Michael S. Pessin

A Reversible Posterior Leukoencephalopathy Syndrome

BACKGROUND AND METHODS In some patients who are hospitalized for acute illness, we have noted a reversible syndrome of headache, altered mental functioning, seizures, and loss of vision associated with findings indicating predominantly posterior leukoencephalopathy on imaging studies. To elucidate this syndrome, we searched the log books listing computed tomographic (CT) and magnetic resonance imaging (MRI) studies performed at the New England Medical Center in Boston and Hôpital Sainte Anne in Paris; we found 15 such patients who were evaluated from 1988 through 1994. RESULTS Of the 15 patients, 7 were receiving immunosuppressive therapy after transplantation or as treatment for aplastic anemia, 1 was receiving interferon for melanoma, 3 had eclampsia, and 4 had acute hypertensive encephalopathy associated with renal disease (2 with lupus nephritis, 1 with acute glomerulonephritis, and 1 with acetaminophen-induced hepatorenal failure). Altogether, 12 patients had abrupt increases in blood pressure, and 8 had some impairment of renal function. The clinical findings included headaches, vomiting, confusion, seizures, cortical blindness and other visual abnormalities, and motor signs. CT and MRI studies showed extensive bilateral white-matter abnormalities suggestive of edema in the posterior regions of the cerebral hemispheres, but the changes often involved other cerebral areas, the brain stem, or the cerebellum. The patients were treated with antihypertensive medications, and immunosuppressive therapy was withdrawn or the dose was reduced. In all 15 patients, the neurologic deficits resolved within two weeks. CONCLUSIONS Reversible, predominantly posterior leukoencephalopathy may develop in patients who have renal insufficiency or hypertension or who are immunosuppressed. The findings on neuroimaging are characteristic of subcortical edema without infarction.

PROACT: A Phase II Randomized Trial of Recombinant Pro-Urokinase by Direct Arterial Delivery in Acute Middle Cerebral Artery Stroke

BACKGROUND AND PURPOSE To test the safety and recanalization efficacy of intra-arterial local delivery of plasminogen activators in acute ischemic stroke, a randomized trial of recombinant pro-urokinase (rpro-UK) versus placebo was undertaken in patients with angiographically documented proximal middle cerebral artery occlusion. METHODS After exclusion of intracranial hemorrhage by CT scan, patients with abrupt onset of symptoms of focal ischemia likely to receive treatment within 6 hours who satisfied all clinical eligibility criteria underwent carotid angiography. Patients displaying Thrombolysis in Acute Myocardial Infarction grade 0 or 1 occlusion of the M1 or M2 middle cerebral artery were randomized 2:1 to receive rpro-UK (6 mg) or placebo over 120 minutes into the proximal thrombus face. All patients received intravenous heparin. Recanalization efficacy was assessed at the end of the 2-hour infusion, and intracerebral hemorrhage causing neurological deterioration was assessed at 24 hours. RESULTS Of 105 patients who underwent angiography, 59 were excluded from randomization. Among the 46 patients randomized, 40 were treated with rpro-UK (n=26) or placebo (n=14) a median of 5.5 hours from symptom onset. Recanalization was significantly associated with rpro-UK (2P=.017). Hemorrhagic transformation causing neurological deterioration within 24 hours of treatment occurred in 15.4% of the rpro-UK-treated patients and 7.1% of the placebo-treated patients (2P=.64). Both recanalization and hemorrhage frequencies were influenced by heparin dose. CONCLUSIONS Intra-arterial local rpro-UK infusion was associated with superior recanalization in acute thrombotic/ thromboembolic stroke compared with placebo. In this regimen, heparin dose influenced hemorrhage frequency and recanalization. Although symptomatic hemorrhage remains a concern, this study suggests that recanalization is enhanced with rpro-UK and heparin.

