Internal carotid artery infusion of bradykinin caused extensive breakdown of the blood-brain barrier to protein as demonstrated by the extravasation of the marker, horseradish peroxidase, into vessel walls and the adjacent parenchyma. Pretreatment of the animals with indomethacin, trifluoperazine, or imidazole significantly reduced the quantity of abnormally permeable vessels as determined by light microscopy. By electron microscopy, it was determined that bradykinin caused an intense increase in the number of pinocytotic vesicles in the permeable segments, but no change in the interendothelial junctions. After imidazole pretreatment, although the extent of the permeability change was markedly reduced, the intensity of pinocytotic activity in the involved areas was not altered.

Forty adult patients (average age 40 years), with the clinical and radiological features of the Chiari malformations, were seen at the Toronto Western Hospital between 1967 and 1984. Surgical confirmation of the diagnosis was obtained in 32 cases; of these, 23 were classified as Chiari I malformation while 9 fulfilled the anatomic criteria of Chiari II. The patient population consisted of 22 males and 18 females. Common presenting symptoms included head and neck pain (60%), sensory complaints (60%), upper extremity weakness (42%), and gait disturbance (40%). Neurological findings included signs of central cord dysfunction (73%), long-tract motor and/or sensory findings (58%), brainstem signs (38%), cerebellar dysfunction (18%), and increased intracranial pressure (15%). The majority of patients underwent myelography with or without computed tomography of the cervical-medullary junction. Two recent patients had 0.15T MRI scans which helped demonstrate an intramedullary syrinx. Thirty-three patients underwent 47 operative procedures (discounting spinal fusion and CSF shunt revisions). Open surgical management was performed in 32 patients, with CSF shunting along in one patient. Five patients (15%) incurred surgical complications within a six week postoperative period. Follow-up to date, ranges from one month to 11 years. In the 33 surgically treated patients, 18 are improved (55%), 10 are neurologically stable (30%), and five have worsened clinically (15%), including one death. Based on this study it appears that the Chiari II malformation maybe more common in adults than previously recognized. Surgical intervention has a favourable outcome in the majority of patients but a significant proportion continue to deteriorate.

We analysed the charts of 131 consecutive cases of spontaneous subarachnoid hemorrhage — without arteriovenous malformations — for seizures. Convulsions occurred in 31 patients (24%) and most often within 24 hours of bleeding. Motor manifestations of partial seizures were of no lateralizing value to aneurysm site. Early mortality, rebleeding and intracerebral hematoma were similar in both seizure and non-seizure groups. Late seizures were infrequent in survivors who had suffered seizures in the acute stage — thus questioning the necessity for routine, long term prophylactic anticonvulsants in these patients.

Embolic and thrombotic infarction in the territory of the posterior cerebral artery (PCA) is described with emphasis on the stroke and cerebrovascular features rather than special neurological syndromes. Of 47 cases of obstruction at the distal bifurcation of the basilar artery, 43 (95%) were consistent with embolism. The clinical categories and pathological findings are presented. Local embolism, vertebral distal-stump embolism, the dynamics of hemorrhagic infarction and embolus-in-transit are briefly described. The prodromal manifestations of PCA thrombotic occlusion include photopsias, hemianopic blackouts, headache, transient episodes of numbness, episodic lightheadedness, spells of bewilderment and rarely tinnitus. Recognition of these may allow prevention of a stroke. Prodromal photopsias did not closely resemble the scintillating displays of migraineurs. When the stroke occurred, visual complaints ususally predominated. A sensory deficit occurred in one-third of cases. In 25 cases of memory impairment the dominant hemisphere was involved in 24. The kinds of visual hallucinations, simple and formed, are described.

Multimodal evoked potentials were analyzed from 58 possible, 62 probable and 100 definite (total 220) multiple sclerosis (MS) patients. Visual evoked potentials (VEP) were most frequently abnormal yielding 39%, 69%, 84% in the three diagnostic groups respectively. Median nerve sensory evoked potentials (SEP) yielded abnormalities in 26%, 65%, 79% respectively. Brainstem auditory evoked responses (BAER) were abnormal in 17%, 39%, 66% respectively. We measured the combined amplitude (CA) of waves III, IV, V in the BAER of these patients as an objective measure of amplitude asymmetry. The CA was considered abnormal if it was 1SD below the lowest CA value in the control group. The CA was abnormal in 9.2% of BAER with normal central conduction time. The BAER diagnostic yield in MS patients increased 11% by using CA analysis.

