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Biomedical subjects

R E Harbaugh

Publications and source records attributed to R E Harbaugh.

At least 37 records · Page 2Linked to original sources
PubMed1996

Developing a neurosurgical carotid endarterectomy practice.

During the 1984-85 academic year, our neurosurgical service performed 60 carotid endarterectomy (CEA) procedures. By 1989 the annual number of CEAs performed by the neurosurgical service had fallen to six procedures, primarily because of the loss of patient referrals to an aggressive and well-trained vascular surgery group. At that time, an effort was begun to establish a neurosurgical cerebrovascular service and to compete more effectively for patients with extracranial cerebrovascular disease. Protocols for assuring rapid neurosurgical evaluation, improving communications with referring physicians, and developing innovative surgical and perioperative management protocols for CEA patients were instituted. By use of these strategies the annual number of CEAs performed on our neurosurgical service has increased substantially; from six CEAs done in academic year 1988-89 to 107 CEAs done in academic year 1994-95. The number of CEAs will surpass 120 for the present academic year. This presentation reviews the causes of the precipitous decline in the number of CEAs done by our neurosurgical service from 1985-89 and outlines strategies I have found effective for reestablishing neurosurgeons in the care of patients with surgically treatable extracranial cerebrovascular disease.

Endarterectomy, Carotid↗
PubMed1996

Neuroprotective effects of preischemia intraarterial magnesium sulfate in reversible focal cerebral ischemia.

The known cytoprotective properties of MgSO4 led the authors to study its effects on infarct size in rats when administered intraarterially before reversible focal ischemia. Following an intracarotid infusion of MgSO4 in the amount of 30 mg/kg (24 animals), 90 mg/kg (18 animals), or an equal volume of vehicle (23 animals), middle cerebral artery occlusion was produced in rats by means of an intraluminal suture technique. Reperfusion occurred after 1.5 (42 animals) or 2 hours (23 animals) of ischemia. Automated, volumetric measurements of 2',3',5'-triphenyl-2H-tetrazolium chloride-stained coronal brain sections demonstrated a statistically significant decrease in infarct size for MgSO4 treatment groups compared to controls. Cytoprotection was greater in animals subjected to 1.5 hours of ischemia (28.4% reduction in infarct volume, p < 0.001, Student's t-test), than in those having 2 hours of ischemia (19.3% reduction, p < 0.05). Animals given 90 mg/kg MgSO4 prior to 1.5 hours of ischemia (12 animals) showed a 59.8% reduction in infarct volume compared to controls (11 animals, p < 0.001) and a 43.1% reduction compared to the 30 mg/kg group (11 animals, p < 0.001). Analysis of variance demonstrated the statistically significant effects of MgSO4 doses on infarct volume across all groups (F = 22.95, p < 0.0001). The neuroprotective effect of intraarterial MgSO4 in this model is robust, dose dependent, and related to the duration of ischemia. The compound may be valuable for limiting infarction if given intraarterially before induction of reversible ischemia during cerebrovascular surgery.

Animals↗
PubMed1995

Three-dimensional computed tomographic angiography in the preoperative evaluation of cerebrovascular lesions.

Although three-dimensional computed tomographic angiography was developed as a screening tool for use in patients with suspected cerebrovascular disease, this imaging modality has also proven to be of value in surgical planning for patients with large or unusual vascular lesions of the brain. The three-dimensional images generated by this technique yield valuable information regarding the size and configuration of intracranial aneurysms and vascular malformations, the presence and extent of intra-aneurysmal thrombus, the relationship of the vascular lesion to other cerebrovascular or skeletal structures, aneurysm wall thickness, and the presence and orientation of an aneurysm neck. The use of three-dimensional computed tomographic angiography in representative cases of patients with large or unusual cerebrovascular lesions is presented. It has been our experience that this imaging modality displays anatomical information that is not readily available from standard, intra-arterial angiography, provides better detail for surgical planning than magnetic resonance angiography, and is less expensive than either of these other imaging modalities.

Adult↗
PubMed1995

Teratoma of the cavernous sinus: case report.

