The motivation of this study was to more precisely define the in vivo role of astrocytes in forebrain ischemia. Controversy exists in the literature as to whether they protect or injure neurons in this setting.

Astrocytes in the rat hippocampus were disabled with stereotactic administration of a gliotoxin, ethidium bromide, 3 days prior to induction of forebrain ischemia. The extent of neuronal injury in this group was compared to a control category receiving intrahippocampal saline only.

Saline-injected animals demonstrated decreased hippocampal CA1 sector injury, and increased gliosis on the side of the injection compared to the contralateral side (P < 0.01) or ethidium bromide-treated animals (P < 0.05).

The results suggest that activated astrocytes are protective to neurons subjected to an ischemic insult. This may result from their ability to elaborate neurotrophic factors, buffer potassium and metabolize a variety of neurotransmitters.

To provide a simple means of ”real time“ recognition of emergence from post-traumatic amnesia (PTA).

Ninety-one patients with traumatic brain injury (PBI); 53 minor (GCS 13-15), 19 moderate (GCS 9-12), 18 severe (GCS 3-8). Twenty-seven control subjects treated at two regional trauma units for their acute phase and followed in a hospital-based research institute were studied prospectively. Subjects were examined repeatedly following injury with the Galveston Orientation and Amnesia Test (GOAT) and tests of their ability to learn and retain new information. Word triplets balanced for concreteness and frequency were presented. Immediate and 24-hour recall were tested. If 24-hour recall was imperfect, recognition was tested by presenting the 3 target words and 6 distracters. The target words were then re-presented and recall was tested the next day. The time intervals to first perfect recognition and first free perfect recall were compared with the patients' first GOAT score of 75 or greater on 2 successive days. Simple line drawings of common objects were also presented to the subjects using an identical paradigm. The outcome measures were GOAT, 3-word recognition and recall, 3 picture recognition and recall.

For all categories of head injury severity, the median interval to perfect free recall of words followed the achievement GOAT criterion by a significant interval. The mean GOAT scores for perfect 3-word recall and recognition corresponding to minor, moderate and severe injuries were 97, 90 and 88, and 97, 76 and 68 respectively. The recognition and recall of pictures preceded the recognition and recall of words by approximately 1 day.

The orientation measures of the GOAT that contain material that the patient knew prior to injury obscure the determination of recovery of continuous memory and should be tested separately. Three-word recall which is simpler to administer than the GOAT is a more reliable measure of emergence from PTA. For patients who are dysphasic or who do not share a common language with the examiner, 3-picture recognition and recall may substitute for word recognition and recall.

In spite of scattered reports to the contrary, concern is continually expressed that the frequency of cerebral palsy has not decreased with modern perinatal/neonatal care. Overall, epidemiological information on cerebral palsy is scant. The generally accepted prevalence is 2 to 2.5 per thousand school-age children.

A population-based record linkage study of a presently living cohort of 96,359 children born from April, 1985 through March, 1988 and followed over an eight-year tracking period captured the diagnostic codes for all fee-for-service physician claims, all hospital separations and individual birth data from the Department of Vital Statistics of the Government of Alberta. The ICD-9 code "343" was used to identify subjects. The childhood prevalence and frequency by birthweight- specific sub-groups of cerebral palsy were determined.

Two hundred and forty-eight living children with confirmed cerebral palsy after age three years (congenital, 229 [92.3%]; probable acquired 19 [7.7%]) were identified giving an overall prevalence of 2.57 per 1000. Seventy percent were diagnosed before their third birthday. Cohort prevalence of cerebral palsy for low birthweight children (< 2500 grams) was 17.7, very low birthweight (< 1500 grams), 78.5; and extremely low birthweight (< 1000 grams), 98.4. Low birthweight children made up just over one-third of cases in this study.

Cerebral palsy continues to affect a significant number of children suggesting the prevalence of cerebral palsy has not decreased. The proportion of affected children with low birthweight in this study is less than that reported in the literature.

The cost of care for hydrocephalic patients is not well established.

This retrospective study for the years 1990-1996 analyzed the cost of surgical intervention and hospitalization of hydrocephalic patients in the community-based setting of Manitoba, Canada, with a stable population of 1.138 million.

The number of discharges with a primary diagnosis of hydrocephalus was greater than 200 annually. The mean duration of hospital stay was 12.4 to 21.9 days, depending on the etiology of hydrocephalus. Approximately 80 shunt procedures were performed annually. The total annual cost of care, excluding outpatient costs and chronic non-hospital based costs which could not be determined accurately, was estimated to be CDN$ 3.5 million in this community.

Hydrocephalus is a chronic condition which puts substantial monetary demands on society and therefore deserves greater attention.