The Harvard Cooperative Stroke Registry A prospective registry

Data from 694 patients hospitalized with stroke were entered in a prospective, computer-based registry. Three hundred and sixty-four patients (53 percent) were diagnosed as having thrombosis, 215 (31 percent) as having cerebral embolism, 70 (10 percent) as having intracerebral hematoma, and 45 (6 percent) as having subarachnoid hemorrhage from aneurysm or arteriovenous malformations. The 364 patients diagnosed as having thrombosis were divided into 233 (34 percent of all 694 patients) whose thrombosis was thought to involve a large artery and 131 (19 percent) with lacunar infarction. Many of the findings in this study were comparable to those in previous registries based on postmortem data. New observations include the high incidence of lacunes and cerebral emboli, the absence of an identifiable cardiac origin in 37 percent of all emboli, a nonsudden onset in 21 percent of emboli, and the occurrence of vomiting at onset in 51 percent and the absence of headache at onset in 67 percent of hematomas.

Broca aphasia Pathologic and clinical

The speech disturbance resulting from infarction limited to the Broca area has been delineated; it differs from the speech disorder called Broca aphasia, which results from damage extending far outside the Broca area. Nor does Broca area infarction cause Broca aphasia. The lesions in 20 cases observed since 1972 were documented by autopsy, computerized tomography, or arteriogram; the autopsy records from the Massachusetts General hospital for the past 20 years and the published cases since 1820 were also reviewed. The findings suggest that infarction affecting the Broca area and its immediate environs, even deep into the brain, causes a mutism that is replaced by a rapidly improving dyspraxic and effortful articulation, but that no significant disturbance in language function persists. The more complex syndrome traditionally referred to as Broca aphasia, including Brocas original case, is characterized by protracted mutism, verbal stereotypes, and agrammatism. It is associated with a considerably larger infarct which encompasses the operculum, including the Broca area, insula, and adjacent cerebrum, in the territory supplied by the upper division of the left middle cerebral artery.

New England medical center posterior circulation registry

Among 407 New England Medical Center Posterior Circulation registry patients, 59% had strokes without transient ischemic attacks (TIAs), 24% had TIAs then strokes, and 16% had only TIAs. Embolism was the commonest stroke mechanism (40% of patients including 24% cardiac origin, 14% intraarterial, 2% cardiac and arterial sources). In 32% large artery occlusive lesions caused hemodynamic brain ischemia. Infarcts most often included the distal posterior circulation territory (rostral brainstem, superior cerebellum and occipital and temporal lobes); the proximal (medulla and posterior inferior cerebellum) and middle (pons and anterior inferior cerebellum) territories were equally involved. Severe occlusive lesions (>50% stenosis) involved more than one large artery in 148 patients; 134 had one artery site involved unilaterally or bilaterally. The commonest occlusive sites were: extracranial vertebral artery (52 patients, 15 bilateral) intracranial vertebral artery (40 patients, 12 bilateral), basilar artery (46 patients). Intraarterial embolism was the commonest mechanism of brain infarction in patients with vertebral artery occlusive disease. Thirty‐day mortality was 3.6%. Embolic mechanism, distal territory location, and basilar artery occlusive disease carried the poorest prognosis. The best outcome was in patients who had multiple arterial occlusive sites; they had position‐sensitive TIAs during months to years. Ann Neurol 2004;56:389–398

Chinese‐white differences in the distribution of occlusive cerebrovascular disease

The distribution of cerebrovascular lesions is affected by race. Blacks and Japanese have more intracranial occlusive cerebrovascular disease, while whites have more extracranial disease. Despite a high incidence of stroke in China, there are few formal studies of the distribution of vascular occlusive disease in Chinese populations. We compared clinical and angiographic features of 24 white and 24 Chinese patients with symptomatic occlusive cerebrovascular disease. In symptomatic vascular territories, whites had more severe (≥50% stenosis) extracranial lesions, while Chinese had more severe intracranial lesions. When we counted mild and severe lesions in a symptomatic territory, whites had more extracranial lesions while Chinese had more intracranial lesions. When we combined symptomatic and asymptomatic temtories, whites had more extracranial lesions, while Chinese had more intracranial lesions. White patients reported more transient ischemic attacks. The distribution of lesions, however, was not explained by differences in incidence of transient ischemia, hypertension, diabetes, hypercholesterol-emia, or ischemic heart disease between the groups. The preponderance of intracranial vascular lesions in Chinese patients is similar to that seen in blacks and Japanese. Racial differences in the occurrence of extracranial and intracranial lesions raise the possibility of a different underlying pathophysiology for the 2 locations.

Serial assessment of acute stroke using the NIH Stroke Scale.

