Regional cerebral glucose metabolism was examined in females with Turner syndrome, a sex chromosome abnormality. Previous studies have found a visual/spatial cognitive anomaly in these women but, to date, no abnormalities in brain structure or function have been associated with the condition. In the present study, decreases in regional metabolism were found in the occipital and parietal cortex. The involvement of the occipital cortex, although consistent with the observed cognitive anomalies, has not been suggested previously as an area dysfunction. Because the occipital cortex is a primary sensory cortex, the reduction of glucose metabolism in the parietal cortex may reflect a lack of innervation from the occipital cortex. Besides insight into the functional specialization of the brain, these findings are also consistent with previous reports on animals regarding the effects of estrogen in brain maturation.

This study presents the clinical characteristics of 8 victims of multiple sclerosis from the hamlet of Henribourg, Saskatchewan with a population of less than 75 people. A diligent victim of the disease had observed that six female classmates from the early 1940's had later developed multiple sclerosis. Two male military personnel who had also resided briefly in close proximity, during the same common exposure time, also later developed multiple sclerosis. The mean onset time of developing the disease after leaving the area was 20 years. This cluster-focus suggests a common exposure to an environmental factor or a common infective agent in the etiology of multiple sclerosis.

Two patients with neuroacanthocytosis are described. One presented with parkinsonism and the other resembled diurnal dystonia of the Segawa type. Both patients responded well to dopaminomimetic therapy. A PET scan with fluorodopa revealed a nigrostriatal deficit in the first patient.

Methaqualone (Mtq; quaaludes or 'ludes) is a controlled substance, having a molecular structure related to the imidiazobenzodiazepine series of drugs, that has gained some notoriety recently due to its history of widespread abuse on the street. Users report experiencing peripheral paresthesia and transient numbness on body parts receiving dense cutaneous innervation (lips, fingertips, etc.). Since the receptive-field (RF)-sizes of many primary somatosensory (SI) cortical neurones are controlled by local, gamma-aminobutyric acid (GABA)-mediated inhibitory processes, we tested Mtq to see whether its clinical symptoms might have a basis in an action through central GABA-mediated synaptic processes. This report supports this contention and describes a likely pharmacological mechanism involved as one being related to the Ro 15-1788-sensitive benzodiazepine (Bzd) recognition site(s) of the GABA receptor complex.

The etiology of Alzheimer disease (AD) remains unknown. The hypothesis of genetic factors playing a role in the causation of the disease, at least in its familial form, has been borne out by results showing linkage in several early-onset AD families to a locus on the proximal part of the long arm of chromosome 21. Linkage was not detected in several other families using the same markers. The metabolism of neurofilaments is perturbed in AD, as indicated by the presence of neurofilament epitopes in neurofibrillary tangles, as well as by the severe reduction of the expression of the gene for the light neurofilament subunit in AD brain. To detect a possible anomaly that might relate to the disease, we have searched for an association between the genes for the light subunit and the heavy subunit of the neurofilament triplet, and AD. Genotypes for restriction fragment length polymorphisms (RFLP) at each of the two loci were determined for an AD group and a control group. Allelic frequencies at a Taql-defined RFLP for the gene for the light neurofilament subunit were 0.70 for the 3.7 kb allele and 0.30 for the 2.9 kb allele. Hindi detected an RFLP for the heavy neurofilament subunit gene with frequencies of 0.31 for the 18.0 kb allele and 0.69 for the 6.8 kb allele. Frequencies were found to be similar in the two groups for both light and heavy neurofilament subunit loci. Although it cannot be excluded that mutations at other sites of the neurofilament genes are relevant to AD, the data reported here do not support an association between these genes and the disease.

During the investigation of intractable epilepsy, neuronal migration anomalies [NMA] were discovered in three patients. The first patient had abnormally positioned gray matter within the walls of both lateral ventricles. The second patient had a post operative cystic area in the right parietal-occipital lobes and an area of NMA within the right temporal lobe. The third patient had abnormally thickened gray matter in the right operculum. Long term CCTV-EEG monitoring of these three patients revealed ictal discharges originating from the area of abnormal gray matter in patients 2 and 3. PET scanning showed the areas of NMA in all three patients to have similar metabolic activity to normal gray matter. These cases illustrate the value of various imaging modalities and suggest some interesting physiology of a spectrum of neuronal migration anomalies.

The incidence of fatal hepatic failure associated with valproic acid (VPA) therapy is highest in children under the age of three years, particularly in those with developmental delay. The pathogenesis of VPA hepatotoxicity is unclear but may relate to the accumulation of a toxic metabolite of VPA which impairs fatty-acid oxidation. We describe two unrelated infants with developmental delay who developed hepatic failure while receiving VPA. Siblings of both children subsequently developed hepatic steatosis and intractable seizures without being exposed to VPA. This suggests that that the two children who developed liver failure when receiving VPA may have had a familial metabolic disorder. Familial metabolic disorders may account partly for the higher incidence of fatal hepatotoxicity described in infants receiving VPA.

