Epileptic seizures can be evoked in chicks homozygous for the epileptic seizure gene (epi, epi) by elevating their body temperature using microwave diathermy. These seizures precede and differ in motor seizure pattern from a second clonic-tonic seizure produced by hyperthermia in both epileptic and carrier (heterozygote, Epi, epi) chicks. Hyperthermia did not evoke seizures in adult epileptic chickens. Phenobarbital delayed the onset of epileptiform seizures whereas phenytoin and valproate had no effect. These data suggest that epileptic chicks may provide a suitable model for studies on febrile convulsions.

Delays of auditory perception at three frequencies were measured in 30 multiple sclerosis patients using a pscyhophysical technique. Nineteen patients had abnormal delays at one or more tone frequencies, though 15 had normal audiograms at those frequencies. In addition, auditory acuity for left-right asynchrony was abnormally poor in 13 patients, 9 of whom had normal audiograms. Such delays of auditory perception within a restricted frequency band may provide a partial explanation for degraded speech comprehension in some multiple sclerosis patients.

Myelin basic protein (MBP) is an antigenic component of circulating immune complexes (CIC) in patients with multiple sclerosis (MS). Immune complexes were isolated from the sera by adsorption to Raji cells and then acid eluted. Final identification of MBP from Raji eluates was done by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by MBP radioimmunoassay (RIA) of gel eluates and by an immunoblot technique.

Using medical files, death certificates and an interview at home for the survivors, a long term retrospective follow-up study was done for 82 subjects operated for carotid stenosis. Causes of death, survival rates and medical history of survivors were studied. Subjects were classified in two preoperative risk categories according to their medical history prior to angiography: low risk (36 subjects) and medium risk (46 subjects). None of the subjects were lost during the follow-up period which varies from 81 to 105 months.

At seven years, observed survival rate is significantly lower for the medium risk patients than for the low risk patients (43.0 ±8.6 versus 80.6 ± 6.6; X2 M-H, p = 0.006). The difference between the survival rates is markedly noticeable after the fifth year of follow-up. Besides, the percentage of survivors who have developed cerebrovascular problems after the operation is significantly higher in the medium risk group than the low risk group (54.5% versus 25.0%, X2 p ≃ 0,04).

Does this mean that the preoperative risk classification separates two different stages or two different forms of atherosclerosis? Can. J. Neurol. Sci. 1983; 10:27–31

A case of presumed anticoagulant induced hemorrhage into infarction is presented along with a retrospective study of 110 cases of cerebral embolus.

An accurate recommendation for the timing of anticoagulation following cerebral embolism hinges on balancing the risk of hemorrhage into infarction against the benefits of early treatment attributed to preventing recurrent embolism. It is felt that the present literature, concepts of pathogenesis and experimental data provide insufficient information to make absolute clinical decisions. The available evidence implies that the risk of further embolic events is three to four times that of hemorrhage into infarction, yet additional randomized prospective studies and better experimental models are needed to establish a valid treatment plan. It may be possible to distinguish separate mechanisms underlying early diffuse hemorrhage into infarction from sudden delayed massive hematoma formation.

A recent questionnaire survey of the life-effects of narcolepsy in 180 patients, 60 each from North American, Asian and European populations, compared to similarly distributed age and sex matched controls, documented multiple and marked effects on work, education, driving, accidents, recreation, personality, memory and other parameters. The data have now been further analysed according to the patients’ geographic (culturo-genetic) origin and to a number of other patient and illness variables. The three different geographic populations showed few significant differences for the some 160 life-effects items in the questionnaire. This strongly indicates that these are an integral part of the disease or of the human reaction to it. Most of the few significant population differences appeared cultural in origin (e.g., concerning driving records, personality changes), although a few may possibly reflect genetic differences (e.g., visual problems). Analysis of the pooled data according to respondees’ age, sex, age at illness onset, duration of illness and treatment led again to relatively few significant findings. It is concluded that, in general, once the disease has been diagnosed, all the major life effects are present and remain so. The results strongly support the contention that most life-effects are not related to the diagnostic ‘tetrad’ symptoms themselves but rather to excessive daytime sleepiness, the symptom most resistant to anti-narcoleptic treatment.

