Patrick S. Reynolds

Asymmetric Neuroimaging in Creutzfeldt‐Jakob Disease: A Ruse

Creutzfeldt‐Jakob disease (CJD) causes diffuse neurological symptoms, but asymmetric lesions have been found on conventional magnetic resonance imaging (MRI) and diffusion‐weighted imaging (DWI).Less often, positron emission tomography (PET) scanning can also reveal asymmetric lesions in patients with CJD. Such imaging may mislead clinicians. The authors present a case of a woman with CJD who was diagnosed as having suffered a stroke because she had asymmetric T2‐weighted imaging (T2WI) MRI abnormalities that were interpreted as a stroke. It was noted that the patient had clinical features consistent with CJD, including rapidly progressive dementia, myoclonus, cerebellar dysfunction, and pyramidal and extrapyramidal signs. This diagnosis was supported by periodic epileptiform discharges on the electroencephalogram (EEG) and by elevated 14‐3‐3 protein in the cerebrospinal fluid. MRI T2WI and DWI showed dramatically asymmetric abnormalities involving the left cortex. A PET study found decreased metabolism in the left cerebral and right cerebellar hemispheres. The patients clinical, EEG, and laboratory data were all consistent with CJD, not other diseases, but the MRI and PET had atypical, asymmetric findings. This case demonstrates that CJD should be considered in the differential diagnosis of patients with rapidly progressive neurological decline, even if they have asymmetric imaging findings.

Ophthalmic artery flow direction on color flow duplex imaging is highly specific for severe carotid stenosis

Background/Purpose. Collateral flow patterns are important risk factors for brain ischemia in the presence of internal carotid artery (ICA) stenosis or occlusion. Ophthalmic artery (OA) flow reversal, routinely studied by transcranial Doppler sonography, is an important marker for high‐grade ICA stenosis or occlusion. The authors sought to define the value of assessing OA flow direction with color flow duplex ultrasonography (CDUS) in the setting of significant ICA disease. Methods. Of all patients having routine carotid ultrasound in the neurosonology laboratory between July 1995 and November 2000, 152 had both carotid and orbital (OA flow direction by reduced power orbital CDUS) examinations as well as angiographic confirmation of stenosis to which North American Symptomatic Carotid Endarterectomy Trial criteria could be applied. Degree of angiographic stenosis in these 152 patients (304 arteries) was correlated with OA flow direction. Results. Of 304 arteries, 101 had greater than 80% stenosis by angiogram. In 56 of these 101 arteries with high‐grade stenosis or occlusion, the ipsilateral OA was reversed; however, OA flow direction was never reversed ipsilateral to arteries with less than 80% stenosis (sensitivity 55%, specificity 100%, negative predictive value 82%, and positive predictive value 100% for OA flow reversal as a marker of high‐grade carotid lesions). Discussion/Conclusions. OA flow direction is easily studied with CDUS. Reversed OA flow direction is highly specific (100%) for severe ipsilateral ICA stenosis or occlusion, with excellent positive predictive value, moderate negative predictive value, and limited sensitivity. OA flow reversal is not only quite specific for severe ICA disease, which may be helpful if the carotid CDUS is difficult or inadequate, but may also provide additional hemodynamic insights (ie, the inadequacy of other collateral channels such as the anterior communicating artery). OA evaluation can provide important hemodynamic information and should be included as part of carotid CDUS if there is any evidence of ICA stenosis or occlusion.

Predictors of 30-Day Hospital Readmission Following Ischemic and Hemorrhagic Stroke

Stroke patients have a high rate of 30-day readmission. Understanding the characteristics of patients at high risk of readmission is critical. A retrospective case-control study was designed to determine factors associated with 30-day readmission after stroke. A total of 79 cases with acute ischemic or hemorrhagic strokes readmitted to the same hospital within 30 days were compared with 86 frequency-matched controls. Readmitted patients were more likely to have had ≥2 hospitalizations in the year prior to stroke (21.5% vs 2.3% in controls, P < .001), and in the multivariate model, admission National Institutes of Health Stroke Score (NIHSS; odds ratio [OR] = 1.072; 95% confidence interval [CI] = 1.021-1.126 per 1 point increase; P = .005), prior hospitalizations (OR = 2.205; 95% CI = 1.426-3.412 per admission; P < .001), and absence of hyperlipidemia (OR = 0.444; 95% CI = 0.221-0.894; P = .023) were independently associated with readmission. The research team concludes that admission NIHSS and frequent prior hospitalizations are associated with 30-day readmission after stroke. If validated, these characteristics identify high-risk patients and focus efforts to reduce readmission.

