Winn Hr

Balloon Angioplasty for the Treatment of Vasospasm: Results of First 50 Cases

OBJECTIVE To report the results of the first 50 consecutive patients with vasospasm secondary to subarachnoid hemorrhage treated with balloon angioplasty after failure of medical management. METHODS Retrospective uncontrolled study of 50 consecutive patients treated with balloon angioplasty between February 1988 and July 1992. Forty-six had objective clinical deterioration despite maximal medical therapy, whereas four were treated on the basis of rapidly accelerating transcranial Doppler velocities and decreased regional blood perfusion detected by technetium-99m-exametazime brain single photon emission computed tomography. All patients had evidence of marked vasospasm demonstrated by angiography. Thirty-two (64%) and 46 (92%) patients underwent angioplasty within 12 and 18 hours, respectively. RESULTS Of the patients with clinical evidence of vasospasm-induced ischemia, 28 (61%) showed sustained neurological improvement within 72 hours of angioplasty. Three (6%) patients deteriorated within 72 hours after angioplasty, with two (4%) patients dying immediately after angioplasty as a result of vessel rupture and the other patients Glasgow Coma Scale score decreasing by 2. Two additional patients in poor condition with Hunt and Hess Grade V at the time of angioplasty subsequently died during hospitalization. Two other patients died as a result of unclipped aneurysms that subsequently bled 4 and 12 days after angioplasty, respectively. The improvement demonstrated clinically, angiographically, and by transcranial Doppler after angioplasty was sustained, with only one patient requiring subsequent angioplasty of a previously dilated segment (total, 170 vessel segments dilated). Two patients developed vasospasm in previously undilated segments. CONCLUSION Timely balloon angioplasty can reverse delayed ischemic deficit caused by vasospasm in patients for whom medical therapy has failed.

Transcranial Doppler in the Evaluation of Internal Carotid Artery Dissection

BACKGROUND AND PURPOSE A subject with dissection of the internal carotid artery (ICA) may present with a variety of symptoms, from headache to stroke. Thus far, it has not been possible to identify the subset of patients at risk for cerebral ischemia. Because the majority of these ischemic events are secondary to embolic phenomena, we used transcranial Doppler (TCD) evaluation with emboli monitoring to study 17 consecutive patients with ICA dissection treated at Harborview Medical Center, Seattle, Wash, during a 2-year period from 1992 until 1994. METHODS Ten patients with ICA dissection secondary to trauma and seven with spontaneous ICA dissection were diagnosed by carotid angiography and studied by TCD from the time of diagnosis through initiation of therapy. Emboli monitoring was performed in the middle cerebral artery (MCA) ipsilateral to the dissection at the initial evaluation and intermittently thereafter to ensure that the emboli stopped with treatment. RESULTS Emboli were detected in the MCA distal to the dissection in 10 of 17 patients (59%). Patients with microemboli detected by TCD presented with a stroke (70%) much more frequently than those without emboli (14%) (P=.0498). The presence of a pseudoaneurysm did not increase the risk of either microemboli or stroke. CONCLUSIONS We have demonstrated a high incidence of intracranial microemboli in the MCA distal to carotid dissections and a significant correlation between the presence of emboli and stroke. TCD can therefore be used as an adjunctive tool to manage patients with suspected carotid dissection and may prove useful in evaluating the efficacy of treatment in reducing microemboli and subsequent stroke.

Effect of transient moderate hyperventilation on dynamic cerebral autoregulation after severe head injury.

OBJECTIVE This study was undertaken to evaluate the effect of acute moderate hyperventilation on cerebral autoregulation in head-injured patients. METHODS Dynamic cerebral autoregulation was analyzed by use of transcranial doppler ultrasonography before and after hyperventilation in 10 patients with severe head injury. All of the patients were artificially ventilated and underwent continuous monitoring of arterial blood pressure, intracranial pressure, and end-tidal carbon dioxide. To test autoregulation, rapid transient decreases in systemic blood pressure were achieved by quickly releasing large blood pressure cuffs that were inflated around both thighs. This resulted in a drop of 24 +/- 6 mm Hg in mean systemic blood pressure, which lasted an average of 49 +/- 24 seconds. Cerebral blood flow velocity was monitored continuously in both middle cerebral arteries by use of transcranial doppler ultrasonography. The percentage change in middle cerebral artery velocity was used as an index of the change in cerebral blood flow during the autoregulatory response. The change in estimated cerebrovascular resistance, immediately after the blood pressure drop, or the rate of regulation was used to analyze the effectiveness of the cerebral autoregulation. This value was calculated by determining the rate of increase in middle cerebral artery velocity during the 1st 5 seconds after a blood pressure drop, relative to the rate of increase of the cerebral perfusion pressure. RESULTS The average rate of regulation during normocapnia at pCO2 of 37 mm Hg was 11.4 +/- 5% per second. After reduction of the pCO2 to 28 mm Hg, the average rate of regulation improved significantly (P < 0.001) to 17.7 +/- 6% per second. Autoregulation improved, despite no significant change in the cerebral perfusion pressure during hyperventilation. The degree of improvement in autoregulation was significantly correlated with the CO2 reactivity (r = 0.45, P < 0.05) but did not correlate (r = -0.23, P = 0.33) with the change in arterial pH value after hyperventilation. CONCLUSION These results confirm the finding that dynamic autoregulation is disturbed in severe head injury and that moderate transient hyperventilation can temporarily improve the efficiency of the autoregulatory response, probably as a result of a transient increase in vascular tone.