We describe nine patients with plexopathies or proximal mononeuropathies due to mass lesions. In four, computed tomography (CT) was the only radiological technique to show the cause of the neuropathy. In five patients, CT either unequivocally confirmed the presence of an abnormality or was superior to other imaging techniques in showing its full anatomical extent. CT scanning is a valuable aid in the assessment of lesions of the peripheral nervous system, particularly plexopathies and mononeuropathies caused by retroperitoneal, pelvic or superior pulmonary sulcus tumors.

Twenty patients with hemifacial spasm were treated between February 1980 and June 1981. All presented with typical disabling unilateral contractions of the face. Computerized Tomographic Scan and angiograms ruled out structural mass lesions. All patients underwent posterior fossa microsurgical relocation of a vessel from the root entry zone of the facial nerve. An offending arterial loop was found in each case. Nineteen patients are free of symptoms and the remaining one is improved. One patient has permanent loss of hearing and two developed mild facial weakness. There has been no recurrence in 18 months follow up. These results give further support to the theory that hemifacial spasm is an affliction of the seventh nerve in the cerebello-pontine angle, most commonly caused by vascular cross compression at the root entry zone. Surgical relocation of the offending vessel relieves the symptoms and there appears to be no recurrence. This procedure is not difficult and carries acceptable risk for the patient with this disabling condition.

In a recent paper (Barbeau and Pourcher, 1982) we demonstrated that so-called “idiopathic” Parkinson’s disease is not a homogeneous entity, and defined the existence of a sub-group of patients with genetic parkinsonism. To investigate this last possibility, and to uncover possible metabolic clues as to the etiology of such cases, we carried out a prospective study of 50 kindreds with “familial” parkinsonism. Two control groups were similarly studied: 50 kindreds with essential tremor (neurological control group) and 50 kindreds originating from spouses of the previous patients (non neurological control group). We uncovered two main patterns of genetic transmission within the parkinsonian patients: a parkinsonism related to dominant essential tremor (34 kindreds; 10% of all Parkinsonians) and a recessive “akineto-rigid syndrome” (10 kindreds; 3–4% of all Parkinsonians). A further 4 kindreds assumed a pseudo-dominant pattern but were probably recessive. Finally 2 kindreds were obviously other entities presenting as “phenocopies” of Parkinson’s disease. Metabolically, hyperthyroidism appeared to be more frequent in essential tremor and “essential-tremor related parkinsonism” kindreds, while hypothyroidism and possibly hypoparathyroidism (post surgery) seemed more frequent in the recessive akineto-rigid syndrome kindreds.

The murine ependymoblastoma is a transplantable tumor of cerebral origin. The growth pattern and survival times of the murine ependymoblastoma implanted peripherally and intracranially in non nude C57B1/6J mice have been found to be predictable and consistent when examined by means of Tumor Cell Dose Assessment (end point solution), Tumor Growth and Survival Assessment. The results suggest that a greater tumor cell dose is required to generate peripheral tumor take than brain tumor take. This difference may result from a greater immunologic response to tumor implanted peripherally than into the immunologically privileged brain.

The lumbar spines of one hundred patients with suspected lumbar disc herniations were analysed with computed tomography. The results are compared with the patients’ surgical diagnosis and with myelography. CT scanning is with few exceptions the diagnostic procedure of choice in investigating lumbar disc disease.

Two cases of intradural disc rupture with cauda equina compression are reported. Myelography demonstrated complete block and at surgery intradural fragments of sequestrated disc material were found. The pathogenesis of this condition is reviewed and our recommendation for management is presented.

Normal values for the amplitudes of digital sensory nerve action potentials were obtained from 190 control subjects, using an orthodromic surface-recording technique. Lower limits were calculated, taking into account laterality, age and sex; the ratios of amplitudes between different digits were also estimated. The results in control subjects were compared with those of 20 cases of trauma involving root avulsion or extraspinal injury, 38 patients with intraspinal disease, 6 patients with extraspinal disorder and 9 cases of neuralgic amyotrophy. The variability of the dermatomes is discussed and it is concluded that digital sensory potential amplitudes offer a useful method of determining the site of a nerve lesion, provided certain limitations are recognized.

