NEW DEFINITIVE HOST RECORD FOR CHORDODES MORGANI (NEMATOMORPHA) IN NEBRASKA WITH NOTES ON ECOLOGY.

The life cycle and ecology of the horsehair worm Chordodes morgani (Nematomorpha) in Nebraska remain unknown. To identify its definitive host, we installed a series of pitfall traps along 3 first-order streams at 4 sites: Elk Creek, Upper Elk Creek, Maple Creek, and West Oak Creek, all located northwest of Lincoln, Nebraska. In addition, we opportunistically hand-collected insects at these sites, including wood cockroaches (Parcoblatta virginica), and maintained them in the lab until they passed adult worms. Two of these field-collected wood cockroaches each yielded 1 adult worm, which was identified as C. morgani by microscopy, showing that P. virginica serves as a definitive host. Experimental infections of captive-reared Parcoblatta americana supported this result. The wood cockroach was found at all 3 creeks, but C. morgani was not found at West Oak Creek, suggesting that the definitive host does not limit the distribution of C. morgani. Physical properties of the streams were measured to examine how these properties influenced the distribution of the worm. Flow rate and pH differed between the 3 sites where C. morgani was found and the West Oak Creek site, suggesting an important role for these abiotic factors in the distribution of this horsehair worm species.

Intraoperative electromyographic assessment of recurrent laryngeal nerve stress and pharyngeal injury during anterior cervical spine surgery with Caspar instrumentation.

OBJECT: Recurrent laryngeal nerve (RLN) injury occurs after anterior cervical spine procedures. In this study the authors used intraoperative electromyographic (EMG) monitoring of the posterior pharynx as a surrogate for RLN function and monitored endotracheal tube (ET) cuff pressure to determine if there was an association between these variables and clinical outcome. METHODS: Sixty patients in whom anterior cervical spine procedures were to be performed comprised the study population. After intubation, the ET cuff was adjusted to a just-seal volume and attached to a pressure monitor. A laryngeal surface electrode was placed in the posterior pharynx, and spontaneous EMG activity was monitored throughout the procedure. Cuff pressures and EMG activity were recorded during neck retraction and when EMG activity increased 20% above baseline. Patients were divided into two groups: those with sore throat/dysphonia and those without symptoms. Cuff pressures and EMG values were compared between groups, and the differences were correlated with clinical outcome. CONCLUSIONS: Hoarseness immediately after surgery was reported in 38% of patients whereas 15% exhibited severe symptoms. In symptomatic patients the period of intubation had been longer, and the ET cuff pressures had been elevated. In most patients EMG activity increased during insertion of the retractor and decreased after its removal. In these patients a greater number of episodes of elevated EMG activity during surgery were also noted. Two patients experienced prolonged hoarseness, and one required teflon injections of the vocal fold. This patient's EMG activity increased (15-18 times baseline) during surgery. In the few patients who were symptomatic with increased EMG activity, neither the timing nor direction of change could be associated with symptoms. Intubation time and elevated ET cuff pressure were the most important contributors to dysphonia and sore throat after anterior cervical spine surgery.

MR of leptomeningeal spinal and posterior fossa amyloid.

We report an unusual cause of leptomeningeal MR enhancement, amyloid, along the surfaces of the spinal cord and brain stem and in the spinal subarachnoid space, with sacral intradural and epidural deposition. Type I familial amyloid polyneuropathy may cause amyloid deposition along the leptomeninges of the spinal cord and brain in addition to the visceral organs and the peripheral somatic and autonomic nerves.

Use of instrumentation in degenerative disease of the cervical spine.

Degenerative diseases of the cervical spine (including cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament) occur predominantly in elderly persons. Decompressive laminectomy has been the standard of surgical treatment in the United States for several decades. Postlaminectomy kyphosis and instability and inadequate decompression of anterior compressing forces can fail to halt and may even contribute to progression of neurologic deterioration. Instrumentation of the cervical spine provides a means of stabilization and allows safer multilevel anterior decompression. The biomechanics of degenerative disease of the cervical spine as well as surgical treatment options are discussed. Atlantoaxial transarticular screw fixation and other modalities of instrumentation are described.

Transoral crossbow injury to the cervical spine: an unusual case of penetrating cervical spine injury.

The complexity of missile injuries to the cervical spine has increased as the technology that causes these injuries has become more sophisticated. Management requires adaptation of conventional neurosurgical approaches to the cervical spine in an effort to limit neurological deficit and establish stability. We report an unusual case of a 19-year-old man who suffered transoral penetration of the cervical spine by an arrow released by a crossbow at close range.

Intracranial hematoma with subsequent brain abscess after carotid endarterectomy.

A 62-year-old man developed an infected left carotid endarterectomy with false aneurysm formation and subsequent bacteremia after staged carotid endarterectomies. He was found to have a right frontal lobe hemorrhage that developed into a staphylococcal brain abscess. We postulate there was bacterial seeding of the hematoma resulting in brain abscess formation.

Cerebellar venous angiomas. A continuing controversy.

We have studied three patients with angiographically documented cerebellar venous angioma (CVA). One patient had a subacute cerebellar hematoma and underwent posterior fossa craniotomy for evacuation of the hematoma and excision of the malformation. A hemorrhagic venous infarction of the brain stem and cerebellum occurred, and the patient died three weeks postoperatively. A second patient with an unruptured CVA had a history of headaches, tinnitus, and vertigo. Conservative treatment was elected, and the patient's condition remains unchanged after 11 months of follow-up. The third patient, recently diagnosed as having an unruptured CVA had episodic vertigo and disequilibrium. Conservative treatment was chosen, and he is asymptomatic after six months of follow-up. Based on a review of 24 other cases of CVA plus our experience we could not conclude any definite trend regarding natural history or treatment. However, conservative treatment seems the logical choice in patients with unruptured CVA.