Use of stimulation mapping and corticography in the excision of arteriovenous malformations in sensorimotor and language-related neocortex.

The excision of an arteriovenous malformation (AVM) located within eloquent neocortex presents a formidable neurosurgical challenge. Compromise of the vascular supply to normal surrounding brain or surgical trauma to essential neighboring neocortex may result in unacceptable postoperative neurological morbidity. In addition, successful removal of these lesions without the benefit of intraoperative corticography may leave in situ areas of highly epileptogenic brain, resulting in continued epilepsy. In this report, we describe eight patients who underwent craniotomy and excision of AVMs at our institutions. Six of these lesions were located in the dominant (left) hemisphere, and two were on the right. All patients underwent preoperative testing with Amytal administered via the carotid artery (Wada test). Subsequently, the patient was placed under local anesthesia, and we performed a craniotomy. Electrocorticography was used to identify epileptogenic brain in the region of the AVM and to establish after-discharge thresholds to electrical stimulation. Stimulation-mapping techniques were then used to delineate critical motor, sensory, and language areas. Trial occlusion of feeding vessels was also carried out to document postocclusion neurological deterioration, if any. At a later time, a second procedure was performed under general anesthesia to excise the lesion and any epileptogenic foci, using the cortical maps derived earlier. Using these techniques, it was possible to effect complete excision of these lesions in seven of eight patients without causing additional neurological deficits.

Relative effects of brain and non-brain injuries on neuropsychological and psychosocial outcome

Based on the 242 consecutive surviving head injury cases and 132 general trauma cases, this study examined the contribution of brain and non-brain injuries to cognitive and psychosocial outcome 1 month postinjury. The study also examined the relationships among various head injury severity indices. The head injury severity indices were all correlated but patients with Glasgow Coma Scale scores in the mild range had broadly ranging scores on the other head injury severity indices (Abbreviated Injury Scale and time to follow commands). Neuropsychological outcome was related to brain injury severity, but was not independently influenced by severity of other systems injuries. Psychosocial outcome related to both brain and non-brain injuries independently. When evaluating trauma outcome, it is important to consider the contributions of both brain and other system injuries.

Evaluation of Brain Death Using Transcranial Doppler

Cerebral blood flow velocities in the middle cerebral arteries were measured using transcranial Doppler in 12 patients with conditions that ultimately resulted in brain death. All patients had sustained closed head injury, gunshot wounds to the head, or spontaneous intracerebral hemorrhages. When clinical criteria for brain death were met, a characteristic pattern was found with transcranial Doppler. This pattern consisted of reverberating flow, with forward flow in systole and retrograde flow in diastole. When this pattern was seen, there was arrest of cerebral flow, as measured by radionuclide scanning using technetium, in all patients studied. Transcranial Doppler is a useful technique for easily assessing the arrest of the cerebral circulation.

Bacterial meningitis associated with lumbar drains: a retrospective cohort study

OBJECTIVES The infective potential of lumbar drainage is an important topic deserving particular study. The aetiology, incidence, and clinical findings associated with bacterial meningitis are described in patients having continuous lumbar CSF drainage to treat communicating hydrocephalus after subarachnoid haemorrhage or CSF leaks after traumatic dural rents. METHODS Retrospective review of the records of patients with a positive CSF bacterial culture who underwent lumbar drain placement over a 39 month period. RESULTS Thirteen cases of bacterial meningitis occurred subsequent to the use of 312 lumbar drain kits (4.2%). All meningitic patients had CSF pleocytosis, but not all had peripheral leukocytosis. Fever, peripheral leukocytosis, and CSF pleocytosis did not help to differentiate the presence of bacterial meningitis from other infections. Eight patients had prior CSF drainage procedures, including ventriculostomy (n=5) or lumbar drain (n=5) placements; two patients received both procedures. Six of 13 patients developed their CSF infection within 24 hours of lumbar drain insertion. Six of 13 patients developed meningitis while receiving antibiotics for other reasons. CONCLUSIONS External lumbar drainage seems to carry a low risk of infectious meningitis and offers a safe alternative to ventriculostomy or serial lumbar punctures. Antibiotics do not seem to protect completely against developing the infection. The infection happens most often with skin organisms. The meningitis often appears within 24 hours after lumbar drain placement. Daily CSF samples should include bacterial cultures but cell counts may not offer any additional useful information in diagnosing the complication. Lumbar drain insertion and management need not be confined to the intensive care unit.

