Our study documents the clinical and electrographic findings in 42 patients with medically refractory occipital lobe epilepsy, who underwent surgery at the Montreal Neurological Institute between 1930 and 1991, and the evolving manner in which those patients were studied by successive generations of investigators. In more than two-thirds of the patients the clinical manifestations indicated the occipital onset of the seizures. Seventy-three percent experienced visual aurae, of which elementary hallucinations were the most common and 12 also had ictal blindness. Other occipital manifestations included: contralateral eye deviation, blinking, a sensation of eye movement and nystagmoid eye movements. Intra-operative cortical stimulation elicited a habitual aura in 37% of 29 patients. Lateralizing clinical features were seen in almost two-thirds of patients: contralateral head deviation occurred in half, 59% had visual field defects contralateral to the epileptogenic area and 64% had abnormal imaging studies ipsilateral to the side of surgery. More than one-third of patients exhibited more than one seizure type, suggesting ictal spread to temporal or frontal lobe: 50% had typical temporal lobe automatisms, and 38% exhibited focal motor seizure activity. Surface electroencephalogram (EEG) recordings showed posterior temporal-occipital epileptiform discharges in 46% of patients. Only 18% had electronegative spiking limited to 01 or 02. Large epileptogenic areas were often found on intracranial recording with depth electrodes and on electrocorticography. Pre-excision electrocorticography spiking was restricted to the occipital lobe in only 13 out of 34 patients. More often spiking also involved the posterior temporal and posterior parietal regions. Twenty-three patients underwent only occipital resections; five had only temporal resections, so as to preserve the visual fields, and the remaining 14 patients had extensive resections, which included the posterior temporal or posterior parietal regions. A follow-up period of 1 to 46 yrs (mean 17 yrs) was available for 37 patients. Forty-six percent became seizure free and 21% had a significant reduction in seizure frequency. A better outcome was observed in those patients in whom there was no post-resection electrocorticographic or surface EEG epileptiform discharge, or who exhibited an occipital lobe lesion.

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Surgery is a safe and effective treatment for patients with temporal lobe epilepsy (TLE) who do not respond adequately to anticonvulsant medication and in whom the seizure generator can be identified and safely removed. Proton MR spectroscopic imaging (MRSI) can image and quantify neuronal damage in patients with TLE based on reduced signals from N-acetylaspartate (NAA), a compound localized exclusively in neurons. We performed proton MRSI in patients with TLE before and after surgical treatment to determine whether NAA or other resonance intensities changed in the temporal lobes of patients with TLE after surgery, and whether these changes correlated with surgical outcome. N-acetylaspartate resonance intensity relative to creatine (NAA/Cr) was abnormally low preoperatively in at least one temporal lobe in all 14 patients examined. It was low ipsilaterally in the patients who became seizure free and bilaterally in those who did not. Postoperatively, it increased to the normal range on the side of surgery in all patients who became seizure free. In the one patient who became seizure free and who had low NAA/Cr in both temporal lobes before surgery, NAA/Cr values in the contralateral, unoperated temporal lobe also increased to the normal range. In contrast, NAA relative intensity ratios did not change in those patients who continued to have seizures after surgery. The creatine resonance intensity (Cr) in the temporal lobes was high, relative to the brainstem, in seven patients preoperatively. After surgery, the Cr remained high in two patients, both of whom continued to have seizures. We conclude that NAA (and Cr) abnormalities in TLE do not result solely from neuronal loss and gliosis but can be reversible after postsurgical control of seizures. This implies that the NAA and Cr abnormalities in patients with TLE, at least in part, are dynamic markers of both local and remote physiologic dysfunction associated with ongoing seizures.

Some 2 years ago we investigated a child with profound psychomotor retardation who had had an occipital meningoencephalocele removed at birth. Contrast studies were carried out which showed a large midline defect in the posterior fossa and absence of the vermis. At the time we disregarded the nurses' comments about the child's abnormal breathing. A year later, Dr P P Demers referred this patient's baby brother to us because he was concerned about his abnormal breathing and retarded development. It was then found that a third and older child in this family was retarded, ataxic, and breathing abnormally. Finally we were able to trace yet another sibling who had died in infancy and who, at autopsy, proved to have agenesis of the vermis. This diagnosis was then confirmed in the two affected living children by contrast studies.From this investigation there emerged a familial syndrome of episodic hyperpnea, abnormal eye movements, ataxia, and mental retardation associated with a common malformation in the four affected siblings, agenesis of the vermis. This syndrome has not previously been described in the literature.The affected children will be presented in the order in which the abnormality was identified, which happens to be in reverse to the birth order (Figure 1). CASE REPORTS Case 1. M.D., a 6-month-old French Canadian boy, was admitted to the Montreal Children's Hospital on Oct. 9, 1967, for evaluation of abnormal breathing and develop-mental retardation. He was the last of six children in his sibship, bom after a normal pregnancy. Forceps were used during delivery. There was no history of trauma or anoxia at birth; however, his breathing, even at birth, was abnormally rapid. He smiled early. At the age of 4 months, he was unable to hold up his head. At 5 months, he showed almost continuous protruding movements of the tongue.Examination on admission revealed a well-developed boy in no distress. His nutritional status was good. His head circumference was 44 cm. A few telangiectasiae were seen on the cheeks, ears, and eyelids, more on the right side. A few dilated blood vessels were seen on the conjunctivae. His pupils were equal and reacted well to light, and the fundi were normal. Abnormal, conjugate, irregular, jerky eye movements were frequently seen, and rotatory nystagmus was present. When fixing with his left eye, the right eye deviated upward and laterally. His mouth was usually held open and his tongue protruded rhythmically His breathing was abnormal, particularly when he was stimulated. Periods of 12 to 16 seconds of hyperpnea, usually around 120 per minute but increasing up to 168 per minute, alternated with periods of apnea lasting 5 to 12 seconds. Occasional respiratory excursions were noted during the periods of apnea (Figure 2). During sleep, this respiratory abnormality was absent.The child moved all extremities well. Tone was diminished in the upper extremities. Deep tendon reflexes were brisk and plantar responses were extensor. His head control was poor. A weak grasping reflex was present. He ...