In previous studies we reported an increased prevalence of Parkinson's disease in several kibbutzim of Southern Israel (cluster kibbutzim). Subsequent studies revealed a significant prevalence of subjects presenting extrapyramidal signs (preparkinsonism) in the same kibbutzim. On follow-up worsening of these signs was observed in some of the older subjects, some of them actually being diagnosed as suffering from I-Dopa responsive Parkinson's disease. The current study was designed to evaluate possible etiologic factors for the development of preparkinsonism.

317 subjects over the age of 40, living in five kibbutzim were examined and interviewed. 95 subjects presenting extrapyramidal signs were compared with 95 control subjects. They were matched for age, sex and length of residence in the kibbutz. Odds ratios were computed to identify exposure variables for logistic regression analyses. Detectors for carbamates and organic phosphates were applied at different sites of these kibbutzim.

The severity and frequency of the extrapyramidal signs were higher in the older age groups, more in the “cluster”, than in other kibbutzim. A very strong association was found between field crop work exposure, particularly cotton, and preparkinsonism (p = 0.0007) and a slightly weaker association for landscape work. The detectors picked up abundant pesticide traces (carbamates and organic phosphates) in the residential areas fairly distant from sites of aerial spray.

We assume a chronic passive exposure of the residents in these kibbutzim to pesticides, in addition to any occupational exposures.

The relationship of ictal and post-ictal cephalic pain to migraine remains debatable. We hereby report 2 patients whose post-ictal migraine-like symptoms ameliorated in response to oral sumatriptan.

Two patients, a 27-year-old woman and 41-year-old man were referred for assessment of migraine of 10 years and 4 years duration, respectively. The man described a recent episode of “vacant stare” and the woman has sensitivity to bright colours and light. Neurological examination, visual field testing, CAT scan, MRI scan, and prolonged EEG recordings were accomplished for each patient.

The man had a spontaneous seizure with ictal discharge arising from the right occipital lobe. Bilateral occipital spikes, associated with palinopsia was triggered in the woman by photic stimulation. Both patients developed post-ictal headaches with symptoms similar to their migraines. The symptoms subsided following treatment with oral sumatriptan.

Migraine-like symptoms occurring following occipital lobe seizures may share similar pathophysiological substrates with idiopathic migraine. Serotonergic mechanisms may be implicated.

The safety, tolerability, efficacy, and impact on quality of life of gabapentin (Neurontin®) as adjunctive therapy to carbamazepine (CBZ) and/or phenytoin (PHT) was assessed in epileptic patients with partial seizures.

NEON (Neurontin Evaluation of Outcomes in Neurological Practice) was an open-label, prospective, multicentre study conducted in patients on a stable dose of CBZ and/or PHT and experiencing an average of up to 4 complex partial seizures with or without secondary generalization per month, with no seizure-free months. The treatment lasted 20 weeks. Gabapentin was started at 400 mg/day and was individually titrated to effective tolerable dose up to 2400 mg/day. Quality of life was evaluated using the QOLIE-10 questionnaire.

A total of 141 patients were enrolled at 36 sites; 114 patients were evaluable for efficacy analyses. The mean maintenance dose of gabapentin was 1600 mg/day (range = 300-3200). A decrease of 50% or more in frequency of complex partial + secondarily generalized seizures was observed in 81 (71 %) patients (p = 0.0001). Fifty two (46%) patients were seizure-free during the last 8 weeks of treatment. A significant improvement (p < 0.05) was observed in 5 of the 10 questions of the QOLIE-10, as well as in the composite QOL score (p = 0.0002). The most frequent adverse events included somnolence (16%), dizziness (9%), and asthenia (6%). Twenty-five (18%) patients prematurely discontinued the study, 16 (11%) of them due to adverse events.

This study indicates that treatment with gabapentin as adjunctive therapy to standard antiepileptic drugs in this group of patients not only provides significant improvement in seizure control, but also has a positive impact on quality of life. The clinical benefits in efficacy, safety and tolerability demonstrated at 20 weeks are sustained, and no tolerance develops with gabapentin in longer term use.

To study the clinical features and treatment given to episodic cluster headache patients in the Calgary region.

Fifty-one (51) patients who responded to a media campaign, had previously been diagnosed by their family physicians, and who met International Headache Society (IHS) criteria for episodic cluster headache, formed the population for this study.

The media campaign consisted of newspaper advertisements and radio publicity including physician interviews and talk shows. Patients were required to complete a 200-item questionnaire detailing clinical features and treatment of their cluster headache syndrome. Each patient was also interviewed by our research nurse for clarification and proper completion of questionnaire.

Fifty-one percent (51%) of our patients had short headache attacks lasting one hour or less. Almost one-half (45%) had three or four attacks per 24 hour period. Eighty-six percent (86%) had been referred to a neurologist. Sixty-nine percent (69%) had never used oxygen, but of those who had, onehalf were still using it. Sumatriptan by injection had been tried by 26% of patients and of these, 93% considered it effective. Subcutaneous dihydroergotamine had been tried by 8%. For prophylaxis, 41% had tried methysergide, 31% prednisone, and 4% verapamil. Many patients had been prescribed migraine prophylactic drugs which are ineffective for cluster headache, and some had also undergone dental procedures or nasal and sinus surgeries.