Thrombotic, Infectious, and Procedural Complications of the Jugular Bulb Catheter in the Intensive Care Unit

OBJECTIVE An assessment of the thrombotic, infectious, and technical complications of continuous jugular bulb catheter monitoring in the intensive care unit (ICU) was made. METHODS Over a 1-year period, 44 patients suffering from traumatic brain injury, subarachnoid hemorrhage, or stroke received jugular bulb catheter monitoring in the ICU. They were followed for catheter insertion complications and the development of bacteremia. In 20 patients chosen randomly, an ultrasonographic evaluation was performed after removal of the catheter for an assessment of internal jugular vein thrombosis. RESULTS Of the 44 patients, 1 became bacteremic; the source was identified as a thoracostomy site. Among the complications related to the 44 catheter insertions, there were 2 instances of carotid artery puncture (4.5%), 1 misplaced catheter (thoracic placement), and 1 clinically insignificant hematoma. Of the 20 patients investigated with ultrasonography, 8 (40%) had nonobstructive, subclinical internal jugular vein thrombi after jugular bulb catheter monitoring (95% confidence interval, 19-61%). The median monitoring duration was 3 days (range, 1-6 d). No clinical factor was identified to be associated with thrombus formation. CONCLUSION We conclude the following: 1) the risk of bacteremia related to the jugular bulb catheter was negligible; 2) complications related to catheter insertion were rare and clinically insignificant; and 3) the incidence of subclinical internal jugular vein thrombosis after jugular bulb catheter monitoring is considerable. Although it is worthy to note this complication, no patient with a thrombus became symptomatic in the present series. The risk-benefit assessment of this monitoring technique must include consideration of subclinical thrombosis.

Management of head injury. Posttraumatic seizures.

Posttraumatic seizures are relatively common among patients with severe head injuries, with major risk factors being penetrating head wound, hematoma, depressed skull fracture, and, for late seizures, early seizures. Management of late posttraumatic seizures, if they do develop, follows the treatment of patients with epilepsy. Their treatment should be determined by the type of seizure (i.e., partial or generalized) and the individual responsiveness of the patient to drug therapy. Prophylactic administration of antiepileptic drugs to prevent posttraumatic epilepsy has been frequently tried. The data supports a short-term but not a long-term effect of the most commonly used drug, phenytoin. A decision of whether to use prophylaxis, with what, and for how long needs to consider the likely benefit (i.e., the chance of seizures if untreated and the likelihood that the proposed treatment will substantially reduce that chance) and risk (i.e., medical or behavioral adverse effects) of this treatment strategy.

Accuracy of continuous jugular bulb oximetry in the intensive care unit.

OBJECTIVE: To address the accuracy of a bedside jugular bulb oxygen saturation (S j O 2 ) catheter monitor (Baxter-Edwards, Santa Ana, CA) versus in vitro co-oximetry measurements in the intensive care unit (ICU). METHODS: By prospective protocol, we compared blood gas measurements with simultaneously recorded continuous bedside oximetric monitor values for 31 ICU patients with traumatic brain injury undergoing jugular bulb catheter monitoring. For suboptimal fiberoptic light signal quality indices, the catheter was repositioned, flushed, or both before drawing the sample for in vitro measurement. Laboratory and bedside monitor data were examined for association using the X 2 and paired t tests and a linear regression model. RESULTS: We assessed 195 samples (median, 5 per patient; range, 1-14) who were monitored an average of 3.4 (range, 1-6) days. The in vivo monitor (range, 32-94%) and in vitro co-oximetry (range, 38-93%) values had acceptable correlation (y = 0.94x + 4.4, r 2 = 0.80). For bedside monitor detection of jugular bulb desaturation (S j O 2 < 50% for 10 min), the kappa statistic was 0.35, the sensitivity was 45 to 50%, and the specificity was 98 to 100%. CONCLUSION: Continuous ICU S j O 2 monitoring correlates significantly with in vitro values, but less so than previously described during intracranial surgery. Although sensitivity of the bedside monitor to detect confirmed desaturations remains an issue, the high specificity indicates that it is less of a concern that patients may be misdiagnosed as having desaturations resulting in unnecessary interventions. Nonetheless, suspected jugular bulb desaturation should be verified before taking therapeutic actions.