We report the case of an infant with a mature teratoma of the lateral wall of the cavernous sinus. A complete excision of the tumor was achieved. There was no evidence of recurrence at 1-year follow-up examination. Intracranial teratomas and the anatomy of the lateral wall of the cavernous sinus are briefly reviewed. To our knowledge, this is the first case of a teratoma confined to the cavernous sinus.

Cavernous Sinus↗
PubMed1995

Early discharge after carotid endarterectomy.

A consecutive series of 233 carotid endarterectomies performed over a 4-year period by one neurosurgeon was reviewed to analyze the number, nature, cause, and time to occurrence of complications. The time to discharge was analyzed regarding the type of anesthesia used and the time period during which surgery was performed. The records were reviewed to determine whether any complication could have been prevented by routine postoperative monitoring in an intensive care unit or by longer postoperative hospitalization. There were no perioperative deaths. The incidence of ipsilateral stroke was 1.7% and of major stroke was 0.9%. Nondisabling myocardial infarctions occurred in 1.3% of the patients. Complications occurred in a bimodal time course, less than 48 hours or greater than 1 week. The time to discharge decreased during the study period from 4.44 +/- 4.22 days for the first year of the study to 1.56 +/- 1.31 days for the last year of the study (P < 0.0001). A trend toward earlier discharge for patients who received cervical block anesthesia rather than general anesthesia did not reach statistical significance. No adverse patient outcome could be attributed to lack of intensive care unit monitoring or to early discharge. Our data demonstrate that patients who have undergone carotid endarterectomies do not routinely require intensive care unit monitoring and that discharge 24 to 48 hours after surgery is safe for the majority of patients. This regimen can result in considerable savings without compromising the quality of patient care.

Adult↗
PubMed1994

Arteriovenous malformations in elderly patients.

This article discusses the presentation, natural history, and management of arteriovenous malformations (AVMs) in elderly patients, based on our experience at the Dartmouth-Hitchcock Medical Center. We also present a review of the literature. In our series of 50 patients with AVMs who were operated on by one surgeon, six patients were 65 years old or older at the time of presentation. All six patients presented with intracerebral hemorrhage, and one patient had developed a seizure disorder 2 months before hemorrhaging. In three patients, the clinical course was consistent with the occurrence of two hemorrhages within a 48-hour period. The patients' preoperative neurological status varied from intact to moribund. In two patients, the diagnosis of AVM was made intraoperatively. Preoperative angiography revealed the diagnosis in the remaining patients. All the patients underwent surgical excision of their AVMs. Despite concurrent medical illnesses, all patients tolerated the procedure well with no new, persistent neurological deficits. At follow-up, all patients showed sufficient neurological recovery to return to the community and four of the patients were neurologically intact. Based on this experience and a review of the literature, we conclude that AVMs in elderly patients are not benign lesions and that surgical excision should be considered among the management options for these patients.

Aged↗
PubMed1994

Surgical decompression of Chiari I malformation for isolated progressive sensorineural hearing loss.

Progressive sensorineural hearing loss has been associated with Chiari type I malformation. Retrocochlear features on auditory brainstem response testing have been reported; however, debate exists over the exact location of the defect. Surgical decompression may be beneficial if brainstem or vascular compression have played a significant role in the pathophysiology of the hearing loss. Lack of specific audiologic data before and after surgical decompression has kept surgical decision making theoretic. This report presents the case of a 10-year-old boy with a progressive, asymmetric sensorineural hearing loss without other neurologic abnormalities. He underwent a posterior fossa decompression that resulted in stable hearing over the 2 years he was followed postoperatively. Preoperative and postoperative audiologic and evoked response features are described, and the rationale for operating with symptoms limited to hearing loss is discussed.

Arnold-Chiari Malformation↗
PubMed1993

Traumatic intracranial aneurysms: a contemporary review.

Intracranial aneurysms are rare complications of head injury. Clinical and pathologic features as well as the surgical treatment of patients harboring traumatic intracranial aneurysms are presented. The latest neuroradiologic procedures as they relate to traumatic aneurysms are discussed. An illustrative case report is followed by a review of the literature.

