Lateral asymmetry of motor unit number estimate (MUNE).

The aspects of lateral asymmetry of the peripheral nervous system have been investigated to a lesser extent than the aspects of lateral asymmetry in the central nervous system. We utilized a statistical method of quantitative MUNE to demonstrate lateral asymmetry of the motor units in healthy individuals, revealing higher values in the nondominant hand. Awareness of this phenomenon will improve the accuracy and reliability of this MUNE method when used in clinical trials.

Massive putaminal-thalamic nontraumatic hemorrhage.

Fourteen patients developed massive putaminal-thalamic hemorrhage. All patients were young black men. They were hypertensive but without chronic hypertensive vascular changes. They had been treated with antihypertensive medication for less than 3 yr. All patients presented with a prodromal headache beginning 18-30 h before the brain hemorrhage. Initial clinical signs were heralded by a change in the headache pattern and vomiting. All patients became comatose and hemiplegic within 4-12 h. CT showed a hyperdense putaminal-thalamic hemorrhage which was 60 to 86 mm in maximal diameter. There was marked mass effect with secondary intraventricular extension. All patients died within 72 h, despite rapid and adequate blood pressure control and maximal medical treatment of cerebral edema and increased intracranial pressure.

Respiratory failure revealing mitochondrial myopathy in adults.

Two patients, a 70-yr-old black woman and a 56-yr-old black man, presented with respiratory failure unexplained by intrinsic lung disease. Both had been dependent on a respirator for several weeks. No abnormalities of the central or peripheral nervous system or long-standing muscle weakness was noted. The findings from ophthalmologic and cardiac evaluations were normal. The serum creatinine kinase concentration was mildly elevated in case 1, and needle electromyography showed myopathic potentials in case 2. In both instances, muscle biopsy established the diagnosis of mitochondrial myopathy. Biochemical studies of muscle extracts showed partial deficiency of complex 3 in patient 2 and of complex 4 in patient 1. Both patients were weaned from the ventilator after long periods of ventilatory assistance. These observations document a hitherto undescribed presentation of adult-onset mitochondrial myopathy.

Nontraumatic posterior temporal lobe hemorrhage: clinical computed tomographic correlations.

Ten patients with nontraumatic posterior temporal hematomas were analyzed. These hemorrhages were spontaneous (four cases) or hypertensive (six cases). With right posterior temporal hematomas, headache and confusion of sudden onset were the initial common characteristic clinical signs. The absence of prominent lateralizing neurological deficit simulated a diffuse toxic or metabolic encephalopathy. With left-sided hematomas, Wernicke-type aphasia was the initial feature. The 10 hematomas were 1.8 to 2.8 cm in maximal diameter. In these 10 cases, clinical outcome was good, as all patients survived and the hematoma resolved spontaneously.

Seizures caused by nontraumatic parenchymal brain hemorrhages.

Seizures occurred in 15% of patients with parenchymal brain hemorrhage (early in 12% and delayed in 3%). Seizures were most frequent with lobar hemorrhages and uncommon with deep subcortical hemorrhages. Lobar hemorrhages in the frontal, parietal, or temporal region were more commonly associated with seizures, whereas occipital hemorrhages were not. Seizures were most common if the hemorrhage was due to an aneurysm, angioma, or neoplasm and less common if hypertensive or spontaneous. If the patient had recurrent seizures or developed delayed seizures, CT showed that the hemorrhage evolved to a hypodense appearance; if the seizure did not recur, CT showed that the hemorrhage evolved to an isodense appearance.

Intraventricular hemorrhage in adults: clinical-computed tomographic correlations.

The clinical and computed tomographic (CT) findings in 100 consecutive adult nontraumatic intraventricular hemorrhage (IVH) cases are analyzed. There were 74 parenchymal brain hemorrhages with secondary ventricular extension. The ventricles were filled with blood and asymmetrically enlarged. If the hemorrhage involved putamen, cerebellum, pons, or subcortical cerebral hemispheric white matter, IVH was associated with large parenchymal hematomas; these patients had poor clinical outcome. With thalamic or caudate hematomas, IVH frequently occurred with large hematomas but may occur with small hematomas. The small hematomas were located directly contiguous to the ventricular walls and caused extensive ventricular blood. Patients with small thalamic and caudate hemorrhage with intraventricular blood had good clinical outcome; whereas patients with large hematomas had poor outcome. Primary IVH occurred in 24 cases. In these cases, blood was seen in all ventricular chambers. Aneurysms involving the anterior cerebral-anterior communicating artery region were the most common etiology for primary IVH.

Nontraumatic parenchymal brain hemorrhages.

