Thanh G. Phan

Neuroimaging in Deteriorating Patients With Cerebellar Infarcts and Mass Effect

Background and Purpose The decision to proceed with surgery in cerebellar infarct with mass effect (CIMASS) in deteriorating patients is based on clinical features. The potential role of neuroimaging in predicting deterioration has not been systematically studied. In this study we determine the role of neuroimaging in predicting deterioration in CIMASS. Methods We retrospectively reviewed the clinical and neuroimaging features in 90 patients with cerebellar infarcts. We selected for detailed analysis CIMASS in 35 patients. Results Eighteen patients remained stable and 17 deteriorated. Of these 17 patients, 8 were treated conservatively and 9 had surgery. Radiological features indicative of progression were more common in deteriorating patients compared with stable patients: fourth ventricular shift (82.3% versus 50%, P =0.075, OR=4.67), hydrocephalus (76.5% versus 11.1%, P =0.0001, OR=26), brain stem deformity (47% versus 5.6%, P =0.0065, OR=15.1), and basal cistern compression (35.3% versus 0%, P =0.0076, OR=20.91). Differences in upward displacement of the aqueduct and pontomesencephalic junction from Twining’s line, tonsillar descent on sagittal MRI, and infarct volumes between stable and deteriorating patients were not statistically significant. Conclusions Hydrocephalus, brain stem deformity, and basal cistern compression may herald deterioration in CIMASS. Admission to a neurological-neurosurgical intensive care unit and consideration of preemptive surgery are warranted in these patients. Vertical displacement of tonsils or aqueduct, demonstrated by MR imaging, did not predict deterioration.

Posttransplant primary CNS lymphoma

The records and neuro-imaging studies of 8 cases of posttransplant primary CNS lymphoma (PT-PCNSL) diagnosed at Mayo Clinic Rochester between 1970 and 1998 were reviewed retrospectively. All patients received organ transplantation. Patients who had hematologic transplantation were not included in the analysis. The median and mean age of the 4 men and 4 women was 45 years (range, 34 to 50 years). The median duration of symptoms before diagnosis was 36 days (range, 5 to 98 days). At diagnosis, the neurologic examination was focally abnormal in 6 of 8 patients. Compared with the initial computed tomographic study, MRI showed 25 additional brain lesions. Only 43.7% of lesions enhanced with contrast agent; of those that did, all but one were heterogeneous. Ependymal contact occurred in 5 patients. MRI lesion burden increased proportionally to the interval between scans. Diagnostic tissue was obtained by stereotactic biopsy from 6 patients and by open biopsy from 2. Hemorrhage occurred in the biopsy area in 4 patients who had stereotactic biopsy and 2 died (all had normal coagulation studies). Slides available for review (7 patients) showed that the tumors were of CD20-positive lineage and were positive for Epstein-Barr virus, using in situ hybridization. Six patients died. Median survival for the cohort was 13 weeks. PT-PCNSL has clinical and imaging features distinct from typical PCNSL. In our series, (1) PT-PCNSL presented nonspecifically and progressed rapidly, (2) stereotactic brain biopsy had significant morbidity, and (3) despite multimodal therapy, survival was poor.

Hydrocephalus Is a Determinant of Early Mortality in Putaminal Hemorrhage

Background and Purpose Previous studies have shown that the volume of intracerebral hemorrhage and Glasgow Coma Score (GCS) on admission are powerful predictors of 30-day mortality. However, the significance of hydrocephalus associated with deep cerebral hemorrhage has not been studied extensively. The purpose of this study was to determine the prognostic indicators of 30-day mortality in patients with deep cerebral hemorrhage. Methods We studied 100 consecutive patients with deep cerebral hemorrhage between 1994 and 1998. Deep cerebral hemorrhage was divided into 2 groups: putaminal hemorrhage (lateral group) and thalamic and caudate hemorrhage (medial group). Univariate and multivariate logistic regression analyses were performed to determine independent prognostic indicators of 30-day mortality. Results Hydrocephalus was present in 40 of the 100 patients. The 30-day mortality was 29%, and hydrocephalus was present in 76% of those who died. Multivariate analyses showed 2 independent prognostic indicators of 30-day mortality for putaminal hemorrhage: GCS ≤8 (P =0.002, odds ratio [OR] 37.7, CI 3.6 to 396.9) and hydrocephalus (P =0.005, OR 27.4, CI 2.7 to 282.6). However, only GCS ≤8 (P =0.0002, OR 16.5, CI 3.7 to 73.4) was predictive of 30-day mortality for thalamic and caudate hemorrhage. This model (GCS ≤8 and hydrocephalus) has a sensitivity of 57% and a specificity of 91% for predicting 30-day mortality for putaminal hemorrhage. When both attributes were present in putaminal hemorrhage (GCS ≤8 and hydrocephalus), 1 (11%) of 9 patients survived, and when both attributes were missing 28 (100%) of 28 patients survived. Conclusions Obstructive hydrocephalus on admission in a comatose patient with a putaminal hemorrhage predicts 30-day mortality.

Hypertensive encephalopathy presenting with thunderclap headache.