Adult↗
PubMed1992

Cortical biopsy in Alzheimer's disease: diagnostic accuracy and neurochemical, neuropathological, and cognitive correlations. Intraventricular Bethanecol Study Group.

Neurochemical assessments were performed on biopsy samples taken from the right frontal lobe of patients diagnosed with Alzheimer's disease (AD), before the implantation of a ventricular catheter and pump assembly for the infusion of bethanechol chloride as an experimental therapy. The pathologically diagnosed patients with AD (n = 35; mean age, 67 +/- 1.5 yr) were compared with a group of samples from normal age-equivalent autopsied controls (n = 22; mean age, 68 +/- 2 yr) and autopsied AD brains (n = 11; mean age, 73 +/- 2 yr). Samples were assayed for choline acetyltransferase (ChAT), acetylcholinesterase, binding to [3H]quinuclidinyl benzilate as an index of total muscarinic cholinergic binding, and [3H]pirenzepine binding as an index of M1 cholinergic receptor subtype binding. Mean levels of ChAT activity were decreased in the biopsied patients to 36% of age-matched autopsied controls. The loss of ChAT activity correlated significantly with the Mini-Mental State Examination, an index of global cognitive function. Mean ChAT activity in autopsied AD cortex was further decreased compared with controls, indicating continuous decline through the course of the disease. Acetylcholinesterase followed a similar, less dramatic decline. No differences were found in [3H]quinuclidinyl benzilate binding or [3H]pirenzepine binding between biopsied and autopsied controls. Neuritic plaque counts did not correlate with either the Mini-Mental State Examination or ChAT activity in the biopsy specimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholinesterase↗
PubMed1992

Results of routine ventriculostomy with external ventricular drainage for acute hydrocephalus following subarachnoid haemorrhage.

We reviewed the results of ventriculostomy with external ventricular drainage in patients with acute hydrocephalus complicating subarachnoid haemorrhage. Of 194 consecutive patients with subarachnoid haemorrhage admitted during the past eight years, 52 (27%) developed hydrocephalus within 72 hours of the ictus. Patients with acute hydrocephalus were in grades III to V (Hunt and Hess) at the time of evaluation and all patients with hydrocephalus underwent ventriculostomy within 24 hours of diagnosis. Twenty-six patients improved within 24 hours of cerebrospinal fluid drainage and 17 of these patients underwent surgery, nine of whom did well (Glasgow Outcome Scale 1 and 2). All 18 patients who did not improve within this period, including one who worsened, died. In eight patients the response to ventriculostomy was considered as undetermined, because of the proximity of the drain insertion to a definitive surgical procedure, and all of them had an excellent outcome (Glasgow Outcome Scale 1). Of 32 patients in grades IV and V, 17 did not improve and all of them died. Eight of the 15 patients in these grades, who were in the improved or undetermined categories, did well. Five patients (10%) developed meningitis. All patients with this complication had drainage for more than four days. Seven patients (14%) had a rebleed during the drainage. All except one patient with a rebleed had no surgery or delayed surgery and in six of them recurrent haemorrhages occurred after more than 24 hours of drainage. We conclude that routine ventriculostomy with external ventricular drainage should be considered for all patients with altered sensorium and acute hydrocephalus following subarachnoid haemorrhage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Three-dimensional computerized tomography angiography in the diagnosis of cerebrovascular disease.

Computer-generated three-dimensional reconstruction of the intracranial vascular system obtained by contrast-enhanced computerized tomography (CT) has been used in the diagnosis of 20 patients with known or suspected intracranial cerebrovascular disease. This technique allows visualization of the intracranial vasculature without exposing patients to the risks associated with intra-arterial angiography. The color prints and videotape images generated have been used to diagnose the presence of intracranial aneurysms, arteriovenous malformations, and venous angiomas. They have also been used to rule out structural abnormalities in patients with suspected intracranial vascular pathology and to screen patients with a strong family history of intracranial aneurysm. In 11 patients who underwent both three-dimensional CT angiography and intra-arterial angiography, the diagnostic correlation was 100%. No complications from the procedures or from incorrect diagnosis have been encountered. Although this technique requires further development and clinical evaluation, the authors' early experience with three-dimensional CT angiography suggests that this may become a valuable tool in the diagnosis of patients with cerebrovascular disease.

