ganglion in which a connection to the proximal tibiofibular joint was demonstrated on magnetic resonance (MR) images and at surgery. Surgical ligation of the articular branch and evacuation of the cyst led to symptomatic relief, and an MR image obtained 1 year after surgery documented no recurrence. This case reinforces the fact that surgeons need to consider and search for an articular connection in all cases of intraneural ganglia, especially in those that have recurred.

Adult↗
PubMed2000

Transcranial-transdural real-time ultrasonography during transsphenoidal resection of a large pituitary tumor. Case report.

Ultrasonography has been used in neurosurgical operative procedures for several decades. The authors report the case of a large pituitary tumor that was subtotally resected using endoscopy via the transnasal-transsphenoidal approach, with the aid of transcranial real-time ultrasound. To our knowledge, this is the first reported case in which intraoperative transcranial-transdural real-time ultrasound was used to facilitate the resection of a skull base tumor.

Adenoma↗
PubMed2000

Surgical evaluation and management of lumbar synovial cysts: the Mayo Clinic experience.

OBJECT: The authors report a retrospective analysis of 194 patients surgically treated at their institutions for symptomatic lumbar synovial cysts from January 1974 to January 1996. METHODS: Patient characteristics including age, sex, symptoms, signs, and preoperative neuroimaging studies were reviewed. Surgical procedures, complications, results, and pathological findings were correlated with preoperative assessment. One hundred ninety-four patients were surgically treated for symptomatic lumbar synovial cysts. Eighty percent were diagnosed and treated between 1987 and 1996. There were 100 men and 94 women with an average age of 66 years (range 28-94 years). The most common symptoms were painful radiculopathy (85%) and neurogenic single or multiroot claudication (44%). However, sensory loss (43%) and motor weakness (27%) were also presenting symptoms. Eleven percent of patients had undergone previous lumbar surgery prior to being referred to the Mayo Clinic. Preoperative neurological examination demonstrated motor weakness (40%), sensory loss (45%), reflex changes (57%), and variants of cauda equina syndrome (13%). In 19% of patients, normal neurological status was demonstrated. There was equal left/right-sided laterality, and eight patients presented with bilateral synovial cysts. The most commonly affected level was L4-5 (64%). All patients underwent laminectomy and resection of the cyst. Concomitant fusion was performed in 18 patients in whom clinical evidence of instability had been observed. However, subsequent fusion was required in only four patients who developed symptomatic spondylolisthesis. Surgery-related complications included cerebrospinal fluid leak (three patients), discitis (one patient), epidural hematoma (one patient), seroma (one patient), and deep vein thrombosis (one patient). One patient died 3 days after surgery of cardiac dysrhythmia. Follow-up data obtained for at least 6 months postoperatively were available in 147 patients. Of these, 134 (91%) reported good relief of their pain and 82% experienced improvement in their motor deficits. CONCLUSIONS: Lumbar synovial cysts are a more common cause of lumbar radicular pain than previously thought. Surgical removal of the cyst is a safe and effective treatment for symptomatic relief in patients with lumbar synovial cysts. A concomitant fusion procedure may be performed in select cases. In this study, only a few patients developed symptomatic spinal instability requiring a second operation.

Adult↗
PubMed2000

The neglected prehospital phase of head injury: apnea and catecholamine surge.

The prehospital phase of head injury, also called the critical phase, consists of trauma-induced apnea and stress catecholamine release. This immediate period after head injury remains poorly summarized in the literature and essentially ignored with respect to treatment. A MEDLINE search of the literature on apneustic response and catecholamine surge after head injury and a review of literature from my acquired references revealed 116 references (from more than 600) that were pertinent. Apnea induced by head injury produces hypoxia, hypercarbia, and subsequent cardiac failure and hypotension, which, along with substantially elevated catecholamine values, promote secondary mechanisms of organ injury. Treatment for this immediate period after head injury requires a rapid response to the scene of trauma and development of treatment options that can be instituted at the scene of injury.

Apnea↗
PubMed1999

Absent pachymeningeal gadolinium enhancement on cranial MRI despite symptomatic CSF leak.

CSF leak is recognized to cause orthostatic headaches and diffuse pachymeningeal gadolinium enhancement (DPMGE) on MRI. We report six patients with typical symptoms and documented CSF leaks without DPMGE. Two had normal meninges from the onset; one initially had normal meninges, but subsequently DPMGE developed. In three, the initially noted DPMGE resolved while they were still symptomatic with documented continued CSF leaks. Absent DPMGE does not rule out CSF leak. When clinical manifestations suggest this disorder, additional diagnostic studies should be pursued.

Adolescent↗
PubMed1999

Familial trigeminal neuralgia and contralateral hemifacial spasm.

A patient was evaluated with familial trigeminal neuralgia (TN) and contralateral hemifacial spasm. The mother of the patient, 5 of 10 siblings, and 1 nephew also had TN confirmed by neurologists. The transmission of TN was suggestive of an autosomal dominant inheritance. This family provides additional evidence of a genetic basis for TN in selected cases and also provokes further speculation on a common unifying hypothesis of pathophysiology in cranial rhizopathies.

Aged↗
PubMed1999

Prolactinoma manifesting with symptomatic hydrocephalus.

Prolactinomas are the most common secretory adenomas of pituitary origin. They typically manifest with symptoms referable to their endocrinologic effects or, if of sufficient size, to visual changes due to compression of the optic chiasm. Pituitary adenomas manifesting with hydrocephalus are rare. To our knowledge, only three such cases have previously been reported. We describe an 81-year-old woman with a pituitary adenoma that manifested with hydrocephalus. In addition, we review the literature and discuss therapeutic options.

