Reversible Posterior Leucoencephalopathy (PLES) Syndrome

Scientific background: The posterior leucoencephalopathy (PLES) is a clinico-radiological syndrome characterised by headache, nausea, vomiting, disturbances in cognition, depressed level of consciousness, visual abnormalities and convulsions. It is commonly associated with malignant hypertension, toxemia of pregnancy or use of immunosuppressive agents. O b j e c t i v e: We, here, report a case of reversible posterior leucoencephalopathy syndrome in a patient submitted with headache, hypertension, quadranopia and the importance of performing cranial imaging and the benefit of diffusion MRI in the differential diagnosis of P L E S. F i n d i n g s: MRI and diffusion MRI studies have been performed in a 35 year old male patient with hypertension and renal failure, and diffuse posterior system lesions have been found. C o n c l u s i o n: The patient’s clinical and radiologic recovery occurs following control of blood pressur

The Effects of Stimulation Frequency Changes on Central Conduction Time in Short Latency SEPs in Multiple Sclerosis Patients.

Background: Somatosensory evoked potentials (SEPs) are widely used in the electrophysiological diagnosis of multiple sclerosis since 1970s The importance of central conduction time among SEP parameters is also well known and it is often regarded as being pathological more often than the absolute latencies. Objective: In this study our aim was to find out the effects of the change of stimulus frequencies on absolute latencies and central conduction time in median SEPs of multiple sclerosis patients. Material and method: Twenty five multiple sclerosis patients and 15 healthy subjects were taken into the study and median SEPs of 80 extremities were studied. During median SEP recordings the stimulus frequencies were changed by 2/sec, 4/sec, 6/sec and 9/sec both in the patient and control groups. N9 peak, N11 peak, N13 peak, N20 peak and N11-13 complex onset latency, N20 onset latency, peak central conduction time and onset central conduction time have been determined both in the patient and the control groups. All the parameters of different stimulation frequencies were compared statistically with each other both in the patient and the control groups. The parameters of the patient and the control groups were also compared statistically with one and other. Results: The results showed that N20 peak latency, peak central conduction time, N20 onset latency and onset central conduction time values were statistically significantly higher in the patient group when compared with the control group. In the patient group, the values of peak central conduction time in 4/sec stimulation frequency were statistically significantly higher than the values in 2/sec stimulation frequency (p<0.01). The same was true for the values in 6/sec stimulation frequency when compared with the values in 2/sec stimulation frequency (p<0.05). There were no such statistically significant results for peak central conduction time values of the control group when different stimulation frequencies were applied (p>0.05). In the patient group, the values of onset central conduction time in 4/sec stimulation frequency were statistically significantly higher than the values in 2/sec stimulation frequency (p<0.05). The values in the control group did not show any statistical differences again (p>0.05). Conclusions: The results obtained in this study showed us that the change of the stimulation frequencies in the patient group enhanced the pathology seen in both peak and central conduction times whereas the normal controls were immune to this effect. Changing the stimulation frequency during short latency SEP recordings has not been studied in multiple sclerosis patients before. We believe that studies on stimulus frequency changes in SEPs in multiple sclerosis, will be very useful both for the electrophysiological diagnosis of MS and the physiological dynamics of SEPs

A Methodological Study on Cervical Responses by Median Nerve Stimulation

Background: Somatosensory evoked potentials (SEPs) have been widely accepted as a noninvasive, easy tolerated and, useful method in the assesment of cervical spinal cord conduction. There are different recording and reference applications for SEP montage in different articles. Objective: This study has planned to determine the best placement of electrodes. Material and Methods: We performed Cv2, Cv3, Cv4, Cv5 recording with Fz or anterior cervical reference points by median nerve stimulation in 30 healthy subjects with an age range of 20-39. We compared the results obtained from both reference recordings. And also we performed detailed correlation analysis between latency, amplitude, duration, intercomponent intervals and age, height, weight, arm lenght, body mass index, (age-20)2. Findings: In conclusion, according to recording points there was no meaningful difference as statistically between parameters. Comparing the reference points; there is an increased possibility to obtain the complex of N11-N13- N14 waves by using Fz reference electrod. The results also revealed a statistically significant correlation between height, arm lenght and, SEP parameters. Conclusion: We conclude that there were no differences in latency and amplitude between Cv2, Cv3, Cv4, Cv5 recordings points. We recommend that the usage Fz reference point for obtaining N11 potential, the usage of AC reference point for more clear N13 potential

Asymmetrical Lobar Degenerations: Clinical, Neuropsychological, Scanning Data

OBJECTIVE: Asymmetric lobar degenerations are clinical syndromes which affect primarily one or more than one cerebral lobe and result progressive language and/or behaviour and/or cognitive dysfunction. METHODS: We report the clinical, neuropsychological and neuroimaging results of 5 patients with asymmetric lobar degeneration an one or more than one clinical syndrome according to Frontotemporal Lobar Degeneration: A Consensus on Clinical Diagnostic Criteria. RESULTS: Asymmetric lobar degeneration may be one of the largest entities after Alzheimer Disease to cause dementia. Not only frontal lobe dementia but also progressive language disorder and corticobasal degeneration syndrome can be produced by frontotemporal lobar degeneration and both clinical and pathological overlap of the syndromes can be seen. The recognition of the relationship between the clinical syndromes has important implications in the diagnosis and treatment of dementia