Adolescent↗
PubMed1991

Acute effects of a pedicled omental graft on cold-induced brain oedema in cats.

When used as a prophylactic measure and in chronic experiments, omental transposition has been shown to reduce ischaemic and traumatic oedema in the spinal cord and ischaemic oedema in the brain. We designed this experiment to evaluate the acute effects of a pedicled omental graft on cold-induced brain oedema in cats. Focal oedema was induced in the left frontoparietal region of the brain of nine anaesthetized cats. In five cats, a laparotomy was done and a pedicled omental graft was placed on the lesioned left hemisphere immediately after the cold lesion was made. All cats were sacrificed 72 hours later, and the water content of the white matter was determined in the lesioned and the normal hemispheres. The mean water content of the lesioned hemisphere of the treated group of animals was not significantly different from that of the control group. We conclude that a pedicled omental graft failed to reduce vasogenic oedema in an acute model and probably has no role in the acute management of brain oedema.

Animals↗
PubMed1991

Neurosurgical complications after intranasal ethmoidectomy.

Intranasal ethmoidectomy is a common otolaryngological procedure. Despite the potential for serious intracranial complications, there is a paucity of reports describing the neurosurgical complications of the procedure. Two patients with intracranial complications of intranasal ethmoidectomy, and the relevant medical literature, are reviewed. The anatomy of the ethmoid air cells and their relation to the intracranial cavity are described. The importance of definitive, emergent repair with attention to the potential for vascular injury is discussed.

Aged↗
PubMed1989

Anticonvulsant activity of the glial GABA uptake inhibitor, THAO, in chemical seizures.

The antiseizure activity of the glia-selective GABA uptake inhibitor, 5,6,7,8-tetrahydro-4H-isoxazolo[4,5-c]azepin-3-ol (THAO), was evaluated in rats in models of acute chemoconvulsion. In these experiments, intracerebroventricular administration of the drug 30 min prior to testing in doses between 100-750 micrograms provided protection against maximal pentylenetetrazol seizures and increased the latency to isonicotinic acid hydrazide seizures. Pentylenetetrazol seizure thresholds, in contrast, were not significantly elevated. The ability of THAO to suppress tonic but not generalized minor seizures suggests that it may block seizure spread.

Animals↗
PubMed1989

Nerve growth factor as a potential treatment in Alzheimer's disease.

An adequate rationale for considering the use of NGF in the treatment of AD exists. Much basic work needs to be done prior to any clinical trials in order to design an ethically and scientifically sound study. The potential use of NGF in patients with AD is a very exciting possibility; enthusiasm should not, however, lead to poorly designed premature clinical trials which are unlikely to provide definitive answers as to the effectiveness of such treatment.

Alzheimer Disease↗
PubMed1989

The spectrum of imaging and neuropsychological findings in Pick's disease.

To seek improved methods for the diagnosis of Pick's disease, we reviewed imaging studies of four women and two men (ages 48 to 65 years at onset) and psychometric testing of three of them with autopsy or biopsy-proved Pick's. The presence of Pick bodies was required for the diagnosis. Seven patients with biopsy-proved Alzheimer's disease served as a comparison group. In the Pick's patients, CT in five of six showed marked frontal pole or temporal pole atrophy, which clearly differed from the pattern of cerebral atrophy seen in the Alzheimer's patients. Psychometric testing showed performance patterns that tended to differ from those of the Alzheimer's patients in that recent memory was relatively preserved despite marked impairment of executive functions. The distinctive psychometric pattern in the Pick's patients was evanescent, however. Thus, there were imaging and psychometric findings of potential diagnostic value for Pick's disease, but, for different reasons, they were imperfect.

Aged↗