The mechanism for the preferential distribution of emboli to cerebral arterial bordcrzone regions, known to cause some watershed infarcts was studied. We hypothesized that emboli of a specific size range are selectively directed to the arterial borderzones due to the tendency of emboli to bypass the small arterial branches which emerge proximal to major borderzones. To test this hypothesis we perfused the brains of cadavers with suspensions of 90-210 µm glass microspheres and chemically extracted the particles from various arterial territories and a watershed zone. Particles in the 150-210 µm size range were found to be preferentially distributed to the watershed zone whereas particles less than 150 µm in size were randomly dispersed in leptomeningeal arteries of all vascular regions. To assess the role of branch size on the concentration of emboli at bifurcations, we perfused artificial analogs of evenly and unevenly branching bifurcations with suspensions of 90-150 µm and 150-210 µm particles. Branching cylinders with symmetrical branches contained the same concentration of particles, independent of particle size. In contrast, when one branch was one-quarter the size of the other, the concentration of 150-210 µm particles in the asymmetric branch was approximately 65% of the main trunk. Particles 90-150 µm in size were evenly distributed despite variation in branch size. These results indicate that emboli, of a limited range of size, may be selectively propagated to the distal ramifications of subarachnoid arteries located in the watershed zone rather than diverging into small calibre branches which arise along the way.

We investigated the possibility of an inherited tendency to faint by studying 30 consecutively referred well children with vasodepressor or vasovagal syncope. The family history of each patient was reviewed for syncope and for 24 cases was compared with the family history of the child's best friend. None of the best friends had syncope. 27/30 cases and 8/24 best friends had at least one first degree relative with syncope (p < 0.01). Of the 8 best friend controls with a parent or sibling with syncope, the mother was affected in 7; 4/7 of these mothers had first degree relative(s) with syncope. In 11/30 patients both a sibling and parent had syncope compared with 1/24 of control families (p < .01). We conclude that there is an inherited tendency to faint since most children who faint have a first degree relative who faints, a useful fact in differential diagnosis. This inherited tendency may be multifactorial but requires an environmental stimulus for expression.

Congenital muscular dystrophy (CMD) is a heterogeneous group of disorders which is associated with more or less degrees of cerebral involvement. There are four separate entities within CMD nosology. Among these Fukuyama's CMD (FCMD) is highly prevalent in Japan, whereas the classic form with normal or subnormal intelligence, also known as the occidental type, covers the vast majority of cases in the West. We report a case of FCMD seen in a Turkish child.

Seventeen patients with petrous meningiomas managed at St. Michael's Hospital, during the years 1973-1987, were retrospectively reviewed. There were 15 females and 2 males; their ages ranged from 42 to 68 years (mean age: 53 years). The clinical presentation most commonly included headache and eighth cranial nerve dysfunction; the average duration of symptoms was 6 years (3 month - 27 years). Computed tomography was performed in 15 cases. The mean tumour size was 2.5 centimeters (0.5 - 4 cm). The most common site of tumour origin was at or medial to the poms acousticus. Meningioma was suspected preoperatively in 10 of the 15 patients who had preoperative CT scans. Complete excision was obtained in 12 cases. There were no operative deaths after initial resections. Postoperative morbidity included worsening of pre-existing hearing loss in six patients, transient facial nerve palsies in six, permanent facial nerve palsies in four and new facial or corneal hypesthesia in three. Two patients developed cerebrospinal fluid fistulae. Tumour recurrence occurred into two patients in whom a complete resection was anticipated. Also, in two patients with incompletely resected tumours second operations were required. Fourteen patients are alive, 13 of whom care for themselves independently. The average follow-up was 5 years (6 months - 9 years). It seems appropriate to recommend initial radical surgical excision of these benign tumours, where possible, in order to prevent tumour recurrence.

Twenty-three children with acute transverse myelopathy (ATM) are reviewed. Antecedent minor trauma or exercise was reported in 10 patients. Despite a positive history in 7 patients no preceding infection was documented. Two patients had a history of less severe ATM followed by recovery prior to a second more severe episode. The most common initial symptom was back pain and the most prominent clinical signs were weakness, sensory level and sphincter disturbances. Myelography and CT myelography at presentation was performed to exclude a compressive lesion. Spinal cord enlargement was demonstrated in 6 of 21 cases. Magnetic resonance imaging (MRI) of the spinal cord, performed in one patient, showed enlargement of the cord. Poor prognostic features were severity of weakness at the time of maximum deficit and a delayed onset of recovery. Maximum motor recovery occurred at a mean of 6½ months but did not occur in one patient until 1½ years. Normal or good outcome was obtained in 64%.

