Slowly progressive aphasia without generalized dementia: studies with positron emission tomography

Slowly progressive aphasia without generalized dementia is a degenerative syndrome selectively affecting dominant hemisphere language areas. We report changes in regional glucose metabolism measured by positron emission tomography in two patients with this condition. Striking abnormalities of glucose utilization in the left cerebral cortex were demonstrated in both patients. The findings of other neurodiagnostic studies were relatively unremarkable. The first patient had a 3-year history of progressive anomia and impaired auditory verbal recall. An electroencephalogram was normal, and computed tomography showed mild left perisylvian atrophy. Positron emission tomography revealed profound hypometabolism in the left temporal regions. The second patient also had a 3-year history of progressive anomia. Electroencephalography, computed tomography, and magnetic resonance imaging scans were normal. Positron emission tomography showed a major reduction in left parietal glucose utilization, with a lesser decrement in left temporal metabolism. Neither patient demonstrated significant contralateral or global abnormalities such as those reported in positron emission tomographic studies of Alzheimer's disease with or without focal clinical features. These observations support the concept of adult-onset progressive aphasia without dementia as a clinical syndrome distinct from Alzheimer's disease.     

Neuropsychological and psychological sequelae of shunt surgery in young adults with hydrocephalus

Three patients with hydrocephalus aged 16, 26, and 33 years demonstrated memory deficits before or after the insertion of a ventricular shunt but at no time demonstrated ataxia, incontinence, or dementia. Following shunt surgery, memory functions improved rapidly in the patient who had had a recent acute onset of hydrocephalus, but in the two patients with a long period of hydrocephalus before shunting, memory impairments did not recover significantly in one patient, and in the other, memory impairments had become more severe by 12 months postshunt. Other neuropsychological and psychological sequelae of adult hydrocephalus are discussed, and it is suggested that for patients with chronic hydrocephalus, an extended period of neurological and neuropsychological monitoring may be advantageous before a decision is made to perform shunt surgery.     

Absence of antibody production in patients treated with botulinum A toxin

To test the possibility of the formation of an antibody to botulinum A toxin after multiple injections of this potent neurotoxin, we collected serum samples from 28 patients who received 57 doses. These injections over a nine-month period with as much as 50 units per injection formed no detectable antibody.