Choreathetoid movement as an unusual presentation of subdural haematoma.

Subdural haematomas can present with a wide variety of symptoms. An atypical presentation can be movement disorders. The key feature is that the history of onset is more rapid than with neurological conditions such as Parkinson's disease. The symptoms can also be an acute worsening of pre-existing disorder. The case discussed involved an 80 year old woman with bilateral choreathetoid movements attributed to a unilateral chronic subdural haematoma. The haematoma was surgically drained and the symptoms resolved. Sporadic reports of similar cases of movement disorders associated with subdural haematomas exist in the literature, but rarely do unilateral haematomas present with bilateral symptoms. Pressure effects, neurotransmitter abnormality and ischaemia have been postulated as reasons for this type of presentation. Unexplained and sudden movement disorders might warrant imaging to rule out a subdural haematoma as the cause.

Directly measured mid-depth circulation in the northeastern North Atlantic Ocean.

The circulation of water masses in the northeastern North Atlantic Ocean has a strong influence on global climate owing to the northward transport of warm subtropical water to high latitudes. But the ocean circulation at depths below the reach of satellite observations is difficult to measure, and only recently have comprehensive, direct observations of whole ocean basins been possible. Here we present quantitative maps of the absolute velocities at two levels in the northeastern North Atlantic as obtained from acoustically tracked floats. We find that most of the mean flow transported northward by the Gulf Stream system at the thermocline level (about 600 m depth) remains within the subpolar region, and only relatively little enters the Rockall trough or the Nordic seas. Contrary to previous work, our data indicate that warm, saline water from the Mediterranean Sea reaches the high latitudes through a combination of narrow slope currents and mixing processes. At both depths under investigation, currents cross the Mid-Atlantic Ridge preferentially over deep gaps in the ridge, demonstrating that sea-floor topography can constrain even upper-ocean circulation patterns.

Discovering novel ligands for macromolecules using X-ray crystallographic screening.

The need to decrease the time scale for clinical compound discovery has led to innovations at several stages in the process, including genomics/proteomics for target identification, ultrahigh-throughput screening for lead identification, and structure-based drug design and combinatorial chemistry for lead optimization. A critical juncture in the process is the identification of a proper lead compound, because a poor choice may generate costly difficulties at later stages. Lead compounds are commonly identified from high-throughput screens of large compound libraries, derived from known substrates/inhibitors, or identified in computational prescreeusing X-ray crystal structures. Structural information is often consulted to efficiently optimize leads, but under the current paradigm, such data require preidentification and confirmation of compound binding. Here, we describe a new X-ray crystallography-driven screening technique that combines the steps of lead identification, structural assessment, and optimization. The method is rapid, efficient, and high-throughput, and it results in detailed crystallographic structure information. The utility of the method is demonstrated in the discovery and optimization of a new orally available class of urokinase inhibitors for the treatment of cancer.

Methoxyamericanolide B.

The title compound, C16H20O5, was isolated from the gorgonian coral P. americana found in the Caribbean zone of the West Indies. The compound belongs to a well known family of sesquiterpenoid lactones. Its structure features a guaiane skeleton incorporating three types of oxygen functionalities. Thus, the five O atoms that are incorporated in the skeleton form two epoxy groups, a lactone moiety and an ether link. This study assigns the relative stereochemistry at the six chiral centers as 1R, 2R, 4S, 5S, 8R, 10S.

Vim thalamotomy for the relief of the intention tremor of multiple sclerosis.

We have reviewed the outcome of patients who have undergone thalamotomy for the intention tremor of multiple sclerosis (MS). Twenty-four patients underwent 29 procedures between 1988 and 1995. These patients were assessed for the degree of disability due to MS and for the impairment of arm function due to the tremor. Preoperative, postoperative and last follow-up score (mean 2.2 years) were determined for arm function following thalamotomy. Patient satisfaction, where expressed, was recorded. Twenty-three procedures (79%) resulted in immediate improvement in arm function. Thirteen complications were recorded. Postoperative fatigue was demonstrated after seven procedures. Sustained benefit was seen after 18 procedures (62%). Out of 23 patients whose opinions are recorded four were enthusiastic and 10 satisfied with the outcome. We conclude that, despite severe disability, a majority of patients with intention tremor of MS may still benefit from thalamotomy and are satisfied with the results.

A clinical, genetic and audiological study of patients and families with bilateral acoustic neurofibromatosis.

The neurofibromatoses consist of at least two distinct autosomal dominant hereditary disorders. Neurofibromatosis type 1 (NF1) is due to a lesion on chromosome 17q. Neurofibromatosis type 2 (NF2) is caused by a defect on chromosome 22q. The hallmark of NF2 is the development, in the second and third decades, of bilateral acoustic neuromas. NF1 is characterized by the appearance of café-au-lait spots and neurofibromas in addition to iris hamartomas, or Lisch nodules, of the eye, during the first and second decades. Ten families were personally studied. A total of 16 members were found to be affected with NF2. A protocol for evaluation and review of subjects and relatives of NF2 families is proposed. A team approach, coordinating the expertise of multiple specialties is recommended.

Haemangiopericytoma of the temporal bone.

Haemangiopericytoma is an uncommon vascular tumour with a widespread distribution. Although meningeal involvement is well recognized, only a few sporadic cases of temporal bone lesions have been documented, all with doubtful sites of origin. Late presentation together with the restrictive anatomy of this region often precludes its effective removal and even minimal residual disease may progress rapidly. A series of three such patients are presented in order to discuss the natural history, histological features and treatment of this disease.

Emergency surgery for haematoma-forming aneurysmal haemorrhage.