Central type benzodiazepine receptors were studied in 9 patients with Friedreich's ataxia and 12 healthy subjects using positron emission tomography (PET) and [11C]Ro 15-1788, a specific antagonist of the central type benzodiazepine receptors, as radioligand. A standard PET procedure was used in 5 patients and 8 controls to obtain brain kinetics of the total binding of the radioligand. The remaining subjects were intravenously injected with a saturating dose of unlabeled Ro 15-1788, 30 minutes after the tracer injection, to determine the nondisplaceable binding of [11C]Ro 15-1788. A semi-quantitative method was used to quantify the [11C]Ro 15-1788 data. None of the quantification indices in the cerebellar hemispheres, or in the other brain areas investigated, was significantly modified in patients with Friedreich's ataxia. These findings suggest that brain benzodiazepine receptors are unaffected in Friedreich's ataxia.

Isolated angiitis of the central nervous system, a rare inflammatory condition of the nervous system, characterized by vasculitis of the small vessels, has not, to the best of our knowledge, been described in childhood. It usually presents with a diversity of neurological symptoms in the fifth to eighth decades of life. We reviewed the case of an 8 year old male with autopsy proven isolated cerebral angiitis, to encourage the consideration of this disorder in children; and to emphasize the lack of sensitivity of present modalities of neurological investigation in the diagnosis.

We studied the value of CT scans for all children referred because of headache to one secondary and one tertiary pediatric centre during a 1 year period. Of 117 children who were seen by the Pediatric Neurology Service, at the I.W.K. Children's Hospital, 4 had CT scans and only 1 of these was abnormal. The consultant Pediatrician saw 40 children because of headache. CT scans were done on 3 of these patients and all were normal. None of the children who had a clinical assessment alone had unrecognized neurological disease during 20 months of follow-up. Therefore only 1 of 157 children had significant intracranial pathology. We conclude that CT scans have a limited role in the management of children with headache.

Dysarthria, dysphagia and repeated aspiration in a 54-year-old woman diagnosed and treated for myasthenia gravis 7 years earlier were initially thought to represent a late exacerbation of myasthenia. A cervical mass invading the jugular foramen and causing multiple lower cranial nerve palsies was biopsied and found to represent invasive ectopic thymoma.

Les mots de Neurochirurgie et de Créativité, semblent à priori antagonistes. D'une part, le monde de cumul, d'érudition, d'exactitude, de codification de la science neurochirurgicale, et d'autre part, celui de la fantaisie et de la liberté de I'improvisation et de l'aléatoire.

Pourtant, devant la stagnation de certaines «récupérations» cérébrales, nous avons senti la nécéssité d'une démarche supplémentaire affranchie des normes traditionnelles.

This is a review of reserpine, haloperidol, and various phenothiazines that produce parkinsonism and other movement disorders. The by-products of illicit meperidine synthesis, MPTP and its more sinister companion, MPP, are also discussed. Movement disorders, transient or fixed, frank parkinsonism and/or dyskinesia, due to a variety of other medications and toxic agents are included. These are methanol, lithium, methyldopa, antimetabolites, antidepressants, sympathomimetic anorexiants, some types of antihistamines, and various combinations of agricultural chemicals.

Clobazam, a novel benzodiazepine, was used as an add-on agent in 47 adult patients with intractable epilepsy and a variety of seizure types. A >75% reduction in seizure frequency was observed in 42% (18) of the patients and a >50% reduction in 65% (29) of the patients which was sustained over a mean follow-up period of 13.3 (±5.6) months. Nine patients had to discontinue the drug due to minor adverse effects or increased seizures. Possible tolerance developed in 6 patients. Plasma levels of the active metabolite N-desmethylclobazam were linearly related to dosage and appeared to correlate with both therapeutic and toxic responses. Clobazam appears to be a safe and effective add-on antiepileptic for a wide variety of seizure types in intractable epilepsy.

Eight patients with myotonic dystrophy underwent comprehensive neuropsychological testing and overnight polysomnography to assess whether the waking cognitive impairment might be attributable to sleep structure abnormalities or to sleep-related respiratory problems. Patients showed substantial neuropsychological deficits, fragmented nocturnal sleep and, in half the patients, sleep apnea and/or hypopnea both mainly of central type. There was no statistically significant correlation between the degree of daytime cognitive deficit and the degree of sleep fragmentation or of respiratory problems at night. It was concluded that the neuropsychological deficit in mytonic dystrophy cannot be attributed to a secondary effect of nocturnal sleep apnea or sleep disruption but probably represents a direct effect of CNS lesions.