Lumbar puncture experience among medical school graduates: the need for formal procedural skills training

Editor ) Over the past 20 years medical school curricula have changed significantly. Curriculum committees have struggled to incorporate research opportunities, technology and emerging subjects into 4-year programmes that were already demanding. Despite these changes, training programmes still have deficiencies, and a major concern is that graduates do not have sufficient experience performing common procedures. To evaluate the validity of this concern, we surveyed recent medical school graduates to determine their level of experience regarding lumbar punctures. This procedure was chosen because it is common and relevant to a variety of specialities.

Intracerebral Hemorrhage Associated with Over-the-Counter Inhaled Epinephrine

He improved rapidly after admission. A repeat CT showed no underlying mass. At follow-up 3 months later, he had stopped using inhaled epinephrine and tobacco, and he remained normotensive. His only residual defi cit was minimal right arm weakness, which had been noted during his hospitalization. This is the fi rst report linking an inhaled over-the-counter sympathomimetic to ICH. While it is possible his excessive epinephrine use did not cause the thalamic hemorrhage, we were unable to identify risk factors such as chronic hypertension, illicit drug use, or a hemorrhagic disorder. He did smoke and take an occasional ibuprofen. Since cigarette use slightly increases the risk of ICH and ibuprofen can induce platelet dysfunction, it is possible these factors played a role in his stroke [2] . Perhaps the excessive use of inhaled epinephrine, combined with smoking and ibuprofen, led to the ICH. Certainly, the increased use of inhaled epinephrine appears temporally related to the stroke. There are many case reports describing ICH after taking overthe-counter sympathomimetics, and sales of two of these drugs, phenylpropanolamine and ephedra, were halted in the US after Over the past 25 years, many case reports have described intracerebral hemorrhage (ICH) after ingestion of over-the-counter sympathomimetics [1] . Both oral and nasal delivery systems have been associated with ICH, but inhaled over-the-counter sympathomimetics have not previously been associated with stroke [1] . We present a patient who experienced an ICH after using excessive amounts of over-the-counter inhaled epinephrine. A 73-year-old male presented with the acute onset of confusion and emesis. His past medical history was signifi cant for a carotid endarterectomy and chronic obstructive pulmonary disease. He had no history of hypertension. Initially, his wife reported his only medication was occasional ibuprofen. He did not drink alcohol but did smoke cigarettes daily. On exam, he was tachycardic (110 beats per-minute) and hypertensive (160/81 mm Hg). He had a fl uent aphasia, with frequent paraphasic errors and impaired comprehension, naming, and repetition. No defi nite facial droop, hemiplegia, or refl ex asymmetry was noted on the initial exam, but both toes were up going. CT revealed a left thalamic hemorrhage ( fi g. 1 ). Since the stroke was in a typical location for a hypertensive hemorrhage, his blood pressure was monitored carefully. After the initial hypertensive reading in the emergency room, he remained normotensive throughout the rest of the hospitalization. No signs of chronic hypertension, such as left-ventricular hypertrophy or renal insuffi ciency, were detected on electrocardiogram, transthoracic echocardiogram or blood chemistries. A urine drug screen was negative and coagulation studies were unremarkable. His wife reported that in addition to ibuprofen, he also used over-the-counter inhaled epinephrine for chronic obstructive pulmonary disease (0.22 mg per puff). She said he took this medication daily and it was not unusual for him to use four puffs at a time. The maximum recommended dose is two puffs every 3 h, and it is not to be used on more than 2 days per week. His wife stated that for several days prior to the stroke, as well as the day the stroke occurred, he had been using ‘large amounts’ of inhaled epinephrine because his dyspnea had worsened. She was unable to accurately quantify how much he was using.

Volume flow rate of common carotid artery measured by Doppler method and Color Velocity Imaging Quantification (CVI-Q).