The effect of clonazepam on the restless legs syndrome was studied in a group of 6 patients. Following a drug-free period, 3 patients received clonazepam for 4 weeks followed by placebo for 4 weeks thereafter and 3 patients received the same medication and for the same length of time but in reverse order. The effectiveness of the medication was evaluated by means of a self-rating system in which patients assigned a score daily to the degree of discomfort experienced in the previous 24 hours. Three patients improved on clonazepam but 2 of these also improved on placebo. Clonazepam was not shown to be significantly more effective than placebo in the treatment of RLS.

A sample of 122 patients with Parkinson's Disease was studied for the purpose of investigating if the frequency of relatives affected with Parkinson in this group was higher than in a control group and to see if the genetic load was more important in some of the subtypes of Parkinson described by Barbeau and Pourcher (1982).7 In our 122 patients, we found that 1.7% were post-encephalic parkinsonian, 12.3% were symptomatic cases and 86% of the idiopathic variety. There were 16.1% early onset patients in the idiopathic group and among these we found 23.5% with a positive family history of Parkinson in the first-degree relatives. In 6 cases with the tremor onset form of the disease, the family history was positive and 5 patients, 4.7% had familial essential tremor-related Parkinsonism. Our results support Barbeau's hypothesis7.19 that Parkinson is a heterogeneous disease in which some subtypes (such as early onset Parkinson) have an important genetic subceptibility component.

The relationships between total and free serum valproate (VPA) concentrations and seizure control, serum liver enzyme activity and plasma ammonia concentration were studied in 61 epileptic children. Enzymeimmunoassay (EMIT)R methods gave higher values of total VPA concentration than gas-liquid chromatography (GLC) methods. In over 80% of children with complete seizure control the ranges of total VPA concentration were 140-420 umol/L with GLC methods and 210-560 umol/L with EMIT methods. The range of free VPA concentrations in 78% of children with complete seizure control was 8.8-26.4 umol/L. Increased liver enzyme activity was observed in 6 of the 61 children and raised plasma ammonia concentration in 11 of 50 children. Plasma ammonia concentration was related to total serum VPA but was not related to free serum VPA. Increased serum liver enzyme activity was related to VPA dose per kg but not to free or total serum VPA concentration. Thus free VPA concentrations do not appear to be more useful than total VPA concentrations in predicting seizure control and do not correlate with liver enzyme activity or plasma ammonia concentration.

The electroencephalograms of 40 children with permanent cortical visual impairment (CVI) were studied. CVI was diagnosed in the presence of severe visual loss, normal or minimal ocular findings and clinical, electrodiagnostic and CT evidence of postgeniculate lesions involving the visual cortex. All patients had a multidisciplinary evaluation, including extensive neurological and ophthalmological investigations. The records did not contain any specific features which would be diagnostic of CVI. Isolated occipital spikes were rare and more commonly multifocal EEG disturbance was seen because of diffuse cerebral involvement. Photic stimulation was of little use in the diagnosis. Multihandicapped children with profound CVI tended to show multifocal abnormalities, no alpha rhythm and a suppressed posterior waking background in their EEGs, whereas those with more residual vision usually had an alpha rhythm. The presence or absence of alpha rhythm seemed to reflect the intactness of the striate cortex. However, the lack of alpha rhythm was not always associated with total blindness and not all children with useful residual vision had alpha rhythm.

Patients with hereditary long QT disorders — Romano-Ward Syndrome and Jervell Lange-Nielsen Syndrome — sometimes present with seizures due to cardiac tachyarrhythmias. Two such patients are presented, emphasizing diagnostic clues — syncope, seizures with onset in early life, precipitation of attacks by emotional or physical stress, positive family history of sudden death and/or seizures, normal EEG and prolonged QT interval on ECG. Treatment is usually with adequate doses of sympathetic betablockers.

A 14 year old boy with scapuloperoneal muscular atrophy, pes cavus, areflexia and distal sensory loss (Davidenkow syndrome) is described. Nerve conduction velocities were diminished. Sural nerve biopsy demonstrated a reduction in the number of myelinated fibers and early “onion-bulb” formation. These observations support the hypothesis that the scapuloperoneal amyotrophy associated with distal sensory loss may represent a variant of type I hereditary motor sensory neuropathy.

Swallow syncope is an often misdiagnosed rare disorder due to enhanced vagal tone during eating in patients with underlying esophageal and/or cardiac abnormalities. We present three cases of this disorder, one related to digitalis toxicity and the other two with diffuse esophageal spasm. The investigation, differential diagnosis, prognosis and management of swallow syncope are discussed.

A 23-year old woman came to the emergency room with an isolated oculomotor nerve palsy (including pupillary dilatation) of rapid onset. Investigations and history revealed no cause. The subsequent course of events indicated a diagnosis of multiple sclerosis. While the third nerve has been shown to be involved during the course of multiple sclerosis, this is the first report of a case presenting as an isolated oculomotor nerve paralysis.