The efficacy of intravenous phenytoin for the treatment of status epilepticus is related to the rapid entry of phenytoin into brain parenchyma. There is no information concerning the correlation between phenytoin serum and CSF concentrations in children, and the application of CSF data to clinical use. We report 7 children (2–11 yrs) who were treated or exposed to phenytoin in doses between 10.5–230 mg/kg. Lumbar puncture was performed 9 times in 6 of the patients. In one patient, an intraventricular catheter permitted successive assessment of CSF phenytoin concentrations. The ratio of CSF/serum phenytoin concentrations was 0.16 ± 0.08, with gradual increase over the first 8 hours as the serum phenytoin concentration decreased. There was good correlation between therapeutic outcome and CSF phenytoin levels higher than 2 mcg/ml. In one patient the coma state secondary to phenytoin intoxication was associated with high CSF concentration (6 mcg/ml).

Cerebral ventricle size was measured in one hundred normal people, age 10 to 50 years. The measurements were obtained from computed tomographic (CT) scan examinations, using the Huckman (1975) method. Normal ventricles were significantly bigger at age 45 than at age 15. These normals were compared to groups of patients with pseudotumor cerebri, water intoxication and cerebral edema, and cerebral hypoxia and edema due to cardio-respiratory arrest.

The relative ventricular size was the same in the normal group and all three disease groups. Measurement of ventricle size from CT scan images is not even a crude index of cerebral edema in these three diseases.

Determinations of CSF HVA before and after Probenecid administration were made in 41 patients with Parkinson’s disease. The means of HVA concentration were lower than those of controls but no correlation with clinical data was found. A negative correlation was demonstrated between post-probenecid HVA levels and subsequent score improvement with L-DOPA at 3,6 and 12 months. Post-probenecid HVA levels suggest that there are distinct forms of parkinsonism and could predict the response to L-DOPA therapy.

Different groups of rats were maintained on choline-deprived (CD), choline-supplemented (CS) or standard rat chow diets beginning at a body weight of approximately 100 g, and electrically kindled in the amygdala beginning not less than 40 days later. The CS group kindled significantly faster than the CD group, whereas the CD and chow-fed groups did not differ in their rate of kindling. This result is consistent with both the known effects of the dietary manipulation of choline on brain acetylcholine level, and the idea that acetylcholine has a role in amygdaloid kindling.

The pattern electroretinogram (PERG) is probably generated by the ganglion cell layer of the retina whose axons constitute the conductive fibres of the optic nerves. A study was undertaken of the PERG in a group of patients with clinically definite multiple sclerosis who had suffered optic nerve demyelination to assess the value of recording the PERG as a method for electrophysiological determination of optic nerve dysfunction. Pattern visual evoked potentials (PVEP) were simultaneously recorded, each eye being stimulated separately, and four different check sizes were used. Although individual patients showed PERG abnormalities the results as a group showed no significant difference from the normal population so far as latency or amplitude of the PERG was concerned. Thus we conclude that the PERG, while an interesting measurement, does not satisfactorily reflect optic nerve dysfunction. Further, our results indicate that it is not such a useful measure as the pattern visual evoked response for detecting optic nerve disease.

A 36 year old male developed bilateral sensorineural deafness as the chief manifestation of secondary syphilis. Cerebrospinal fluid showed pleocytosis. Treatment with penicillin and prednisone resulted in good recovery of hearing. Initial recovery seemed dependent on corticosteroids. Deafness can complicate acquired syphilis in both early and late stages of the disease and may be its sole manifestation. Early acquired syphilitic deafness is usually the result of a meningitis affecting the eighth nerve and responds well to treatment. These features are contrasted with those of late acquired syphilitic deafness.

The clinical and EEG findings were reviewed for 270 juvenile children from the Montreal Children’s Hospital Diabetic Clinic in an attempt to correlate the EEG findings at the onset of diabetes mellitus with the future risk of having a convulsion with a hypoglycemic reaction. Compared to a non-diabetic control population, the number of epileptiform EEG abnormalities was significantly increased in the initial EEG of diabetic patients who later had a hypoglycemic convulsion. The initial epiliptiform EEG did not help to differentiate those diabetics with recurrent hypoglycemic induced convulsions from diabetics who would have only a single convulsion.