In the brains of patients with senile dementia of the Alzheimer type (SDA T), the quantitatively pathognomonic neuronal lesions (tangles, plaques, granulovacuolar degeneration, Hirano bodies, and nerve cell loss) are predisposed to occur especially within the limbic system. Anatomical and physiological studies indicate that fibres from the trigeminal ganglia innervate meninges and vessels within the middle and anterior cranial fossae, especially in the same subfrontal and mesial temporal regions preferentially afflicted in acute herpes encephalitis. These limbic regions are critical for normal memory processing and recall. Explantation and cocultivation techniques have recently demonstrated Herpes simplex virus in many human trigeminal ganglia, which also reveal a life-long lymphocytic infiltration in the absence of any pathological changes in the sensory neurones. These lymphocytes may represent a histological marker of latent herpes virus, which when reactivating is well-established as the ganglionic source of recurrent herpes labialis. It is suggested that reactivation of the same dormant viral material travelling centripetally instead might be the cause of the “degenerative” lesions typical both of Alzheimer’s Disease and of the normal aged human brain.

Sixty-five children with seizure disorders, who had been treated with multiple anticonvulsants but were poorly controlled, were selected from the Montreal Children’s Hospital Convulsive Disorder Clinic and Neurology Service and were treated with sodium valproate (valproate). All types of seizure disorders were included in the group.

Rapid oral absorption of the drug lead to peak plasma levels in one to three hours (later peaks occurring if administered after meals). A mean plasma half-life of 12.8 hours was calculated. Correlation between oral dose and plasma levels was poor. The side effects which occurred in this study were trivial. Drug interactions occurred with phenobarbital, diphenylhydantoin and clonazepam.

Sixty percent of patients had a greater than 50% reduction in seizure frequency with sodium valproate, but the best response was in generalized absence seizures. Since all types of seizures responded to some degree, a trial of sodium valproate is warranted in intractable seizure disorders of childhood regardless of classification.

Anticholinergics are one of the most common treatments used in adult-onset focal dystonias although their general efficacy has not been proven. We have investigated the effects of intravenous administration of atropine, benztropine and chlorpheniramine, in comparison to normal saline, in 20 patients with adult-onset focal dystonias (spasmodic torticollis (9), cranial dystonia (6), writer’s cramp (5)), and have retrospectively reviewed the notes of 78 patients (spasmodic torticollis (38), cranial dystonia (25), writer’s cramp (15)), who had received chronic oral anticholinergic therapy in varying doses at some time in the past. Patients with spasmodic torticollis and writer’s cramp showed no consistent change with any of the intravenous drugs, while the few with cranial dystonia who improved usually did so at the expense of drug-induced sedation. The natural variability of these disorders was evident in the response to normal saline, which caused changes in the scores for severity of the involuntary movements of 20% or more in some patients. Only 8 of the patients who had received chronic oral therapy obtained more than mild benefit, and in 3 of them this improvement was transient. We conclude that cholinergic mechanisms are not of general or prime importance in the pathogenesis of adult-onset focal dystonias. However, each new patient warrants a trial of chronic oral anticholinergic therapy in view of the occasional useful responses obtained with these drugs.

Epidural hematomas occasionally have a prolonged clinical course with gradual evolution of the neurologic symptoms. Seven such cases are reviewed in this report. Although the clinical course is insidious, there are certain features which should signal the presence of a slowly expanding hematoma. After an apparently minor head injury, the patient who is usually in the younger age group, develops headache. This persists and is accompanied by other non-specific neurologic symptoms which may lead to a mistaken diagnosis of “post-concussion syndrome”. Papilledema and focal neurologic deficits eventually appear. Definitive diagnosis is made by the CT scan, although contrast enhancement may be necessary to confirm the nature of the lesion. The treatment is craniotomy and evacuation of the hematoma before serious neurologic deterioration occurs.

We studied the flash electroretinograms (ERGs) of 105 patients with multiple sclerosis who were divided into four groups. The first group had no history or clinical evidence of optic nerve dysfunction, the second and third groups had either left or right optic nerve disease respectively, and the fourth group had historical or clinical evidence of bilateral optic nerve disease.

Statistical analysis of the data using analysis of variance (ANOVA) showed that the group of patients with no history or clinical evidence of optic nerve disease had no significant difference from the control group for their peak b-wave implicit times but the other three groups were significantly delayed on the affected side(s). Using the Mann-Whitney U-test we found all four patient groups had significantly greater absolute interocular latency differences from the control group. The electroretinal contribution to flash VEP delay was also investigated. In those patients with unilateral or bilateral optic nerve disease we found that in 14–31% of those patients with flash VEP delay there was also abnormal prolongation of the ERG b-wave. These results confirm a high incidence of retinal dysfunction in multiple sclerosis patients and may suggest that transynaptic degeneration of retinal structures occurs in optic nerve demyelination. The significant absolute interocular latency difference in particular may provide another electrophysiological parameter to establish a diagnosis of multiple sclerosis in suspect cases.

Checkerboard pattern reversal visual evoked potentials (VEPs) have proved useful in the confirmation of optic nerve disease in patients with multiple sclerosis (MS). Recently, evidence of orientation-specific loss in contrast sensitivity and the presence of orientation-specific visual evoked potential (VEP) deficits in MS patients has been obtained using sinusoidal gratings as stimuli. This study reports the presence of orientation-specific VEP delay in MS using the conventional checkerboard pattern presented in two orientations: normally oriented (check condition) or diagonally oriented (diamond condition).

Peak latency values of the N70 and P100 components of the VEP were statistically analyzed using appropriate ANOVA and nonparametric statistics. As a group MS patients showed significant VEP delays under check and diamond pattern conditions. However, individual subject analysis revealed that about 20% of the MS population show VEP delay to only one pattern orientation. It was shown that by including a diamond pattern condition the diagnostic yield of VEP delay in these clinically definite MS patients was increased 11% over that obtained with check stimulation alone.

The brains of 18 twins dying in the perinatal period showed a variety of lesions. Eleven had subependymal cell plate hemorrhage which had ruptured into the lateral ventricles in five. Five had periventricular damage. Three had anoxic neuronal damage. One acardiac monster had bilateral cerebral infarction. One pair had unequal sized brains, probably due to unequal intrauterine nutrition. Twins have a high perinatal mortality and morbidity; as well, intrauterine events may alter brain growth and development in each twin unequally, so they are an imperfect model to study the effect of genes and environment on intelligence.

Benign familial neonatal convulsions are a rare genetic seizure disorder inherited as an autosomal dominant trait. They consist of brief episodes of seizures, recurring during the first few days or weeks of life in otherwise normal babies; their prognosis is good. We report a family in which at least 12 members in three generations presented with this condition; they all had an excellent outcome.