SPECT findings in an unusual case of visual hallucinosis.

A 64-year-old right-handed man acutely developed elementary visual hallucinations (monochromatic, moving geometrical figures), visual illusions (distortion of the right side of faces) with achromatopsia and blurred vision restricted to the left visual hemi-field. CT of the brain before and after administration of contrast medium and a repeat examination 2 months later showed no abnormalities, while brain mapping (power analysis of EEG) demonstrated theta wave slowing of the curve over the posterior part of the right hemisphere. 99mTC HMPAO SPECT of the brain, however, demonstrated an area of definite focal hypoperfusion in the right occipito-temporal region. Echo-Doppler-duplex and continuous wave examination of the cervical arterial blood vessels disclosed bilateral discrete atheromatous plaques that did not affect the blood flow. Transoesophageal echocardiography demonstrated slight mitral valve insufficiency. Cerebral angiography showed an occlusion of the right posterior cerebral artery. After the visual hallucinations had subsided, SPECT showed partial normalization of the right occipito-temporal perfusion. In the absence of CT evidence for a structural lesion in the clinically suspected areas, only functional imaging revealed an obviously significant lesion. This case furthermore demonstrates that SPECT can contribute to the identification of the pathophysiology underlying visual hallucinosis.

Dementia paralytica in a fifteen-year-old boy.

A 15-year-old boy, whose history revealed an unremarkable pregnancy, birth and neonatal period and who had shown a normal motor and mental development, presented at the hospital with deterioration of cognitive functions since the age of 7. He was bedridden with manifest ataxia involving all limbs, anisocoria and a sluggish to absent pupil reaction to light. Syphilis serology was positive with a Venereal Disease Research Laboratory (VDRL) titer of 1:256 and a Treponema pallidum Haemagglutination Assay (TPHA) titer of 1:163840. Cerebrospinal fluid (CSF) protein concentration was 55 mg/dl and CSF-leucocyte count was 14/mm3 (85% mononuclear cells). CSF-VDRL-titer was 1:16. A diagnosis of congenitally acquired dementia paralytica was made, since the boy's parents' clinical exam and serology results were suggestive for latent syphilis. Although cognition was still very much deteriorated five months following penicillin treatment, clinical examination revealed partial recuperation. Screening for syphilis should be part of routine testing in every subject presenting with cognitive deterioration, regardless of age.

Clinical and neurophysiological correlations in patients with refractory partial epilepsy and intracranial structural lesions.

Twenty patients (13 males, 7 females), who presented with refractory partial epilepsy and a CT and/or MR detected intracranial intra-axial structural lesion were admitted to the University of Gent Epilepsy Monitoring Unit. Mean duration of the epilepsy was 17 years (2-47 years). All patients were enrolled in a comprehensive presurgical protocol including neurological examination, video-scalp-EEG monitoring with prolonged interictal and ictal recording, neuropsychological assessment and positron emission tomography (PET). Intracranial EEG monitoring was performed in 5 patients in whom discrepancies between different tests were found during the non-invasive evaluation. Clinical neurological examination was normal in 16 patients; 4 patients had a mild contralateral hemiparesis. Lesions were mainly located in the temporal lobe (55%). Most patients presented with complex partial seizures (90%). Clinical seizure characteristics correlated well with the lesion location in 55% of patients. Interictal EEG showed focal epileptic activity and focal slowing in respectively 85% and 30% of patients. Interictal EEG lateralization was congruent with the side of the lesion in 17 patients (85%). Interictal EEG localization was congruent with the lobe of the lesion in 13 patients (65%). Ictal EEG lateralized correctly in 14 patients (70%) and localized correctly in 10 patients (50%). Neuropsychological assessment lateralized and localized congruently in respectively 8/17 (47%) and 7/17 (41%) of patients. Interictal PET showed focal interictal hypometabolism, congruent with the lesion, in 13/16 (81%) of patients. Intracranial EEG was congruent with the lesion location in 3 patients but non-congruent in 2 patients. All patients underwent surgical procedures: average follow-up was 14 months (6-24 months). Complete surgical removal of the lesion with free margins resulted in a more than 90% reduction of seizures without postoperative neurological deficit in 12/13 patients.