Background and Purpose The National Institutes of Health (NIH) Stroke Scale has been used in clinical trials to assess neurological outcome after investigational therapy for acute stroke. We used the NIH Stroke Scale to study the degree and time course of recovery in patients with acute stroke who were treated with conventional therapy. Methods We serially assessed 50 patients with ischemic stroke who presented within 24 hours of onset of symptoms. Patients were grouped by stroke subtype. Major neurological improvement was defined as a decrease in the stroke score by 4 points or more. Results The mean NIH stroke score for all patients improved significantly by 7 to 10 days and at last follow-up (average, 44 days). Major neurological improvement was seen in 5 of 41 patients (12%; 95% confidence interval [CI], 2% to 22%) by 24 hours, 11 of 40 patients (28%; 95% CI, 14% to 41%) by 48 hours, and 19 of 37 patients (51%; 95% CI, 35% to 67%) by follow-up. The subgroup of patients with middle cerebral artery territory embolism showed a similar pattern of improvement; in contrast, patients with lacunar infarcts did not show significant change in scores during the study period. The score on admission did not correlate with the degree of subsequent improvement or deterioration. Conclusions A significant percentage of patients with acute ischemic stroke treated with conventional therapy show early improvement as assessed by the NIH Stroke Scale. The degree and time course of recovery may be influenced by stroke type. (Stroke. 1994;25:362-365.)

Dissection of the intracranial vertebral artery

We describe four patients and review prior reports to clarify the clinical, radiographic, and pathologic findings of intracranial vertebral artery (VA) dissection. A 43-year-old man and a 33-year-old woman had chronic bilateral VA dissecting aneurysms. The man had multiple episodes of subarachnoid hemorrhage (SAH) and necropsy showed multiple dissections and defects in the internal elastica. The woman had many brainstem TIAs and strokes during 3 years. Two other patients had SAH and unilateral dissections. Intracranial VA dissection causes four overlapping syndromes: (1) brainstem infarcts are usually due to subintimal dissection extending into the basilar artery, affect younger patients, and often are single fatal events; (2) SAH is due to subadventitial or transmural dissection; (3) aneurysms cause mass effect on the brainstem and lower cranial nerves; and (4) chronic dissections due to connective tissue defects cause extensive bilateral aneurysms and repeated TIAs, small strokes, and SAH.

Clinical and Angiographic Features of Carotid Transient Ischemic Attacks

To determine the prevalence of radiologically evident carotid stenosis in patients with transient cerebral ischemic attacks, we analyzed 95 consecutive hospitalized patients who during a two-year period had appropriate symptoms and also underwent angiography. Pure transient hemisphere symptoms affected 52 patients, pure monocular blindness occurred in 33, and 10 experienced each type of attack separately. Tight stenosis (less than or equal to 2 mm) or occlusion was present in 49 patients (52 per cent). Thirteen patients showed intracranial-branch occlusion, nine of whom had no notable stenosis. Only two clinical transient ischemic attack features correlated with angiographic findings: in transient hemisphere attacks lasting for one hour or longer, the carotid arteries revealed no notable stenosis (0.05 less than P less than 0.1); and separate hemisphere and ocular attacks in the same patient correlated with tight carotid stenosis. On the basis of the angiographic findings, the study indicates there are several distinct groups of patients with carotid transient ischemic attacks.

Limb shaking--a carotid TIA.

Eight patients are described with an unusual form of carotid transient ischemic attack, limb shaking. The basic features included a brief, involuntary, coarse, irregular, wavering movement or tremble involving arm-hand alone, or arm-hand and leg together. In 2 patients limb shaking was the initial manifestation of carotid occlusive disease, and all but one patient had other typical carotid transient ischemic attacks. Major atheromatous carotid occlusive disease was present in all patients on the side opposite the limb movements. Four patients had bilateral carotid occlusive disease. Cerebral ischemia from a carotid territory low-perfusion state may be the pathogenesis of these limb movements, an idea supported by the apparent benefit of surgical revascularization in abolishing or reducing the limb shaking in 6 patients. There was no clinical or EEG evidence to document an epileptiform etiology. Recognition of this uncommon form of carotid transient ischemic attack may be important in the early diagnosis and treatment of carotid occlusive disease.