We present a case of recurrent glioma, previously treated with maximal surgery and radiation in which a high dose of tamoxifen has stabilized the tumour clinically and has resulted in it's radiologic regression. Given tamoxifen's relative lack of toxicity, it might serve as a useful adjuvant in the treatment of recurrent glioma.

Low-intensity repetitive electrical stimulation such as dorsal column and transcutaneous electrical nerve stimulation (TENS) reportedly decreases spasticity and improves voluntary motor control. However, the mechanisms mediating these effects are unclear. Recent findings suggest that spasticity may be characterized more appropriately by a decrease in the stretch reflex threshold than by an increase in gain. Our objectives were: (1) to examine possible changes in stretch reflex excitability following 45 min of TENS, (2) to map out the time course of possible post-stimulation effects via both latency and magnitude (amplitude or area) measurements, and (3) to determine the role of segmental versus non-segmental mechanisms involved in mediating these changes. The effects of 45 min of segmentally and heterosegmentally applied TENS on lower limb reflexes in ten spastic hemiparetic subjects were contrasted with those resulting from placebo stimulation. We found that both segmentally and heterosegmentally applied TENS caused an immediate increase in soleus H reflex latencies that was evident for up to 60 minutes post-stimulation in over 75% of the subjects. Similar increases for up to 60 and 40 minutes post-stimulation was noted for the stretch reflex latencies in 50% and 67% of the subjects respectively for segmental and heterosegmental stimulation. These results suggested that manipulation of segmental and heterosegmental afférents for 45 min may lead to a decrease of the otherwise augmented stretch reflex excitability accompanying hemiparetic spasticity.

A closed-loop or recurrent neural network was taught to generate output discharges to reproduce the prototypical activations in agonist and antagonist muscles which produce the displacement of a limb about a single joint. By introducing a generalized decrease in the excitability of the pre-output layer in the network, the network made the displacement more slowly and also showed an inability to maintain a repetitive movement. These concepts can be applied to the human nervous system in the understanding of the physical basis of movement and its disorders. It is suggested that a movement represents the output of a closed-loop network, such as the cortical-basal ganglia-thalamic-cortical motor loop, which iterates repetitively to its end point or attractor. The model provides an explanation of how the state of thalamic inhibition seen in Parkinson's disease physically may produce bradykinesia and the inability to maintain a repetitive movement.

Parkinsonian features, notably resting tremor may be seen in some essential tremor patients but the significance of those is unknown. The reported risk of parkinsonism in essential tremor patients varies from being unchanged to 35 times higher than expected. We studied 9 patients with essential tremor who had autopsies. In 6 of the 9 (66%) resting tremor was noted and in 3 (33%) cases fully developed parkinsonism was noted. The parkinsonism was consequent to neuroleptic usage in 2 and to basal ganglia status lacunaris and cribrosus in one case but no consistent abnormalities were noted in 3 essential tremor only and 3 essential tremor plus resting tremor cases. We conclude that resting tremor is an age-related natural evolution in some essential tremor patients. We recommend that the additional diagnosis of parkinsonism in the essential tremor be made only when resting tremor, bradykinesia and rigidity are all evident. The risk of ideopathic Parkinson's disease in essential tremor cases is similar to the general population.

A retrospective study of patients with cerebrospinal fluid shunt infections was undertaken from 1975 to 1989 in a university hospital. The data were analyzed with emphasis on the choice of treatment and outcome. There were 44 infectious episodes in 38 patients for an overall rate of 2.6%, including 30 ventriculoperitoneal, 11 ventriculoatrial and 3 lumboperitoneal shunts. The most frequently isolated pathogens were staphylococci in 61% of the cases followed by gram-negative bacilli in 25%. Different modalities of treatment were used: support (2), intravenous antibiotics alone (6), intravenous antibiotics and shunt revision (3), intravenous antibiotics and shunt removal with or without prior externalization of the distal end (33: 13 + 20). The cure rate was 94% (31/33) with this last modality of treatment. Only 3 patients received intraventricular antibiotics. All deaths occurred in patients treated with support only (2) or with antibiotics alone (1). Four of the six recurrent episodes occurred in patients treated with antibiotics alone (2) or with a shunt revision (2). We conclude that carefully chosen intravenous antibiotics combined with shunt removal preceded or not by externalization of the distal end as an alternative therapy to repeated ventricular taps or insertion of an external ventricular drainage device is an appropriate therapy.

