The paracentral visual field in multiple sclerosis: evidence for a deficit in interneuronal spatial summation?

A visual complaint such as blurred or "washed-out vision" can be one of the early signs of multiple sclerosis (MS). Although visual deficits are commonly attributed to optic nerve demyelination even with preserved visual acuity, the results of a considerable number of visual studies are inconsistent with this interpretation [Camisa, Mylin, & Bodis-Wollner, Annals of Neurology 10 (1981) 532-539; Regan & Neima, British Journal of Ophthalmology 68 (1984) 310-315]. However, a retinal axonal (nerve fiber layer) defect can be detected in some eyes, this is not the rule. Routine visual field (VF) tests, with a low sampling rate may also be non-informative in MS and optic neuritis, possibly because the VF abnormalities may be small and spotty or they can be found between tested points. The present study combined the advantages of VF and contrast sensitivity (CS) testing by applying contrast perimetry (CP), to the central 16 degrees of the VF. Four paracentral VF quadrants were tested in clinically affected and unaffected eyes of 31 MS patients and 26 controls. The stimuli were vertical Gaussian apertured sinusoidal gratings (Gabors) of 1 cpd. CS was obtained as a function of the diameter of the Gábor ranging from 1 to 7.4 degrees. The CP data of controls and definite and probable MS groups were significantly different for each pattern size, but the largest difference was found at diameters 2.5-3.7 degrees. Our study adds to previous evidence showing that optic nerve pathology does not explain "subclinical" and manifest visual dysfunction in MS. Given previous studies revealing orientation dependent monocular visual deficits and our study results, parsimony suggests that MS affects a network relying on myelinated lateral axonal branches of the visual cortex, binding monocular columns of neurons with like-with-like specificity.

[Late-presenting congenital diaphragmatic hernia: a possible cause of sudden respiratory distress in children] / Hérnia diafragmática congênita de apresentação tardia: uma possível causa de dificuldade respiratória aguda na criança.

OBJECTIVE: To emphasize that congenital defects of the diaphragm should be considered in the differential diagnosis of sudden onset of respiratory distress in children. MATHOD: Two illustrative cases of children (aged 2 years) with late presenting congenital diaphragmatic hernia who developed sudden respiratory distress and were managed at the University Hospital of Santa Maria are reported. The medical literature was reviewed to identify cases reports and other articles related to late presenting congenital diaphragmatic hernia. A computerized search was performed using the MEDLINE data base to identify papers published within the last 25 years. RESULTS: In both cases the initial clinical examination and plain chest X-rays were misinterpreted as another pleuropulmonary disease like pneumothorax/pneumatoceles. One of the children underwent to emergency chest tube placement without clinical improvement. The absence of respiratory symptoms that could justify this kind of pathology motivated a more careful investigation, involving fiberoptical endoscopy and intestinal seriography. This subsequent investigation revealed that the cause was late-presenting congenital diaphragmatic hernia. CONCLUSION: Although many congenital diaphragmatic hernias that present late have a history of chronic respiratory symptoms, some of them present with acute symptoms. A higher degree of attention is required to avoid confusion with other intrathoracic conditions, such as pneumatoceles and pneumothorax, if an incorrect diagnosis is to be avoided. Misinterpretation of the radiographs is likely if the possibility of a congenital diaphragmatic hernia is not considered, and may result in increased morbidity. Gastric atony may occur in the early postoperative period.

Neuropsychological test performance in patients with dominantly inherited spinocerebellar ataxia: relationship to ataxia severity.

