Improved detection of amnestic MCI by means of discriminative vector quantization of single-trial cognitive ERP responses.

Cognitive event-related potentials (ERPs) are widely employed in the study of dementive disorders. The morphology of averaged response is known to be under the influence of neurodegenerative processes and exploited for diagnostic purposes. This work is built over the idea that there is additional information in the dynamics of single-trial responses. We introduce a novel way to detect mild cognitive impairment (MCI) from the recordings of auditory ERP responses. Using single trial responses from a cohort of 25 amnestic MCI patients and a group of age-matched controls, we suggest a descriptor capable of encapsulating single-trial (ST) response dynamics for the benefit of early diagnosis. A customized vector quantization (VQ) scheme is first employed to summarize the overall set of ST-responses by means of a small-sized codebook of brain waves that is semantically organized. Each ST-response is then treated as a trajectory that can be encoded as a sequence of code vectors. A subject's set of responses is consequently represented as a histogram of activated code vectors. Discriminating MCI patients from healthy controls is based on the deduced response profiles and carried out by means of a standard machine learning procedure. The novel response representation was found to improve significantly MCI detection with respect to the standard alternative representation obtained via ensemble averaging (13% in terms of sensitivity and 6% in terms of specificity). Hence, the role of cognitive ERPs as biomarker for MCI can be enhanced by adopting the delicate description of our VQ scheme.

Autologous stem-cell transplantation in malignant multiple sclerosis: a case with a favorable long-term outcome.

Malignant multiple sclerosis (MS) is a rare but clinically important subtype of MS characterized by the rapid development of significant disability in the early stages of the disease process. These patients are refractory to conventional immunomodulatory agents and the mainstay of their treatment is plasmapheresis or immunosuppression with mitoxantrone, cyclophosphamide, cladribine or, lately, bone marrow transplantation. We report on the case of a 17-year old patient with malignant MS who was treated with high-dose chemotherapy plus anti-thymocyte globulin followed by autologous stem cell transplantation. This intervention resulted in an impressive and long-lasting clinical and radiological response. It is concluded that intensive immunosuppression followed by autologous stem cell transplantation is a viable therapeutic option in patients with malignant MS unresponsive to conventional forms of treatment.

A randomized, double-blind, placebo-controlled study of venlafaxine XR in out-patients with tension-type headache.

The aim of this study was to evaluate in a double-blind, randomized, placebo-controlled study the safety and efficacy of venlafaxine extended release (XR) in the prophylactic treatment of out-patients with tension-type headache (TTH) and no current depression or anxiety disorders. Sixty neurology and headache clinic out-patients meeting the International Headache Society diagnostic criteria for TTH were treated with venlafaxine XR (150 mg/day, n = 34) or placebo (n = 26) for 12 weeks. The primary efficacy variable was the decline in number of days with headache. At end-point, the venlafaxine XR group had a significantly greater decrease in the number of days with headache compared with placebo (P = 0.05). Differences with regard to secondary efficacy variables where not significant. The number needed to treat for responders (>or=50% reduction in days with headache) was 3.48. Six patients in the venlafaxine XR group interrupted therapy due to adverse events, while no patients in the placebo group did so for the same reason. The number needed to harm was 5.58. This study provides preliminary evidence for the efficacy and safety of venlafaxine XR 150 mg/day in reducing the number of days with TTH.

Schizophrenic-like symptoms in a patient with thrombo-angiitis obliterans (Winiwarter-Buerger's disease).

In this article a case of schizophrenic-like symptoms in a patient with thrombo-angiitis obliterans (TAO) is presented. His CT and MRI findings indicated a diffuse ischemia in the white matter, suggestive of TAO, not of focal lesions. The patient, except for age, did not have other risk factors for other cerebrovascular diseases. Psychotic symptoms may be the result of cerebral TAO, via deep and periventricular white matter lesions.

Symptomatic trigeminal neuralgia.

In four cases with trigeminal neuralgia an intracranial neoplasm was detected. In the first two cases a meningioma of the cerebellopontine angle was producing symptomatic trigeminal neuralgia almost identical to the essential one. In the other two cases with a tumor in the gasserian ganglion area the facial pain was of a more atypical nature. In all four cases associated sensory trigeminal deficits were present. The causative factors which may produce symptomatic trigeminal neuralgia are especially discussed in this paper.

CT in the diagnosis of cerebral vascular malformations.

In 72 patients with spontaneous intracranial haemorrhage and vascular malformation, 27 of 49 arterial aneurysms were diagnosed by CT (the smallest one of 4mm diameter being stalked), as were all (18) of the arteriovenous aneurysms (angiomas), but of the venous malformations (5) only 2 (aneurysms of the vein of Galen) were so diagnosed. In the 25 patients with spontaneous subarachnoid haemorrhage, in whom vascular malformation had not been diagnosed through angiography or CT, CT showed the position and extent of the parenchymatous lesion or the existence of blood in the subarachnoid space or ventricules. Finally, in 15 patients with subjective or neuropsychiatric disturbances, 9 arterial and 6 arteriovenous aneurysms were diagnosed by CT and were verified by angiography, which would probably not have been performed if CT had not been performed. Thus it is clear that vascular malformations are often diagnosed by CT. In many cases information is revealed which would not be suspected with angiography, while in other cases angiography is more selective and accurate.

[Cranial computerized tomography in senile dementia]. / Die craniale Computer-Tomographie bei Demenz im Alter.

Axial tomograpum (CAT), of 59 patients with dementia and 102 controls suffering from headaches and dizziness were examined. The CAT was normal in 13 demented patients (22%) and in 37 controls (36,3%), and revealed enlarged spaces of the CSF in 46 anoic patients (78%) and 65 controls (63.7%). Multiple areas of subnormal density were observed in 23 anoic patients (39%) and in 6 controls (5.9%). This indicates that the multi infarct syndrome is frequently associated with dementia, while the correlations between Hydrocephalus and dementia is weak.

Fever and evoked potentials in multiple sclerosis.

The somatosensory evoked potentials (SEPs) and visual evoked potentials (VEPs) were studied in 19 patients with multiple sclerosis; 17 controls were studied during fever (38.0 degrees - 39.7 degrees C) and 2-3 days following return to normal temperature. The latencies of components N20 and P114 were measured and specified as abnormal when their value exceeded the standard deviation of the controls by 2.5 times. The corresponding criterion for the evaluation of the amplitude of components N20 and P114 was a reduction in amplitude of more than 50%. In the controls fever did not cause significant changes in evoked potentials. On the other hand, patients with multiple sclerosis showed abnormalities in evoked potentials during fever in a greater number of recordings (26 of SEPs and 33 of VEBs) than after return to normal temperature (19 and 27 respectively). In addition, the average latency of components N20 and P114 was clearly greater in the patients during fever (N20 = 29.5 +/- 5.2 ms and P114 = 143 +/- 18.1 ms) than after return to normal temperature (N20 = 6.6 +/- 3.5 ms and P114 = 134 +/- 16 ms). The amplitude of components N20 and P114 in patients during fever was clearly smaller than after return to normal temperature. These differences were statistically significant. Finally, in two patients, a decrease was found, during fever, in the conduction velocity of the peripheral somatosensory pathway from the median nerve to the wrist at Erb's point.