E. Wayne Massey

Spinal cord infarction Etiology and outcome

We reviewed 44 cases of ischemia and infarction of the spinal cord at two university hospitals.Three patients experienced transient ischemic attacks. Etiologies of completed strokes were diverse and included rupture and surgical repair of aortic aneurysms, aortic dissection, aortic rupture and thrombosis, global ischemia, anterior spinal artery embolism, repair and thrombosis of spinal arteriovenous malformations, hematomyelia, epidural hematoma, cervical osteophytosis, celiac plexus block, systemic lupus erythematosus, coagulopathy, and decompression sickness. Motor function improved in 12 patients, was substantial in only one, and occurred largely within the first 2 to 4 weeks. Favorable ambulatory outcome correlated with improving neurologic examinations and relatively preserved strength in hip abductors and knee extensors. More extensive deficits without initial improvement portended a more severe prognosis. Autonomic dysfunction, pain, paresthesia, and depression were common and impeded recovery in some patients. The mean level of deficit was at T-8 and in cases of global ischemia was at T-9, which leads us to dispute the classical view of a midthoracic watershed zone of ischemic vulnerability near T-4. NEUROLOGY 1996;47: 321-330

Multiple sclerosis risk after optic neuritis: Final optic neuritis treatment trial follow-up

OBJECTIVE To assess the risk of developing multiple sclerosis (MS) after optic neuritis and the factors predictive of high and low risk. DESIGN Subjects in the Optic Neuritis Treatment Trial, who were enrolled between July 1, 1988, and June 30, 1991, were followed up prospectively for 15 years, with the final examination in 2006. SETTING Neurologic and ophthalmologic examinations at 13 clinical sites. PARTICIPANTS Three hundred eighty-nine subjects with acute optic neuritis. MAIN OUTCOME MEASURES Development of MS and neurologic disability assessment. RESULTS The cumulative probability of developing MS by 15 years after onset of optic neuritis was 50% (95% confidence interval, 44%-56%) and strongly related to presence of lesions on a baseline non-contrast-enhanced magnetic resonance imaging (MRI) of the brain. Twenty-five percent of patients with no lesions on baseline brain MRI developed MS during follow-up compared with 72% of patients with 1 or more lesions. After 10 years, the risk of developing MS was very low for patients without baseline lesions but remained substantial for those with lesions. Among patients without lesions on MRI, baseline factors associated with a substantially lower risk for MS included male sex, optic disc swelling, and certain atypical features of optic neuritis. CONCLUSIONS The presence of brain MRI abnormalities at the time of an optic neuritis attack is a strong predictor of the 15-year risk of MS. In the absence of MRI-detected lesions, male sex, optic disc swelling, and atypical clinical features of optic neuritis are associated with a low likelihood of developing MS. This natural history information is important when considering prophylactic treatment for MS at the time of a first acute onset of optic neuritis.

Myocardial infarction and stroke

We used a computer data bank to evaluate 740 consecutive patients admitted to a cardiac care unit with myocardial infarction. Stroke occurred in 18 (2.4%) patients in the hospital; the anterior circulation was involved in 76% of strokes. Hospital mortality was 61% in patients with stroke and 13% in patients without stroke. Atrial arrhythmia was a significant (p 5 0.03) risk factor for stroke, but peak creatine kinase and ventricular arrhythmia were not. Cardiac pump failure, apical or anterior-lateral myocardial infarction, and history of previous stroke were associated with an increased risk of stroke. Clinical and pathologic data suggested an embolic etiology for most strokes that complicate acute myocardial infarction.

Carbon monoxide, skeletal muscle oxidative stress, and mitochondrial biogenesis in humans

Given that the physiology of heme oxygenase-1 (HO-1) encompasses mitochondrial biogenesis, we tested the hypothesis that the HO-1 product, carbon monoxide (CO), activates mitochondrial biogenesis in skeletal muscle and enhances maximal oxygen uptake (Vo(2max)) in humans. In 10 healthy subjects, we biopsied the vastus lateralis and performed Vo(2max) tests followed by blinded randomization to air or CO breathing (1 h/day at 100 parts/million for 5 days), a contralateral muscle biopsy on day 5, and repeat Vo(2max) testing on day 8. Six independent subjects underwent CO breathing and two muscle biopsies without exercise testing. Molecular studies were performed by real-time RT-PCR, Western blot analysis, and immunochemistry. After Vo(2max) testing plus CO breathing, significant increases were found in mRNA levels for nuclear respiratory factor-1, peroxisome proliferator-activated receptor-gamma coactivator-1alpha, mitochondrial transcription factor-A (Tfam), and DNA polymerase gamma (Polgamma) with no change in mitochondrial DNA (mtDNA) copy number or Vo(2max). Levels of myosin heavy chain I and nuclear-encoded HO-1, superoxide dismutase-2, citrate synthase, mitofusin-1 and -2, and mitochondrial-encoded cytochrome oxidase subunit-I (COX-I) and ATPase-6 proteins increased significantly. None of these responses were reproduced by Vo(2max) testing alone, whereas CO alone increased Tfam and Polgamma mRNA, and COX-I, ATPase-6, mitofusin-2, HO-1, and superoxide dismutase protein. These findings provide evidence linking the HO/CO response involved in mitochondrial biogenesis in rodents to skeletal muscle in humans through a set of responses involving regulation of the mtDNA transcriptosome and mitochondrial fusion proteins autonomously of changes in exercise capacity.

Effort Headache in Runners

SYNOPSIS

Compression Injury of the Sciatic Nerve During a Prolonged Surgical Procedure in a Diabetic Patient

Patients with diabetes mellitus and an underlying mixed axonal and demyelinating polyneuropathy are particularly prone to compression neuropathies with consequent axonal degeneration and a poor prognosis for recovery. This hazard should be taken into account whenever a prolonged surgical procedure is contemplated. An illustrative case is presented.

Pseudoseizures: recognition and treatment.

Abstract Pseudoseizures involve a subjective loss of consciousness, usually resulting from a psychological disturbance. Drug intoxication, panic or anxiety attacks, or hypoglycemia may also induce behavior that resembles epileptic manifestations. Multiple EEG evaluations and careful clinical observation can rule out epilepsy. Psychiatric treatment, including family interviews and sympathetic discussion of the underlying emotional problem with the patient, should be provided when appropriate.

Lumbosacral Plexus Stretch Injury Following the Use of the Modified Lithotomy Position

The modified lithotomy position is used to provide simultaneous operative exposure to the abdomen and perineum. We report 3 lumbosacral plexus complications following use of this position. A mechanism involving stretch secondary to hyperabduction seems most likely. Electromyography is helpful in the diagnosis and the prognosis seems to be good.

Familial benign intracranial hypertension and depression.

Two sisters developed benign intracranial hypertension (BIH) two weeks following the resolution of a major depressive episode. The association of BIH and a major affective disorder in genetically related individuals has not been previously reported to our knowledge. Both conditions are associated with disturbances in the hypothalamic-pituitary-adrenal axis. Falling corticosteroid levels in a resolving depression may result in impaired cerebrospinal fluid absorption and subsequent BIH.

Mononeuropathy in diabetes mellitus: A phenomenon easily overlooked

In patients with diabetes, a carefully taken history and meticulously performed neurologic examination enable the clinician to separate superimposed mononeuropathy from more generalized symmetric polyneuropathy. Recognition of mononeuroparhy is important, since often it is reversible.