The serious, late complication of superficial cerebral hemosiderosis, which appears after several years in 1/4–1/3 of patients who have undergone hemispherectomy, has resulted in recent years in a considerable reluctance to carry out this operation despite the fact it has proved to be highly effective in patients with medically refractory seizures associated with hemiplegia. Preservation of a small portion of the hemisphere, usually the frontal or occipital pole, has proved to be effective in preventing this late complication, but at the cost of a significant reduction in the effectiveness of the operation in reducing the patients’ seizure tendency. Preserving the frontal and occipital poles but disconnecting them from the rest of the brain, resulting in a functional complete but anatomical subtotal hemispherectomy, retains the therapeutic effectiveness of a complete hemispherectomy while still protecting adequately against the serious late postoperative complication of superficial cerebral hemosiderosis and its associated neurologic deterioration, hydrocephalus and sometimes death.

A review of the literature points to the many causes of arachnoiditis and the failure of treatment to arrest or reverse its effects. The true incidence cannot be determined, although it is probably lower than might at first appear from the published articles. In the radiological literature the diagnosis seems to derive from an examination of the films alone, often without reference to the clinical findings or appearance at operation. While attempts at treatment are usually unsuccessful, some iatrogenic cases can be prevented by the avoidance of intrathecal steroid injections or unduly rough or repeated surgical exploration of the lumbar vertebral canal.

Three techniques to produce experimental spinal cord injuries in the rat are compared; 1) the weight dropping method, 2) the aneurysm clip compression method and 3) the extradural balloon compression method. In principle, different forces were used in technique one, while a constant force for different durations is maintained in techniques two and three. The relationship between these different types of injuries and subsequent clinical recovery was assessed quantitatively by the inclined plane method of Rivlin and Tator. The weight dropping technique was found unreliable for experimental spinal cord injury in the rat while the aneurysm clip compression technique resulted in consistent cord injuries with respect to subsequent clinical recovery. The extradural balloon compression method invariably resulted in complete recovery after three and five minutes but no recovery after seven minutes of 0.1 cc air inflated balloon compression of the cord indicating a steep dose — response curve. However, using a 0.2 cc air inflated balloon, no recovery was noted after one minute compression. The major factor in the pathogenesis of spinal cord injury produced by the weight dropping technique is believed to be mechanical, while both mechanical and vascular factors seem to operate in the clip and balloon compression techniques.

Since the introduction of levodopa therapy, there have been major advances in the understanding and treatment of Parkinson’s disease. However, the problems and limitations associated with this form of treatment are now becoming increasingly apparent. This article reviews some of the current knowledge concerning the etiology and pathophysiology of Parkinson’s disease and discusses some-practical approaches to drug therapy.

We describe a computer program which facilitates the analysis of a series of C.T. scans made while a stereotaxic frame is fixed to the patient.

The program has 2 modes of operation:

a) The operator may select a region and determine the three-dimensional frame coordinate.

b) The operator may select a set of frame coordinates and have the computer program display these at the appropriate sites on the C.T. scans. If these sites are the positions of depth electrodes, then a recording of the epileptic spike activity may be displayed at the appropriate sites on the scans.

Periventricular/intraventricular hemorrhage occurs commonly in the premature newborn. Recent studies indicate an incidence of 35–45%. Following PVH/IVH, the likelihood of developing hydrocephalus is related to the severity of the hemorrhagic lesion. Ventricular dilation may be due to an obliterative arachnoiditis affecting principally the posterior fossa or, less commonly, due to obstruction of flow of cerebrospinal fluid within the ventricular system by clots or other debris. With moderate to severe hemorrhagic lesions, ventricular dilation may occur at the time of PVH/IVH. More commonly, progressive dilation begins one to three weeks following PVH/IVH. The classical clinical signs of hydrocephalus, ie. bulging of anterior fontanelle and inappropriate increase in head circumference, may not appear for days to weeks following onset of ventricular dilation. The precise significance of such normal-pressure hydrocephalus in the genesis of brain injury in the newborn is unknown. Following diagnosis of PVH/IVH, close surveillance of ventricular size with ultrasound scans is indicated. When there is slowly progressive ventricular dilation with normal intracranial pressure, the choice of therapy is made difficult because of frequent spontaneous arrest in such cases. Several modes of therapy have been reported including drugs to decrease the formation of cerebrospinal fluid and the use of serial lumbar punctures. When ventricular dilation is rapid with intracranial hypertension, ventricular drainage is indicated.