A 68‐year‐old woman presented with thunderclap headache, which led to a search for subarachnoid hemorrhage. Both computerized tomography of the head and cerebrospinal fluid examination were normal. Magnetic resonance imaging revealed abnormalities in the white matter in the parieto‐occipital regions. There was no aneurysm on magnetic resonance angiography. Treatment of hypertension led to resolution of the posterior leukoencephalopathy. Hypertensive encephalopathy with reversible posterior leukoencephalopathy can present as a thunderclap headache.

Pseudoulnar palsy from a small infarct of the precentral knob

Discrete stroke in the parietal lobe or the white matter of the angular gyrus, ventroposterior thalamus, and in the posterior limb of the internal capsule can mimic peripheral nerve lesions.1,2 Recently, the motor hand area has been localized to a knob on the precentral gyrus by functional MRI studies.3 We describe a case in which diffusion-weighted imaging confirmed the observation that the precentral knob is the motor hand area.nnA 74-year-old right-handed man, a retired physician, awoke with right-hand weakness and numbness. He noted difficulty holding a glass of water and numbness involving digits III through V. There was no history of previous stroke. His risk factors for stroke included previous episodes of atrial fibrillation and noninsulin-dependent diabetes. Examination showed weakness (Medical Research Council [MRC] grade, 4/5) of the long finger flexors …

False subarachnoid hemorrhage in anoxic encephalopathy with brain swelling.

The authors present two comatose patients with brain swelling from anoxic encephalopathy. Nonenhanced computed tomography (CT) images showed increased density on the falx, on the tentorium, and in the basal cisterns, all of which falsely suggested subarachnoid hemorrhage. Autopsy in both patients failed to show subarachnoid hemorrhage. In rare circumstances, anoxic encephalopathy can mimic subarachnoid hemorrhage on nonenhanced CT.

Ovarian hyperstimulation syndrome with ischemic stroke due to an intracardiac thrombus.

Ovarian hyperstimulation syndrome (OHSS) is a rare complication in patients undergoing ovarian induction therapy.1 The clinical symptoms include nausea, vomiting, abdominal and pleural effusions, and ovarian enlargement. Hemoconcentration, owing to the large fluid shifts from the intravascular space to the peritoneal cavity, results in increased blood viscosity and sometimes a coagulopathy that can lead to arterial and venous occlusions. Thromboembolic stroke,1-3⇓⇓ cerebral venous thrombosis,4 and systemic arteriovenous thrombosis5 have been reported in OHSS.nnWe describe a young woman who developed OHSS after in vitro fertilization and subsequently had an embolic stroke from an intracardiac thrombus.nnA 34-year-old right-handed woman underwent in vitro fertilization–embryo transfer treatment. The standard stimulation protocol included pituitary downregulation with injections of the gonadotropin-releasing hormone agonist leuprolide, followed by recombinant follicle-stimulating hormone. Peak serum estradiol level was 2,852 pg/mL, at which time human chorionic gonadotropin was given intramuscularly. Oocyte retrieval was followed by daily intramuscular progesterone administration and oocyte fertilization. Two embryos were transferred 2 days after oocyte retrieval.nnSeven days later, she was hospitalized with symptoms …

Value of Diffusion-Weighted Imaging in Patients with a Nonlocalizing Examination and Vasospasm from Subarachnoid Hemorrhage

We evaluated the value of diffusion-weighted imaging (DWI) in patients with suspected vasospasm from subarachnoid hemorrhage (SAH). Magnetic resonance imaging (MRI), including DWI, was performed in 5 patients with vasospasm resulting from SAH. Restricted diffusion (ischemia) was present in 3 patients with symptomatic vasospasm. A diffusion abnormality was not demonstrated in 2 patients with asymptomatic vasospasm despite persistently elevated velocities by transcranial Doppler ultrasonography in 1. In this patient, serial MRI studies showed no ischemia. Our results suggest that DWI may provide a method to assess the presence and severity of ischemia in patients with SAH and vasospasm and assist in patient management.

INTRA-ARTERIAL THROMBOLYSIS FOR VERTEBROBASILAR CIRCULATION ISCHEMIA

Acute basilar artery occlusion is usually associated with a poor prognosis despite therapy with antiplatelet and anticoagulant agents. The natural history of this disorder should be fully understood before clinicians make decisions on therapy. Recent advances in angiography technique and the use of newer mobile microcatheters have made intra-arterial thrombolysis therapy feasible. There have been several small, uncontrolled series of intra-arterial thrombolysis in basilar artery occlusion with promising results.

Recurrent lumbar ependymoma presenting as headache and communicating hydrocephalus

We describe a patient with a recurrent spinal cord ependymoma who initially presented with symptoms of increased intracranial pressure rather than symptoms directly relating to involvement of the conus medullaris. Brain magnetic resonance imaging with gadolinium showed communicating hydrocephalus. Magnetic resonance imaging of the entire spinal cord with gadolinium revealed recurrent tumor. Postoperatively, a permanent ventriculoperitoneal shunt was placed. Recognition of the association between spinal cord ependymoma and hydrocephalus is important in the evaluation of patients with headache.