Many cluster headache patients had not, to their knowledge, been prescribed or used the best symptomatic and prophylactic treatments for cluster headache. This should be addressed through educational programs and through making up-to-date information on the treatment of cluster headache readily available to physicians and patients.

The treatment of chronic daily headache (CDH) due to medication overuse remains a common and difficult problem. For selected patients refractory to outpatient management we have used a treatment protocol using dihydroergotamine (DHE) as introduced by Raskin, during a brief (typically 48 hours) in-patient stay. While many studies have documented the short-term efficacy of the DHE protocol, there are limited data on its long-term effects. The purpose of this study was to evaluate the efficacy of the protocol on headache frequency and severity, analgesic use, absences from work, and quality of life, at three months post treatment and the present time.

A retrospective chart review of all patients admitted for the DHE protocol from 1991 to 1996 revealed 174 cases. Of these, 132 patients were interviewed by phone.

The DHE protocol was shown to decrease headache frequency, severity, headache medication use, and absences from work both at three months and the time of interview.

This study has the largest patient base and the longest follow-up period for the use of DHE for CDH. The results confirm that the DHE protocol is helpful in breaking the cycle of CDH, although the long-term outcomes of this study are more conservative than other studies have reported.

We report a possible risk factor which could identify patients with chronic hydrocephalus who are at risk for sudden death.

A retrospective review of medical records and computed tomographic (CT) scans was conducted on three patients with chronic hydrocephalus who suffered acute cardiorespiratory arrest without those signs which are normally associated with a progressive worsening of hydrocephalus.

All three of these patients were awake and communicative shortly before the life threatening or terminal event. All had experienced some recent worsening of neurologic signs or symptoms, but none had shown a progressive impairment of consciousness or major neurologic decline ordinarily associated with life threatening elevation of intracranial pressure. Absence of the perimesencephalic cisterns on head CT scans done prior to or just after the life threatening event was the only new radiologic finding common to all these patients.

The absence of the perimesencephalic cisterns in an awake and alert patient with severe hydrocephalus indicates that the patient may be at risk for neurogenic cardiorespiratory failure. In such cases, (especially when there has been a recent, albeit mild, change in neurologic signs or symptoms), the neurologist should urge emergency ventriculostomy or shunting for the hydrocephalus.

In cases of acute spontaneous spinal epidural hematoma producing neurological deficits, emergency surgical evacuation is the standard treatment.

Such a case is presented in which complete resolution of neurological deficits occurred without surgical intervention.

This is the fifth reported case of complete recovery in a patient managed conservatively. In most reports, significant and sustained neurological recovery had occurred within 12 hours of impairment of walking.

In cases of acute spontaneous spinal epidural hematoma in which neurological deterioration is followed by early and sustained recovery, non-operative therapy may be considered.

Intracranial schwannoma involving the XIIth cranial nerve is rare. We report an unusual clinical presentation and pathological verification of a schwannoma, which had become haemorrhagic and necrotic, simulating acute purulent meningitis.

A literature review of intracranial tumors presenting as acute purulent meningitis, with emphasis on schwannomas, was undertaken.

Few cases of hypoglossal schwannoma have been reported; the association with purulent meningitis has not been previously documented.

In patients presenting with sterile purulent meningitis, a necrotic tumor should be considered as a possible etiology.

Presentation of an unusual case of congenital entrapment of the lateral cutaneous nerve of the calf (LCNC) mimicking a peroneal sensory neuropathy.

We report the case of a 16-year-old girl with a 3 year history of progressive tingling, numbness and pain in her right calf precipitated by athletic activities involving repeated flexion and extension of the knee. A Tinel's sign was present over the common peroneal nerve in the distal popliteal fossa but absent at the fibular neck. Motor and sensory examination of the common peroneal nerve was normal as were electrophysiological studies and MRI.

At surgery, the LCNC, a sensory branch of the common peroneal nerve, was entrapped at a point where it pierced the tendon of the biceps femoris muscle. Transection of the part of the tendon overlying the LCNC resulted in complete and permanent relief of symptoms.

The proximal location of the Tinel's sign, absence of motor or sensory deficits and normal electrophysiology suggested, preoperatively, that this was not an entrapment of the common peroneal nerve at the fibular neck but rather a more proximal abnormality likely involving only a part of the peroneal nerve or one of its sensory branches. As a result, more proximal exposure of the peroneal nerve within the popliteal fossa revealed entrapment of the LCNC due to its anomalous course through the biceps femoris tendon. This case has two noteworthy features. It is a unique example of an entrapment neuropathy of the common peroneal nerve or one of its branches, due to a normal nerve piercing an otherwise normal tendon. Secondly, there are no previously reported cases of surgically documented compression of the LCNC in an otherwise normal patient (i.e., non-diabetic).