It is an honor to be asked to deliver the Silversides Lecture. Dr. Silversides’ clear understanding of the need for the collaboration of the basic and clinical sciences is a measure of the good sense for which he is admired. For a clinician, the greatest challenge to his clinical judgment lies in formulation of strategies to deal with vexing and serious conditions. Often we are called upon to treat conditions for which no satisfactory pathophysiologic mechanism has been elucidated. It is said that the clinician must frequently “get on top of the problem before he gets to the bottom of it.” In the spirit of all clinicians who seek better clinical approaches to poorly understood disease, I will devote this discussion to the diagnosis and treatment of pseudotumor cerebri.

Thirty-seven patients with advanced Parkinson’s disease who initially tolerated, and responded to bromocriptine therapy were followed for 12 to 50 (mean 28) months. Using a method of gradual increase of bromocriptine, with concomitant levodopa reduction, the peak effect of the drug was apparent by three months, at which time the mean daily dose of bromocriptine was 23.9 mg and Sinemet (levodopa + carbidopa) had been reduced by 34 percent.

Eight patients had sustained improvement without further drug changes for an average of 29 (range 14–50) months. After periods of improvement varying between 3 and 30 months, 29 patients had a fall-off from peak effect. Peak effect was regained in 21 of these 29 patients for an average of 16 additional months by initially increasing bromocriptine or Sinemet, or by eventually increasing both drugs. The main adverse effect was a confusional state which necessitated late withdrawal of bromocriptine in four patients. The best results were in younger patients with end-of-dose deterioration and levodopa induced dyskinesias.

With cautious introduction, and intermittent dosage adjustment, bromocriptine can be of long-term benefit to patients with advanced Parkinson’s disease. The majority of patients have a gradual late fall-off in effect which can frequently be reversed with dosage adjustment.

The muscles of four infants with cerebro-hepato-renal (Zellweger) syndrome were studied during life and/or at necropsy. A mitochondrial myopathy was demonstrated, similar to mitochondrial alterations demonstrated in liver and brain in this disease. Muscle fibers with red-staining subsarcolemmal aggregates were identified with Gomori trichome stain in two cases. Subsarcolemmal and intermyofibrillar zones of increased concentrations of NADH-TR, SDH, and cytochrome-c-oxidase activity were demonstrated histochemically in all four cases. Degenerative and cytoarchitectural changes in muscle fibers were not found. Ultrastructural studies showed large aggregates of mitochondria and increased lipid in the subsarcolemmal and intermyofibrillar spaces. Degenerative changes in mitochondria and lipid also were demonstrated, but paracrystalline inclusions were not seen. The distribution of these changes was not uniform between patients or between different muscles in the same patient. The diaphragm was affected more severely than proximal or distal muscles of the extremities. Direct involvement of muscle mitochondria in this disease may interfere with energy metabolism and contribute to the clinical findings of hypotonia, weakness, and respiratory insufficiency. The muscle biopsy with histochemistry and electron microscopy may be used as a diagnostic adjunct in suspected cases, but the variation encountered dictates caution in the interpretation of negative findings.

To evaluate the usefulness of CT in detecting unexpected brain lesions in epileptics, scan results were analyzed in a consecutive series of 196 adult epileptics in whom there was no known etiology for their seizures nor any abnormality on neurological examination. Nineteen additional epileptics, selected on the basis of an unexpected positive CT were also included for analysis.

In the consecutive series, the overall incidence of abnormal scans was 16% with the highest yield (44%) found in patients with partial elementary seizures. Partial seizures secondarily generalized were correlated with a significantly higher CT positivity than purely partial seizures. Patients with seizures for less than six months more frequently showed CT abnormalities than patients with a longer history.

In 25 of 51 cases with abnormal scans a specific lesion amenable to therapy was detected, including 16 neoplasms and 5 arteriovenous malformations. Other lesions included generalized or focal atrophy, infarcts, calcified lesions of tuberous sclerosis, unexplained calcifications and focal low-density or enhancing lesions.

Neurologists have had a long tradition of commitment and excellence in education. Whether we see our major role in clinical practice or clinical investigation, whether we are based in the community or in a university, virtually all of us have a role as teachers, a role in which we take great pride.

