PubMed HealthSearch

Biomedical subjects

R E Steg

Publications and source records attributed to R E Steg.

18 recordsLinked to original sources

Clinical neurophysiologic findings in patients with rapidly progressive familial parkinsonism and dementia with pallido-ponto-nigral degeneration.

OBJECTIVE: To present clinical electrophysiologic studies performed on the pallido-ponto-nigral degeneration (PPND) family linked to chromosome 17q21-22. METHODS: Nine patients from this kindred were studied with 11 electroencephalograms (EEGs), 4 electroencephalographic background frequency analysis (BFA) studies, 4 electromyographic recordings (EMGs) including nerve conduction studies (NCSs), 4 electromyographic multichannel surface recordings (MSRs), one pattern visual evoked potential (VEP) study and one median nerve somatosensory evoked potential (SEP) study. RESULTS: EEGs revealed normal findings early in the disease and diffuse slowing which became more prominent with disease progression. BFA studies demonstrated rapid decrease in mean parietal frequencies with disease progression. EMGs and NCSs showed no abnormalities. MSRs revealed action myoclonus and a dystonic process. Long loop reflexes were absent in resting hand muscles. VEPs and SEPs were normal. CONCLUSIONS: Clinical neurophysiologic studies were consistent with a cortical and subcortical degenerative process. With clinical deterioration, there is a progressive decline in the mean parietal frequency and background rhythms. Tremor studies were consistent with action myoclonus and a dystonic process and did not show parkinsonian features of resting tremor or agonist-antagonist cocontraction. There was no evidence of peripheral nerve involvement or slowing in central sensory pathways. Electrophysiologic findings are characteristic for this illness.

Adult

Seizures after orthotopic liver transplantation.

Orthotopic liver transplantation is the accepted treatment for endstage liver disease. In the US alone, more than 3000 patients receive liver transplants yearly distributed through more than 100 liver transplant programmes. Neurological complications occur in up to 47% of these patients. Among them, seizures are one of the most common. They tend to occur during the first few weeks after transplantation. Generalized seizures are the most frequently encountered. Their aetiology is usually multifactorial requiring a comprehensive diagnostic and therapeutic approach. Seizures must be differentiated from a variety of behavioural and movement disorders. In this review article, the frequency and time of occurrence of seizures, their types and aetiology, diagnostic approaches and treatment are discussed.

Brain

Complex partial status epilepticus after bone marrow transplantation for non-Hodgkin's lymphoma.

We report a case of complex partial status epilepticus presenting as recurring episodes of altered mental status and subtle automatisms after bone marrow transplantation (BMT) for non-Hodgkin's lymphoma. Early recognition of complex partial status epilepticus as a cause of altered mental status is important as prompt treatment with antiepileptic drugs improves neurologic outcome.

Bone Marrow Transplantation

Electroencephalographic abnormalities in liver transplant recipients: practical considerations and review.

This article reviews the central nervous system complications of orthotopic liver transplantation (OLT) and the contribution of EEG in their assessment. The utility of EEG in the evaluation of disturbances of the level of consciousness, cerebrovascular disorders, infections, seizures, medication effects, and central pontine myelinolysis is discussed. EEG may aid in the assessment of altered levels of consciousness, correlate a variety of behavioral manifestations, demonstrate the presence of subclinical seizure patterns, and monitor the treatment response, thus contributing to the management of the OLT patient.

Adult

Epileptiform electroencephalographic abnormalities in liver transplant recipients.

We retrospectively studied patients who had undergone orthotopic liver transplantation and who also had electroencephalography to determine whether epileptiform changes were associated with a poor neurological outcome. Study groups were 36 patients who died after transplantation (141 electroencephalograms) and underwent neuropathological examination, 11 who died (18 electroencephalograms) but did not have autopsy, and a third group of 34 (62 electroencephalograms) who remained alive. Epileptiform activity was seen in electroencephalograms of 14 of the patients who died (11 from the autopsy group) and in 2 of those who remained alive. All had multiple epileptiform abnormalities and clinical or subclinical seizures. The incidence of epileptiform activity after orthotopic liver transplantation was fivefold higher in the nonsurvivors. Serious cerebral structural changes were found in 10 of the 11 patients who underwent autopsy. Epileptiform activity in the electroencephalograms of patients who had undergone orthotopic liver transplantation indicates a poor prognosis. It should alert the clinician to investigate further for potentially treatable causes.

Adolescent

Correlation of early MRI with CT scan, EEG, and CSF: analyses in a case of biopsy-proven herpes simplex encephalitis.

Herpes simplex encephalitis (HSE) carries a high mortality rate. Therefore, an early diagnosis and institution of acyclovir are essential. We report a case of biopsy-proven HSE with 2 negative cerebrospinal fluid (CSF) analyses and 2 normal CT scans. However, MRI together with EEG were abnormal early in the disease stressing their significant role in any suspected case of HSE. Although brain biopsy remains controversial, CSF herpes simplex antigen detection offers hope in providing an early or retrospective diagnosis while specific antiviral therapy with acyclovir is initiated. Overdependency on routine CSF analysis or head CT scan can result in unnecessary delays in diagnosis and treatment.

Acyclovir

Determining the cause of dementia.

In conclusion, dementia remains a major health problem among the elderly. Although Alzheimer's disease is now recognized as the major cause of dementia, there exist many other conditions which can be easily confused with Alzheimer's disease and for which specific treatment is available. Despite inherent problems in clinically diagnosing Alzheimer's disease, a careful and organized approach to the evaluation of the dementia patient will usually allow the clinician to determine the specific cause of the dementia and with a fairly high degree of accuracy.

Aged

Pontine and extrapontine myelinolysis following liver transplantation. Relationship to serum sodium.

The relationship between central pontine myelinolysis (CPM) and extrapontine myelinolysis (EPM) and serum sodium changes in the setting of orthotopic liver transplantation (OLT) is examined. Postmortem examination of 14 patients with end-stage liver disease who underwent liver transplantation revealed CPM in four, of which three also had EPM. A retrospective review of clinical and laboratory data was performed on all patients. There were marked perioperative rises (21-32 mEq/L) in the serum sodium concentration in all four patients who developed myelinolysis. In contrast, the largest increase in sodium in patients without demyelination was 16 mEq/L. We conclude that perioperative rises in the serum sodium concentration increase the risk of myelinolysis. CPM and EPM should be considered if the patient develops mental status changes or focal neurological deficits several days after OLT.

Adult

Age-related amplitude variations of the posterior tibial nerve spinal SEP P21 component.

The effects of aging on the amplitude of the surface-recorded tibial nerve spinal somatosensory-evoked potential P21 component (L5-T12 electrode derivation) were studied in 79 subjects. The results of this investigation indicate that a significant moderately negative correlation (r = -0.46) exists between subject age and the amplitude of component P21. These findings suggest that the absence of a P21 potential in an elderly patient does not necessarily represent evidence of neural pathology.

Adolescent