Biomedical subjects

J E Harpring

Publications and source records attributed to J E Harpring.

4 recordsLinked to original sources

PubMed2000

Traumatic intracranial aneurysms.

Traumatic intracranial aneurysms are rare, occurring in fewer than 1% of patients with cerebral aneurysms. They can occur following blunt or penetrating head trauma and are more common in the pediatric population. Traumatic aneurysms can be categorized histologically as true, false, or mixed, with false aneurysms being the most common. These aneurysms can present in a variety of ways, but are typically associated with an acute episode of delayed intracranial hemorrhage with an average time from initial trauma to aneurysm hemorrhage of approximately 21 days. The mortality rate for patients harboring these aneurysms may be as high as 50%. Prompt diagnosis based on arteriography and aggressive surgical management are associated with better outcome than conservative treatment. The authors describe a classification scheme for traumatic aneurysms based on their anatomical location and conclude that 1) posttraumatic aneurysm must be considered in patients with acute neurological deterioration following closed head injury; 2) they can occur following mild closed head injury; 3) they occur more commonly in children than in adults; and 4) surgical clipping and/or endovascular occlusion is the definitive treatment.

Age Factors↗

PubMed1999

Magnetic motor evoked potential monitoring in the rat.

OBJECT: The authors conducted a study to provide an objective electrophysiological assessment of descending motor pathways in rats, which may become a means for predicting outcome in spinal cord injury research. METHODS: Transcranial magnetic motor evoked potentials (TMMEPs) were recorded under various conditions in awake, nonanesthetized, restrained rats. Normative data were collected to determine the reproducibility of the model and to evaluate the effect of changing the stimulus intensity on the evoked signals. In addition, an experiment was performed to determine if the TMMEPs produced were the result of auditory startle response (ASR) potentials elicited by the sound generated by the movement of the copper coil inside its casing during magnetic stimulation. Transcranial magnetic motor evoked potentials were elicited after magnetic stimulation. At 100% stimulus intensity, the mean forelimb onset latency was 4.2 +/- 0.39 msec, and the amplitude was 9.16 +/- 3.44 mV. The hindlimb onset latency was 6.5 +/- 0.47 msec, and the amplitude was 11.47 +/- 5.25 mV. As the stimulus intensity was decreased, the TMMEP onset latency increased and the response amplitude decreased. The ASR potentials were shown to have longer latencies, smaller amplitudes, and were more variable than those of the TMMEPs. CONCLUSIONS: These experiments demonstrate that TMMEPs can be recorded in awake, nonanesthetized rats. The evoked signals were easy to elicit and reproduce. This paper introduces noninvasive TMMEPs as a new technique for monitoring the physiological integrity of the rat spinal cord.

Animals↗

PubMed1998

Effect of a clinical pathway for severe traumatic brain injury on resource utilization.

BACKGROUND: The usefulness of clinical pathways for the complex trauma patient is unclear. We analyzed the effect of a clinical pathway for severe traumatic brain injury (TBI) on resource utilization. METHODS: A clinical pathway for severe TBI (Glasgow Coma Scale (GCS) score < or = 8 at 24 hours) was developed by a multidisciplinary team and used for all patients with severe TBI. Data were gathered prospectively for 15 months and compared with data from historical controls from the previous year. Patients who survived < 48 hours were excluded. RESULTS: The clinical pathway was used for 84 patients with severe TBI and compared with 49 historical controls. No differences in Injury Severity Scores (27 vs. 27) or GCS scores at 24 hours (6.2 vs. 6.5) existed between control or pathway patients. There was an overall increase in the mortality rate of pathway patients (from 12.2 to 21.4%), but this was entirely attributable to withdrawal of care that was initiated by family members in patients with an average age of 71 years, an average GCS score of 4.7, and an average Injury Severity Score of 29. Among survivors, pathway patients had a significant decrease in ventilator days (11.5 +/- 0.9 vs. 14.6 +/- 1.2; p < 0.05), intensive care unit days (16.7 +/- 1.0 vs. 21.2 +/- 1.4; p < 0.05), and hospital days (23.4 +/- 1.2 vs. 31.0 +/- 3.0; p < 0.05). There were no differences in the incidence of complications or functional outcomes. CONCLUSION: The use of a clinical pathway for severe TBI resulted in a significant reduction in resource utilization. This study suggests that clinical pathways may be a useful component of patient care after blunt trauma.

Adult↗

PubMed1985

Subclassification of neurons in the ventrobasal complex of the dog: quantitative Golgi study using principal components analysis.

The neuronal architecture of the ventrobasal complex (VB) in dog is examined in coronal and horizontal brain sections processed by Golgi- and Nissl-staining methods. Presumed projection and intrinsic neurons are identified by differences in soma size and shape, dendritic branch pattern, the morphology and distribution of appendages, and the appearance of axons. Forty-five projection neurons are examined by quantifying (1) soma cross-sectional area, (2) dendritic field extent and shape, (3) appendages on the soma, primary dendrites, and in a defined major dendritic branch zone, and (4) location in the VB. When considered independently, each variable offers little evidence for separation into morphological classes. However, several of the variables have wide ranges and show significant correlation with other parameters. Using the multivariate descriptive methods of principal components analysis and cluster analysis, a separation of the projection neurons into three morphological classes designated as large, medium, and small neurons is indicated. The features most critical in distinguishing between the groups are, in descending order of importance: (1) dendritic field extent; (2) number of primary dendrites; (3) soma cross-sectional area; (4) number of appendages per major branch point (MBP); (5) number of appendages on the soma; and, (6) number of appendages on the primary dendrites. Dendritic field shape and neuron location have little influence in determining classification.

Analysis of Variance↗