Before the availability of computerized tomography (CT), it was estimated that 25% of parenchymal brain hemorrhages (PBH) was diagnosed as ischemic stroke. Clinical studies were biased toward large hemorrhages with high mortality rates. More recently, the full clinical spectrum of PBH has been appreciated only with studies correlating clinical findings and CT results. In the pre-CT era, hypertension was thought to be the major risk factor for PBH. Chronic hypertensive vascular changes were believed to cause arteriolar wall damage, and rupture of weakened dilated vessels thought to result in PBH. The occurrence of PBH in previously normotensive patients was underrepresented in pre-CT era studies. Current CT findings in PBH patients have shown that normotensive patients and hypertensive patients with chronic vascular changes have smaller hemorrhages resulting in lower mortality than hypertensive patients without chronic vascular changes. Because chronic hypertensive vascular changes are believed to be common in patients with PBH, this finding is unexpected and previously unreported. Chronic vascular changes may therefore offer some unexplained "protection" for brain blood vessels. Alternatively the mechanism of hypertensive PBH may be somewhat different than previously postulated.

Lacunar infarction in patients with hypertensive intracerebral hemorrhage.

Of 300 patients with computerized tomographic (CT) evidence of acute hypertensive intracerebral hemorrhage, high-resolution CT scans showed cerebral lacunar infarction (lacunes) in only nine cases (3%). The lacunes were seen in putaminal (six cases), thalamic (one case), and occipital (two cases) hematomas. All patients with lacunes and intracerebral hemorrhage had had systemic arterial hypertension for 7 to 14 years, cardiographic evidence of ventricular hypertrophy, chest radiographic evidence of cardiomegaly, and funduscopic evidence of retinopathy. The intracerebral hemorrhages were small, with maximal diameters of the hematomas 9 to 18 mm. All patients had good clinical outcome. In a 3-year follow-up, three patients had symptomatic lacunar infarcts but none had recurrent hemorrhage, whereas six patients had myocardial infarction or congestive heart failure.

Nontraumatic temporal subcortical hemorrhage. Clinical-computed tomographic analysis.

Thirty patients with temporal hematomas were analyzed. Four with frontal extension survived. Of 6 with ganglionic extension, three had residual deficit. Of 8 with parietal extension, 4 had delayed deterioration and died, two patients recovered, and two with peritumoral hemorrhage due to glioblastoma multiforme died. Five patients with posterior temporal hematomas recovered. In 7 patients with basal-inferior temporal hematomas, angiography showed aneurysms in 3 cases, angiomas in 2 cases and no vascular lesion in 2 cases. Of 23 cases with negative angiography and no systemic cause for temporal hematoma, 12 patients were hypertensive and 11 were normotensive. Ten hypertensive patients without evidence of chronic vascular disease had the largest hematomas, extending into the parietal or ganglionic regions. Seven of these patients died; 3 had residual deficit. Eleven normotensive and two hypertensive patients with evidence of chronic vascular change had smaller hematomas. They survived with good functional recovery.

Putaminal hemorrhage: clinical-computed tomographic correlations.

Ninety-two percent of 100 patients with putaminal hemorrhage were hypertensive. Of the eight normotensive patients, seven were substance abusers or had bilateral putaminal hemorrhages. The one other normotensive patient was less than 40 years old. The 100 hemorrhages had the following locations: 1. medial putaminal (17 cases; six were normotensive and less than 40 years old and five were substance abusers); 2. lateral putaminal extending through the external capsule (eleven cases); 3. putaminal-capsular and subcortical white matter (32 cases); 4. putaminal cerebral hemispheric (19 cases); 5. putaminal-thalamic (19 cases); 6. bilateral (two cases). A disproportionate number of black patients suffered hematoma extension to the cerebral hemispheres or thalamus (46%) compared to Caucasians (23%). Overall mortality was 20% (17 blacks and three Caucasians) and occurred in patients with hematoma extension to the thalamus or cerebral hemispheres. Contrast-enhanced CT was performed in all 100 patients and provided no additional diagnostic yield. This indicates limited use for enhanced CT in hypertensive patients with putaminal hemorrhage who have a characteristic appearance of the acute hemorrhage on the nonenhanced CT.

Kearns-Sayre syndrome and complex II deficiency.

A 25-year-old woman with Kearns-Sayre syndrome (KSS) had complete external ophthalmoplegia, short stature, ataxia, cardiac conduction defects, and pigmentary retinopathy. Muscle biopsy revealed ragged-red fibers. Electron microscopy showed increased numbers of mitochondria with disordered structure and paracrystalline inclusions. Enzymatic analysis revealed a deficiency of complex II of the mitochondrial respiratory chain, and, more specifically, a deficiency of succinic dehydrogenase, although both subunits of this enzyme proved to be present by immunologic analysis. Therapy with vitamin cofactors did not result in short-term improvement. This appears to be the first report of complex II deficiency in a patient with KSS.

Growth of skeletal muscle from patients with amyotrophic lateral sclerosis transplanted into nude mice.

We studied the fate of skeletal muscle obtained from patients with amyotrophic lateral sclerosis (ALS) after transplantation into immunodeficient nude mice. The transplanted muscle consistently survived in the nude mice without immunological rejection. The myofibers in these muscles underwent degeneration, followed by regeneration, maturation, and eventual functional innervation by the mouse motor neurons. The ability to grow diseased human muscle successfully over a prolonged period in nude mice offers an in vivo model to study the etiology of ALS and possibly of other neuromuscular disorders.