Background. Common carotid artery (CCA) volume flow rate (VFR) is clinically useful for study of cerebrovascular disease. Color Velocity Imaging Quantification (CVI‐Q; Philips Ultrasound International, Irvine, CA), previously reported as accurate and reliable, tracks the flow lumen over the cardiac cycle, as well as mean spatial velocity, which is multiplied by vessel area to obtain VFR. VFR can also be obtained by Doppler sampling for mean velocity, and vessel area based on static B‐mode lumen diameter. We compared CCA VFR by CVI‐Q and Doppler method (DM), since knowledge of how they compare is crucial when both are used clinically. Method. We prospectively studied patients having clinical carotid duplex exams and healthy controls. All had CCA VFR measured by both methods in the same exam session. Results. Thirty‐four studies were reviewed. CCA VFR by CVI‐Q in those without ICA stenosis was 337 ± 96 mL/m, and by DM 359 ± 130 mL/m; P= .33. There was no difference between methods for 50‐75% or 75‐95% ICA stenosis. In 7 patients with ICA occlusion, and 3 with 95‐99% stenosis, VFR was higher by DM than by CVI‐Q (Occlusion: 125 vs 58 mL/m, P= .007; 95‐99%: 152 vs 63 mL/m, P= .038). There was no statistically significant difference between methods for measurement of the ratio of VFR between right and left CCA. Conclusion. In patients with 0‐95% ICA stenosis, VFR by CVI‐Q and DM showed no difference. For 95‐100% ICA stenosis the methods differ; with higher VFR by DM. Side‐to‐side VFR ratios remain constant, irrespective of VFR method, and can still provide clinically useful information.

Comparison of Transcranial Color‐Coded Sonography and Magnetic Resonance Angiography in Acute Ischemic Stroke

Background and Purpose. This study was designed to assess the accuracy of transcranial color‐coded sonography (TCCS) as compared to magnetic resonance angiography (MRA) for detecting intracranial arterial stenosis in patients with acute cerebral ischemia. Methods. The authors prospectively identified 120 consecutive patients admitted with acute ischemic stroke and performed both TCCS and MRA with a mean interval of 1 day. TCCS data (sampling depth, peak systolic and end diastolic angle‐corrected velocity, mean angle‐corrected velocity, and pulsatility index) for middle cerebral arteries (MCAs) were compared to MRA data and classified into 4 grades: normal (grade 1): normal caliber and signal; mild stenosis (grade 2): irregular lumen with reduced signal; severe stenosis (grade 3): absent signal in the stenotic segment (flow gap) and reconstituted distal signal; and possible occlusion (grade 4): absent signal. The cutoffs were chosen to maximize diagnostic accuracy. Results. Interobserver agreement for MRA grading resulted in a weighted‐kappa value of 0.776. The rate of poor temporal window was 37% (89/240). Doppler signals were obtained in 135 vessels, and the angle‐corrected velocities (peak systolic, end diastolic, mean) were significantly different (P= .001, P= .006, P < .001) among the MRA grades: grade 1 (100, 47, 68 cm/s), grade 2 (171, 72, 110 cm/s), grade 3 (226, 79, 134 cm/s), grade 4 (61, 26, 39 cm/s). Additionally, an angle‐corrected MCA peak systolic velocity ≥120 cm/s correlates with intracranial stenosis on MRA (grade 2 or worse) with high specificity (90.5%; 95% confidence interval = 78.5%∼96.8%) and positive predictive value (93.9%) but relatively low sensitivity (66.7%; 95% confidence interval = 61.2%∼69.5%) and negative predictive value (55.1%). Conclusion. Elevated MCA velocities on TCCS correlate with intracranial stenosis detected on MRA. An angle‐corrected peak systolic velocity ≥120 cm/s is highly specific for detecting intracranial stenosis as defined by significant MRA abnormality.

Opinion & Special Articles: The lost resident Why resident physicians still need mentoring

Mentoring is deeply rooted in medical practice. More than just a role model, a mentor is invested in the development of the mentee, providing personal and professional support, guidance, and the means for advancement. Mentoring is vital at all levels of medical training and plays an important role in the development of academicians. Increasing clinical demands, the competitive research environment, numerous administrative pressures, and the relative undervaluing of mentoring for faculty promotion have created challenges to resident mentoring. A greater emphasis on promoting mentoring opportunities for residents is needed at many levels.

Pneumonia in Dysphagic Stroke Patients: Effect on Outcomes and Identification of High Risk Patients

Objectives : To identify variables associated with the development of pneumonia in patients with ischemic stroke and to assess the utility of both the clinical swallowing examination and the videofluoroscopic modified barium swallow (VMBS) to identify stroke patients at risk for aspiration and subsequent pneumonia and to measure the effect of pneumonia on hospital outcomes. Design/Methods: Bedside clinical evaluation and VMBS were performed on 102 patients admitted with acute ischemic stroke who were referred for swallowing eval uation because of clinical suspicion of dysphagia. The clinical features, stroke loca tion and severity, pneumonia, length of stay (LOS), mortality, and costs were evalu ated retrospectively. Results: Pneumonia occurred in 21 of 102 patients (20.6%) and was more fre quent in those with aspiration on VMBS (p < 0.01). Those with pneumonia had longer median LOS (29 days vs. 10 days), higher total costs (

Hemodynamic effects of innominate artery occlusive disease on anterior cerebral artery

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