Tumoural parietal lobe epilepsy. Clinical manifestations and outcome in 34 patients treated between 1934 and 1988.

Between 1934 and 1988, 34 patients with tumoural parietal lobe epilepsy were treated surgically at the Montreal Neurological Institute (MNI). Fifteen had right-sided and 16 left-sided resections. The remaining three patients had biopsies only. Follow-up ranging from 1 to 40 years (mean 12.3 years) was available for 28 patients. Seventy-five percent (21 out of 28) became seizure free or had rare seizures. Permanent post-operative sensory deficits were described in 12% of patients. An aura was described by 79%. 62% had somatosensory symptoms, contralateral to the epileptogenic region in all but one. Visual illusions (12%), aphasia (9%) and disturbances of body image (6%), were much less common at the beginning of the attacks. Intra-operative cortical stimulation reproduced the habitual aurae in 10 out of 25 (40%) of the patients. The clinical manifestations suggested different spread patterns: 21% had tonic posturing of the extremities, 82% focal clonic activity, 15% head deviation, 9% automatisms and 6% difficulty speaking. Eleven (32%) had Todd's paralysis and 18% postictal dysphasia. Almost half the patients had impaired two-point discrimination in contralateral fingers; two of these also had impaired stereognosis, but only one had astereognosis without coexisting primary cortical sensory deficit. Review of this, now historical, series shows that parietal lobe tumours can be resected with good control of previously intractable seizures. Such an approach is preferable to postponing resection until the lesion is shown to increase in volume.