To determine whether the cognitive status of patients with dominantly inherited spinocerebellar ataxia (DSCA) might be related to neurologic severity, we administered a comprehensive neuropsychological test battery to 43 patients with DSCA, ranging in ataxia severity from mild to end-stage. As compared with the controls, the mildly ataxic patients scored normally or close to normal as a group on all of the neuropsychological tests. In contrast, approximately one-half of the moderately and all of the severely ataxic patients showed poor performance, independent of age, Hamilton Rating Scale for Depression score, or education, on the Wisconsin Card Sorting Test, suggesting impaired executive system function. In addition, a subgroup of these patients had a neuropsychological profile suggestive of mild generalized cognitive impairment. We conclude that DSCA is not a homogeneous group of disorders with respect to cognitive status and that the neurologic severity of the disorder is a major factor. Impaired executive system function could be explained by damage to olivopontocerebellar system control over cerebral cortical function or to damage to other neuronal systems (especially cholinergic) that degenerate in parallel with the olivopontocerebellar system.

Etiology of syncope in 100 patients with associated pale facial appearance.

Since publication and discussion of the original patients, I have continued to evaluate patients with loss or near loss of consciousness using the patient's facial color as a guide to underlying etiology. This has consistently provided a quick, reliable method for trying to sort through these difficult cases. Others have similarly noted value of a pale, ashen facial color in diagnosing patients with transient loss of consciousness. I present now my experience with the first 100 patients presenting with syncope and associated pale facial appearance.

Transient ischemic attack (TIA) secondary to subdural hematoma.

Subdural hematomas many sometimes clinically resemble Transient Ischemic Attacks (TIA's). We present three cases which were initially evaluated for, diagnosed as having and were treated for TIA's, but later were found to have subdural hematomas. As in case one, patients with subdurals may have antecedent head trauma which they may or may not recall. Patients presenting with symptoms resembling TIA's need a complete neurologic evaluation. The differential diagnosis for TIA's includes arteriosclerotic extracranial vascular disease, cardiac emboli, migraine, seizure disorder, and mass lesions. Since the prognosis and treatment differs one needs to determine the etiology of the symptoms before treatment is initiated. Specifically, other diagnoses must be excluded prior to anticoagulation therapy, as evidenced by case 2.

Autosomal dominant spinocerebellar ataxia: locus heterogeneity in a Nebraska kindred.

SCA1 is an adult-onset autosomal dominant ataxia that is genetically linked to loci on chromosome 6p. A highly informative GT-repeat marker, D6S89, has been closely linked to the SCA1 locus in five large kindreds. We have used this marker to perform linkage analysis in a smaller autosomal dominant ataxia family consisting of five generations designated as the Nebraska kindred. This kindred includes 33 affected (12 living) and 40 first-generation at-risk individuals. We examined eight affected individuals; all had gait and limb ataxia. We analyzed the D6S89 locus by the polymerase chain reaction. Based on the analysis of 31 individuals from this kindred, we statistically excluded linkage to D6S89 for moderate-to-tight linkage (less than 11% recombination). These data clearly demonstrate genetic heterogeneity among the autosomal dominant ataxias. In addition, we obtained linkage data for HLA-A and SCA1 in this kindred. Comparison of HLA-A with D6S89 shows the latter marker to be more powerful. Use of D6S89 and other highly polymorphic markers in this region will greatly facilitate genetic classification of ataxias and make presymptomatic diagnosis of SCA1 feasible.

Psychosurgery: a retrospective.

Of the 56 patients within the Yakovlev collection who had undergone psychosurgery 11 (20%) improved, 18 (32%) were either worse or without improvement, and 27 (48%) were without any clinical follow-up. Thus, in retrospect, psychosurgery was perhaps not as successful as once envisioned.

A case report of Forestier's disease.

Radiologic studies are essential in diagnosing Forestier's disease and include lateral cervical spine roentgenograms, thoracic and lumbosacral vertebrae roentgenograms, esophagram, vertebrae roentgenograms, esophagram, and computed tomography. Patients with Forestier's disease may be considered to be operative candidates if they have persistent dysphagia, dysphonia, and a feeling of fullness or foreign body in the throat. The patient in our case report underwent anterior surgical resection of her anterior cervical osteophytes. Two months following surgery, she was no longer experiencing dysphagia or dyspnea.