Over a period of 12 years, 80 patients underwent ventricular shunting for normal pressure hydrocephalus. Three developed sixth cranial nerve palsy in the first two weeks after surgery. This uncommon complication is usually transitory following the same pattern of abducens palsy after lumbar puncture or spinal anesthesia. Traction on the nerve with local ischemia has been involved as the responsible mechanism in both instances.

The incidence of vestibular schwannoma (acoustic neuroma) in Manitoba, Canada was reviewed. From 1987 through 1991, 71 tumors were diagnosed in 69 patients. The overall annual incidence rate for both sexes was 1.27/100,000 with male and female annual incidences of 1.31/100,000 and 1.24/100,000 respectively. For males, there was an early peak in the age group 30 - 39 years (2.1/100,000). Following the fifth decade, the incidence for males plateaued (2.7 - 3.6/100,000). For females, the incidence increased with age up to age 60 - 69 years (4.1/100,000). This was followed by a progressive decline in the incidence. Although the incidence of vestibular schwannoma was relatively high, the clinical features were not unlike those previously reported in the literature.

A large sample of Canadian adults was surveyed by telephone to determine the prevalence and characterization of headache, and the effects of headache on life-style, consulting behaviours and medication use. We reported prevalence and characterization in a previous issue; here, we detail the effects of headaches on sufferers. Sixteen and one-half percent of adult Canadians experience migraine and 29% tension-type headaches. In over 70% of headache sufferers interpersonal relationships are impaired. Regular activities are limited in 78% of migraine attacks and 38% of tension-type headaches. Despite this, only 64% of migraine and 45% of tension-type headache sufferers had ever sought medical attention, and of these only 32% returned for ongoing care. Fourteen percent of migraine and 8% of tension-type headache sufferers had used emergency departments. Most headache sufferers take medication, primarily over-the-counter varieties. Measures to reach the headache population are needed, as are safe effective treatment options that will encourage them to participate in their medical care.

By applying vibratory stimulation to patients suffering from pain, it is possible to set up an inhibitory control on the pain pathways which is based on the activation of large-sized afferent fibres. The exact mechanisms responsible for these analgesic effects still remain to be determined, however. For this purpose, we investigated in the present study whether or not the analgesic effects were accompanied by a decrease in the CSF substance P-like immunoreactivity levels (SPLI) of seven patients suffering from chronic pain, who were fitted with a ventriculo-peri-toneal drain. The SPLI levels were determined before and after 30-min vibratory stimulation sessions. The results show that the SPLI levels decreased as the result of the vibration, but this decrease seems to be too slight to account for the pain relief obtained.

Excessive fragmentary myoclonus during sleep consists of high amounts of brief twitch-like movements occurring asynchronously and asymmetrically in different body areas and has been reported to occur in association with a number of sleep disorders. It was analyzed using a new technique of quantification, the fragmentary myoclonus index (FMI). The FMI exhibited high rates in all stages of sleep but with a somewhat lower frequency in slow wave sleep explaining, as well, a significantly lower rate in the first hour after sleep onset compared to later hours. There was no evidence for greater sleep fragmentation or lighter sleep compared to a matched patient group in whom it had not been noted.