Aged↗
PubMed1999

Preliminary comparison of the endoscopic transnasal vs the sublabial transseptal approach for clinically nonfunctioning pituitary macroadenomas.

OBJECTIVE: To assess the advantages and disadvantages of an endoscopic transnasal approach to pituitary surgery for a select group of clinically nonfunctioning macroadenomas and to compare results of this approach with the sublabial transseptal approach at a single institution. PATIENTS AND METHODS: We retrospectively reviewed the records of 26 patients with clinically nonfunctioning pituitary macroadenomas approached endoscopically and 44 matched control patients with the same tumors approached sublabially between January 1, 1995, and October 31, 1997. RESULTS: At baseline, the groups were not significantly different for age, sex distribution, number of comorbid conditions, visual field defects, degree of anterior pituitary insufficiency, or preoperative assessment of tumor volume or invasiveness. Mean (SD) operative times were significantly reduced in the endoscopic group vs the sublabial group: 2.7 (0.7) hours vs 3.4 (0.9) hours (P < .001). Postoperative assessment of surgical resection and postoperative alterations of anterior pituitary function or visual fields were not significantly different between groups, and complication rates were similar in both groups. CONCLUSION: This endoscopic transnasal approach to pituitary resection results in significantly shorter operative time without compromising the extent of tumor resection. The distinct disadvantage of this approach is an off-center view of the sella and a diminished working channel to the sella turcica. For these reasons, the endoscopic approach or its variation is an alternative to the sublabial approach but should be considered only by experienced pituitary neurosurgeons.

Adenoma↗
PubMed1998

Traumatic internal carotid artery dissections caused by blunt softball injuries.

This report describes recently treated patients with carotid artery dissection caused by blunt softball injuries, as well as the results of a study of carotid artery trauma in a community. Data obtained through the medical records linkage system used for epidemiologic studies in Olmsted County, MN were used to identify all cases of traumatic internal carotid artery dissection diagnosed from 1987 through 1994. Four patients with traumatic internal carotid artery dissections were identified during the 8-year period under study. In two patients (50%) the carotid dissection was a result of the direct impact of a softball. A 39-year-old-man, who developed transient cerebral ischemic symptoms, and a 35-year-old woman, who developed a painful Horner's syndrome, were struck by a softball on the anterolateral aspect of the neck. Both patients had a low carotid bifurcation. These data suggest that internal carotid artery dissections may be underrecognized sequelae of direct softball injuries to the anterolateral neck. A low carotid bifurcation may be a risk factor for such injuries.

Adult↗
PubMed1998

Size and components of poult yolk sacs.

An experiment was designed to examine the effects of strain of turkey, size of egg, and stage of embryonic development on yolk and yolk sac utilization. Sixty eggs from Nicholas and British United Turkeys of America (BUTA) breeders were selected within each of the weight categories 70 to 76, 80 to 86, and 90 to 96 g. These eggs were incubated under commercial conditions, and eggs selected at 0 or 25 d incubation, at hatch, and 24 h posthatch and yolk and embryos were weighed and assayed for fat, protein, or fatty acids. Yolk weight declined from 23.7 g at setting to 4.66 g at hatch and subsequently to 2.87 g, 24 h posthatch. Yolk weight was affected by strain and egg weight and a number of significant (P < 0.05) interactions were observed. Nicholas strain birds yielded the largest yolks, with the strain difference being most pronounced for the largest egg weight category. Larger turkey eggs contained more water, such that at 24 h posthatch there was double the amount of residual water in the yolk sac. At 24 h posthatch, the Nicholas poults had more water available in the residual yolk. Egg weight had little effect on lipid reserve in the yolk or yolk sac after 25 d incubation. Fatty acid profile of yolk lipids changed little throughout incubation. A number of strain differences are seen in fatty acid profile in the yolk during utilization, although these are quite small and may not be of sufficient magnitude to account for any strain differences seen in early poult viability or growth. Data suggests that the poult and chick may be different in metabolism of various lipid fractions, although in general nutrient utilization by the poult follows a fairly well established sequence of events.

Animals↗
PubMed1998

The early critical phase of severe head injury: importance of apnea and dysfunctional respiration.

BACKGROUND: Apnea is a known response of concussive head injury. Hypoxic or ischemic brain injury has been documented in a high percentage of severe head injury deaths. The respiratory response after head injury remains poorly defined, however, and its contribution to hypoxic or ischemic mechanisms after severe head injury is unknown. METHODS: Eighteen anesthetized but spontaneously breathing rats were subjected to fluid percussion head injury of varying severities. Respiratory rate and volume of air were recorded before and after injury with a Hans Rudolph/Varadyne pneumotach differential pressure transducer and graphically measured. Postmortem inspection of the brains was performed. RESULTS: Apnea and subsequent respiratory dysfunction are directly proportional to the magnitude of energy delivered to the brain. Higher energy results in a dysfunctional or absent respiratory response, probably attributable to failure or disorganized function of the medullary respiratory center. CONCLUSION: This study for the first time graphically depicts the respiratory response after head injury. Higher energy delivered to the brain directly correlates with a markedly abnormal respiratory response that probably contributes significantly to subsequent hypoxic or ischemic brain injury. The absence of the space-occupying hematoma or gross parenchymal disruption suggests that in the clinical setting many of these patients may otherwise have survivable head injury if rescued by early ventilatory assistance.

Animals↗