Patients with intracerebral haematomas (ICH) secondary to aneurysmal bleeds usually have a poor prognosis or die if treated conservatively. Younger patients with rupture of a middle cerebral artery (MCA) aneurysm and temporal haematomas have the potential to return to useful life. They should be assessed separately from other subarachnoid haemorrhage (SAH) patients and considered for emergency surgery. Seven such cases are presented, five made an acceptable recovery. The experience of other units as represented in the literature is considered.

Spinal cord compression: delay in the diagnosis and referral of a common neurosurgical emergency.

In 76 consecutive patients with spinal cord compression the process of diagnosis and referral was investigated. This investigation was carried out at the time of admission to the neurosurgical unit when it was possible to obtain fresh information about each patient's pre-admission management. All the patients had been referred from District General Hospitals and 71 had previously consulted their general practitioners. Sixty-two per cent took over a week from the time they first saw their own doctor to reach the referring hospital, after reaching hospital 47% of patients waited a week or more before they were referred to a neurosurgeon. During the process of referral, the proportion of patients able to walk unaided and control their sphincters fell from 68% to 10% while the proportion with complete cord lesions rose from 1.5% to 28%. In 48% of cases there had been delays in diagnosis and referral which appeared avoidable. The reasons for these delays and their effect on the eventual outcome are assessed.

Progressive change in cerebral blood flow during the first three weeks after subarachnoid hemorrhage.

Cerebral blood flow (CBF) was estimated from each cerebral hemisphere by the 133Xe inhalation method. Daily estimates were made during the first 3 weeks after subarachnoid hemorrhage (1265 studies in 116 patients). Some of the patients were taking adrenergic blocking drugs (propranolol and phentolamine), others were taking tranexamic acid, and the rest were taking no drugs. CBF was also studied in 67 normal subjects. The resting CBF was related inversely to age not only for normal subjects but also for patients after subarachnoid hemorrhage (SAH). The CBF fell progressively during the first 2 weeks after SAH and was abnormally low throughout the 3 weeks after hemorrhage. For any 1 day after SAH, those patients who were fully alert had the smallest reduction in CBF. The progressive changes in CBF occurred whether or not an aneurysm was present on angiograms. For aneurysms situated to one side of the midline, the changes in CBF affected both sides of the brain. The progressive decline in CBF was least in those patients who subsequently made the best clinical recovery. Arterial pCO2 seemed to influence CBF throughout the 3 weeks after SAH. During the 2nd week, CBF was especially low in SAH patients treated with tranexamic acid. The serial changes in CBF are discussed in relation to current views concerning the timing of operation for ruptured aneurysms.

Subarachnoid haemorrhage: older patients have low cerebral blood flow.

Daily estimations of hemispheral cerebral blood flow using the xenon-133 inhalation technique was made in 116 patients during the first three weeks after subarachnoid haemorrhage. The patients' cerebral perfusion on average remained less than the normal perfusion expected for their age (based on a single estimation of cerebral blood flow in 67 volunteers). On each separate day after subarachnoid haemorrhage cerebral blood flow was inversely related to the patient's age. Older patients seem especially at risk of developing cerebral ischaemia after subarachnoid haemorrhage. The clinical outcome was more often unfavourable in older patients--that is, in those who tended to have the lowest cerebral blood flow. Present results support the view that episodes of low cerebral blood flow lead to a poor outcome after subarachnoid haemorrhage. Because of the risk of inducing cerebral ischaemia great care should be exercised by physicians administering hypotensive drugs to older patients after subarachnoid haemorrhage.

Cardiac sequelae of acute head injury.

An intensive 72 hour study of the cardiovascular effects of severe diffuse brain injury was made in seven patients. No other major injury was present. Patients received optimal care very rapidly after injury and intracranial pressure, which was continuously monitored, was maintained at or just above normal by elective positive pressure ventilation techniques. Three patients showed evidence of progressive myocardial ischaemia on continuous electrocardiographic monitoring. Two of these patients died. Ventricular arrhythmias were uncommon but one of the patients with ischaemia developed ventricular tachycardia. Heart rate patterns were very abnormal but did not predict complications. Blood pressure did not vary greatly and cardiac outputs were usually normal. Pronounced excesses of urinary catecholamines and serum creatine kinase 2 isoenzyme (CK MB) as well as total creatine kinase were found. Histological evidence of myocardial damage could be shown at necropsy in the one case whose heart was available for study. This study shows that the cardiac effects of isolated diffuse cerebral injury may be harmful and even fatal despite correction of secondary factors such as anoxia and raised intracranial pressure. The findings suggest that evaluation of the potential benefits of sympathetic blockade is warranted. Cardiac complications of cerebral damage deserve wider recognition by intensive care personnel, neurologists, and neurosurgeons.

North Atlantic Subtropical Gyre: SOFAR Floats Tracked by Moored Listening Stations.

In 1980, SOFAR (sound fixing and ranging) floats were tracked acoustically in the western North Atlantic entirely by means of moored autonomous listening stations. During a 5-month period 17 float trajectories were obtained in the eastern (45 degrees to 65 degrees W) Gulf Stream and subtropical gyre interior at depths of 700 and 2000 meters. These mid-depth trajectories suggest a time-varying Gulf Stream with instances of both a narrow, swift, westward recirculation south of the stream and a northeastward penetration into the Newfoundland Basin. A hundredfold increase of eddy kinetic energy was observed at 2000 meters from the gyre interior (south of 30 degrees N) to the Gulf Stream.

Benjamin Franklin and Timothy Folger's First Printed Chart of the Gulf Stream.

A print of the Benjamin Franklin and Timothy Folger 1769-1770 chart of the Gulf Stream, all copies of which have been "lost" for nearly 200 years, was found in the Bibliothèque Nationale in Paris. This is the first chart of the Gulf Stream and continues today to be a good summary of its strength, course, and breadth.