Thirty-six patients with suspected or myelographically proven radiculopathies were investigated with motor and sensory conductions, F-waves, needle electromyography, and somatosensory evoked potentials (SEPs). SEPs were elicited by cutaneous nerve stimulation representative of input from individual cervical and lumbosacral dorsal roots. A myelographic defect was present in 83% of 30 patients who had myelograms. Overall 78% of patients had one or more abnormal electrophysiologic tests, the needle EMG giving the best diagnostic yield (75%). F-waves and SEPs were abnormal in 43% and 57% of cases respectively. Motor deficit correlated best with abnormal EMGs, whilst abnormal SEPs occurred most frequently when sensory deficit predominated. Prolonged latency of the SEP occurred rarely, reduced amplitude or abnormal morphology being the most useful characteristics. SEPs evoked by cutaneous nerve stimulation are a useful addition to conventionally available electrophysiological methods of evaluating radiculopathies, especially in the absence of motor deficit.

Twenty-seven patients with epilepsy as the only manifestation of a cerebral AVM were seen at the MNI/MNH from 1973 to 1981. The nine females and eighteen males between the ages of fourteen and fifty-four years (Mean 25.2 years) had epilepsy for an average of 3.5 years prior to the diagnosis of AVM.

Seven patients had primarily generalized seizures, ten patients had partial seizures with complex symptoms, fourteen patients had partial seizures with elementary symptoms, and thirteen patients had secondarily generalized seizures. Although there was no history of intracranial hemorrhage, seven patients had negative hemispheric signs (hemiatrophy, hemianopia, dysphasia, hemiparesis), two had impaired mentation, and two were ataxic. The EEG, normal in ten cases, showed non-epileptiform activity in six cases, and focal epileptiform activity in eleven cases. Angiographic and/or histological examination revealed eight small (less than 2 cm in diameter) and nineteen large lesions. Fifteen AVMs involved the frontal lobe, ten the temporal lobe, five the parietal lobe, and one the occipital lobe. Angiography failed to demonstrate three frontal and three temporal AVMs.

Plain CT scanning demonstrated a high or low density lesion without a mass effect in sixteen cases, enlargement of the ipsilateral ventricle or Sylvian fissure in seven cases, and diffuse ventricular enlargement in three cases. CT scanning was performed after the intravenous injection of contrast material in nineteen cases and demonstrated vascular enhancement in fifteen cases and an abnormal blood vessel in six cases. Two angiographically occult AVMs demonstrated vascular enhancement with infusion CT scanning, thereby demonstrating the vascular nature of the lesion where angiography had failed to do so.

Normal CSF-MBP levels as determined by a RIA were <6.2 ng/ml CSF (mean 3.9). Eighty percent of patients with acute optic neuritis have CSF-MBP levels greater than 6.2 ng/ml (mean 7.6 ng/ml CSF). Five of 7 patients with acute internuclear ophthalmoplegia due to an initial exacerbation of demyelination have CSF-MBP levels above 6.2 ng/ml (mean 6.8 ng/ml). Fifty percent of MS patients with chronic progressive disease have CSF-MBP levels above 6.2 ng/ml (mean 6.7 ng/ml). MS patients experiencing monosymptomatic exacerbations show elevated CSF-MBP levels in 75% of cases (mean 8.2 ng/ml). MS patients experiencing polysymptomatic exacerbations show significantly higher levels of CSF-MBP (mean 22.3 ng/ml) than the patients with monosymptomatic exacerbations. Ninety-five percent of MS patients experiencing polysymptomatic exacerbations have elevated levels of CSF-MBP.

Chronic subdural hematomas in adults are not technically difficult to treat. They probably constitute one of the most common potentially curable lesions with which the average neurosurgeon deals. Despite this (or perhaps because of it) numerous treatments, radically differing from one another, have been advocated. Fine judgement is called for in deciding whether or not to operate in the first instance, make a flap or one or more burr or twist drill holes, use a drain, employ suction, inflate the brain, leave the bone flap out. In a personal series of 71 chronic subdural hematomas, 46 were treated with a red rubber catheter drain through a burr hole and 23 with a closed system suction drain. The results of this series suggest that closed system suction drainage through a single burr hole is the better of the two techniques. It has important theoretical advantages and the procedure is simple and fast. The complication rate is low and patients have a shortened postoperative hospital stay.