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Biomedical subjects

K Nudleman

Publications and source records attributed to K Nudleman.

7 recordsLinked to original sources

Cognitive evoked potentials (P300) in early Huntington's disease.

The P3 component of both auditory-event- and visual-event-related potentials of 13 patients with Huntington's disease was studied and compared with the P3 component of normal patients. The latencies of the patients' P3 components were compared with the latency-age regression lines generated by the normal population in both modalities. A P3 latency was considered abnormal if it fell above the 2-SE limit for the latency-age regression line. The incidence of normal or abnormal P3 latencies in the two modalities was compared with the results of computed tomography, electroencephalography, and neuropsychological testing. Nine patients had abnormal P3 latencies and ten patients had abnormal visual P3 latencies, with seven having abnormal latencies on both tests and 12 having abnormal latencies on one of the two tests. An abnormal P3 latency in one modality did not imply an abnormal P3 latency in the other. An abnormality of the P3 latency did not correlate with an abnormality in results from computed tomography, electroencephalography, or neuropsychological testing.

Adult↗

The hemi 3 syndrome. Hemihypertrophy, hemihypaesthesia, hemiareflexia and scoliosis.

Three unrelated girls presented with a developmental syndrome of hypertrophy involving half or a quadrant of the body and not involving the face. The appearance was one of inappropriately large size of the affected side rather than contralateral atrophy. On the larger side, there was hypertrophy of muscle and increased power as well as an increase in diameter, but not in length, of long bones. There was areflexia and decreased pain and temperature sensation on that side. The patients also had progressive scoliosis and foot deformities on the enlarged side. One patient had a lumbar myelomeningocoele , and all 3 had a family history of neural tube closure defects. EMG, nerve conduction studies, EEG, skull x-rays, PEG, and cerebral CT scans were normal. Myelography did not demonstrate an enlarged cord, and in particular there was no evidence for syringomyelia. Chromosome studies revealed normal karyotypes. Sex chromatin was female on both sides in one patient. A defect of the dorsal lip of the neural tube or the neural crest is postulated to explain the abnormality. The association with closure defect in one patient and a positive family history of other neural tube defects in all 3 patients suggests that the developmental defect occurs at an early embryonic stage. Recognition of the syndrome is important. It can be distinguished clinically from hemiatrophy of cerebral origin. The neurological abnormalities are static, but the scoliosis is progressive and requires correction. The condition is associated with an increased prevalence of neural tube closure defects in the family, and forms part of a spectrum of genetically and embryologically related CNS malformations with multifactorial inheritance. Probands, parents, siblings and parents' siblings should be counselled that the risks of spina bifida and anencephaly in their offspring are the same as those in relatives of probands with classical neural tube defects, and should be offered prenatal diagnosis.

Adult↗

Assessment of sensory function in the operating room utilizing cerebral evoked potentials: a study of fifty-six surgically anesthetized patients.

Sensory evoked potentials (visual, auditory, and somatosensory) were recorded from 56 patients at the time of surgery to monitor neural function during critical portions of the operation. Fluctuations in latency and amplitude of the components occurred with changes in depth of anesthesia, blood pressure, irrigation, and neural tissue manipulation. Most of these changes were only transient. Permanent changes in evoked potentials occurred with decompression of neural tissue and prolonged retraction. Transient changes were not associated with any change in postoperative neurological function whereas changes in evoked potentials that persisted through the operation were highly likely to be associated with a postoperative change.

Adolescent↗

Cord to cortex conduction in multiple sclerosis.

We studied 30 controls and 28 patients with multiple sclerosis (MS). M-waves, F-waves, and somatosensory responses evoked by median and peroneal nerve stimulation were used to estimate conduction times from the lumbar cord to the cortex; the cervical cord to the cortex; through the spinal cord; and in proximal segments of peripheral nerve. The central conduction times were significantly prolonged in the MS patients, giving an overall 79 percent incidence of abnormalities. Several patients who were asymptomatic in the tested arm (36 percent) or leg (16 percent) showed electrophysiologic abnormalities. By comparing conduction time from the lumbar cord to the cortex with the conduction time from the cervical cord to the cortex, the site of the lesion could be deduced, but not proven. The diagnostic yield from measuring the latencies of the somatosensory responses was 68 percent. We concluded that measuring central conduction times indirectly by use of M- and F-waves adds little to simple measurement of somatosensory responses.

Adult↗

Short-latency somatosensory responses in multiple sclerosis.

Cervical and cortical somatosensory evoked potentials were measured in 80 patients with suspected or established multiple sclerosis (MS). The cervical response was a more sensitive diagnostic indicator than the cortical response, and was abnormal in 86.7 percent of patients with definite MS and in 40.9 percent of MS suspects. The complementary value of measuring both responses was greatest (89.3 percent) in early probable or latent MS. Comparing the responses obtained from stimulation of the left and right extremities increased the overall diagnostic yield by 25 percent. Abnormal responses were frequently obtained from clinically normal limbs.

Adolescent↗

F-wave and cervical somatosensory response conduction from the seventh cervical spinous process to cortex in multiple sclerosis.

Transit (conduction) times from the wrist to the seventh cervical spinous process (C7) were measured by using the F-wave response (TA) and the cervical somatosensory response (SEPC). The mean values obtained in 25 controls were 10.1 +/- 0.9 s-3 and 10.9 +/- 1.0 s-1 respectively. The 0.8 +/- 1.0 s-3 difference between the two methods represents central delay of SEPC, possibly at the level of the dorsal root ganglion. The mean onset latency of the cortical somatosensory response (SEPA) evoked by median nerve stimulation in the same subjects was 15.5 +/- 1.0 s-3. Transit time from C7 to the cortex (TB) given by either SEPA - TA or SEPA - SEPC - 0.8, where 0.8 is the necessary corrective factor for central delay of SEPC, WAS 5.3 +/- 1.0 S-3. These techniques were applied to 10 patients suspected of having multiple sclerosis, but without clinical evidence of involvement above C7. Six of the 10 cases showed prolongation of TB. In 4 of these, this could only be calculated by the F-wave method since SEPC was absent. It is concluded that transit times derived from either the F-wave or SEPC are equally valid and interchangeable. The absence of one response allows for its replacement by the other.

Action Potentials↗