The present study deals with observations on the "speech evoked potential"-a late positive potential evoked by word repetition. These potentials, evoked by "silent" repetition of polysyllabic words, were averaged and recorded from the scalp overlying the inferior frontal regions on both sides in 20 normal healthy subjects of ages ranging from 13-58 years. The potential had a triphasic negative, positive, negative morphology and was present over both hemispheres in left as well as right handed subjects. The main positive deflection and mean latencies of 219.2 msec and 221.6 msec and mean amplitude of 6.2 muv and 6.5 muv respectively on the left and right sides. Though there were interindividual variations in latency, amplitude and morphology, there was a high degree of intraindividual similarity and reproducibility in subjects. The variations in these parameters with age, sex and handedness are discussed. In 10 patients with cerebral lesions, the evoked potential was normal in 5 cases with right frontal lesions and showed abnormalities in 3 of 5 cases with left frontal lesions. The speech evoked potential may be useful in the further study of electrical correlates of speech output in speech disorders.
The present study outlines the clinical profile and patterns of extracranial vascular abnormalities detected by continuous wave doppler ultrasonography (CWDU) in 100 patients with cerebrovascular insufficiency states. Males outnumbered females (65:35); completed stroke (CS) was a more common mode of presentation than transient ischaemic attacks (TIA); carotid strokes were more common than vertebro-basilar ones; and hypertension was the most common predisposing factor. The CWDU evaluation revealed extracranial vascular disease in 73% of patients. Vascular occlusions were more common in patients with TIA. Overall, 33% of the patients had evidence of proximal obstruction of the cerebral vessels below the neck. The clinical prediction of vascular territory (carotid or vertebro-basilar) matched with the findings on CWDU, but evidence of subclinical multiple-vessel involvement could be detected in 48% of the patients.
We describe a case of cervical cord compression due to ossified posterior longitudinal ligament in association with diffuse idiopathic skeletal hyperostosis, in a young female. Characteristic CT findings are described.
The clinical and electroencephalographic (EEG) features were evaluated in a consecutive series of 50 infants with complex partial seizures. The age of onset of seizures showed a peak at age of 2 months. Significant development delay was seen in 60% of the infants. In 92% an underlying aetiological factor could be identified. Birth asphyxia was the commonest aetiological factor (30%). The seizure patterns were most frequently described as behavioural arrest, upward deviation of eyes, tonic posturing of the limbs, apnoea and cyanosis. Interictal EEG showed bilateral temporal lobe foci in 22%, unilateral foci in 78% and multiple foci in 46% of the cases. The response of the seizures to anticonvulsant drugs is discussed.
A 30 year old Malay male developed bilateral choroiditis followed by vitiligo, poliosis and canities. CT scan showed nodular thickening of the optic nerves. Characteristic abnormalities were seen in visual and brainstem auditory evoked potentials and fluorescein angiography. These findings were in keeping with the diagnosis of Vogt-Koyanagi-Harada syndrome. Treatment with dexamethasone resulted in complete recovery of vision and partial improvement in skin and hair lesions.
To determine the clinical and radiological features of the patients who were found to have cavum septum pellucidum (CSP) on the cranial computerized tomographic (CT) scans.