We studied the activity of glutamate dehydrogenase (GDH) in leukocytes from 23 patients with domi-nantly inherited ataxia. All the patients were assessed with a rating scale for ataxias and met the clinical criteria for the diagnosis of Machado-Joseph disease. The mean age of onset of symptoms was 37.8, SD 13.4 years and the duration of the disease was 7.4, SD 4.9. Leukocyte GDH activity was significantly decreased (p < 0.001) when compared to 20 normal controls. These data extend previous reports indicating that a GDH deficiency is present in peripheral tissues from some patients with spinocerebellar degenerations. Furthermore, this study suggests that a genetic deficiency of GDH may underlie some forms of dominant ataxias; this deficiency may be marked in patients with Machado-Joseph disease and is not specific for any type of multiple system atrophy.

The association of movement disorders with hypoglycemia has been rarely noted in the past. We recently observed 2 patients with documented hypoglycemia and paroxysmal dyskinesias. One patient had evidence of an insulin-secreting tumor. The other patient had insulin-dependent diabetes, and also experienced recurrent episodes of hypoglycemic hemiparesis. Classical adrenergic symptoms of hypoglycemia were absent in both patients. Our observations support the concept that the development of neuroglycopenic symptoms cannot be predicted from blood glucose measurements alone, but must depend on other factors controlling the availability or metabolism of glucose in the brain.

A 72-year-old man developed a very progressive neuropsychologic deficit 6 years ago, beginning with isolated visual topographic memory disturbances and visuo-constructive apraxia without additional manifestations of dementia. The syndrome worsened thereafter with the emergence of visual agnosia, simultagnosia, psychic paralysis of gaze, auditivo-verbal agnosia, and recently an amnestic syndrome with confabulation and confusion (at the end of 1989). CT scans, which remained unchanged over the years, showed mild, focal atrophic changes revealed by dilatation of the right occipital horn. His angiograms were normal. Two SPECT studies (with HMPAO measurements), performed 6 years from the onset, detected marked hypoperfusion in both parieto-occipital regions, mainly on the right side. Progressive focal degenerative disease without dementia is a relatively new syndrome, especially in cases with progressive aphasia.1 As noted in our patient, progressive disturbances initially localized in the right parieto-occipital region followed by posterior bilobar degeneration (pronounced on the right side) without dementia until late in the course may represent another exceptionally reported characteristic of this new syndrome. It is suggested that this variant of the Mesulam syndrome is more likely explained by progressive atrophy of the Alzheimer type.

Cerebral vein thrombosis, also called superior sagittal sinus thrombosis, is a well recognized clinical and radiologic entity associated with a variety of medical disorders. We report a patient with fatal cerebral vein thrombosis following myelography, in whom the cause was familial antithrombin III (AT3) deficiency. Unsuspected AT3 deficiency should be considered in cases of unexplained cerebral venous thromboses.

An association exists between antiphospholipid antibodies and chorea. As these antibodies are associated with thrombosis, it has been suggested that cerebral infarction might cause chorea. However, CT and MRI typically do not demonstrate focal basal ganglionic lesions in such patients and an autoimmune mechanism for chorea has also been proposed. We report a young woman with left hemichorea and dyspnea. She was found to have lupus anticoagulant, large aortic and tricuspid vegetations, and pulmonary emboli. CT and MRI showed a small lesion in the head of the right caudate. In the presence of a definite cardiac source for emboli (valvular vegetations) with embolic activity (pulmonary emboli), it is likely that this patient's hemichorea was caused by cardioembolic caudate infarction.

In a patient receiving intrathecal baclofen injections for intractable trunk and leg spasms, positioning the subarachnoid catheter tip just caudal to the spinal segments innervating the spastic muscles enhanced the spasmolytic effect of bolus injections of intrathecal baclofen on the affected muscles. Such selective positioning of subarachnoid catheters may facilitate segmental spasmolysis with lower intrathecal doses of baclofen and provide an important alternative to relying only on ascending CSF concentration gradients of baclofen from chronic lumbar intrathecal infusion.